COMPRESSOR AND REFRIGERATION CYCLE DEVICE

Abstract

According to one embodiment, a compressor includes a cylinder, a rotation shaft, a roller, a blade, and an injection flow channel. The cylinder includes a spring insertion hole in which the spring, which presses the blade against the roller is arranged. The injection flow channel includes a blade groove formed in a surface portion facing the compression chamber, of side surface portions constituting a pair on the blade and facing a circumferential direction with respect to the center of axis of the rotation shaft. A surface on which a part of the refrigerant flows into the blade groove is flush with a surface discharging the part of the refrigerant from the blade groove to the compression chamber.

Description

FIELD

Embodiments described herein relate generally to a compressor and a refrigeration cycle device comprising the compressor.

BACKGROUND

A refrigeration cycle device such as an air conditioner comprises a compressor, a condenser, an expansion valve, and an evaporator as main elements. The compressor comprises, for example, a motor unit for rotating a rotation shaft, a compression mechanism unit connected to the motor unit through the rotation shaft, and a sealed container containing the motor unit and the compression mechanism unit, as main elements. The motor unit includes, for example, an inner rotor motor and comprises a rotor fixed to the rotation shaft, and a stator fixed to an inner peripheral part of the sealed container. The rotation shaft includes a crank pin portion (eccentric portion). The compression mechanism unit comprises, for example, a cylinder constituting a cylinder chamber and a roller fitted into the eccentric portion of the rotation shaft and eccentrically rotates in the cylinder chamber. The cylinder chamber is partitioned by a blade into a suction chamber and a compression chamber for refrigerants. The rotation shaft is rotatably supported by a bearing provided in the compression mechanism unit.

For example, in a warming operation and a heating operation, the air conditioner absorbs heat from the outside air by means of the evaporator and provides this heat to air inside chamber or hot-water by means of the condenser. At this time, as the temperature of the outside air becomes higher, an amount of heat absorption by the evaporator increases and the temperature and the pressure of the refrigerant sucked into the compressor increase. When the compressor becomes overheat state due to this increase, a temperature of refrigerant discharged from the compressor may increase extraordinarily. Therefore, a compressor comprising an injection mechanism is known for a measure to suppress such an increase in temperature in the compressor.

The injection mechanism includes a flow channel (injection flow channel) to divide a refrigerant at the downstream side of the condenser and the like in a circuit of the refrigerant. The injection flow channel is connected to the compression chamber of the compressor through a connection pipe, a path constituted in the compression mechanism unit, and the like. Such an injection mechanism injects a part of the refrigerant having passed the condenser, for example, a liquid-phase refrigerant and a gas-liquid two-phase refrigerant, into the compression chamber. Then, this gas-phase refrigerant sucked into the suction chamber is cooled by the refrigerant. As a result, the compressor is prevented from being overheated.

As embodiments of the injection mechanism, a mechanism in which an injection port is opened/closed by an end surface of the roller which eccentrically rotates in the compression chamber, a mechanism in which an operation mechanism such as an injection piston, a valve, and the like are provided in a cylinder for controlling timing are known.

However, a mechanism in which the injection port is opened/closed by the end surface of the roller may make the compression chamber and the suction chamber in communication with each other in the cylinder chamber through the injection mechanism, depending on a position at which liquid-phase refrigerants and gas-liquid two-phase refrigerants are injected into the compression chamber, for example. This leads to re-expansion loss, decreasing efficiency of the compressor. In addition, when the operation mechanisms such as the injection piston, valve mechanism, and the like are provided, the number of portions increases and thus the structure becomes complicated. This leads to the increase in manufacturing cost. The increase in the number of operation portions may increase a risk of breakdown and decrease the reliability. When the compressor comprises a plurality of cylinders, the compression chambers of these cylinders may be in communication with one another through the injection mechanism, for example, depending on a path in each of the cylinders in the injection flow channel. These communications may decrease the cooling effect of the compressor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a circuit diagram schematically showing a configuration of an air conditioner of a first embodiment.

FIG. 2 is a longitudinal sectional view of a compressor of the first embodiment.

FIG. 3 is a longitudinal sectional view schematically showing a part of the compressor shown in FIG. 2 in an enlarged manner.

FIG. 4 is a diagram schematically showing a compression mechanism unit of the compressor of the first embodiment as seen from above.

FIG. 5 is a diagram schematically showing a relationship between a blade groove and a spring insertion hole in a state where a blade is most retracted with respect to a cylinder chamber in the first embodiment.

FIG. 6A is a first diagram schematically showing a state transition in an injection mechanism in the cylinder during a compression process of a refrigerant in the first embodiment.

FIG. 6B is a second diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the first embodiment.

FIG. 6C is a third diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the first embodiment.

FIG. 6D is a fourth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the first embodiment.

FIG. 6E is a fifth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the first embodiment.

FIG. 6F is a sixth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the first embodiment.

FIG. 7A is a table indicating, per a cylinder, a transition between a state in which an injection hole and a compression chamber are in communication with each other through the blade groove and thus injection can be performed (injection-open state) and a state in which the injection hole and the compression chamber are not in communication with each other and thus injection cannot be performed (injection-close state) according to a rotational angle.

FIG. 7B is a table indicating, per a cylinder, a transition between the injection-open state and the injection-close state where the number of cylinders is three, according to a rotational angle.

FIG. 8 is a longitudinal sectional view schematically showing a part of a compressor of a second embodiment in an enlarged manner.

FIG. 9 is a diagram schematically showing a blade of the second embodiment from a circumferential direction.

FIG. 10A is a first diagram schematically showing a state transition in an injection mechanism in a cylinder during a compression process of a refrigerant in the second embodiment.

FIG. 10B is a second diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the second embodiment.

FIG. 10C is a third diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the second embodiment.

FIG. 10D is a fourth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the second embodiment.

FIG. 10E is a fifth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the second embodiment.

FIG. 10F is a sixth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the second embodiment.

FIG. 11 is a diagram showing a locus of relationship in the second embodiment among rotational angles, ratios of compression loads, and ratios of groove cross-section areas.

FIG. 12 is a diagram showing a relationship in the second embodiment among injection states, rotational angles, and ratios of groove cross-section areas.

FIG. 13 is a longitudinal sectional view showing a part of a compressor of a third embodiment in an enlarged manner.

FIG. 14 is a diagram schematically showing a blade of the third embodiment from a circumferential direction.

FIG. 15A is a first diagram schematically showing a state transition in an injection mechanism in a cylinder during a compression process of a refrigerant in the third embodiment.

FIG. 15B is a second diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the third embodiment.

FIG. 15C is a third diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the third embodiment.

FIG. 15D is a fourth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the third embodiment.

FIG. 15E is a fifth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the third embodiment.

FIG. 15F is a sixth diagram schematically showing the state transition in the injection mechanism in the cylinder during the compression process of a refrigerant in the third embodiment.

FIG. 16 is a diagram showing a relationship in the third embodiment among injection states, rotational angles, and ratios of cross-section areas of grooves.

DETAILED DESCRIPTION

In general, according to one embodiment, a compressor includes a cylinder, a rotation shaft, a roller, a blade, and an injection flow channel. The cylinder has an annular shape and constitutes a cylinder chamber including a suction chamber for sucking a refrigerant and a compression chamber for compressing the refrigerant. The rotation shaft includes an eccentric portion arranged in the cylinder chamber. The roller is fitted into the eccentric portion and eccentrically rotates with respect to a center of axis of the rotation shaft in the cylinder chamber. The blade has a flat shape, advances or retracts in the cylinder chamber according to the eccentric rotation of the roller, and partitions the cylinder chamber into the suction chamber and the compression chamber. The injection flow channel branches from a cyclic circuit, through which the refrigerant circulates, and guides a part of the refrigerant circulating through the cyclic circuit to the compression chamber. The injection flow channel includes at least a blade groove formed in a surface portion facing the compression chamber, of side surface portions constituting a pair on the blade and facing a circumferential direction with respect to the center of axis of the rotation shaft. A surface into which the part of the refrigerant flows is flush with a surface discharging the part of the refrigerant from the blade groove to the compression chamber.

First Embodiment

FIG. 1 is a refrigeration cycle circuit diagram of an air conditioner 1 of the present embodiment. The air conditioner 1 is a device that performs air conditioning using this refrigeration cycle, and is an example of a refrigeration cycle apparatus. The air conditioner 1 comprises a compressor 2, a four-way valve 3, an outdoor heat exchanger 4, an outdoor blower 400, an expansion device 5, an indoor heat exchanger 6, and an indoor blower 600, as main elements.

As shown in FIG. 1, a discharge side of the compressor 2 is connected to a first port 3a of the four-way valve 3. A second port 3b of the four-way valve 3 is connected to the outdoor heat exchanger 4.

The outdoor heat exchanger 4 is connected to the indoor heat exchanger 6 through the expansion device 5. The indoor heat exchanger 6 is connected to a third port 3c of the four-way valve 3. A fourth port 3d of the four-way valve 3 is connected to a suction side of the compressor 2 through an accumulator 8.

A refrigerant circulates through a cyclic circuit 7, which is a path from the discharge side of the compressor 2 to the suction side through the outdoor heat exchanger 4, the expansion device 5, the indoor heat exchanger 6, and the accumulator 8. It is preferable that a refrigerant does not contain chlorine. For example, R32, R448A, R449A, R449B, R407G, R407H, R449C, R454A, R454B, R454C, R456A, R516A, R460B, R463A, R744, and HC type refrigerants can be adopted as the refrigerant.

For example, when the air conditioner 1 operates in a cooling mode, the four-way valve 3 is switched such that the first port 3a is in communication with the second port 3b, and the third port 3c is in communication with the fourth port 3d. When the air conditioner 1 starts operation in the cooling mode, a high-temperature, high-pressure, and gas-phase refrigerant compressed by the compressor 2 is discharged to the cyclic circuit 7. The discharged gas-phase refrigerant is guided to the outdoor heat exchanger 4 functioning as a condenser (radiator) through the four-way valve 3.

The gas-phase refrigerant guided to the outdoor heat exchanger 4 is condensed by means of heat exchange with air (outside air) sucked by the outdoor blower 400 and then changes into a high-pressure and liquid-phase refrigerant. The high-pressure and liquid-phase refrigerant is decompressed in the process of passing through the expansion device 5 and changes into a low-pressure and gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant is guided to the indoor heat exchanger 6 functioning as an evaporator (heat absorber) and is subjected to the heat exchange with the air (inside air) sucked into the indoor blower 600 in the process of passing through the indoor heat exchanger 6.

As a result, the gas-liquid two-phase refrigerant absorbs heat from air and evaporates to change into a low-temperature, low-pressure, and gas-phase refrigerant. The air passing through the indoor heat exchanger 6 is cooled by latent heat of vaporization of the liquid-phase refrigerant and is sent as cooled air by the indoor blower 600 to, for example, a place to be air-conditioned (cooled).

The low-temperature, low-pressure, and gas-phase refrigerant that has passed through the indoor heat exchanger 6 is guided to the accumulator 8 through the four-way valve 3. When the liquid-phase refrigerant that has not been completely evaporated exists in the refrigerant, the refrigerant is divided into the liquid-phase refrigerant and a gas-phase refrigerant. The low-temperature, low-pressure, and gas-phase refrigerant divided from the liquid-phase refrigerant is sucked into the compressor 2 from the accumulator 8, and is compressed into a high-temperature, high-pressure, and gas-phase refrigerant by the compressor 2 again and then is discharged to the cyclic circuit 7.

On the other hand, when the air conditioner 1 operates in the warming operation, the four-way valve 3 is switched such that the first port 3a is in communication with the third port 3c and the second port 3b is in communication with the fourth port 3d. When the air conditioner 1 starts operation in the warming mode, the high-temperature, high-pressure, and gas-phase refrigerant discharged from the compressor 2 is guided to the indoor heat exchanger 6 through the four-way valve 3, and is subjected to the heat exchange with air passing through the indoor heat exchanger 6. In this case, the indoor heat exchanger 6 functions as the condenser.

As a result, the gas-phase refrigerant passing through the indoor heat exchanger 6 is condensed by heat exchange with the air (inside air) sucked into the indoor blower 600 and then changes into a high-pressure and liquid-phase refrigerant. The air passing through the indoor heat exchanger 6 is heated by heat exchange with the gas-phase refrigerant, and is sent as warm air by the indoor blower 600 to a place to be air-conditioned (warmed).

The high-temperature and liquid-phase refrigerant that has passed through the indoor heat exchanger 6 is guided to the expansion device 5 and is decompressed in the process of passing through the expansion device 5 to change into a low-pressure and gas-liquid two-phase refrigerant. The gas-liquid two-phase refrigerant is guided to the outdoor heat exchanger 4 functioning as the evaporator and is evaporated by the heat exchange with the air (outside air) sucked into the outdoor blower 400 and changes into the low-temperature, low-pressure, and gas-phase refrigerant. The low-temperature, low-pressure, and gas-phase refrigerant that has passed through the outdoor heat exchanger 4 is sucked into the compressor 2 through the four-way valve 3 and the accumulator 8, is compressed into the high-temperature, high-pressure, and gas-phase refrigerant by the compressor 2 again and then is discharged to the cyclic circuit 7.

The air conditioner 1 in the present embodiment can operate in both of the cooling mode and the warming mode. The air conditioner 1 may be, for example, a machine for cooling that can operate only in the cooling mode or a machine for warming that can operate only in the warming mode.

Furthermore, in the present embodiment, the cyclic circuit 7 includes a flow channel (hereinafter referred to as an injection flow channel) 7a that divides a refrigerant in the downstream side of the condenser. The injection flow channel 7a is a bypass channel (injection flow channel), which guides a part of the refrigerant flowing from the condenser to the evaporator (hereinafter referred to as an injection refrigerant) to the compressor 2 (specifically, compression chambers 23b and 24b described later) by dividing the part of the refrigerant at a position that is the downstream side of the condenser and the upstream side of the evaporator. The injection refrigerant is, for example, the liquid-phase refrigerant or the gas-liquid two-phase refrigerant. In the example shown in FIG. 1, the injection flow channel 7a branches between the outdoor heat exchanger 4 and the expansion device 5, and is connected to the compressor 2 through a connection pipe 7b. The injection flow channel 7a may have, for example, a solenoid valve, an expansion valve, a check valve, and the like (all of these portions are not shown) on its path. By comprising this injection flow channel 7a, the injection refrigerant is injected into the compression chambers 23b and 24b of cylinders 13 and 14, which will be described later, of the compressor 2 and the high-temperature and gas-phase refrigerant sucked into the compressor 2 is cooled by the injection refrigerant. This prevents the compressor 2 from being overheated.

Next, the specific configuration of the compressor 2 used in the air conditioner 1 will be described with reference to FIG. 2. FIG. 2 is a longitudinal sectional view schematically showing the compressor 2. FIG. 3 is a longitudinal sectional view schematically showing a part of the compressor 2 shown in FIG. 2 in an enlarged manner. As shown in FIG. 2 and FIG. 3, the compressor 2 is a vertical rotary compressor, and includes a sealed container 10, a compression mechanism unit 11, and a motor unit 12 as main elements. In the following description, with reference to the relative positional relationship between the compression mechanism unit 11 and the motor unit 12 that are arranged along a central axis O1, which will be described later, of the sealed container 10, the side where the compression mechanism unit 11 is located is referred to as the lower side and the side where the motor unit 12 is located is referred to as the upper side.

The sealed container 10 includes a cylindrical peripheral wall 10a and stands perpendicular to a installation surface. The installation surface is, for example, the bottom plate of an outdoor unit. A discharge pipe 10b is provided at the upper end of the sealed container 10. The discharge pipe 10b is connected to the first port 3a of the four-way valve 3 through the cyclic circuit 7. An oil reservoir 10c for storing lubricating oil is provided at the lower part of the sealed container 10.

The compression mechanism unit 11 is a mechanism unit for compressing a refrigerant. The compression mechanism unit 11 is accommodated in the lower part of the sealed container 10 such that the compression mechanism unit 11 is immersed in the lubricating oil. In the example shown in FIG. 2, the compression mechanism unit 11 comprises a twin-type cylinder structure and includes a first cylinder 13, a second cylinder 14, and a rotation shaft 15 as main elements. The first cylinder 13 has an annular shape and constitutes a cylinder chamber 23 including a suction chamber 23c sucking a refrigerant, which will be described later, and a discharge port for discharging the compressed refrigerant. Similarly, the second cylinder 14 has an annular shape and constitutes a cylinder chamber 24 including a suction chamber 24c sucking a refrigerant, which will be described later, and a discharge port for discharging the compressed refrigerant. The first cylinder 13 includes a roller (rolling piston) 16 and a blade 18 therein. Similarly, the second cylinder 14 includes a roller 17 and a blade 19 therein. The number of the cylinders in the compression mechanism unit is not limited to two, and may be one or three or more.

The first cylinder 13 is fixed to the inner peripheral surface of the peripheral wall 10a of the closed container 10 through a first bearing 21 or a frame. The second cylinder 14 is fixed to the lower surface of the first cylinder 13 through a partition plate 20.

The first bearing 21 is fixed above the first cylinder 13. The first bearing 21 covers an inner diameter portion of the first cylinder 13 from above and protrudes toward the upper part of the first cylinder 13. A space surrounded by the inner diameter portion of the first cylinder 13, the partition plate 20, and the first bearing 21 constitutes the first cylinder chamber 23. The partition plate 20 corresponds to a closure portion defining the lower surface of the first cylinder chamber 23. The first bearing 21 corresponds to a closure portion defining the upper surface of the first cylinder chamber 23. A second bearing 22 is fixed below the second

cylinder 14. The second bearing 22 covers the inner diameter portion of the second cylinder 14 from below and protrudes toward the lower part of the second cylinder 14. A space surrounded by the inner diameter portion of the second cylinder 14, the partition plate 20, and the second bearing 22 constitutes the second cylinder 24. The partition plate 20 corresponds to a closure portion defining the upper surface of the second cylinder chamber 24. The second bearing 22 corresponds to a closure portion defining the lower surface of the cylinder chamber 24. The first cylinder chamber 23 and the second cylinder chamber 24 are provided concentrically with the central axis O1 of the sealed container 10.

The first cylinder chamber 23 and the second cylinder chamber 24 are connected to the accumulator 8 through respective suction pipes 10d and 10e, which are a part of the cyclic circuit 7. The gas-phase refrigerant from which the liquid-phase refrigerant has been separated in the accumulator 8 is guided respectively from the suction ports 23c and 24c to the first cylinder chamber 23 and the second cylinder chamber 24 through the suction pipes 10d and 10e.

The rotation shaft 15 has an axial center located coaxially with the central axis 01 of the sealed container 10, and passes through the first cylinder chamber 23, the second cylinder chamber 24, and the partition plate 20. The rotation shaft 15 has a first journal portion 27a, a second journal portion 27b, and a pair of crank pin portions (eccentric portions) 28a and 28b. That is, the rotation shaft 15 is configured as a crankshaft. The first journal portion 27a is rotatably supported by the first bearing 21. The second journal portion 27b is rotatably supported by the second bearing 22.

Further, the rotation shaft 15 includes an extension portion 27c extending coaxially from the first journal portion 27a. The extension portion 27c passes through the first bearing 21 and protrudes toward the upper part of the compression mechanism unit 11. A rotor 33, which will be described later, of the motor unit 12 is fixed to the extension portion 27c.

The eccentric portions 28a and 28b are located between the first journal portion 27a and the second journal portion 27b. The eccentric portions 28a and 28b are arranged in the circumferential direction with phase difference of 180 degrees and have the same eccentric amount with respect to the central axis O1 of the sealed container 10. The eccentric portion (hereinafter referred to as a first eccentric portion) 28a is arranged in the first cylinder chamber 23. The eccentric portion (hereinafter referred to as a second eccentric portion) 28b is arranged in the second cylinder chamber 24.

FIG. 4 is a diagram schematically showing the compression mechanism unit 11 from above. FIG. 4 shows the inner configuration of the first cylinder 13. Except portions different from each other due to the phase difference between the first eccentric portion 28a and the second eccentric portion 28b, the inner configuration of the first cylinder 13 and the inner configuration of the second cylinder 14 are approximately equivalent to each other. Therefore, the inner configuration of the second cylinder 14 corresponds to the configuration shown in FIG. 4.

As shown in FIG. 3 and FIG. 4, the cylindrical first roller 16 is fitted into an outer peripheral surface 29a of the first eccentric portion 28a. A slight gap to allow the first roller 16 to rotate with respect to the first eccentric portion 28a is provided between an inner peripheral surface 16a of the first roller 16 and the outer peripheral surface 29a of the first eccentric portion 28a. According to this configuration, when the rotation shaft 15 rotates, the first roller 16 eccentrically rotates with respect to the center of axis (center of rotation O1) of the rotation shaft 15 in the first cylinder chamber 23, and a part of an outer peripheral surface 16b of the first roller 16 abuts the inner peripheral surface of the first cylinder chamber 23.

The cylindrical second roller 17 is fitted into an outer peripheral surface 29b of the second eccentric portion 28b. A slight gap to allow the second roller 17 to rotate with respect to the second eccentric portion 28b is provided between an inner peripheral surface 17a of the second roller 17 and the outer peripheral surface 29b of the second eccentric portion 28b. According to this configuration, when the rotation shaft 15 rotates, the second roller 17 eccentrically rotates with respect to the center of axis (center of rotation O1) of the rotation shaft 15 in the second cylinder chamber 24, and a part of an outer peripheral surface 17b of the second roller 17 abuts the inner peripheral surface of the second cylinder chamber 24.

As shown in FIG. 3 and FIG. 4, the first blade 18 is provided in the first cylinder 13, and the second blade 19 is provided in the second cylinder 14. The first blade 18 and the second blade 19 have an approximately flat shape. Respectively, the cylinders 13 and 14 include blade holes 13a and 14a that are open to the inner peripheral part, extend outwardly along the diameter direction, and accommodate the blades 18 and 19. The first blade 18 is supported by the first blade hole 13a while being inwardly biased inside the diameter direction by a spring 13b. Similarly, the second blade 19 is supported by the second blade hole 14a while being biased inside the diameter direction by a spring 14b. Respectively, the springs 13b and 14b are arranged in spring insertion holes 13c and 14c of the cylinders 13 and 14, and press the blades 18 and 19 toward the rollers 16 and 17 in the blade holes 13a and 14a. The spring insertion hole 13c is a space constituted between the blade hole 13a and the outer peripheral surface of the cylinder 13 and is in communication with the outside of the cylinder 13 in the internal space of the sealed container 10. Similarly, the spring insertion hole 14c is a space constituted between the blade hole 14a and the outer peripheral surface of the cylinder 14 and is in communication with the outside of the cylinder 14 in the internal space of the sealed container 10. Respectively, distal end portions 18a and 19a of the blades 18 and 19 are pressed against the outer peripheral surfaces 16b and 17b of the rollers 16 and 17 by the pressing force of the springs 13b and 14b. The blade 18 cooperates with the roller 16 to partition the cylinder chamber 23 into the suction chamber 23a and the compression chamber 23b. Similarly, the blade 19 cooperates with the roller 17 to partition the cylinder chamber 24 into the suction chamber 24a and the compression chamber 24b. According to the eccentric rotation of the respective rollers 16 and 17, these blades 18 and 19 respectively move in the direction of entering (advancing to) the cylinder chambers 23 and 24 or move in the direction of exiting (retracting) from the cylinder chambers 23 and 24, in other words, advance or retract. Respectively, these advancing or retracting of the blades 18 and 19 with respect to the cylinder chambers 23 and 24 in this manner change the volumes of the suction chambers 23a and 24a and the compression chambers 23b and 24b of the cylinder chambers 23 and 24. Then, the gas-phase refrigerant sucked from the suction pipes 10d and 10e into the cylinder chambers 23 and 24 is compressed, respectively.

The high-temperature, high-pressure, and gas-phase refrigerants compressed in the first cylinder chamber 23 and the second cylinder chamber 24 are discharged to the inside of the sealed container 10 through a discharge valve mechanism (not shown). The discharged gas-phase refrigerant ascends inside the sealed container 10. While the compression mechanism unit 11 operates, lubrication oil (refrigerator oil) stored in the oil reservoir 10c in the sealed container 10 is stirred into mist and then ascends inside the sealed container 10 toward the discharge pipe 10b according to the flow of the gas-phase refrigerant.

The motor unit 12 drives the compression mechanism unit 11, in short, the rotation shaft 15.

The motor unit 12 is accommodated in an intermediate portion along the central axis O1 of the closed container 10 so as to be located between the compression mechanism unit 11 and the discharge pipe 10b. The motor unit 12 includes an inner rotor type motor and comprises the rotor 33 fixed to the rotation shaft 15 and a stator 34 fixed to the inner peripheral surface of the peripheral wall 10a of the closed container 10.

The rotor 33 includes, for example, a cylindrical rotor iron core coaxially fixed to the rotation shaft 15, a plurality of permanent magnets provided on the rotor iron core, and the like. The rotor 33 is provided coaxially with the stator 34 to have a slight gap (air gap) inside the stator 34.

The stator 34 includes, for example, a cylindrical stator iron core and a winding (coil) wound around the stator iron core, and is arranged to surround the rotor 33. By suppling the coil with electricity, the rotor 33 rotates relative to the stator 34 around the central axis O1, and the rotation shaft 15 rotates together with the rotor 33.

The compressor 2 having this configuration comprises an injection mechanism. Therefore, the compression mechanism unit 11 includes a part of the injection flow channel 7a of the cyclic circuit 7 as the injection mechanism. The compression mechanism unit 11, specifically the injection mechanism in the cylinders 13 and 14, will be described in detail below. As described above, in the present embodiment, the internal configuration of the first cylinder 13 and the internal configuration of the second cylinder 14 are approximately equivalent to each other except portions different from each other due to the phase difference between the first eccentric portion 28a and the second eccentric portion 28b.

In the present embodiment, the injection flow channel 7a includes flow channels 40, 50, and 60 each constituted in the compressor 2. These flow channels 40, 50, and 60 constitute a part of the injection flow channel 7a in the compressor 2, and guides a part of the liquid-phase refrigerant diverted from the respective cyclic circuit 7 (injection refrigerant) to the compression chambers 23b and 24b of the cylinders 13 and 14. The flow channel 40 is constituted inside the partition plate 20 and connects the connecting pipe 7b and a flow channel 50 together. The flow channel 50 is constituted inside the cylinders 13 and 14 and connects the flow channel 40 and the flow channel 60. The flow channel 60 is formed in side surfaces of the blades 18 and 19 and links the flow channel 50 and the compression chambers 23b and 24b together. Each of the flow channels 40, 50, and 60 will be described further below.

The flow channel (hereinafter referred to as an injection communication channel) 40 is open to an outer peripheral surface 20a of the partition plate 20, extends in the radial direction and further along the central axis O1, and is open at an upper surface 20b and a lower surface 20c. The radial direction of the partition plate 20 is a direction toward the central axis 01 along the normal to the outer peripheral surface 20a. The injection refrigerant flows into the injection communication channel 40 from an aperture 41 in the outer peripheral surface 20a, and is guided to an aperture 42a in the upper surface 20b and an aperture 42b in the lower surface 20c. That is, in the injection communication channel 40, a partition plate inlet side flow channel (lateral flow channel) 40a extending in the radial direction, and two partition plate outlet side flow channels 40b and 40c that branch vertically from the partition plate inlet side flow channel 40a along the central axis 01 are continuously constituted. The aperture 41 is in communication with the connection pipe 7b. The aperture 42a is in communication with an aperture 53, which will be described later, of the cylinder 13. The aperture 42b is in communication with an aperture 55, which will be described later, of the cylinder 14.

The flow channel 50 includes a flow channel constituted inside the first cylinder 13 (hereinafter referred to as a first cylinder flow channel) 51 and a flow channel constituted inside the second cylinder 14 (hereinafter referred to as a second cylinder flow channel) 52.

The first cylinder flow channel 51 is open to a lower surface 13d of the first cylinder 13. The second cylinder flow channel 52 is open to an upper surface 14d of the second cylinder 14. Each of the first cylinder flow channel 51 and the second cylinder flow channel 52 extends along the central axis O1. The first cylinder flow channel 51 is open to a lower surface 13d of the first cylinder 13 and extends along the central axis O1. The first cylinder flow channel 51 is bent to further extend in a direction intersecting the central axis O1 and is open to a sidewall 13e of the first blade hole 13a. Among a pair of sidewalls 13e and 13f opposed to each other along the circumferential direction of the first blade hole 13a, the sidewall 13e is the side wall of the compression chamber 23b side of the first cylinder chamber 23. That is, the sidewall 13e is located on a side opposite to the suction side (suction chamber 23a) for a refrigerant in the first cylinder chamber 23, in other words, is the sidewall on the discharge side. The sidewall 13e is opposed to a surface described later (side surface portion 18b) facing the compression chambers 23b side of the blade 18 in the first blade hole 13a. An injection refrigerant flows into the first cylinder flow channel 51 from the aperture 53 of the lower surface 13d and then is guided to an aperture (hereinafter referred to as an injection hole) 54 of the side wall 13e. That is, in the first cylinder flow channel 51, inlet side flow channel (vertical flow channels) 51a extending along the central axis O1 and outlet side flow channel (lateral flow channel) 51b, which is bent to extend from the inlet side flow channel 51a to the direction intersecting the central axis O1 are continuously configured. The aperture 53 is in communication with the aperture 42b of the partition plate outlet side flow channels 40c of the injection communication channel 40. The injection hole 54 can be in communication with a groove, which will be described later, of the first blade 18.

The second cylinder flow channel 52 is open to a lower surface 14d of the second cylinder 14 and extends along the central axis O1. The second cylinder flow channel 52 is bent to further extend in the direction intersecting the central axis O1 and is open to a sidewall 14e of the second blade hole 14a. Among a pair of sidewalls 14e and 14f opposed to each other along the circumferential direction of the second blade hole 14a, the sidewall 14e is the side wall of the compression chamber 24b side of the second cylinder chamber 24. That is, the sidewall 14e is located on a side opposite to the suction side (suction chamber 24a) for a refrigerant in the second cylinder chamber 24, in other words, is the sidewall on the discharge side. The sidewall 14e is opposed to a surface described later (side surface portion 19b) facing the compression chamber 24b side of the blade 19 in the second blade hole 14a. An injection refrigerant flows into the second cylinder flow channel 52 from the aperture 55 of the upper surface 14d and then is guided to an aperture (hereinafter referred to as an injection hole) 56 of the side wall 14e. That is, in the second cylinder flow channel 52, an inlet side flow channel (vertical flow channels) 52a extending along the central axis O1 and an outlet side flow channel (lateral flow channel) 52b, which is bent to extend from the inlet side flow channel 51a to the direction intersecting the central axis O1 are continuously configured. The aperture 55 is in communication with the aperture 42b of the outlet side flow channel 40c of the injection communication channel 40. The injection hole 56 can be in communication with a groove, which will be described later, of the second blade 19.

The flow channel 60 includes a flow channel (hereinafter referred to as a first blade groove) 61 constituted in the first blade 18 and a flow channel (hereinafter referred to as a second blade groove) 62 constituted in the second blade 19. Each of the first blade groove 61 and the second blade groove 62 has a groove shape respectively extending along the advancing/retracting direction of the blades 18 and 19 with respect to the cylinder chambers 23 and 24. The advancing/retracting directions of the blades 18 and 19 are respectively along the radial directions of the cylinders 13 and 14. In the present embodiment, the first blade groove 61 and the second blade groove 62 have the approximately same shapes. However, these blade grooves 61 and 62 may have shapes different from each other.

The first blade groove 61 is a groove (injection groove) constituted in the side surface 18b of the first blade 18 and extends with regarding the advancing/retracting direction of the first blade 18 as the longitudinal direction. Among a pair of the side surfaces 18b and 18c opposed to each other in the circumferential direction of the first blade 18, the side surface 18b is a surface facing the compression chamber 23b of the first cylinder chamber 23. That is, the side surface 18b is on a side opposite to the suction side for a refrigerant in the first cylinder chamber 23, in other words, is the sidewall on the discharge side. Therefore, the first blade groove 61 is not in communication with the suction port 23c, which sucks refrigerants from the suction pipe 10d, in the suction chamber 23a. The injection refrigerant flows from a place in the vicinity of an end portion 61a in the retracting side in the first blade groove 61 and is guided to a place in the vicinity of an end portion 61b in the advancing side. The advancing direction of the first blade 18 to the cylinder chamber 23 corresponds to the flow direction of an injection refrigerant in the first blade groove 61. The place in the vicinity of the end portion 61a in the retracting side can be in communication with the injection hole 54 of the first cylinder flow channel 51. The place in the vicinity of the end portion 61b in the advancing side can be in communication with the compression chamber 23b, in other words, be open to the compression chamber 23b.

The second blade groove 62 is a groove (injection groove) constituted in the side surface 19b of the second blade 19, and extends with regarding the advancing/retracting direction of the second blade 19 as the longitudinal direction. Among a pair of the side surfaces 19b and 19c opposed to each other in the circumferential direction of the second blade 19, the side surface 19b is a surface facing the compression chamber 24b of the second cylinder chamber 24. That is, the side surface 19b is on a side opposite to the suction side (suction chamber 24a) for a refrigerant in the second cylinder chamber 24, in other words, is the sidewall on the discharge side. Therefore, the second blade groove 62 is not in communication with the suction port 24c, which sucks refrigerants from the suction pipe 10e, in the suction chamber 24a. The injection refrigerant flows from a place in the vicinity of an end portion 62a in the retracting side in the second blade groove 62 and is guided to a position in the vicinity of an end portion 62b in the advancing side. The advancing direction of the second blade 19 to the cylinder chamber 24 corresponds to the flow direction of an injection refrigerant in the second blade groove 62. The place in the vicinity of the end portion 62a in the retracting side can be in communication with the injection hole 56 of the second cylinder flow channel 52. The place in the vicinity of the end portion 62b in the advancing direction can be in communication with the compression chamber 24b, in other words, be open to the compression chamber 24b.

FIG. 5 is a diagram schematically showing a relationship between the blade grooves 61 and 62 and the spring insertion holes 13c and 14c in a state where the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24. As shown in FIG. 3 to FIG. 5, in the present embodiment, the groove cross-section areas of the first blade groove 61 and the second blade groove 62 are approximately constant over the entire length of the groove (the dimension, which is represented by L in FIG. 5 and is hereinafter referred to as a groove length L), in other words, the entire length in the longitudinal direction. The groove length L is a dimension between the groove ends of the blades 18 and 19 in the advancing/retracting direction of the respective blade grooves 61 and 62 (length between the end portions 61a and 61b and length between the end portions 62a and 62b). That is, the groove length L is an entire length of the groove along the direction in which the blades 18 and 19 respectively advance/retract in the blade holes 13a and 14a. The groove cross-section area is an area of the cross section intersecting the longitudinal direction of each of the blade grooves 61 and 62. The longitudinal direction of each of the blade grooves 61 and 62 is the advancing/retracting direction of the blades 18 and 19, in other words, the flow direction of the injection refrigerant. As the groove cross-section area becomes larger, the maximum flow rate of the injection refrigerant in each of the blade grooves 61 and 62 increases.

The groove cross-section area is estimated by the groove widths and the groove depths (groove profundity) of the blade grooves 61 and 62. The groove width is a dimension indicated by W in FIG. 5 and is the distance between groove walls 61c and 61d opposed to each other along the central axis O1 of the blade grooves 61 and is the distance between groove walls 62c and 62d opposed to each other along the central axis O1 of the blade grooves 62. The groove depth (groove profundity) is the dimension indicated by D in FIG. 4 and is a distance between the side surface portion 18b of the blade 18 in the blade groove 61 and a groove bottom (continuous surface between the groove walls 61c and 61d) 61e and is a distance between the side surface portion 19b of the blade 19 in the blade groove 62 and a groove bottom (continuous surface between the groove walls 62c and 62d) 62e.

The groove cross-section area (W×D) of the first blade groove 61 is equal to or smaller than the aperture area (S1) of the aperture (injection hole) 54 of the first cylinder flow channel 51 (W×D≤S1).

Further, the groove cross-section area (W×D) of the second blade groove 62 is equal to or smaller than the aperture area (S2) of the aperture (injection hole) 56 of the second cylinder flow channel 52 (W×D≤S2). In the present embodiment, the groove cross-section area of the first blade groove 61 and the groove cross-section area of the second blade groove 62 are approximately equivalent to each other but may be different from each other. In addition, the aperture area (S1) of the injection hole 54 and the aperture area (S2) of the injection hole 56 are approximately equivalent to each other but may be different from each other.

As described above, the first blade groove 61 and the second blade groove 62 that have the groove width W, the groove width D, and the groove length L are formed on the side surfaces 18b and 19b of the blades 18 and 19, respectively. Further, respectively, the cylinders 13 and 14 include the spring insertion holes 13c and 14c in which the springs 13b and 14b are arranged. The blades 18 and 19 are respectively supported in the blade holes 13a and 14a while being biased by the springs 13b and 14b. In a state where the blade 18 is supported by the blade hole 13a, the side surface portion 18b of the blade 18 and the sidewall 13e of the blade hole 13a are provided to be opposed to each other. Similarly, in a state where the blade 19 is supported by the blade hole 14a, the side surface portion 19b of the blade 19 and the sidewall 14e of the blade hole 14a are provided to be opposed to each other. That is, in this state, the blade grooves 61 and 62 and the injection holes 54 and 56 are respectively positioned to face each other.

Respectively, the first blade groove 61 and the second blade groove 62 can be in communication with the injection holes 54 and 56 in the vicinity of the end portions 61a and 62a in the retracting side and can be in communication with the compression chambers 23b and 24b in the vicinity of the end portions 61b and 62b in the advancing side. In contrast, the first blade groove 61 and the second blade groove 62 cannot be in communication with the spring insertion holes 13c and 14c, respectively. That is, within the range in which the blades 18 and 19 respectively advance and retract in the blade holes 13a and 14a, the blade grooves 61 and 62 cannot be in communication with the spring insertion holes 13c and 14c. That is, the blade grooves 61 and 62 are provided such that they cannot be open to the spring insertion holes 13c and 14c, respectively.

The state in which the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24 is, for example, the state in which the first eccentric portion 28a (first roller 16) or the second eccentric portion 28b (second roller 17) is at the top dead point. A position of each of the first blade groove 61 and the second blade groove 62, for example, the groove length L is set such that the end portions 61a and 62a in the retracting side do not respectively overlap with the spring insertion holes 13c and 14c in the circumferential direction in the state in which the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24, respectively.

Respectively, as an example, the end portions 61a and 62a in the retracting side do not reach the end surface portions 18d and 19d in the retracting side of the blades 18 and 19 and reach end stops in front of the end surface portions 18d and 19d. Therefore, in the state where the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24, the end portions 61a and 62a in the retracting side are located closer to the axis of the rotation shaft 15 (center axis O1) than the spring insertion holes 13c and 14c are, respectively.

In the present embodiment, the first eccentric portion 28a of the rotation shaft 15 and the first roller 16 and the second eccentric portion 28b of the rotation shaft 15 and the second roller 17 are provided to have the phase difference (β) of 180 degrees on the rotation shaft 15. Therefore, the first blade groove 61 and the second blade groove 62 have the groove length L and the arrangement in which the first blade groove 61 and the second blade groove 62 can respectively be in communication with the injection holes 54 and 56 and the compression chambers 23b and 24b and cannot be respectively in communication with the spring insertion holes 13c and 14c in the range in which the rotation phase (angle) of the eccentric portions 28a and 28b of the rotation shaft 15 is smaller than 180 degrees with the bottom dead point being interposed therebetween. The first blade groove 61 and the second blade groove 62 have the length L and arrangement such that they are not respectively in communication with spaces behind the blade holes 13a and 14a at the top dead point.

FIG. 6A to FIG. 6F schematically show the state transition in the injection mechanism in the cylinders 13 and 14 in the compression process for refrigerants. The first blade groove 61 and the second blade groove 62 can respectively in communication with the injection holes 54 and 56, in other words, the compression chambers 23b and 24b in the range where the rotation phase (angle) from the top dead point of the respective eccentric portions 28a and 28b, in other words, the rollers 16 and 17 is smaller than 180 degrees. The rotational direction of the rollers 16 and 17 is the direction shown by arrow A in FIG. 6A to FIG. 6F. In the examples shown in FIG. 6A to FIG. 6F, the first blade groove 61 and the second blade groove 62 respectively are in communication with the injection holes 54 and 56 and the compression chambers 23b and 24b in the range in which the rotational angle (crank angle) of the eccentric portions 28a and 28b (rollers 16 and 17) from the top dead center is more than or equal to 91 degrees and less than or equal to 269 degrees, in other words, the rotation phase (α) is 178 degrees. At this time, the injection holes 54 and 56 are in communication with the compression chambers 23b and 24b through the blade grooves 61 and 62, respectively. In other words, the rotation phase (α) of the eccentric portions 28a and 28b (rollers 16 and 17) at which the injection refrigerant is injected into the compression chambers 23b and 24b is 178 degrees, respectively. Therefore, the rotational phase (α) that allows injection is smaller than the equidistant angle of the eccentric portions 28a and 28b (rollers 16 and 17) on the rotation shaft 15. That is, the rotational phase (α) is smaller than the phase difference (β) (α<β). The compression chambers 23b and 24b, the blade grooves 61 and 62, and the injection holes 54 and 56 (in short, the cylinder flow channels 51 and 52) respectively are in communication with one another at the equidistant angle of the eccentric portions 28a and 28b, in other words, the angular range (α), which is smaller than the phase difference (β) while the rotation shaft 15 rotates once. In addition, the outlet side flow channels (lateral flow channels) 51b and 52b of the first cylinder flow channels 51 and the second cylinder flow channel 52 that are respectively constituted in the cylinders 13 and 14, for example, pass through the outer peripheral surface of the cylinder to the side walls 13e and 14e of the blade holes 13a and 14a and configure the outer peripheral surface of the cylinder by sealing by means of pins.

In the present embodiment, the phase difference between the eccentric portions 28a and 28b (rollers 16 and 17) on the rotation shaft 15 is 180 degrees. Therefore, when the position of the first blade 18 in a case where the rotational angle of the eccentric portions 28a and 28b and the rollers 16 and 17 is 0 degrees is regarded as the top dead point, the position of the second blade 19 in this case is regarded as the bottom dead point. Therefore, although the injection mechanisms in the cylinders 13 and 14 have different injection states at the start time depending on the phase differences, the state transition cycles of the injection mechanism are the same.

FIG. 7A is a table indicating, per cylinders 13 and 14, a transition between a state in which the injection holes 54 and 56 respectively communicate with the compression chambers 23b and 24b through the blade grooves 61 and 62 (injection-open state) and a state in which they do not communicate with each other (injection-close state) according to the rotational angle of the eccentric portions 28a and 28b and the rollers 16 and 17.

As shown in FIG. 6A and FIG. 7A, when the rotational angle of the eccentric portion 28a and the roller 16 is 0 degrees, the first blade 18 is located at the top dead point and is not in communication with either the compression chamber 23b or the injection hole 54. That is, the compression chamber 23b, in short, the first cylinder 13, is in a state in which injection of the injection refrigerant is not performed (hereinafter referred to as an injection-close state). At this time, the second blade groove 62 is in communication with both of the compression chamber 24b and the injection hole 56. That is, the compression chamber 24b, in short, the second cylinder 14, is in a state in which the injection of the injection refrigerant is performed (hereinafter referred to as an injection-open state).

As shown in FIG. 6B and FIG. 7A, the first cylinder 13 remains in the injection-close state when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 0 degrees and less than a predetermined rotational angle. On the other hand, the second cylinder 14 remains in the injection-open state.

As shown in FIG. 6C and FIG. 7A, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 91 degrees, the first blade groove 61 is in communication with the injection hole 54 and further starts communication with the compression chamber 23b. That is, the first cylinder 13 is in a state in which the injection of the injection refrigerant is performed (injection-open state). On the other hand, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 90 degrees, the second blade groove 62 is not in communication with either the compression chamber 24bor the injection hole 56. That is, the compression chamber 24b, in short, the second cylinder 14, is in a state in which the injection of the injection refrigerant is not performed (injection-close state). Therefore, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 90 degrees, both of the first cylinder 13 and the second cylinder 14 are in the injection-close state. Even when the rotational angle of the eccentric portion 28a and the roller 16 reaches 91 degrees, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 6D and FIG. 7A, when the rotational angle of the eccentric portion 28a and the roller 16 is 180 degrees, the first blade 18 is positioned at the bottom dead point. At this time, the blade groove 61 remains in a state of being in communication with both of the compression chamber 23b and the injection hole 54. That is, the first cylinder 13 remains in the injection-open state. Further, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 6E and FIG. 7A, the first cylinder 13 remains in the injection-open state when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 180 degrees and less than a predetermined rotational angle. On the other hand, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 6F and FIG. 7A, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 270 degrees, the first blade groove 61 is in communication with the injection hole 54, but is not in communication with the compression chamber 23b. That is, the first cylinder 13 is in the injection-close state. On the other hand, the second cylinder 14 remains in the injection-close state. Therefore, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 270 degrees, the first cylinder 13 and the second cylinder 14 are both in the injection-close state. Thereafter, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 271 degrees, the first cylinder 13 remains in the injection-close state, and the second cylinder 14 is in communication with the injection hole 56 and further starts communication with the compression chamber 24b. That is, the second cylinder 14 transitions to the injection-open state. Then, the rotational angle of the eccentric portion 28a and the roller 16 reaches 360 degrees and they rotate once, the first cylinder 13 remains in the injection-close state and the second cylinder 14 remains in the injection-open state.

That is, while the eccentric portions 28a and 28b and the rollers 16 and 17 rotate once, the cylinders 13 and 14 both become the injection-close state twice, specifically when the rotational angle is 90 degrees and 270 degrees. When the rotational angle is other than these degrees, one of the cylinders 13 and 14 is in the injection-close state, and the other is in the injection-open state. Therefore, the first cylinder 13 and the second cylinder 14 are not in communication with each other through the injection mechanism (flow channels 40, 50, and 60).

Thereafter, in the first cylinder 13 and the second cylinder 14, the injection-open state and the injection-close state are repeated according to the rotational angles of the eccentric portions 28a and 28b and the rollers 16 and 17.

As shown in FIG. 7A, for example, when the rotational angle of the eccentric portion 28a and the roller 16 is 449 degrees, the first cylinder 13 remains in the injection-close state and the second cylinder 14 remains in the injection-open state. Even when the rotational angle reaches 450 degrees, the first cylinder 13 remains in the injection-close state. On the other hand, when the rotational angle reaches 450 degrees, the second cylinder 14 transitions to the injection-close state. That is, at this time, both of the first cylinder 13 and the second cylinder 14 are in the injection-close state.

Then, when the rotational angle reaches 451 degrees, the first cylinder 13 transitions to the injection-open state. On the other hand, the second cylinder 14 remains in the injection-close state. Thereafter, when the rotational angle is 629 degrees, the first cylinder 13 remains in the injection-open state and the second cylinder 14 remains in the injection-close state. When the rotational angle reaches 630 degrees, the first cylinder 13 transitions to the injection-close state. On the other hand, even when the rotational angle reaches 630 degrees, the second cylinder 14 remains in the injection-close state.

Even when the rotational angle reaches 631 degrees from this state, the first cylinder 13 remains in the injection-close state. On the other hand, when the rotational angle reaches 631 degrees, the second cylinder 14 transitions to the injection-open state. After that, when the rotational angle reaches 720 degrees and the eccentric portions 28a and 28b and the rollers 16 and 17 rotate twice, the first cylinder 13 remains in the injection-closed state and the second cylinder 14 remains in the injection-open state.

Although the present embodiment has described the case where the compressor 2 comprises two cylinders 13 and 14 (twin cylinder type), the number of cylinders is not limited to this example. For example, when the compressor comprises three cylinders, the transition of the possibility of performing the injection in each of these cylinders is as follows. In this case, the rotation shaft has three eccentric portions arranged at equal intervals (with phase difference of 120 degrees).

These eccentric portions comprise a roller to be arranged in each of the cylinders. When the rotation shaft rotates, these eccentric portions and rollers eccentrically rotate with respect to the rotation shaft with a phase difference of 120 degrees. The three cylinders comprise injection mechanisms that have flow channels approximately equivalent to the flow channels 40, 50, and 60 of the above-described injection mechanism. That is, the three cylinders have flow channels, which communicate with the compression mechanism unit 11 through the injection flow channel 7a and the connection pipe 7b from the refrigeration cycle circuit of the air conditioner 1 and communicate with one another by branching into the first, second, and third cylinders inside the compression mechanism unit 11.

FIG. 7B is a table indicating, per a cylinder (first, second, and third cylinders), a transition example between the injection-open state and the injection-close state according to a rotational angle of the eccentric portions and the rollers, in a case where the compressor comprises three cylinders.

Here, each of the three eccentric portions is eccentric at an angle of 120 degrees. The compression process progresses in the order of the first cylinder, the second cylinder, and the third cylinder as the rotating shaft rotates.

In the example shown in FIG. 7B, when the rotational angle is 0 degrees, the first cylinder, the second cylinder, and the third cylinder are all in the injection-close state. When the rotational angle reaches 2 degrees, the third cylinder transitions to the injection-open state. On the other hand, the first cylinder and the second cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 60 degrees or even 118 degrees, the first cylinder and the second cylinder remain in the injection-close state and the third cylinder remains in the injection-open state.

When the rotational angle reaches 121 degrees, the third cylinder transitions to the injection-close state. On the other hand, the first cylinder and the second cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

When the rotational angle reaches 122 degrees, the first cylinder transitions to the injection-open state. On the other hand, the second cylinder and the third cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 180 degrees or even 238 degrees, the first cylinder remains in the injection-open state and the second cylinder and the third cylinder remain in the injection-close state.

When the rotational angle reaches 239 degrees, the first cylinder transitions to the injection-close state. On the other hand, the second cylinder and the third cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

When the rotational angle reaches 242 degrees, the second cylinder transitions to the injection-open state. On the other hand, the first cylinder and the third cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 300 degrees or even 358 degrees, the first cylinder and the third cylinder remain in the injection-close state and the second cylinder remains in the injection-open state.

When the rotational angle reaches 359 degrees, the second cylinder transitions to the injection-close state. On the other hand, the first cylinder and the third cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

When the rotational angle reaches 362 degrees, the third cylinder transitions to the injection-open state. On the other hand, the first cylinder and the second cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 420 degrees or even 478 degrees, the first cylinder and the second cylinder remain in the injection-close state and the third cylinder remains in the injection-open state.

When the rotational angle reaches 479 degrees, the third cylinder transitions to the injection-close state. On the other hand, the first cylinder and the second cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

When the rotational angle reaches 482 degrees, the first cylinder transitions to the injection-open state. On the other hand, the second cylinder and the third cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 540 degrees or even 598 degrees, the first cylinder remains in the injection-open state and the second cylinder and the third cylinder remain in the injection-close state.

When the rotational angle reaches 599 degrees, the first cylinder transitions to the injection-close state. On the other hand, the second cylinder and the third cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

When the rotational angle reaches 602 degrees, the second cylinder transitions to the injection-open state. On the other hand, the first cylinder and the third cylinder remain in the injection-close state. Thereafter, even when the rotational angle reaches 660 degrees or even 718 degrees, the first cylinder and the third cylinder remain in the injection-close state and the second cylinder remains in the injection-open state.

When the rotational angle reaches 719 degrees, the second cylinder transitions to the injection-close state. On the other hand, the first cylinder and the third cylinder remain in the injection-close state. That is, at this time, all of the cylinders are in the injection-close state.

Even when the rotational angle reaches 720 degrees, all of the cylinders remain in the injection-close state. This state is equivalent to a case where the rotational angle is 0 degrees. Thereafter, in each of the cylinders, the above-mentioned injection-open state and the injection-close state are appropriately transitioned from each other.

That is, except when all of the cylinders are in the injection-close state, one of the three cylinders is in the injection-open state and the other two cylinders are in the injection-close state. Furthermore, at the timing of a cylinder that is in the injection-open state being switched, all of the cylinders instantly become the injection-close state. Therefore, the three cylinders are not in communicate with each other through the injection mechanism. As a result, an injection refrigerant does not flow into a plurality of cylinders at the same time, and thus the refrigerant in the injection flow channel does not flow backward among the cylinders. In particular, even when the distance between injection discharge ports, which are open to the inside of the compression chamber, and the common parts of the plurality of injection flow channels is short in the configuration in which the injection flow channel branches in the compression mechanism unit 11, the backflow to the injection flow channels can be prevented by the simple structure including the small number of parts.

According to the present embodiment, respectively, the blade grooves 61 and 62 are arranged not to be in communication with the spring insertion holes 13c and 14c, in other words, are arranged not to be respectively open to the spring insertion holes 13c and 14c within a range in which the blades 18 and 19 advance and retract in the blade holes 13a and 14a. Therefore, the blade grooves 61 and 62 can be prevented from being in communication with the inside of the sealed container 10 filled with lubricating oil (refrigerator oil). Therefore, the compressor 2 can be cooled by appropriately injecting the injection refrigerant into the compression chambers 23b and 24b. As a result, it is possible to suppress a decrease in the cooling effect of the compressor 2 and thus to improve reliability.

Further, in the present embodiment, the rotational phase (α) of the eccentric portions 28a and 28b (rollers 16 and 17), at which injection can be performed, is smaller than the phase difference (β) of the eccentric portions 28a and 28b (rollers 16 and 17) on the rotation shaft 15 (α<β). Therefore, the blade grooves 61 and 62, the cylinder flow channels 51 and 52, and the injection communication channel 40 can be prevented from being in communication with one another. According to this, the compression chamber 23b of the first cylinder 13 and the compression chamber 24b of the cylinder 14 can be prevented from being in communication with each other through the blade grooves 61 and 62, the cylinder flow channels 51 and 52, and the injection communication channel 40. Thereby, it is possible to suppress a decrease in compression performance in the compressor 2.

In addition, in the present embodiment, the blade grooves 61 and 62 are provided on the side surfaces 18b and 19b. That is, the blade grooves 61 and 62 are arranged on the opposite side of the refrigerant suction side (suction chambers 23a and 24a) in the cylinder chambers 23 and 24, in other words, are arranged on the discharge side. Therefore, the blade grooves 61 and 62 can be made incommunicable with the refrigerant suction ports 23c and 24c in the suction chambers 23a and 24a, respectively. Therefore, a decrease in the amount of refrigerants to be sucked, which derives from the respective communication between the blade grooves 61 and 62 and the suction ports 23c and 24c can be suppressed. As a result, decrease in the performance of the compressor 2 can also be suppressed.

In addition, by the configuration of the injection flow channel respectively communicating the blade grooves 61 and 62 provided in the side surfaces 18b and 19b of the blades 18 and 19 from the side walls 13e and 14e of the first and second blade holes 13a and 14a, the processed surfaces of the blades 18 and 19 can be only part of the side surfaces 18b and 19b. Therefore, there is no need to provide through holes in the blades 18 and 19, and thus it is possible to suppress a decrease in the strength of the blades 18 and 19 themselves.

In the present embodiment, the compressor having two cylinders and the compressor having three cylinders have been described. In both of the compressors, the injection flow channel is not open to a plurality of cylinders at the same time. Furthermore, when the plurality of cylinder have the common middle part of the injection circuit in communication with the plurality of cylinders, backflow from each of the plurality of cylinders to the injection flow channel can be prevented even in a state where a pressure difference occurs due to a difference in the compression process in the plurality of cylinders. By preventing the backflow of the refrigerant, the decrease in the performance can be suppressed and thus high COP can be maintained.

Second Embodiment

In the first embodiment described above, the groove cross-section areas (W×D) of the first blade groove 61 and the second blade groove 62 are approximately constant over the groove length L. However, the groove cross-section area of the blade groove may not be approximately constant over the groove length and may have a plurality of portions having different groove cross-section areas. Hereinafter, such a groove configuration will be described as a second embodiment. A compressor 2a in the second embodiment has the same basic configuration as that of the compressor 2 in the first embodiment shown in FIG. 2. Thus, in the second embodiment, with respect to configurations of the compressor 2a that are same or similar to those of the compressor 2, the configurations of the compressor 2 shown in FIG. 2 will be referred to. Further, these same or similar configurations are denoted by the same reference numbers as those of FIG. 2, and the detailed description thereof is omitted. Further, similarly to the compressor 2, the compressor 2a can be applied as one of the constituent elements of the air conditioner 1 (FIG. 1) of the first embodiment.

FIG. 8 is a longitudinal sectional view schematically showing a part of the compressor 2a in an enlarged manner. As shown in FIG. 8, each of a first blade groove 63 and a second blade groove 64 of the present embodiment has two parts having different cross-section areas. The number of these parts may be three or more. In the present embodiment, the configurations of the first blade groove 63 and the second blade groove 64 are approximately equivalent to each other.

FIG. 9 is a diagram schematically showing a blade of the second embodiment from a circumferential direction. As shown in FIG. 8 and FIG. 9, each of the blade grooves 63 and 64 includes two portions that have different cross-section areas, in other words, a first groove portion 71 and a second groove portion 72. The first groove portion 71 and the second groove portion 72 are continuous in the entire length direction of the blade grooves 63 and 64 and constitute each of the blade grooves 63 and 64. The first groove portion 71 is arranged on the advancing side of the advancing/retracting direction of blades 18 and 19 with respect to cylinder chambers 23 and 24, respectively. The second groove portion 72 is arranged on the retracting side of the advancing/retracting direction of the blades 18 and 19 with respect to the cylinder chambers 23 and 24, respectively. That is, in the advancing/retracting direction, the first groove portion 71 is located closer to the advancing direction than the second groove portion 72 is. In other words, the second groove portion 72 is located closer to the retracting direction than the first groove portion 71 is.

In the present embodiment, the first groove portion 71 and the second groove portion 72 have the approximately same groove depths (groove profundity) but have different groove widths. As a result, the first groove portion 71 and the second groove portion 72 have different groove cross-section areas. In the example shown in FIG. 8 and FIG. 9, the groove width of the first groove portion 71 (dimension indicated by W1 in FIG. 9) is smaller than a groove width W2 of the second groove portion 72 (W1<W2). For example, the groove depth of the first groove portion 71 and the groove depth of the second groove portion 72 are equivalent to the groove depths D of the blade grooves 61 and 62 of the first embodiment. For example, the width W1 of the first groove portion 71 is smaller than the groove widths W of the blade grooves 61 and 62 of the first embodiment, and the groove width W2 of the second groove portion 72 is greater than the groove widths W of the blade grooves 61 and 62 of the first embodiment. Thus, the groove cross-section area of the first groove portion 71 (W1×D) is smaller than the groove cross-section areas of the blade grooves 61 and 62. Further, the groove cross-section area of the second groove portion 72 (W2×D) is greater than the groove cross-section areas of the blade grooves 61 and 62. That is, the blade grooves 63 and 64 are tapered toward the advancing direction of the blades 18 and 19 with respect to the cylinder chambers 23 and 24, respectively.

In the present embodiment, the groove length of the blade grooves 63 and 64 (dimension represented by La in FIG. 9) may be the same as or different from the groove lengths L of the blade grooves 61 and 62 of the first embodiment. For example, the groove lengths La of the blade grooves 63 and 64 are configured such that an end portion in the retracting side, in other words, an end portion 72a of the second groove portion 72 does not overlap with insertion holes 13c and 14c in the circumferential direction when the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24. In the examples shown in FIG. 8 and FIG. 9, the groove lengths La of the blade grooves 63 and 64 are equivalent to the groove lengths L of the blade grooves 61 and 62.

FIG. 10A to FIG. 10F schematically show the state transition in the injection mechanisms in the cylinders 13 and 14 in the compression process for a refrigerant. In the present embodiment, a first eccentric portion 28a and a first roller 16 in a first cylinder 13 and a second eccentric portion 28b and a second roller 17 in a second cylinder 14 are arranged on a rotation shaft 15 with the phase difference of 180 degrees. Therefore, when the position of the first blade 18 in a case where the rotational angle of the eccentric portions 28a and 28b and the rollers 16 and 17 is 0 degrees is regarded as the top dead point, the position of the second blade 19 in this case is regarded as the bottom dead point. Therefore, although the injection mechanisms in the cylinders 13 and 14 have different injection states at the start time depending on the phase differences, the state transition cycles of the injection mechanism are the same.

As shown in FIG. 10A, for example, when the rotational angle of the eccentric portion 28a and the roller 16 is 0 degrees, the first blade 18 is positioned at the top dead point. At this time, the first blade groove 64 is not in communication with either a compression chamber 23b or an injection hole 54. That is, the first cylinder 13 is in the injection-close state. Further, at this time, the second blade groove 64 is in communication with both of a compression chamber 24b and an injection hole 56. That is, the second cylinder 14 is in the injection-open state.

As shown in FIG. 10B, the first cylinder 13 remains in the injection-close state when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 0 degrees and less than a predetermined rotational angle. On the other hand, the second cylinder 14 remains in the injection-open state.

As shown in FIG. 10C, when the rotational angle of the eccentric portion 28a and the roller 16 reaches, for example, 135 degrees, the first blade groove 63 is in communication with the injection hole 54 and starts communication with the compression chamber 23b. That is, the first cylinder 13 is in the injection-open state. At this time, the first blade groove 63 is in communication with the compression chamber 23b in the first groove portion 71, and is not communication with the compression chamber 23b in the second groove portion 72. In other words, the first blade groove 63 communicates with the compression chamber 23b only in the first groove portion 71, which has a smaller groove cross-section area than that of the second groove portion 72.

On the other hand, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 90 degrees, the second blade groove 64 is not in communication with either the compression chamber 24b or the injection hole 56. That is, the second cylinder 14 is in the injection-close state. Therefore, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 90 degrees, both of the first cylinder 13 and the second cylinder 14 are in the injection-close state. Even when the rotational angle of the eccentric portion 28a and the roller 16 reaches 91 degrees, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 10D, when the rotational

angle of the eccentric portion 28a and the roller 16 is 180 degrees, the first blade 18 is positioned at the bottom dead point. At this time, the blade groove 63 remains in a state of being in communication with both of the compression chamber 23b and the injection hole 54. That is, the first cylinder 13 remains in the injection-open state. At this time, the first blade groove 63 is in communication with the compression chamber 23b in the first groove portion 71 and also is in communication with the compression chamber 23b in the second groove portion 72. Further, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 10E, the first cylinder 13 remains in the injection-open state when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 180 degrees and less than a predetermined rotational angle. On the other hand, the second cylinder 14 remains in the injection-close state.

As shown in FIG. 10F, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 270 degrees, the first blade groove 63 is in communication with the injection hole 54 but is not in communication with the compression chamber 23b. That is, the first cylinder 13 is in the injection-close state. On the other hand, the second cylinder 14 remains in the injection-close state. Therefore, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 270 degrees, the first cylinder 13 and the second cylinder 14 are both in the injection-close state. Thereafter, when the rotational angle of the eccentric portion 28a and the roller 16 reaches 271 degrees, the first cylinder 13 remains in the injection-close state, and the second cylinder 14 is in communication with the injection hole 56 and further starts communication with the compression chamber 24b. That is, the second cylinder 14 transitions to the injection-open state. Then, the rotational angle of the eccentric portion 28a and the roller 16 reaches 360 degrees and they rotate once, the first cylinder 13 remains in the injection-close state and the second cylinder 14 remains in the injection-open state.

That is, while the eccentric portions 28a and 28b and the rollers 16 and 17 rotate once, the cylinders 13 and 14 both become the injection-close state twice, specifically when the rotational angle is 90 degrees and 270 degrees. When the rotational angle is other than these degrees, one of the cylinders 13 and 14 is in the injection-close state, and the other is in the injection-open state. Therefore, the first cylinder 13 and the second cylinder 14 are not in communication with each other through the injection mechanism (flow channels 40, 50, and 60).

Thereafter, in the first cylinder 13 and the second cylinder 14, the injection-open state and the injection-close state are repeated according to the rotational angles of the eccentric portions 28a and 28b and the rollers 16 and 17.

FIG. 11 is a diagram showing the locus of the relationship among rotational angles, ratios of compression loads, and ratios of groove cross-section areas. FIG. 12 is a diagram showing the relationship among the injection state, the rotational angles, and the ratios of the groove cross-section areas. The rotational angle is the rotational angle of the eccentric portion and the roller from the top dead portion. The ratio of the compression load is a locus indicated by a broken line in FIG. 11, and is a value which indicates 0 in a case where a refrigerant is not compressed in the compression chamber of the cylinder.

The groove cross-section area ratio is the locus indicated by a solid line in FIG. 11 and is the groove cross-section area ratio of the blade grooves 63 and 64 in a case where the groove cross-section area of the blade grooves 61 and 62 of the first embodiment is regarded as 1. The injection state is either the injection-open state or the injection-close state in the compression chamber of the cylinder.

In the example shown in FIG. 11, the ratio of the compression load is 0 when the rotational angle is 0 degrees. Then, this ratio gradually increases, reaches a peak at about 200 degrees, gradually decreases, and becomes 0 again at 360 degrees. As shown in FIG. 11 and FIG. 12, since the injection-close state continues while the rotational angle is more than or equal to 0 degrees and less than 135 degrees, the groove cross-section area ratio is 0.

The injection-open state continues while the rotational angle is more than or equal to 135 degrees and less than 160 degrees. At this time, for example, the first blade groove 63 is in communication with the compression chamber 23b only in the first groove 71, which has a smaller cross-section area than that of the second groove 72. Therefore, the groove cross-section area ratio is a value smaller than 1. Here, the value is 0.9.

The injection-open state continues while the rotational angle is more than or equal to 160 degrees and less than 200 degrees. At this time, for example, the first blade groove 63 is in communication with the compression chamber 23b in the first groove portion 71, and also is in communication with the compression chamber 23b in the second groove portion 72. That is, the first blade groove 63 is in communication with the compression chamber 23b in the second groove portion 72, which has a greater cross-section areas than those of the blade grooves 61 and 62. Therefore, the groove cross-section area ratio has a value greater than 1. Here, the value is 1.8.

The injection-open state continues while the rotational angle is more than or equal to 200 degrees and less than 225 degrees. At this time, for example, the first blade groove 63 is not in communication with the compression chamber 23b in the second groove portion 72, but is in the communication with the compression chamber 23b in the first groove portion 71 alone. Therefore, the groove cross-section area ratio is a value smaller than 1. Here, the value is 0.9.

Then, the injection-close state continues while the rotational angle is more than or equal to 225 degrees and less than 360 degrees. Therefore, the groove cross-section area ratio becomes 0 again.

In this way, when the respective communication among the blade grooves 63 and 64 and the compression chambers 23b and 24b, and the injection holes 54 and 56 start, the injection-open state starts in the groove cross-section area of the first groove portion 71. When the rotational angle increases from this state, the injection-open state where the second groove portion 72, which has a greater groove cross-section area than that of the first groove 71, is in communication with the compression chambers 23b and 24b starts. When the rotational angle becomes greater than 180 degrees, the injection-open state where the second groove portion 72 is in communication with the compression chambers 23b and 24b ends. On the other hand, the first groove portion 71 is in communication with the compression chambers 23b and 24b, and the injection-open state in the cross-section area of the first groove 71 continues. When the rotational angle further increases, the first groove portion 71 also stops communication with the compression chambers 23b and 24b, resulting in the injection-close state. When the respective communication among the blade grooves 63 and 64, the compression chambers 23b and 24b, and the injection holes 54 and 56 start from this state, the injection-open state starts again in the groove cross-section area of the first groove portion 71. Thereafter, such a transition between the injection open-state and the injection-close state is repeated.

By making the groove cross-section areas of the first groove portion 71 and the second groove portion 72 different from each other, the present embodiment can increase the groove cross-section area of each of the blade grooves 63 and 64 from the groove cross-section area of the first groove portion 71 to the groove cross-section area of the second groove portion 72 before the pressure in each of the compression chambers 23b and 24b increases to the discharge pressure of the refrigerant. In other words, the injection amount of the injection refrigerant into the compression chambers 23b and 24b can be suppressed at the start and end of the compression of the refrigerant, and the injection amount of the injection refrigerant can be increased to be more than that in the start and end, when compression is progressing. That is, the amount of the injection refrigerant can be increased during the progress of compression, which requires cooling more than at the start or the end of compression does. Further, the groove cross-section areas of the blade grooves 63 and 64 can be expanded in a short section corresponding to the entire length of these grooves. Thereby, the flow rate of the injection refrigerants in the compression process can be set to an appropriate amount. Thus, the cooling performance of the compressor 2a using the heat of vaporization (latent heat and sensible heat) of the injection refrigerant can be increased.

Furthermore, the time required for switching between the injection-open state and the injection-close state can be shortened. The time in which the pressure in the compression chambers 23b and 24b is greater than the pressure in the injection flow channel 7a and in which the injection-open state continues can be shortened.

Further, when the pressure in the compression chambers 23b and 24b is greater than the pressure in the injection flow channel 7a and the injection-open state continues, the groove cross-section areas of the blade grooves 63 and 64 can be smaller than the groove cross-section areas of the blade grooves 61 and 62. As a result, the refrigerant being compressed can be prevented from backflowing into the injection flow channel 7a. Therefore, it is possible to suppress a decrease in the cooling effect of the compressor 2a and thus to improve reliability. In addition, it is possible to prevent the backflow of refrigerants, suppress the decrease in the performance, and maintain a high COP.

Third Embodiment

In the first and second embodiments described above, the first blade 18 and the second blade 19 each have one blade grooves, in other words, the respective blade grooves 61 and 62. However, each blade may have plurality of blade grooves. Hereinafter, such a groove configuration will be described as a third embodiment. A compressor 2b in the third embodiment has the same basic configuration as that of the compressor 2 in the first embodiment shown in FIG. 2. Thus, in the third embodiment, with respect to configurations of the compressor 2b that are same or similar to those of the compressor 2, the configurations of the compressor 2 shown in FIG. 2 will be referred to. Further, these same or similar configurations are denoted by the same reference numbers as those of FIG. 2, and the detailed description thereof is omitted. Further, similarly to the compressor 2, the compressor 2b can be applied as one of the constituent elements of the air conditioner 1 (FIG. 1) of the first embodiment.

FIG. 13 is a longitudinal sectional view schematically showing a part of the compressor 2b in an enlarged manner. As shown in FIG. 13, in the present embodiment, a first blade 18 includes two blade grooves 651 and 652, and a second blade 19 includes two blade grooves 661 and 662. However, the number of blade grooves may be three or more, or may be different between the first blade 18 and the second blade 19. In the present embodiment, the configurations of the blade groove 651 and the blade groove 661 and the configurations of the blade groove 652 and the blade groove 662 are approximately the same.

FIG. 14 is a diagram schematically showing a blade of the third embodiment from a circumferential direction. As shown in FIG. 13 and FIG. 14, the groove lengths of the blade grooves 651 and 661 and the blade grooves 652 and 662 are different from each other. In the illustrated example, groove lengths L1 of the blade grooves 651 and 661 are longer than groove lengths L2 of the blade grooves 652 and 662 (L1>L2). In the blades 18 and 19, the blade grooves 651 and 661 are provided on one side (lower side) in the direction along the central axis O1, and the blade grooves 652 and 662 are arranged on the other side (upper side) in this direction. Hereinafter, the blade grooves 651 and 661 will be referred to as lower blade grooves 651 and 661, and the blade grooves 652 and 662 will be referred to as upper blade grooves 652 and 662.

Respectively, in the advancing/retracting direction of the blades 18 and 19, end portions 651a and 661a and end portions 652a and 662a in the retracting direction of the lower blade grooves 651 and 661 and the upper blade grooves 652 and 662 are arranged at the approximately same positions. In contrast, end portions 651b and 661b and end portions 652b and 662b in the advancing side are respectively arranged at different positions. Respectively, in the illustrated example, the end portions 651b and 661b in the advancing side of the lower blade grooves 651 and 661 are arranged closer to the central axis 01 than the end portions 652b and 662b in the advancing side of the upper blade grooves 652 and 662 (left side in FIG. 14).

In a state where the blades 18 and 19 are most retracted with respect to the cylinder chambers 23 and 24, the groove lengths L1 of the lower blade grooves 651 and 661 and the groove lengths L2 of the upper blade grooves 652 and 662 must have dimension such that the end portions 651a, 661a, 652a, and 662a in the retracting side do not overlap with spring insertion holes 13c and 14c in the circumferential direction.

As described above, in the examples shown in FIG. 13 and FIG. 14, the groove lengths L1 of the lower blade grooves 651 and 661 are longer than the groove lengths L2 of the upper blade grooves 652 and 662. However, the length relationship of the grooves may be reversed from the illustrated example. The groove length may be different between the first blade 18 and the second blade 19, but in one blade, the upper blade groove and the lower blade groove have different groove lengths.

In the present embodiment, the groove widths of the lower blade grooves 651 and 661 and the groove widths of the upper blade grooves 652 and 662 are the approximately same, respectively. The groove depths (groove profundity) of the lower blade grooves 651 and 661 and the groove depths (groove profundity) of the upper blade grooves 652 and 662 are the approximately same, respectively. Therefore, the groove cross-section areas of the lower blade grooves 651 and 661 and the groove cross-section areas of the upper blade grooves 652 and 662 are approximately equivalent to each other, respectively. However, the groove widths and the groove depths of the lower blade grooves 651 and 661 may be different from the groove widths and groove depths of the upper blade grooves 652 and 662, respectively. In addition, in the present embodiment, the groove cross-section areas of the lower blade grooves 651 and 661 and the groove cross-section areas of the upper blade grooves 652 and 662 are smaller than the groove cross-section areas (W×D) of the blade grooves 61 and 62 of the first embodiment, respectively. On the other hand, the sum of the respective groove cross-section areas of the lower blade grooves 651 and 661 and the upper blade grooves 652 and 662 is larger than the respective groove cross-section areas (W×D) of the blade grooves 61 and 62.

Further, similarly to the first embodiment (FIG. 3), the first cylinder flow channel 51 is configured such that an inlet side flow channel (vertical flow channel) 51a and two outlet side flow channels 511b and 512b are continuously constituted.

That is, the inlet side flow channel 51a branches into the two outlet side flow channels 511b and 512b. The one outlet side flow channel 511b is in communication with an aperture (injection hole 54a) of a side wall 13e of a first blade hole 13a. The other outlet side flow channel 512b is in communication with an aperture (injection hole 54b) of the side wall 13e of the first blade hole 13a. The injection hole 54a and the injection hole 54b are open to different portions of the side wall 13e. An injection refrigerant flows into the inlet side flow channel 51a and then is divided into the outlet side flow channels 511b and 512b and then is guided to the respective injection holes 54a and 54b. The injection hole 54a can be in communication with the lower blade groove 651 of the first blade 18, and the injection hole 54b can be in communication with the upper blade groove 652 of the first blade 18.

In the second cylinder flow channel 52, an inlet side flow channel (vertical flow channel) 52a and two outlet side flow channels 521b and 522b are continuously constituted. That is, the inlet side flow channel 52a branches into the two outlet side flow channels 521b and 522b. The one outlet side flow channel 521b is in communication with an aperture (injection hole 56a) of a side wall 14e of a second blade hole 14a. The other outlet side flow channel 512b is in communication with an aperture (injection hole 56b) of the side wall 14e of the second blade hole 14a. The injection hole 56a and the injection hole 56b are open to different portions of the side wall 14e. An injection refrigerant flows into the inlet side flow channel 52a and then is divided into the outlet side flow channels 521b and 522b and is guided to the respective injection holes 56a and 56b. The injection hole 56a can be in communication with the lower blade groove 661 of the second blade 19. The injection hole 56b can be in communication with the upper blade groove 662 of the second blade 19.

FIG. 15A to FIG. 15F are diagrams schematically showing the state transition in the injection mechanism in the cylinders 13 and 14 in the compression process for a refrigerant. In the present embodiment, a first eccentric portion 28a and a first roller 16 in the first cylinder 13 and a second eccentric portion 28b and a second roller 17 in the second cylinder 14 are arranged on a rotation shaft 15 with the phase difference of 180 degrees. Therefore, when the position of the first blade 18 in a case where the rotational angle of the eccentric portions 28a and 28b and the rollers 16 and 17 is 0 degrees is regarded as the top dead point, the position of the second blade 19 in this case is regarded as the bottom dead point. Therefore, although the injection mechanisms in the cylinders 13 and 14 have different injection states at the start time depending on the phase differences, the state transition cycles of the injection mechanism are the same.

As shown in FIG. 15A, for example, when the rotational angle of the eccentric portion 28a and the roller 16 is 0 degrees, the first blade 18 is positioned at the top dead point. At this time, the lower blade groove 651 is not in communication with either a compression chamber 23b or an injection hole 54a. In addition, the upper blade groove 652 is not in communication with either the compression chamber 23b or the injection hole 54b. That is, the first cylinder 13 is in the injection-close state.

As shown in FIG. 15B, when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 0 degrees and less than a predetermined rotational angle, the lower blade groove 651 remains in a state of not being in communication with either the compression chamber 23b or the injection hole 54a. Further, the upper blade groove 652 remains in a state of not being in communication with either the compression chamber 23b or the injection hole 54b. Therefore, the first cylinder 13 remains in the injection-close state.

As shown in FIG. 15C, when the rotational angle of the eccentric portion 28a and the roller 16 reaches, for example, 135 degrees, the lower blade groove 651 is in communication with the injection hole 54a and further starts communication with the compression chamber 23b. That is, the first cylinder 13 is in the injection-open state. On the other hand, the upper blade groove 652 remains in a state of not being in communication with either the compression chamber 23b or the injection hole 54b.

As shown in FIG. 15D, when the rotational angle of the eccentric portion 28a and the roller 16 is 180 degrees, the first blade 18 is positioned at the bottom dead point. At this time, the lower blade groove 651 remains in a state of being in communication with both of the compression chamber 23b and the injection hole 54a. On the other hand, when the rotational angle of the eccentric portion 28a and the roller 16 reaches, for example, 160 degrees, the upper blade groove 652 is in communication with the injection hole 54b and further starts communication with the compression chamber 23b. Even when the rotational angle of the eccentric portion 28a and the roller 16 reaches 180 degrees, the upper blade groove 652 remains in a state of being in communication with both of the compression chamber 23b and the injection hole 54b. That is, the first cylinder 13 remains in the injection-open state.

As shown in FIG. 15E, the lower blade groove 651 remains in a state of being in communication with both of the compression chamber 23b and the injection hole 54a when the rotational angle of the eccentric portion 28a and the roller 16 is more than or equal to 180 degrees and less than a predetermined rotational angle. That is, the first cylinder 13 remains in the injection-open state. On the other hand, when the rotational angle of the eccentric portion 28a and the roller 16 reaches, for example, 200 degrees, the upper blade groove 652 is in communication with the injection hole 54b but is not in communication with the compression chamber 23b. At the rotational angle shown in FIG. 15E, the upper blade groove 652 remains in this state.

Thereafter, when the rotational angle of the eccentric portion 28a and the roller 16 reaches, for example, 225 degrees, the lower blade groove 651 is in communication with the injection hole 54a but is not in communication with the compression chamber 23b. That is, the first cylinder 13 transitions to the injection-close state.

As shown in FIG. 15F, even when the rotational angle of the eccentric portion 28a and the roller 16 reaches 270 degrees, the lower blade groove 651 remains in a state of being in communication with the injection hole 54a but not being in communication with the compression chamber 23b. At this time, the upper blade groove 652 is not in communication with either the compression chamber 23b or the injection hole 54b. That is, the first cylinder 13 remains in the injection-close state.

Then, the rotational angle of the eccentric portion 28a and the roller 16 reaches 360 degrees and the eccentric portion 28a and the roller 16 rotate once, the lower blade groove 651 is not in communication with either the compression chamber 23b or the injection hole 54a. Further, the upper blade groove 652 remains in a state of not being in communication with either the compression chamber 23b or the injection hole 54b.

Thereafter, in the first cylinder 13, the above-described injection-open state and injection-close state are repeated according to the rotational angles of the eccentric portion 28a and the roller 16.

FIG. 16 is a diagram showing the relationship among the injection states, the rotational angles, and the groove cross-section area ratios. The injection state is either the injection-open state or the injection-close state in the compression chamber of the cylinder. The rotational angle is the rotational angle of the eccentric portion and the roller from the top dead portion. The ratio of the compression load is a value which indicates 0 in a case where a refrigerant is not compressed in the compression chamber of the cylinder. The groove cross-section area ratio is the sum of the ratio of an upper groove cross-section area and the ratio of a lower groove cross-section area.

The upper groove cross-section area ratio is a groove cross-section area ratio of the upper blade grooves 652 and 662 of the present embodiment when the groove cross-section areas of the blade grooves 61 and 62 of the first embodiment are expressed as 1, respectively.

The lower groove cross-section area ratio is a groove cross-section area ratio of the lower blade grooves 651 and 661 of the present embodiment when the groove cross-section areas of the blade grooves 61 and 62 of the first embodiment are expressed as 1, respectively.

In the present embodiment, the relationship among rotational angles, ratios of compression loads, and ratios of groove cross-section areas is approximately equivalent to the relationship in the second embodiment shown in FIG. 11. Therefore, the ratio of the compression load is 0 when the rotational angle is 0 degrees. Then, this ratio gradually increases, reaches a peak at about 200 degrees, gradually decreases, and becomes 0 again at 360 degrees. The ratio of the compression load is a value which indicates 0 in a case where a refrigerant is not compressed in the compression chamber of the cylinder.

As shown in FIG. 16, the injection-close state continues when the rotational angle is more than or equal to 0 degrees and less than 135 degrees, and thus upper groove cross-section area ratio, the lower groove cross-section area ratio, and the groove cross-section area ratio are all 0.

The injection-open state continues while the rotational angle is more than or equal to 135 degrees and less than 160 degrees. At this time, for example, the compression chamber 23b, the lower blade groove 651, and the injection hole 54a are in communication with each other. The groove cross-section area of the lower blade groove 651 is smaller than the groove cross-section areas (W×D) of the blade grooves 61 and 62. Therefore, the lower groove cross-section area ratio is a value smaller than 1. Here, the value is 0.9. On the other hand, the compression chamber 23b, the upper blade groove 652, and the injection hole 54b are not in communication with each other. Therefore, the upper groove cross-section area ratio is 0. Therefore, the groove cross-section area ratio is 0.9. In this manner, the fist cylinder 13 is in the injection-open state through the lower blade groove 651 alone.

The injection-open state continues while the rotational angle is more than or equal to 160 degrees and less than 200 degrees. At this time, for example, the compression chamber 23b, the lower blade groove 651, and the injection hole 54a remain in communication with each other. Therefore, the lower groove cross-section area ratio is 0.9. On the other hand, the compression chamber 23b, the upper blade groove 652, and the injection hole 54b are in communication with each other. The groove cross-section area of the upper blade groove 652 is smaller than the groove cross-section areas (W×D) of the blade grooves 61 and 62. Therefore, the upper groove cross-section area ratio is a value smaller than 1. Here, the value is 0.9. Therefore, the groove cross-section area ratio is 1.8. In this manner, the first cylinder 13 is in the injection-open state through both of the upper blade groove 652 and the lower blade groove 651.

The injection-open state continues while the rotational angle is more than or equal to 200 degrees and less than 225 degrees. At this time, for example, the compression chamber 23b, the lower blade groove 651, and the injection hole 54a remain in communication with each other. Therefore, the lower groove cross-section area ratio is 0.9. On the other hand, the compression chamber 23b, the upper blade groove 652, and the injection hole 54b are not in communication with each other. Therefore, the upper groove cross-section area ratio is 0. Therefore, the groove cross-section area ratio is 0.9. In this manner, the fist cylinder 13 is in the injection-open state through the lower blade groove 651 alone.

Then, the injection-close state continues while the rotational angle is more than or equal to 225 degrees and less than 360 degrees. Therefore, the upper groove cross-section area ratio, the lower groove cross-section area ratio, and the groove cross-section area ratio all become 0 again.

In the present embodiment, by making the groove lengths of the upper blade grooves 652 and 662 and the lower blade grooves 651 and 661 different from each other (L1>L2) respectively, the injection-open state only through the lower blade grooves 651 and 661 can be transitioned to the injection-open state through both of the upper blade grooves 652 and 662 and the lower blade grooves 651 and 661 before the pressure in the compression chambers 23b and 24b increase to the discharge pressure of the refrigerant. In other words, the injection amount of the injection refrigerant into the compression chambers 23b and 24b can be suppressed at the start and end of the compression of the refrigerant, and the injection amount of the injection refrigerant can be increased to be more than that in the start and end, when compression is progressing. That is, the amount of the injection refrigerant can be increased during the progress of compression, which requires cooling more than at the start or the end of compression does. In addition, the groove cross-section area contributing to the injection can be expanded in a short section corresponding to the groove length. Thereby, the cooling performance of the compressor 2b using the heat of vaporization (latent heat and sensible heat) of the injection refrigerant can be improved.

Furthermore, the time required for switching between the injection-open state and the injection-close state can be shortened. The time in which the pressure in the compression chambers 23b and 24b is greater than the pressure in the injection flow channel 7a and in which the injection-open state continues can be shortened.

Further, when the pressure in the compression chambers 23b and 24b is higher than the pressure in the injection flow channel 7a and the injection is in the open state, the groove cross-section area contributing to the injection can be made smaller than in other states. As a result, backflow of the injection refrigerant into the injection flow channel 7a can be suppressed. Therefore, it is possible to suppress a decrease in the cooling effect of the compressor 2b and thereby improve reliability. In addition, it is possible to prevent the backflow of refrigerants, suppress the decrease in the performance, and maintain a high COP.

In the above-described second and third embodiments, the compressors having two cylinders have been described, but this configuration be applied to a compressor having three cylinders as the one described in other embodiments of the first embodiment. In that case, similarly to the first embodiment, it is preferable that the opening/closing timing of the injection flow channel in each cylinder is such that only a single cylinder is open without a plurality of cylinders being open at the same time. That is, when the injection flow channel in the first cylinder is in the open state, the injection channels in the second and third cylinders are in the close state. Similarly, when the injection flow channel in the second cylinder is in the open state, the injection flow channels in the first and third cylinders are in the close state, and when the injection flow channel in the third cylinder is in the open state, the injection flow channels in the first and second cylinders are in the close state.

The shapes of the blade grooves in the above-described embodiments may be varied as long as the effects of the invention are achieved. For example, the cross-section area may have a gradually-tapered shape, a round shape, or a combination thereof.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.

Claims

1. A compressor, comprising: an annular cylinder, which constitutes a cylinder chamber including a suction chamber for sucking a refrigerant and a compression chamber for compressing the refrigerant;a rotation shaft, which includes an eccentric portion arranged in the cylinder chamber;a roller, which is fitted into the eccentric portion and eccentrically rotates with respect to a center of axis of the rotation shaft in the cylinder chamber;a flat blade, which advances or retracts in the cylinder chamber according to an eccentric rotation of the roller and partitions the cylinder chamber into the suction chamber and the compression chamber; andan injection flow channel branching from a cyclic circuit, through which the refrigerant circulates, and guiding a part of the refrigerant circulating through the cyclic circuit to the compression chamber, whereinthe injection flow channel includes at least a blade groove formed in a surface portion facing the compression chamber, of side surface portions constituting a pair on the blade and facing a circumferential direction with respect to the center of axis of the rotation shaft, anda surface on which the part of the refrigerant flows into the blade groove is flush with a surface discharging the part of the refrigerant from the blade groove to the compression chamber.

2. A compressor, comprising: an annular cylinder, which constitutes a cylinder chamber including a suction chamber for sucking a refrigerant and a compression chamber for compressing the refrigerant;a rotation shaft, which includes an eccentric portion arranged in the cylinder chamber;a roller, which is fitted into the eccentric portion and eccentrically rotates with respect to a center of axis of the rotation shaft in the cylinder chamber; anda substantially flat blade, which advances or retracts in the cylinder chamber according to an eccentric rotation of the roller and partitions the cylinder chamber into the suction chamber and the compression chamber, whereinthe cylinder and the blade include an injection flow channel branching from a cyclic circuit, through which the refrigerant circulates, and guiding a part of the refrigerant circulating through the cyclic circuit to the compression,the cylinder includes:a blade hole, which is open to an inner peripheral part, extends outwardly along a diameter direction, and accommodates the blade;a spring, which presses the blade against the roller in the blade hole; anda spring insertion hole in which the spring is arranged,the injection flow channel includes:a blade groove formed in a groove shape in a surface portion facing the compression chamber, of side surface portions constituting a pair on the blade and facing a circumferential direction with respect to the center of axis of the rotation shaft; anda cylinder flow channel open to be communicable with the blade groove on a wall portion opposed to the surface portion facing the compression chamber of the blade in the blade hole, andthe blade groove is arranged on the surface portion facing the compression chamber of the blade so as not to overlap with the spring insertion hole in the circumferential direction.

3. The compressor of claim 2, wherein an end portion in a retraction side of the blade in the blade groove does not reach an end surface portion in the retraction side of the blade, andin a state where the blade is most retracted with respect to the cylinder chamber in the blade hole, the end portion is located closer to the center of axis of the rotation shaft than the spring insertion hole is.

4. The compressor of claim 2, wherein the rotation shaft includes the plurality of eccentric portions equidistantly arranged in the circumferential direction at intervals in a direction of the center of axis, andthe cylinder includes the plurality of cylinder chambers each accommodating one of the plurality of eccentric portions, andwhile the rotation shaft rotates once, the compression chamber, the blade groove, and the cylinder flow channel are in communication with each other at an angle range smaller than an equidistant angle of the plurality of eccentric portions.

5. The compressor of claim 2, wherein the blade groove has a longitudinal side along an advancing/retracting direction in the blade hole, anda groove cross-section area of the blade groove intersecting a longitudinal direction is approximately constant over the entire longitudinal direction.

6. The compressor of claim 2, wherein the blade groove has a longitudinal side along an advancing/retracting direction in the blade hole and includes a plurality of portions having different groove cross-section areas intersecting a direction of the longitudinal side.

7. The compressor of any one of claims 5 and 6, wherein the groove cross-section area of the blade groove is smaller than or equal to an aperture area of the aperture in the cylinder flow channel in the wall portion of the blade.

8. The compressor of claim 2, wherein the blade includes the plurality of blade grooves in the surface portion facing the compression chamber,the cylinder includes the plurality of cylinder flow channels, which are open to different parts of the wall portion opposed to the surface portion facing the compression chamber of the blade in the blade hole, andthe plurality of blade grooves have different entire lengths along the advancing/retracting direction in the blade hole.

9. A refrigeration cycle device, comprising: the compressor of any one of claims 1 and 2;a condenser connected to the compressor;an expansion device connected to the condenser; andan evaporator connected to the expansion device.