Patent Application
20150369526
The present invention relates to a sealed compressor for use in a refrigeration cycle of refrigeration devices or the like, and a refrigeration device using the sealed compressor.
Refrigeration devices including refrigeration cycles are widely used for household purposes or business purposes, as home electric freezers/refrigerators, or show cases. In recent years, there has been an increasing demand for global environment conservation. Under the circumstances, there has been a strong demand for the high efficiency of a sealed compressor used in the refrigeration cycle.
Conventionally, as an example of a technique for preventing a decrease in the compression efficiency of the sealed compressor, an air compressor disclosed in Patent Literature 1 is known. This air compressor is configured such that a cylinder head is provided with a discharge chamber and a suction chamber, and a peripheral wall defining the discharge chamber and a peripheral wall defining the suction chamber are separated from each other by a cooling groove.
Specifically, as shown in
The piston 512 reciprocates inside of the cylinder 513. The end surface of the cylinder 513 is provided with the valve seat plate 514. The valve seat plate 514 includes a suction port 528 and a discharge port (not shown) and is provided with a suction valve 529 and a discharge valve 531. The suction port 528 is opened and closed by the suction valve 529, while the discharge port is opened and closed by the discharge valve 531. A cylinder head 518 is provided above the valve seat plate 514. The cylinder head 518 includes a suction chamber 515 which is in communication with the suction port 528 and a discharge chamber 516 which is in communication with the discharge port.
The cylinder head 518 is formed by a single member and fastened to the cylinder 513 together with the valve seat plate 514. The suction chamber 515 defined by a peripheral wall 525 is provided at one side of the cylinder head 518. The discharge chamber 516 surrounds the peripheral wall 525 defining the suction chamber 515, and is defined by a peripheral wall 517 extending over the entire upper surface of the cylinder head 518. Between the peripheral wall 525 and the peripheral wall 517, a cooling groove 526 with a large depth is formed.
However, in the above-described configuration, since the cylinder head 518 is formed by the single member, the peripheral wall 525 defining the suction chamber 515 and the peripheral wall 517 defining the discharge chamber 516 are in communication with each other, even though the cooling groove 526 is formed. For this reason, when the peripheral wall 517 is heated by a high-temperature refrigerant gas in the interior of the discharge chamber 516, this heat is transferred from the peripheral wall 517 to the peripheral wall 525, which increases the temperature of the peripheral wall 525. The refrigerant gas suctioned into the suction chamber 515 is also heated. As a result, volumetric efficiency is reduced.
The valve seat plate 514 is provided with the suction port 528. The valve seat plate 514 is also heated by the refrigerant gas in the interior of the discharge chamber 516 and the compressed refrigerant gas in the interior of the cylinder 513. Since the suctioned refrigerant gas is also heated by the heat of the valve seat plate 514, the volumetric efficiency is reduced as in the above case.
The present invention has been made to solve the above described problem, and an object of the present invention is to provide a sealed compressor with high efficiency which is capable of suppressing a temperature increase in a suctioned refrigerant gas to thereby effectively suppress a decrease in volumetric efficiency.
To solve the above described problem, the present invention provides a sealed compressor comprising: a sealed container having a sealed space inside thereof; an electric component accommodated in the sealed container; and a compression component accommodated in the sealed container and driven by the electric component to compress a refrigerant gas, wherein the compression component includes: a crankshaft supported such that an axis of the crankshaft extends vertically, the crankshaft being rotated by the electric component; a piston which is provided such that an axis of the piston crosses an axial direction of the crankshaft and is reciprocatable according to a rotation of the crankshaft; a cylinder having a compression chamber inside thereof, the piston being reciprocatably inserted into the cylinder through one end of the cylinder; a valve plate which closes the other end of the cylinder and is provided with a suction hole and a discharge hole; a cylinder head which is fastened to the other end of the cylinder via the valve plate and has a discharge space inside thereof which is in communication with the discharge hole; and a suction muffler which is located below the cylinder, has a muffling space inside thereof, and includes a communication pipe coupled to the suction hole, wherein the communication pipe extends upward from the suction muffler toward the other end of the cylinder and includes a communication pipe exit section at an upper end of the communication pipe such that the communication pipe exit section is in communication with the suction hole, wherein a recess accommodating the communication pipe exit section inside thereof is provided on a lower portion of the cylinder head, and wherein a gas inflow space in an interior of the sealed container is formed between the communication pipe exit section and the recess and is in communication with the sealed space.
The present invention provides a refrigeration device comprising a refrigeration circuit configured such that the sealed compressor having the above configuration, a heat radiator, a pressure-reducing device, and a heat absorbing unit are annularly coupled to each other by use of a pipe.
The above and further objects, features and advantages of the present invention will more fully be apparent from the following detailed description of preferred embodiments with accompanying drawings.
With the above described configuration, the present invention has an advantage that it is possible to provide a sealed compressor with high efficiency which is capable of suppressing a temperature increase in a suctioned refrigerant gas to effectively suppress a decrease in volumetric efficiency.
The present invention provides a sealed compressor comprising: a sealed container having a sealed space inside thereof; an electric component accommodated in the sealed container; and a compression component accommodated in the sealed container and driven by the electric component to compress a refrigerant gas, wherein the compression component includes: a crankshaft supported such that an axis of the crankshaft extends vertically, the crankshaft being rotated by the electric component; a piston which is provided such that an axis of the piston crosses an axial direction of the crankshaft and is reciprocatable according to a rotation of the crankshaft; a cylinder having a compression chamber inside thereof, the piston being reciprocatably inserted into the cylinder through one end of the cylinder; a valve plate which closes the other end of the cylinder and is provided with a suction hole and a discharge hole; a cylinder head which is fastened to the other end of the cylinder via the valve plate and has a discharge space inside thereof which is in communication with the discharge hole; and a suction muffler which is located below the cylinder, has a muffling space inside thereof, and includes a communication pipe coupled to the suction hole, wherein the communication pipe extends upward from the suction muffler toward the other end of the cylinder and includes a communication pipe exit section at an upper end of the communication pipe such that the communication pipe exit section is in communication with the suction hole, wherein a recess accommodating the communication pipe exit section inside thereof is provided on a lower portion of the cylinder head, and wherein a gas inflow space in an interior of the sealed container is formed between the communication pipe exit section and the recess and is in communication with the sealed space.
In accordance with this configuration, the heat insulating layer which is the gas inflow space in the interior of the sealed container is formed between the communication pipe exit section and the cylinder head. In this structure, it becomes possible to suppress heat transfer from the high-temperature cylinder head to the communication pipe exit section. Because of this, it becomes possible to suppress a temperature increase in the suctioned refrigerant gas flowing through the communication pipe, and to effectively suppress a decrease in the volumetric efficiency of the refrigerant gas. As a result, the efficiency of the sealed compressor can be improved.
In the sealed compressor configured as described above, when the axial direction of the crankshaft is a longitudinal direction and an axial direction of the piston is a lateral direction, the gas inflow space in the interior of the sealed container may include a first space located below the discharge space and extending in the lateral direction to face an upper peripheral surface of the communication pipe exit section, and a second space extending in the longitudinal direction to face a side peripheral surface of the communication pipe exit section, and the first space may have a thickness larger than a thickness of the second space.
In accordance with this configuration, the first space is located in the cylinder head upper section of the cylinder head, including the discharge space, while the second space is located in the cylinder head lower section of the cylinder head. The interior of the discharge space is in a higher-temperature state than the sealed space inside of the sealed container is. In view of this, by setting the thickness of the first space larger than the thickness of the second space, the heat transfer from the discharge space with a large heat amount to the refrigerant gas flowing through the communication pipe can be suppressed. Thus, a temperature increase in the refrigerant gas flowing through the communication pipe can be suppressed more effectively.
In the sealed compressor configured as described above, the communication pipe exit section may have an opening section at a tip end, the opening section being inserted into the suction hole.
In accordance with this configuration, since the opening section is inserted into the suction hole, the refrigerant gas flowing through the communication pipe exit section is suctioned into the compression chamber through the opening section without contacting the valve plate in a high-temperature state. Thus, the gas inflow space in the interior of the sealed container makes it possible to suppress a temperature increase in the refrigerant gas due to the heat transfer from the valve plate as well as a temperature increase in the refrigerant gas.
In the sealed compressor configured as described above, the cylinder head may be formed with a hollow space on a projection plane formed by projecting the suction hole in the lateral direction to the lower portion of the cylinder head.
In accordance with this configuration, between the cylinder head and the communication pipe exit section, a space defined by the hollow space as well as the gas inflow space in the interior of the sealed container is formed. This makes it possible to further suppress the heat transfer from the cylinder head in a high-temperature state to the communication pipe exit section.
In the sealed compressor configured as described above, the communication pipe exit section may be provided with a heat insulating space isolated from the sealed space, on an outer periphery facing the valve plate, and a communication hole which provides communication between the heat insulating space and an interior of the communication pipe exit section.
In accordance with this configuration, the heat insulating space into which the refrigerant gas is introduced is formed between the communication pipe exit section and the valve plate. This makes it possible to keep the temperature of the heat insulating space at a value which is substantially equal to that of the refrigerant gas. In this way, the heat transfer from the valve plate to the communication pipe exit section can be further suppressed.
In the sealed compressor configured as described above, the suction muffler may be molded by use of a resin, and the heat insulating space may be formed integrally with the suction muffler, when the suction muffler is molded.
In accordance with this configuration, the heat insulating space is formed integrally as a part of the shape of the communication pipe when the suction muffler is molded by use of a resin. This allows the heat insulating space to more effectively perform heat insulation.
The sealed compressor may be configured to be driven at one of a plurality of operating frequencies.
In accordance with this configuration, since the gas inflow space in the interior of the sealed container can suppress the heat transfer to the communication pipe exit section, a temperature increase in the refrigerant gas flowing through the communication pipe can be suppressed effectively, even when the refrigerant gas is flowing through the communication pipe at a low velocity. Therefore, even in the case of using the operating frequency at which the sealed compressor is inverter-driven by a low-speed rotation in which the flow velocity of the refrigerant gas is low, the efficiency of the sealed compressor can be improved.
The present invention also provides a refrigeration device comprising a refrigeration circuit configured such that the sealed compressor having the above configuration, a heat radiator, a pressure-reducing device, and a heat absorbing unit are annularly coupled to each other by use of a pipe.
In accordance with this configuration, since the refrigeration device includes the refrigeration circuit incorporating the sealed compressor having the above configuration, the refrigeration device is able to reduce electric power consumption and realize energy saving.
Hereinafter, the preferred embodiment of the present invention will be described with reference to the drawings. Throughout the drawings, the same or corresponding components are identified by the same reference symbols, and will not be described repeatedly.
[Exemplary Configuration of Sealed Compressor]
Initially, the exemplary configuration of the sealed compressor according to the present embodiment will be described with reference to
As shown in
The sealed container 101 is provided with a suction pipe 104 and a discharge pipe 105. One end of the suction pipe 104 is in communication with the inner space of the sealed container 101, while the other end thereof is connected to a refrigeration device which is not shown, thus constituting a refrigeration cycle. One end of the discharge pipe 105 is connected to the compression component 130, while the other end thereof is connected to a refrigeration device which is not shown. As will be described later, the refrigerant gas compressed by the compression component 130 is guided to the refrigeration cycle through the discharge pipe 105, and the refrigerant gas from the refrigeration cycle is guided to the inner space of the sealed container 101 via the suction pipe 104.
The specific configuration of the sealed container 101 is not particularly limited. In the present embodiment, for example, the sealed container 101 is manufactured by a drawing process of an iron plate. The refrigerant gas is filled in the sealed container 101 under a pressure equal to a pressure at a lower-pressure side in the refrigeration cycle into which the sealed compressor 100 is incorporated, and at a relatively low temperature. The lubricating oil 103 is filled to lubricate a crankshaft 140 (which will be described later) included in the compression component 130. As shown in
The kind of the refrigerant gas is not particularly limited, and a gas known in the field of the refrigeration cycle is suitably used. In the present embodiment, for example, hydrocarbon-based refrigerant gas such as R600a is suitably used. R600a has a low global warming potential and is one of refrigerant gases favorably used in terms of global environment conservation. In addition, the kind of the lubricating oil 103 is not particularly limited, and lubricating oil known in the fields of the compressor may be suitably used.
As shown in
The compression component 130 is driven by the electric component 120 and compresses the refrigerant gas. As shown in
The cylinder block 131 is provided with the cylinder 133 and the bearing section 135. When a vertical direction is a longitudinal direction and a horizontal direction is a lateral direction, in a state in which the sealed compressor 100 is placed on a horizontal plane, the cylinder 133 is placed along the lateral direction and fastened to the bearing section 135 in the interior of the sealed container 101. The cylinder 133 is formed with a bore of a substantially cylindrical shape with a diameter substantially equal to that of the piston 132. The piston 132 is reciprocatably inserted into the cylinder 133. The cylinder 133 and the piston 132 define the compression chamber 134, and the refrigerant gas is compressed in the interior of the compression chamber 134. The bearing section 135 supports the main shaft 142 of the crankshaft 140 such that the main shaft 142 is rotatable.
The crankshaft 140 is supported in the interior of the sealed container 101 in such a manner that its axis (axis of the crankshaft 140) extends in the longitudinal direction. The crankshaft 140 includes the main shaft 142, an eccentric shaft 141, an oil feeding mechanism 143, and others. As described above, the main shaft 142 is fastened to the rotor 122 of the electric component 120. The eccentric shaft 141 is configured to be eccentric with respect to the main shaft 142. The oil feeding mechanism 143 is provided so as to provide communication between the lower end of the main shaft 142 immersed in the lubricating oil 103 and the upper end of the eccentric shaft 141. The oil feeding mechanism 143 includes an oil feeding pump, a spiral channel formed on the surface of the main shaft 142, etc. The oil feeding mechanism 143 feeds the lubricating oil 103 to the crankshaft 140.
The piston 132 inserted into the cylinder 133 is coupled to the coupling section 136. The piston 132 is placed such that its axis crosses the axial direction of the crankshaft 140. In the present embodiment, as shown in
As described above, the piston 132 is inserted into one end portion (closer to the crankshaft 140) of the cylinder 133. The other end portion (end portion which is away from the crankshaft 140) of the cylinder 133 is closed by a valve plate 151 and the cylinder head 152. The cylinder head 152 is fastened together with the valve plate 151 to the cylinder 133 by use of a fastening member such as a head bolt. The valve plate 151 is placed between the cylinder 133 and the cylinder head 152. As shown in
The cylinder head 152 is divided into a cylinder head upper section 152-1 and a cylinder head lower section 152-2 by a lateral broken line C of
Hereinafter, for easier description, the surface (surface closer to the compression chamber 134 and closer to the cylinder 133) of the cylinder head 152 which contacts the valve plate 151 will be referred to as a “contact surface 152p” and a surface which is on an opposite side of the contact surface 152p will be referred to as “non-contact surface 152q”. As shown in
As described above, the contact surface 152p is the flat surface. The non-contact surface 152q is also present in the cylinder head lower section 152-2. The upper portion of the non-contact surface 152q is a curved surface 152q-1 protruding downward from the upper side of
The inner surface of the recess 152d of the cylinder head lower section 152-2 is a curved surface conforming in shape to the communication pipe exit section 162a. In other words, the inner surface of the recess 152d of the cylinder head lower section 152-2 faces the outer surface of the communication pipe exit section 162a. Hereinafter, the surface facing the outer surface of the communication pipe exit section 162a will be referred to as “opposed surface 152r” for easier description. As shown in
The suction hole 151a provides communication between the communication pipe 162 (the communication pipe exit section 162a) of the suction muffler 160 and the compression chamber 134. A suction valve 153 for opening and closing the suction hole 151a is provided on the surface of the valve plate 151 which is closer to the compression chamber 134. The suction hole 151a can be opened and closed by the suction valve 153. The refrigerant gas is suctioned from the suction muffler 160 into the compression chamber 134, via the suction hole 151a, when the suction valve 153 is opened.
The discharge hole 151b provides communication between the cylinder head 152 and the compression chamber 134. The discharge hole 151b is opened and closed by a discharge valve (not shown). The cylinder head 152 is formed with the discharge space 152a inside thereof. The refrigerant gas is discharged from the compression chamber 134 to the discharge space 152a through the discharge hole 151b. The discharge pipe 154 is coupled to the cylinder head 152 and to a discharge pipe 105. Therefore, the discharge space 152a is in communication with the discharge pipe 105 via the discharge pipe 154. The suction muffler 160 is located at a lower side in the interior of sealed container 101, from the perspective of the cylinder 133 and the cylinder head 152. The suction muffler 160 is made of, for example, a composite material comprising a resin such as PBT (polybuthylene terephthalate) and reinforced fibers such as glass fibers added to the resin. The suction muffler 160 includes a tail pipe 161, the communication pipe 162, a muffler body 163, and others. The material of the suction muffler 160 is not limited to the composite material containing the PBT so long as the suction muffler 160 is molded by use of least a resin.
A muffling space 163a of the suction muffler 160 is formed by the muffler body 163. The tail pipe 161 is in communication with the internal space of the sealed container 101, and serves to guide the refrigerant gas to the interior of the muffler body 163. The communication pipe 162 is located at the upper side of the muffler body 163. The communication pipe 162 is in communication with the compression chamber 134 via the suction hole 151a of the valve plate 151. The communication pipe 162 guides the refrigerant gas from the interior of the muffler body 163 to the interior of the compression chamber 134.
The communication pipe 162 of the suction muffler 160 extends upward toward the other end portion (end portion which is away from the crankshaft 140) of the cylinder 133, in a location between the valve plate 151 and the cylinder head 152. As shown in
As described above, the cylinder head 152 is provided with the recess 152d in a location that is closer to the compression chamber 134. The communication pipe exit section 162a is inserted into the recess 152d such that a specified space (the gas inflow space 152b in the interior of the sealed container) is formed between the communication pipe exit section 162a and the opposed surface 152r (inner surface of the recess 152d). For example, an elastic member (not shown) is placed inside of the recess 152d. This elastic member presses the communication pipe exit section 162a against the valve plate 151, and thus the communication pipe exit section 162a is retained between the elastic member and the valve plate 151.
An opening section 162b is provided at the tip end of the communication pipe exit section 162a. The opening section 162b is in communication with the suction hole 151a of the valve plate 151. The state in which the opening section 162b and the suction hole 151a are in communication with each other is not particularly limited. In the present embodiment, as shown in
Since the opening section 162b of the communication pipe exit section 162a and the suction hole 151a are in communication with each other as described above, the communication pipe 162 and the compression chamber 134 are in communication with each other via the suction hole 151a (and the suction valve 153). Therefore, the suction muffler 160 is in communication with the compression chamber 134 inside of the cylinder 133 via the communication pipe 162, and the upper end (the communication pipe exit section 162a) of the communication pipe 162 is placed in a biased manner inside of the recess 152d of the cylinder head 152. In this way, the suction muffler 160 is fastened to the valve plate 151.
[Operation of Sealed Compressor]
Next, the operation and advantages of the sealed compressor 100 configured as described above will be specifically described. Although not shown in
Initially, when the electric component 120 is applied with a current from an external electric power supply, the current flows through the stator 121, to generate a magnetic field, causing the rotor 122 to rotate. According to the rotation of the rotor 122, the main shaft 142 of the crankshaft 140 rotates, and then the rotational motion of the main shaft 142 is transmitted to the piston 132 via the eccentric shaft 141 and the coupling section 136. The piston 132 reciprocates in the interior of the cylinder 133. According to the reciprocation motion of the piston 132, the refrigerant gas is suctioned, compressed and discharged in the interior of the compression chamber 134.
This will be described more specifically. Now, of the direction in which the piston 132 moves in the interior of the cylinder 133, a direction in which the volume of the compression chamber 134 increases will be referred to as “increase direction” and a direction in which the volume of the compression chamber 134 decreases will be referred to as “decrease direction”. When the piston 132 moves in the increase direction, the refrigerant gas in the interior of the compression chamber 134 expands. When a pressure in the interior of the compression chamber 134 falls below a suction pressure, the suction valve 153 starts to open due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the suction muffler 160.
According to this operation, the low-temperature refrigerant gas which has returned from the refrigeration device is released to the interior of the sealed container 101 from the suction pipe 104. Then, the refrigerant gas is suctioned from a suction port (not shown) provided on the suction muffler 160 and introduced to the interior of the muffling space 163a of the muffler body 163 via the tail pipe 161. At this time, since the suction valve 153 starts to open as described above, the introduced refrigerant gas flows into the compression chamber 134 through the communication pipe 162 and the suction hole 151a. After that, when the piston 132 moves from a bottom dead center in the decrease direction in the interior of the cylinder 133, the refrigerant gas is compressed in the interior of the compression chamber 134, so that the pressure in the interior of the compression chamber 134 increases. In addition, due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the suction muffler 160, the suction valve 153 is closed.
Then, when the pressure in the interior of the compression chamber 134 exceeds the pressure in the interior of the discharge space 152a, the discharge valve (not shown) starts to open, due to a difference between the pressure in the interior of the compression chamber 134 and the pressure in the interior of the discharge space 152a.
According to this operation, during a period that passes until the piston 132 reaches a top dead center in the interior of the cylinder 133, the compressed refrigerant gas is discharged to the discharge space 152a through the discharge hole 151b. The refrigerant gas discharged to the discharge space 152a is sent out to the refrigeration device via the discharge pipe 154 and the discharge pipe 105.
After that, when the piston 132 moves again in the increase direction from the top dead center in the interior of the cylinder 133, the refrigerant gas in the interior of the compression chamber 134 expands, so that the pressure in the interior of the compression chamber 134 decreases. When the pressure in the interior of the compression chamber 134 falls below the pressure in the interior of the discharge space 152a, the discharge valve is closed.
The above described suction stroke, compression stroke and discharge stroke are repeatedly performed in every rotation of the crankshaft 140, and thus the refrigerant gas is circulated within the refrigeration cycle.
[Configuration of Cylinder Head and Configuration of Communication Pipe Exit Section]
Next, the gas inflow space 152b in the interior of the sealed container (gas inflow space 152b), which is defined by the cylinder head 152 and the communication pipe exit section 162a, will be specifically described with reference to
As shown in
The first space 152b-1 is formed between the lower surface of the cylinder head 152 inside of the recess 152d and the upper peripheral surface of the communication pipe exit section 162a. The lower surface of the cylinder head 152 inside of the recess 152d corresponds to a curved surface (upper curved surface of the recess 152d) of the opposed surface 152r of the recess 152d, which is closer to the discharge space 152a. The second space 152b-2 is formed between the side surface of the cylinder head 152 inside of the recess 152d and the side peripheral surface of the communication pipe exit section 162a. The side surface of the cylinder head 152 inside of the recess 152d corresponds to the inner peripheral curved surface of the opposed surface 152r of the recess 152d, which is other than the upper curved surface. The first space 152b-1 and the second space 152b-2 constitute a continuous one space formed around the communication pipe exit section 162a, i.e., the gas inflow space 152b. The first space 152b-1 and the second space 152b-2 are in communication with the sealed space in the interior of the sealed container 101.
Since the first space 152b-1 is the lateral space of the gas inflow space 152b, the first space 152b-1 is regarded as the space extending along the axial direction of the piston 132 so as to face the upper peripheral surface of the communication pipe exit section 162a. In contrast, since the second space 152b-2 is the longitudinal space of the gas inflow space 152b, the second space 152b-2 is regarded as the space extending along the axial direction of the crankshaft 140 so as to face the side peripheral surface of the communication pipe exit section 162a. As shown in
The thickness W1 of the first space 152b-1 is set to the average value of the lengths of a plurality of perpendicular lines which are drawn from the upper curved surface of the recess 152d to the upper peripheral surface of the communication pipe exit section 162a. Also, the thickness W2 of the second space 152b-2 is set to the average value of the lengths of a plurality of perpendicular lines which are drawn from the inner peripheral curved surface of the recess 152d to the side peripheral surface of the communication pipe exit section 162a.
Further, in the present embodiment, as shown in
As shown in
In addition to the above, in the present embodiment, as shown in
The interior of the heat insulating space 162c and the interior of the communication pipe 162 are in communication with each other via a communication hole 162d. In other words, on the outer periphery of the communication pipe exit section 162a, which is immediately below the opening section 162b, the heat insulating space 162c and the communication hole 162d penetrating the communication pipe 162 are formed. As shown in
The advantage attained by suppressing a temperature increase in the suctioned refrigerant gas and effectively suppressing a decrease in the volumetric efficiency, which is associated with the gas inflow space 152b, will be now described.
The cylinder head 152 and the valve plate 151 which is in sealing contact with the cylinder head 152 are heated by the high-temperature refrigerant gas in the interior of the discharge space 152a and raised in temperature. In addition, the valve plate 151 is also heated by the compressed refrigerant gas in the interior of the compression chamber 134 and raised in temperature. In a sealed compressor having a typical configuration, the refrigerant gas suctioned into the suction muffler 160 is heated and its volume is increased by the valve plate 151, while the refrigerant gas is flowing from the communication pipe exit section 162a and through the suction hole 151a of the valve plate 151. For this reason, in the conventional sealed compressor, the volumetric efficiency is decreased.
In contrast, in the present embodiment, since the gas inflow space 152b in the interior of the sealed container is formed between the communication pipe exit section 162a and the cylinder head 152, the gas inflow space 152b becomes a heat insulating layer which can suppress heat transfer from the high-temperature cylinder head 152 to the communication pipe exit section 162a. Since heating of the refrigerant gas can be suppressed effectively when the refrigerant gas is suctioned into the compression chamber 134, the volumetric efficiency of the sealed compressor 100 can be increased.
The space temperatures will now be described. The temperature of the discharge space 152a inside of the cylinder head 152 is the highest, and the temperature of the inner space of the sealed container 101 is higher than the temperature of the interior of the communication pipe 162 of the suction muffler 160. In order to suppress heat transfer to the refrigerant gas flowing through the communication pipe 162 (especially the communication pipe exit section 162a), the gas inflow space 152b is configured in such a manner that the thickness W1 of the first space 152b-1 extending along the axial direction (lateral direction) of the piston 132 is set larger than the thickness W2 of the second space 152b-2 extending along the axial direction (longitudinal direction) of the crankshaft 140. In other words, by setting the thickness W1 of the first space 152b-1 located below the discharge space 152a larger than the thickness W2 of the second space 152b-2, it becomes possible to effectively suppress the heat transfer from the discharge space 152a with a large heat amount to the communication pipe exit section 162a.
As shown in
In accordance with the present embodiment, the second space 152b-2 of the gas inflow space 152b suppresses the heat transfer from the cylinder head lower section 152-2 of the cylinder head 152 to the refrigerant gas flowing through the communication pipe exit section 162a, while the first space 152b-1 of the gas inflow space 152b suppresses the heat transfer from the discharge space 152a inside of the cylinder head upper section 152-1 to the refrigerant gas flowing through the communication pipe exit section 162a. Because of this, it becomes possible to effectively suppress a temperature increase in the refrigerant gas suctioned from the opening section 162b to the interior of the compression chamber 134 via the suction hole 151a. In addition, as described above, the opening section 162b inserted into the suction hole 151a also serves as the heat insulating layer. Since it becomes possible to suppress the heat transfer from the high-temperature valve plate 151 to the refrigerant gas which has been suppressed in temperature increase, the low-temperature refrigerant gas which has been suppressed in temperature increase can be suctioned into the compression chamber 134.
The cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152c with a size including the opening area of the suction hole 151a, on the lateral projection plane of the suction hole 151a. In this structure, a portion of the high-temperature cylinder head 152 (cylinder head lower section 152-2) does not exist in the lateral direction, from the perspective of the opening section 162b of the communication pipe exit section 162a. Further, the second space 152b-2 of the gas inflow space 152b is formed between the communication pipe exit section 162a and the cylinder head lower section 152-2, while the first space 152b-1 of the gas inflow space 152b is formed between the communication pipe exit section 162a and the cylinder head upper section 152-1. This structure can reduce the area of a portion of the cylinder head 152 and a portion of the communication pipe exit section 162a, which overlap with each other, with the gas inflow space 152b located between the cylinder head 152 and the communication pipe exit section 162a. As a result, it becomes possible to more effectively suppress the heat transfer from the high-temperature cylinder head 152 to the communication pipe exit section 162a, and more effectively suppress a temperature increase in the refrigerant gas.
Further, the communication pipe exit section 162a is formed with the heat insulating space 162c isolated from the sealed space, on the outer periphery immediately below the opening section 162b. As described above, the heat insulating space 162c is formed integrally when the suction muffler 160 is manufactured by molding. The refrigerant gas is introduced into the heat insulating space 162c through the communication hole 162d. Therefore, the heat insulating space 162c can be kept at a low temperature which is close to the temperature of the refrigerant gas by the low-temperature refrigerant gas introduced thereinto. In this way, it becomes possible to provide heat insulation between the outer periphery of the communication pipe exit section 162a which is closer to the valve plate 151 and the valve plate 151. Thus, the communication pipe exit section 162a can be thermally insulated from the cylinder head 152 by the gas inflow space 152b and further thermally insulated by the heat insulating space 162c. As a result, it becomes possible to more effectively suppress a temperature increase in the refrigerant gas flowing through the communication pipe exit section 162a.
As described above, in the present embodiment, since at least the gas inflow space 152b in the interior of the sealed container is formed, the heat transfer from the cylinder head 152 to the communication pipe exit section 162a can be suppressed. In addition, since the cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152c, the heat transfer to the communication pipe exit section 162a can be suppressed more effectively. Further, since the opening section 162b of the communication pipe exit section 162a is inserted into the suction hole 151a, the heat transfer from the valve plate 151 to the refrigerant gas inside of the opening section 162b can be suppressed. Since the heat insulating space 162c is provided immediately below the opening section 162b of the communication pipe exit section 162a, the heat transfer from the valve plate 151 to the communication pipe exit section 162a can be suppressed more effectively. Because of the above, in accordance with the present embodiment, it becomes possible to effectively suppress a temperature increase in the suctioned refrigerant gas, flowing though the communication pipe 162. As a result, the volumetric efficiency can be increased, and hence the efficiency of the sealed compressor 100 can be increased.
Although in the present embodiment, the operating frequency of the sealed compressor 100 is not particularly limited, the sealed compressor 100 may be configured to be inverter-driven at one of a plurality of operating frequencies. As described above, in the present embodiment, since at least the gas inflow space 152b in the interior of the sealing container is formed, the heat transfer from the cylinder head 152 and the valve plate 151 which are in high-temperature states to the refrigerant gas flowing through the communication pipe exit section 162a can be suppressed. In this configuration, even when the refrigerant gas flows through the communication pipe 162 at a relatively low velocity, the heat transfer from the cylinder head 152 and the valve plate 151 to the refrigerant gas can be suppressed effectively. Therefore, the sealed compressor 100 can be inverter-driven to rotate at a low speed.
In the present embodiment, the gas inflow space 152b includes the first space 152b-1 extending in the lateral direction (axial direction of the piston 132) and having the curved cross-section and the second space 152b-2 extending in the longitudinal direction (axial direction of the crankshaft 140) and having the curved cross-section. However, the configuration of the gas inflow space 152b is not limited to this, and may include the first space 152b-1 and the second space 152b-2, depending on the specific configuration of the sealed compressor 100.
The first space 152b-1 of the gas inflow space 152b thermally insulates the upper peripheral surface of the communication pipe exit section 162a, while the second space 152b-2 of the gas inflow space 152b thermally insulates the side peripheral surface of the communication pipe exit section 162a which is other than the location facing the valve plate 151. Alternatively, the sealed compressor 100 may include a space which thermally insulates another peripheral surface of the communication pipe exit section 162a or a space which thermally insulates the peripheral surface of a portion of the communication pipe 162 which is other than the communication pipe exit section 162a, depending on the configuration of the sealed compressor 100.
Although in the present embodiment, the cylinder head lower section 152-2 of the cylinder head 152 is formed with the hollow space 152c, the cylinder head lower section 152-2 may not be formed with the hollow space 152c, as shown in
Further, a known spacer may be provided between the communication pipe exit section 162a and the recess 152d of the cylinder head 152, to suitably maintain the thickness W1 and the thickness W2 of the gas inflow space 152b. This spacer may have a low heat conductivity and have a stiffness which can maintain the shape between the opposed surface 152r of the recess 152d, facing the outer surface of the communication pipe exit section 162a, and the outer peripheral surface of the communication pipe exit section 162a.
In Embodiment 2, an exemplary refrigeration device including the sealed compressor 100 described in Embodiment 1 will be described specifically with reference to
The sealed compressor 100 of the present invention can be suitably incorporated into a refrigeration cycle or various devices (refrigeration devices) having a configuration similar to that of the refrigeration cycle. Specifically, for example, the devices may be a refrigerator (refrigerator for household use or refrigerator for business purpose), an ice making machine, a show case, a dehumidifier, a heat pump type hot water supply device, a heat pump type laundry/drying machine, an automatic vending machine, an air conditioner, an air compressor, etc. However, these are merely exemplary. In the present embodiment, the basic configuration of a refrigeration device 200 will be described in conjunction with an article storage device of
The refrigeration device 200 of
The refrigeration circuit 205 is configured such that the sealed compressor 100 of Embodiment 1, a heat radiator 206, a pressure-reducing device 207, and a heat absorbing unit 208 are connected together in an annular shape by use of a pipe 209. In brief, the refrigeration circuit 205 is an exemplary refrigeration cycle using the sealed compressor 100 of the present invention.
In the refrigeration circuit 205, the sealed compressor 100, the heat radiator 206, and the pressure-reducing device 207 are placed in the mechanical room 203, while the heat absorbing unit 208 is placed in the storage space 202 including a blower (not shown in
As described above, the refrigeration device 200 of the present embodiment incorporates the sealed compressor 100 of Embodiment 1. As described above, since the sealed compressor 100 includes the gas inflow space 152b in the interior of the sealed container, a decrease in the volumetric efficiency can be suppressed effectively by suppressing a temperature increase in the refrigerant gas. Thus, the efficiency of the sealed compressor 100 is high. By operating the refrigeration circuit 205 by use of the sealed compressor 100 with such high efficiency, electric consumption in the refrigeration device 200 can be reduced, and hence energy saving can be realized.
Numerous improvements and alternative embodiments of the invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, the description is to be construed as illustrative only, and is provided for the purpose of teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and/or function may be varied substantially without departing from the spirit of the invention.
The present invention can increase the efficiency of a sealed compressor, and therefore is suitably used in the fields of the sealed compressor. For example, the present invention can be widely suitably used in the fields of refrigeration devices including sealed compressors, such as refrigeration devices for household uses such as electric freezers/refrigerators or air conditioners, or refrigeration devices for business purposes such as a show case for business purpose or an automatic vending machine, etc.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-021887 | Feb 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/000633 | 2/6/2014 | WO | 00 |
