Patent Grant
9512841
The present invention relates to rotary compressors.
Rotary compressors are widely used in electrical appliances such as air conditioners, heaters, and hot water dispensers. As one approach to improve the efficiency of rotary compressors, there has been proposed a technique for suppressing so-called heat loss, i.e., a decrease in efficiency caused by the fact that a refrigerant drawn into a compression chamber (a drawn refrigerant) receives heat from the environment.
A rotary compressor of Patent Literature 1 has a closed space provided in a suction-side portion of a cylinder as a means for suppressing heat reception by a drawn refrigerant. The closed space suppresses heat transfer from a high-temperature refrigerant in a closed casing to the inner wall of the cylinder.
Patent Literature 1: JP 02(1990)-140486 A
However, it is not necessarily easy to form a closed space in a cylinder as in Patent Literature 1. Therefore, another technique capable of effectively suppressing heat reception by a drawn refrigerant has been desired.
That is, the present disclosure provides a rotary compressor including:
a closed casing having an oil reservoir;
a cylinder disposed inside the closed casing;
a piston disposed inside the cylinder;
a bearing member attached to the cylinder so as to form a cylinder chamber between the cylinder and the piston;
a vane that partitions the cylinder chamber into a suction chamber and a discharge chamber;
a suction port though which a refrigerant to be compressed is introduced into the suction chamber;
a discharge port through which the compressed refrigerant is discharged from the discharge chamber, the discharge port being formed in the bearing member; and
a partition member attached to the bearing member so as to form, together with the bearing member, a refrigerant discharge space capable of retaining the refrigerant discharged from the discharge chamber through the discharge port.
In this rotary compressor, the partition member or another member is attached to the bearing member so as to form a space enclosed by the partition member and the bearing member or a space enclosed by the another member and the bearing member at a position adjacent to the bearing member,
a portion of an oil stored in the oil reservoir flows into the enclosed space, and thereby an oil retaining portion is formed, and
the oil retaining portion is located on the same side as the suction port with respect to a reference plane, the reference plane being a plane including a central axis of the cylinder and a center of the vane when the vane protrudes maximally toward the central axis of the cylinder.
According to the above-described rotary compressor, a portion of the oil stored in the oil reservoir flows into the space enclosed by the partition member and the bearing member or the space enclosed by the another member and the bearing member, and thereby the oil retaining portion is formed. In addition, the oil retaining portion is located on the same side as the suction port with respect to the reference plane. Once the oil flows into the enclosed space, the oil is allowed to stagnate in the enclosed space. Therefore, the oil retaining portion suppresses heat reception by the bearing member, and accordingly suppresses heat reception by the drawn refrigerant.
A first aspect of the present disclosure provides a rotary compressor including:
a closed casing having an oil reservoir;
a cylinder disposed inside the closed casing;
a piston disposed inside the cylinder;
a bearing member attached to the cylinder so as to form a cylinder chamber between the cylinder and the piston;
a vane that partitions the cylinder chamber into a suction chamber and a discharge chamber;
a suction port though which a refrigerant to be compressed is introduced into the suction chamber;
a discharge port through which the compressed refrigerant is discharged from the discharge chamber, the discharge port being formed in the bearing member; and
a partition member attached to the bearing member so as to form, together with the bearing member, a refrigerant discharge space capable of retaining the refrigerant discharged from the discharge chamber through the discharge port.
In this rotary compressor, the partition member or another member is attached to the bearing member so as to form a space enclosed by the partition member and the bearing member or a space enclosed by the another member and the bearing member at a position adjacent to the bearing member,
a portion of an oil stored in the oil reservoir flows into the enclosed space, and thereby an oil retaining portion is formed, and
the oil retaining portion is located on the same side as the suction port with respect to a reference plane, the reference plane being a plane including a central axis of the cylinder and a center of the vane when the vane protrudes maximally toward the central axis of the cylinder.
A second aspect provides the rotary compressor according to the first aspect, wherein the another member may be an oil cup that covers the bearing member so as to form the oil retaining portion. With the use of an oil cup as a member other than the partition member, it is possible to form the oil retaining portion of a relatively simple structure with fewer design constraints.
A third aspect provides the rotary compressor according to the first or second aspect, wherein the rotary compressor may further include a shaft to which the piston is fitted. The bearing member may include a circular plate portion adjacent to the cylinder, a bearing portion formed integrally with the circular plate portion so as to support the shaft, and a bank portion protruding from the circular plate portion so as to surround a recess adapted to serve as the refrigerant discharge space. The refrigerant discharge space can be formed by closing the recess by the partition member. With such a structure, it is possible to reliably separate the refrigerant discharge space from the oil retaining portion.
A fourth aspect provides the rotary compressor according to the first aspect, wherein the another member may be an oil cup that covers the bearing member so as to form the oil retaining portion, the partition member may cover the bearing member so as to form the refrigerant discharge space, and the oil cup may be disposed inside the partition member. With such a structure, it is possible to form the oil retaining portion using a bearing member having the same structure as a bearing member for a conventional rotary compressor.
A fifth aspect provides the rotary compressor according to any one of the first to fourth aspects, wherein the rotary compressor may further include a communication path that communicates the oil reservoir with the oil retaining portion. The oil in the oil reservoir can flow into the oil retaining portion through the communication path.
In a sixth aspect, two planes each including the central axis, each being tangent to the oil retaining portion, and forming an angle within which the oil retaining portion is located are defined as tangent planes, a plane including the central axis and bisecting the angle so as to divide the oil retaining portion into two parts is defined as a bisecting plane, and one of the two parts formed by the bisecting plane is defined as an anterior portion located relatively close to the suction port in a rotational direction of the piston and the other part is defined as a posterior portion located relatively far from the suction port in the rotational direction of the piston. The sixth aspect provides the rotary compressor according to the fifth aspect, wherein the oil in the oil reservoir may flow into the anterior portion only through the posterior portion. The communication path may communicate the oil reservoir with the posterior portion. When the communication path is provided in such a position, heat reception by a drawn refrigerant can be suppressed more effectively.
A seventh aspect provides the rotary compressor according to any one of the first to fourth aspects, wherein the oil retaining portion may include an anterior portion located relatively close to the suction port in a rotational direction of the piston, a posterior portion located relatively far from the suction port in the rotational direction of the piston, and a narrow portion located between the anterior portion and the posterior portion. The narrow portion suppresses the movement of the oil between the anterior portion and the posterior portion. As a result, the flow of the oil in the anterior portion is suppressed, and accordingly heat reception by the drawn refrigerant is also suppressed effectively.
An eighth aspect provides the rotary compressor according to the seventh aspect, wherein the rotary compressor may further include a communication path that communicates the oil reservoir with the oil retaining portion. The communication path may communicate the oil reservoir with the posterior portion. The oil in the oil reservoir may flow into the anterior portion only through the posterior portion and the narrow portion. Thereby, the flow of the oil in the anterior portion is effectively suppressed.
A ninth aspect provides the rotary compressor according to any one of the first to eighth aspects, wherein the bearing member may be provided with a recess and the recess may be closed by the partition member so as to form the refrigerant discharge space. The bearing member may have a larger thickness in the oil retaining portion than in the recess. Thereby, the volume of the discharge port can be reduced sufficiently. This means that the dead volume caused by the discharge port can be reduced.
A tenth aspect provides the rotary compressor according to any one of the first to ninth aspects, wherein in a projection view obtained by projecting the refrigerant discharge space and the oil retaining portion onto a plane perpendicular to the central axis, a projection region of the refrigerant discharge space may have a smaller area than a projection region of the oil retaining portion. With such a configuration, a large heat barrier area can be obtained. Therefore, heat reception by the drawn refrigerant is effectively suppressed.
In an eleventh aspect, (i) the reference plane is defined as a first reference plane, (ii) a plane including the central axis and perpendicular to the first reference plane is defined as a second reference plane, and (iii) four segments obtained by dividing the rotary compressor by the first reference plane and the second reference plane are defined as a first quadrant segment including the suction port, a second quadrant segment including the discharge port, a third quadrant segment opposite to the first quadrant segment and adjacent to the second quadrant segment, and a fourth quadrant segment opposite to the second quadrant segment and adjacent to the first quadrant segment, respectively. The eleventh aspect provides the rotary compressor according to any one of the first to tenth aspects, wherein in a projection view obtained by projecting the first to fourth quadrant segments and the refrigerant discharge space onto a plane perpendicular to the central axis, an entire projection region of the refrigerant discharge space may fall within a combined region consisting of a projection region of the first quadrant segment, a projection region of the second quadrant segment, and a projection region of the third quadrant segment. With such a configuration, heat reception by the drawn refrigerant can be suppressed, with an increase in pressure loss being suppressed.
In a twelfth aspect, (a) the reference plane is defined as a first reference plane, (b) a plane including the central axis and a center of the suction port is defined as a third reference plane, (c) one of two segments obtained by dividing the rotary compressor by the first reference plane is defined as a first high-temperature segment including the discharge port, (d) one of two segments obtained by dividing the rotary compressor by the third reference plane is defined as a second high-temperature segment including the discharge port, and (e) three of four segments obtained by dividing the rotary compressor by the first reference plane and the third reference plane are collectively defined as a combined high-temperature segment, the three segments being included in the first high-temperature segment or the second high-temperature segment. The twelfth aspect provides the rotary compressor according to any one of the first to eleventh aspects, wherein in a projection view obtained by projecting the combined high-temperature segment and the refrigerant discharge space onto a plane perpendicular to the central axis, 70% or more of a projection region of the refrigerant discharge space may overlap a projection region of the combined high-temperature segment. With such a configuration, the total loss including heat reception by the drawn refrigerant (heat loss) and pressure loss can be minimized.
A thirteenth aspect provides the rotary compressor according to any one of the first to twelfth aspects, wherein the rotary compressor may further include a shaft to which the piston is fitted. This rotary compressor may be a vertical rotary compressor in which a rotational axis of the shaft is parallel to a direction of gravity and the oil reservoir is formed at a bottom of the closed casing. In the vertical rotary compressor, the oil retaining portion is less likely to be affected by swirling flow generated by a motor that drives the shaft.
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiment given below.
As shown in
The motor 2 is composed of a stator 17 and a rotor 18. The stator 17 is fixed to the inner wall of the closed casing 1. The rotor 18 is fixed to the shaft 4, and rotates together with the shaft 4.
A discharge pipe 11 is provided in the upper part of the closed casing 1. The discharge pipe 11 penetrates the upper part of the closed casing 1, and opens into an internal space 13 of the closed casing 1. The discharge pipe 11 serves as a discharge flow path for discharging the refrigerant compressed in the compression mechanism 102 to the outside of the closed casing 1. During the operation of the rotary compressor 100, the internal space 13 of the closed casing 1 is filled with the compressed refrigerant.
The compression mechanism 102 is driven by the motor 2 to compress the refrigerant. Specifically, the compression mechanism 102 has a first compression block 3, a second compression block 30, an upper bearing member 6, a lower bearing member 72, an intermediate plate 38, a first partition member 9 (a first muffler or a first closing member), and a second partition member 64 (a second muffler or a second closing member). The refrigerant is compressed in the first compression block 3 or the second compression block 30. The first compression block 3 and the second compression block 30 are immersed in the oil stored in the oil reservoir 22. In the present embodiment, the first compression block 3 is composed of the same components as those of the second compression block 30. Therefore, the first compression block 3 has the same suction volume as that of the second compression block 30.
As shown in
The shaft 4 has a first eccentric portion 4a and a second eccentric portion 4b. The eccentric portions 4a and 4b each protrude radially outward. The first piston 8 and the second piston 28 are disposed inside the first cylinder 5 and the second cylinder 15, respectively. In the first cylinder 5, the first piston 8 is fitted to the first eccentric portion 4a. In the second cylinder 15, the second piston 28 is fitted to the second eccentric portion 4b. A first vane groove 34 and a second vane groove 35 are formed in the first cylinder 5 and the second cylinder 15, respectively. In the rotational direction of the shaft 4, the position of the first vane groove 34 coincides with the position of the second vane groove 35. The first eccentric portion 4a protrudes in a direction 180 degrees opposite to the direction in which the second eccentric portion 4b protrudes. That is, the phase difference between the first piston 8 and the second piston 28 is 180 degrees. This configuration is effective in reducing vibration and noise.
The upper bearing member 6 is attached to the first cylinder 5 so as to form a first cylinder chamber 25 between the inner circumferential surface of the first cylinder 5 and the outer circumferential surface of the first piston 8. The lower bearing member 72 is attached to the second cylinder 15 so as to form a second cylinder chamber 26 between the inner circumferential surface of the second cylinder 15 and the outer circumferential surface of the second piston 28. More specifically, the upper bearing member 6 is attached to the top of the first cylinder 5, and the lower bearing member 72 is attached to the bottom of the second cylinder 15. The intermediate plate 38 is disposed between the first cylinder 5 and the second cylinder 15.
The first suction port 19 and the second suction port 20 are formed in the first cylinder 5 and the second cylinder 15, respectively. The first suction port 19 and the second suction port 20 open into the first cylinder chamber 25 and the second cylinder chamber 26, respectively. A first suction pipe 14 and a second suction pipe 16 are connected to the first suction port 19 and the second suction port 20, respectively.
The first discharge port 40 and the second discharge port 41 are formed in the upper bearing member 6 and the lower bearing member 72, respectively. The first discharge port 40 and the second discharge port 41 open into the first cylinder chamber 25 and the second cylinder chamber 26, respectively. The first discharge port 40 is provided with a first discharge valve 43 so as to open and close the first discharge port 40. The second discharge port 41 is provided with a second discharge valve 44 so as to open and close the second discharge port 41.
A first vane 32 (blade) is slidably fitted in the first vane groove 34. The first vane 32 partitions the first cylinder chamber 25 in the circumferential direction of the first piston 8. That is, the first cylinder chamber 25 is partitioned into a first suction chamber 25a and a first discharge chamber 25b. A second vane 33 (blade) is slidably fitted in the second vane groove 35. The second vane 33 partitions the second cylinder chamber 26 in the circumferential direction of the second piston 28. That is, the second cylinder chamber 26 is partitioned into a second suction chamber 26a and a second discharge chamber 26b. The first suction port 19 and the first discharge port 40 are located on both sides of the first vane 32. The second suction port 20 and the second discharge port 41 are located on both sides of the second vane 33. The refrigerant to be compressed is supplied to the first cylinder chamber 25 (first suction chamber 25a) through the first suction port 19. The refrigerant to be compressed is supplied to the second cylinder chamber 26 (second suction chamber 26a) through the second suction port 20. The refrigerant compressed in the first cylinder chamber 25 pushes the first discharge valve 43 open, and is discharged from the first discharge chamber 25b through the first discharge port 40. The refrigerant compressed in the second cylinder chamber 26 pushes the second discharge valve 44 open, and is discharged from the second discharge chamber 26b through the second discharge port 41.
The first piston 8 and the first vane 32 may constitute a single component, a so-called swing piston. The second piston 28 and the second vane 33 may constitute a single component, a so-called swing piston. The first vane 32 and the second vane 33 may be coupled to the first piston 8 and the second piston 28, respectively. The specific type of the rotary compressor is not particularly limited, and a wide variety of types of rotary compressors, such as a rolling piston type rotary compressor and a swing piston type rotary compressor, can be used.
The first spring 36 and the second spring 37 are disposed behind the first vane 32 and the second vane 33, respectively. The first spring 36 and the second spring 37 push the first vane 32 and the second vane 33, respectively, toward the center of the shaft 4. The rear end of the first vane groove 34 and the rear end of the second vane groove 35 each communicate with the internal space 13 of the closed casing 1. Therefore, the pressure in the internal space 13 of the closed casing 1 is applied to the rear surface of the first vane 32 and the rear surface of the second vane 33. The oil stored in the oil reservoir 22 is supplied to the first vane groove 34 and the second vane groove 35.
As shown in
The refrigerant discharge space 52 communicates with the refrigerant discharge space 51 via a through flow path 46. The through flow path 46 penetrates through the lower bearing member 72, the second cylinder 15, the intermediate plate 38, the first cylinder 5, and the upper bearing member 6, in a direction parallel to the rotational axis of the shaft 4. The refrigerant compressed in the second compression block 30 and the refrigerant compressed in the first compression block 3 are merged together in the internal space of the first partition member 9, that is, the refrigerant discharge space 51. Therefore, even if the volume of the refrigerant discharge space 52 is slightly smaller than the required volume, the silencing effect by the refrigerant discharge space 51 can be obtained within the first partition member 9. The cross-sectional area of the through flow path 46 (flow path area) is larger than the cross-sectional area (flow path area) of the second discharge port 41. Therefore, an increase in the pressure loss can be prevented.
As shown in
The second vane groove 35 has an opening that faces the second cylinder chamber 26. When the position of the center of the opening of the second vane groove 35 is defined as a reference position in the circumferential direction of the inner circumferential surface of the second cylinder 15, the first reference plane H1 can be a plane passing through this reference position and including the central axis O1. That is, the “center of the second vane groove 35” refers to the center of the opening of the second vane groove 35. The first reference plane H1 can be a plane including the central axis O1 of the second cylinder 15 and a point of contact (specifically, a tangent line) between the second cylinder 15 and the second piston 28 when the second vane 33 protrudes maximally toward the central axis O1 of the second cylinder 15. The central axis O1 of the second cylinder 15 specifically refers to the central axis of the cylindrical inner circumferential surface of the second cylinder 15.
As shown in
In the rotary compressor 100, the level of the oil in the oil reservoir 22 is higher than the lower surface of the first cylinder 5. In order to ensure reliability, it is desirable that the level of the oil in the oil reservoir 22 be higher than the upper surface of the first cylinder 5 and lower than the lower end of the motor 2 during the operation. The second cylinder 15, the lower bearing member 72, and the second partition member 64 are immersed in the oil in the oil reservoir 22. Therefore, the oil in the oil reservoir 22 can flow into the oil retaining portion 53.
The refrigerant to be compressed is in a low-temperature and low-pressure state. On the other hand, the compressed refrigerant is in a high-temperature and high-pressure state. Therefore, during the operation of the rotary compressor 100, the lower bearing member 72 has a certain temperature distribution. Specifically, when the lower bearing member 72 is divided into a suction-side portion and a discharge-side portion, the former has a relatively low temperature and the latter has a relatively high temperature. When the lower bearing member 72 is divided into two parts by the first reference plane H1, the suction-side portion is one part including a portion directly below the second suction port 20. The discharge-side portion is the other part having the second discharge port 41 formed therein.
In the present embodiment, the oil retaining portion 53 is formed on the same side as the second suction port 20 with respect to the first reference plane H1. The oil retaining portion 53 is in contact with the lower surface of the lower bearing member 72. The oil in the oil retaining portion 53 suppresses reception of heat from the environment by the refrigerant drawn into the second cylinder chamber 26 (drawn refrigerant). More specifically, the oil retaining portion 53 suppresses heat reception by the drawn refrigerant mainly for the following reasons.
Oil is a liquid and has a high viscosity. Once the oil in the oil reservoir 22 flows into the space forming the oil retaining portion 53, the oil is allowed to stagnate in the oil retaining portion 53. Therefore, the flow speed of the oil in the oil retaining portion 53 is lower than that of the oil in the oil reservoir 22. In general, the heat transfer coefficient on the surface of a substance is proportional to the square root of the flow speed of a fluid. Therefore, when the flow speed of the oil in the oil retaining portion 53 is low, the heat transfer coefficient on the lower surface of the lower bearing member 72 is also low. As a result, the heat is transferred slowly from the oil in the oil retaining portion 53 to the lower bearing member 72. Since the lower bearing member 72 is hard to receive the heat from the oil, reception of the heat by the drawn refrigerant from the lower bearing member 72 is also suppressed. For this reason, the oil retaining portion 53 suppresses the heat reception by the drawn refrigerant. Even if another member is disposed between the oil retaining portion 53 and the lower surface of the lower bearing member 72, the another member can be regarded as a part of the lower bearing member 72.
The effect of suppressing the heat reception by the drawn refrigerant also results from not only the oil retaining portion 53 but also the fact that most of the refrigerant discharge space 52 is formed on the same side as the second discharge port 41 with respect to the first reference plane H1. This means that the present embodiment makes it possible to increase the distance over which the heat of the discharged refrigerant is transferred to the drawn refrigerant. More specifically, the heat needs to be transferred through a heat transfer path inside the lower bearing member 72 to transfer the heat from the discharged refrigerant in the refrigerant discharge space 52 to the drawn refrigerant in the second suction chamber 26a. In the present embodiment, the heat transfer path is relatively long. According to the Fourier's law, the amount of heat transfer is inversely proportional to the distance of the heat transfer path. This means that the present embodiment makes it possible to increase the heat resistance of the heat transfer from the discharged refrigerant to the drawn refrigerant.
In addition, the oil retaining portion 53 allows the closed casing 1 to store extra oil in an amount equal to the volume of the oil retaining portion 53. Therefore, the oil retaining portion 53 contributes to an improvement in the reliability of the rotary compressor 100.
As shown in
The second partition member 64 has a circular shape in plane view, and has, in the central portion thereof, a through hole into which the shaft 4 is inserted. Specifically, the second partition member 64 is composed of a plate-shaped portion 64a (bottom portion) and an arc-shaped portion 64b (side wall portion). The second partition member 64 is attached to the lower bearing member 72 so as to form the refrigerant discharge space 52 and the oil retaining portion 53 respectively on the opposite side to the second cylinder chamber 26 with respect to the lower bearing member 72. A part of the plate-like portion 64a is in contact with the bank portion 70c and closes the recess 72t surrounded by the bearing portion 70b and the bank portion 70c. The rest of the plate-like portion 64a faces the circular plate portion 70a of the lower bearing member 72 so as to form the oil retaining portion 53. The arc-shaped portion 64b is a portion that is formed integrally with the plate-like portion 64a, and is formed along the outer edge of the plate-like portion 64a. The arc-shaped portion 64b further extends in the thickness direction of the plate-like portion 64a (in a direction parallel to the rotational axis of the shaft 4). A gap 64p serving as a communication path communicating the oil reservoir 22 with the oil retaining portion 53 is formed between the end of the arc-shaped portion 64b and the lower bearing member 72. The size of the communication path 7p (the width of the gap 64p) is adjusted to a size necessary and sufficient for the oil in the oil reservoir 22 to flow into the oil retaining portion 53. Therefore, the flow of the oil in the oil retaining portion 53 is slower than that of the oil in the oil reservoir 22. As a result, relatively stable thermal stratification of the oil is observed in the oil retaining portion 53.
As shown in
When the refrigerant discharge space 52 and the oil retaining portion 53 are in such a positional relationship, the heat transfer from the refrigerant discharged into the refrigerant discharge space 52 to the refrigerant drawn into the second cylinder chamber 26 can be suppressed.
In the present embodiment, a part of the oil retaining portion 53 is formed on the same side as the second discharge port 41 with respect to the first reference plane H1. However, the entire oil retaining portion 53 may be formed on the same side as the second suction port 20 with respect to the first reference plane H1.
As shown in
The occupancies of the refrigerant discharge space 52 and the oil retaining portion 53 in the lower bearing member 72 are not particularly limited. For example, in a projection view obtained by (orthogonally) projecting the refrigerant discharge space 52 and the oil retaining portion 53 onto a plane perpendicular to the central axis O1, the area of the projection region of the refrigerant discharge space 52 may be larger than the area of the projection region of the oil retaining portion 53. Such a configuration is desirable in suppressing an increase in the pressure loss of the refrigerant.
On the other hand, in the projection view obtained by (orthogonally) projecting the refrigerant discharge space 52 and the oil retaining portion 53 onto a plane perpendicular to the central axis O1, the area S3 of the projection region of the refrigerant discharge space 52 may be smaller than the area S4 of the projection region of the oil retaining portion 53. Such a configuration is desirable in suppressing heat reception by the drawn refrigerant. The area S3 and the area S4 satisfy the relation 1.1≦(S4/S3)≦5, for example. When the volume of the refrigerant discharge space 52 is V3 and the volume of the oil retaining portion 53 is V4, they satisfy the relation 1.1≦(V4/V3)≦10, for example. When the oil retaining portion 53 has a sufficiently large area and/or volume, the effect of suppressing heat reception by the drawn refrigerant can be fully obtained. It should be noted that the area S3 may be equal to the area S4. The volume V3 may be equal to the volume V4.
The positions of the refrigerant discharge space 52 and the oil retaining portion 53 are described in further detail.
As shown in
As shown in
In a typical rotary compressor, a suction port and a discharge port are provided as close to a vane as possible in order to avoid formation of a dead volume. The refrigerant discharge space is formed below the lower bearing member, and the discharge port opens into the refrigerant discharge space. It is desirable that the refrigerant discharge space be formed only on the same side as the discharge port with respect to the first reference plane H1 in order to reduce the heat loss. On the other hand, in order to reduce the pressure loss, it is desirable that there be a sufficiently large space around the discharge port. If the range of the refrigerant discharge space is limited in view of the heat loss, the space around the discharge port becomes insufficient, which may cause a significant increase in the pressure loss. That is, there is a trade-off relationship between the reduction of the heat loss and the reduction of the pressure loss.
In the present embodiment, a part of the refrigerant discharge space 52 is allowed to be located directly below the second suction port 20 for the purpose of reducing the pressure loss. The effect of reducing the heat loss can be obtained at least as long as the refrigerant discharge space 52 is not present in the projection region of the fourth quadrant segment Q4.
From another point of view, the position of the refrigerant discharge space 52 can be determined in the following manner.
As shown in
As shown in
In some cases, as shown in
Next, another structure that forms the oil retaining portion 53 is described.
As shown in
Hereinafter, the position of the communication path 7p is described in detail.
As shown in
During the operation of the rotary compressor 100, the second piston 28 rotates counterclockwise around the central axis O1 shown in
As shown in
The communication path 7p communicates the oil reservoir 22 with the posterior portion 53b of the oil retaining portion 53. The oil in the oil reservoir 22 flows into the anterior portion 53a only through the posterior portion 53b and the narrow portion 53c. Thereby, the flow of the oil in the anterior portion 53a is effectively suppressed.
The oil retaining portion 53 may be formed by any of the following structures.
In the example shown in
According to the structure shown in
In an example shown in
According to the structures described with reference to
The rotary compressor 100 of the present embodiment is a vertical rotary compressor. During the operation of the rotary compressor 100, the rotational axis of the shaft 4 is parallel to the direction of gravity, and the oil reservoir 22 is formed at the bottom of the closed casing 1. During the operation of the rotary compressor 100, the upper portion of the oil in the oil reservoir 22 has a relatively high temperature and the lower portion of the oil in the oil reservoir 22 has a relatively low temperature. Therefore, in the vertical rotary compressor 100, it is desirable to form the oil retaining portion 53 below the lower bearing member 72 (or 70).
As shown in
In the present modification, the lower bearing member 70 is composed of a circular plate portion 70a and a bearing portion 70b. The lower bearing member 70 has the same structure as the lower bearing member 72 described with reference to
In the present modification, the oil cup 62 is additionally disposed inside the second partition member 61. A certain area of the lower surface of the lower bearing member 70 is covered by the oil cup 62, and thereby the oil retaining portion 53 is formed. The position of the oil retaining portion 53 is as described above with reference to
As shown in
The lower bearing member 7 further has a communication path 7p formed therein. The communication path 7p extends in a lateral direction so as to communicate the oil reservoir 22 with the oil retaining portion 53. The oil in the oil reservoir 22 can flow into the oil retaining portion 53 through the communication path 7p (communication hole). When a plurality of communication paths 7p are provided, the oil in the oil reservoir 22 can surely flow into the oil retaining portion 53. In order to minimize the movement of the oil between the oil retaining portion 53 and the oil reservoir 22, only one communication path 7p may be provided in the lower bearing member 7.
In the present modification, the communication path 7p is formed of a small through hole. However, the communication path 7p may be formed of another structure such as a slit. As shown in
The refrigerant discharge space 52 is formed by closing the second recess 7s provided in the lower bearing member 7 by the second partition member 10. That is, the first recess 7t serving as the oil retaining portion 53 and the second recess 7s serving as the refrigerant discharge space 52 are formed in the lower bearing member 7. The second partition member 10 includes a single plate-like member. Both the first recess 7t and the second recess 7s are closed by the second partition member 10. In the present modification, the lower surface of the second partition member 10 is a flat surface. The open end face of the first recess 7t and the open end face of the second recess 7s are on the same plane so that both of the first recess 7t and the second recess 7s can be closed by the second partition member 10. This structure is very simple and therefore an increase in the number of components can also be avoided.
As shown in
As shown in
In the present modification, the first recess 7t provided in the lower bearing member 7 is closed by the second partition member 10 and thereby the oil retaining portion 53 is formed. However, the oil retaining portion 53 may be formed only by the first recess 7t provided in the lower bearing member 7 as long as the flow speed of the oil can be reduced. This means that the oil retaining portion 53 can have a structure that does not require the second partition member 10. For example, in the case where the first recess 7t has a sufficiently large depth (or volume), the first recess 7t serves to allow the oil to stagnate. Therefore, the flow speed of the oil in the first recess 7t is lower than that of the oil in the oil reservoir 22. In the case where the first recess 7t is formed in a hook shape as shown in
As shown in
As shown in
As shown in
The present invention is useful for compressors of refrigeration cycle apparatuses that can be used in electrical appliances such as hot water dispensers, hot-water heaters, and air conditioners.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-250262 | Nov 2011 | JP | national |
| 2012-177877 | Aug 2012 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2012/007302 | 11/14/2012 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2013/073183 | 5/23/2013 | WO | A |
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| 2005-256816 | Sep 2005 | JP |
| 2007-309146 | Nov 2007 | JP |
| 2009-002298 | Jan 2009 | JP |
| 2009-002299 | Jan 2009 | JP |
| 2012-122452 | Jun 2012 | JP |
| Entry |
|---|
| Search Report issued in corresponding Chinese Patent Application No. 201280056574.X, Sep. 21, 2015, 4 pages with translation. |
| Search Report issued in corresponding Chinese Patent Application No. 201280056562.7, Sep. 2, 2015, 4 pages with and English translation. |
| Extended European Search Report issued in the corresponding European Patent Application No. 12849536.3 dated Apr. 7, 2015. |
| Number | Date | Country | |
|---|---|---|---|
| 20140301881 A1 | Oct 2014 | US |
