JP2019007435A - Variable displacement swash plate type compressor - Google Patents

Abstract

To provide a variable displacement swash plate type compressor capable of guiding excessive oil in a crank chamber to a suction chamber that is formed in a rear housing, without applying special processing to a cylinder block.SOLUTION: An oil release passage 50 causing a crank chamber 2 and a suction chamber 31 to communicate with each other is formed by: a bolt insertion hole 53 formed in a cylinder block 1 for inserting a fastening bolt 6 which fastens at least the cylinder block 1 and a rear housing 5 in an axial direction; a bolt receiving hole 54 which communicates with the bolt insertion hole 53 and is formed in the rear housing 5 for threading the fastening bolt 6; and communication means (e.g., a communication path 55 formed in the rear housing 5 and a slit 36a formed in a gasket 36) for causing the bolt receiving hole 54 to communicate with the suction chamber 31.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a variable displacement swash plate compressor having a structure for appropriately adjusting oil in a crank chamber defined by a cylinder block and a housing assembled thereto.

  This type of compressor is assembled with a cylinder block having a plurality of cylinder bores, a front housing that is assembled to the front side of the cylinder block to define a crank chamber, and a valve plate on the rear side of the cylinder block. And a rear housing in which a suction chamber and a discharge chamber are formed. In each cylinder bore of the cylinder block, a piston is disposed so as to be able to reciprocate. A shaft is rotatably supported by the front housing and the cylinder block, and a swash plate is tilted so as to be able to tilt and rotate integrally with the shaft. The engaging portion of the piston is moored to the peripheral portion of the swash plate via a shoe, so that the rotational motion of the swash plate is converted into the reciprocating motion of the piston via the shoe.

In such a compressor, if the oil is accumulated too much in the crank chamber, the swash plate stirs the highly viscous oil, and there is a disadvantage that the temperature in the crank chamber rises due to heat generation due to shear friction between the swash plate and the oil. .
Therefore, conventionally, a configuration has been conceived in which oil accumulated in the crank chamber is recirculated to the suction chamber regardless of the operating state by using a pressure difference between the crank chamber and the suction chamber (see Patent Document 1). .

  FIG. 8 shows an example of this. In addition to the extraction passage 46 for allowing the refrigerant gas in the crank chamber 2 to escape to the suction chamber, a bypass passage (hereinafter referred to as an oil release passage) that always connects the crank chamber 2 and the suction chamber 31. 50). The oil release passage 50 includes a first passage constituting portion 101 that is drilled obliquely upward from the end face facing the crank chamber 2 of the cylinder block 1 through the adjacent cylinder bores 14, and the cylinder block 1. A second passage constituting portion 102 which is drilled in parallel with the shaft 7 from the end surface opposite to the end face facing the crank chamber 2 and communicates with the first passage constituting portion 101. The oil in the crank chamber 2 is guided to the suction chamber 31 through the oil release passage 50 so that the oil does not accumulate excessively in the crank chamber 2.

  Further, in this document, as shown in FIG. 9, an oil release passage 50 is inserted into the cylinder block 1 in order to insert a fastening bolt 6 for fastening the front housing 3, the cylinder block 1, and the rear housing 5. The formed bolt insertion hole 53 and a groove 103 that extends in the radial direction through the space between the adjacent cylinder bores 14 on the end face of the cylinder block 1 on the valve plate 4 side and communicates with the bolt insertion hole 53 are provided. Configuration examples have also been proposed.

International Publication WO2015 / 199207

  However, the conventional oil release passage shown in FIG. 8 requires a hole to be formed between the adjacent cylinder bores, which increases the manufacturing cost and may reduce the strength between the cylinder bores. Further, when forming a groove in the end face of the cylinder block, in addition to being difficult to process, the seal between the cylinder bores is liable to be damaged, and there is a risk of refrigerant leakage between the cylinder bores.

  The present invention has been made in view of such circumstances, and is a variable capacity swash plate type compression capable of guiding excess oil in a crank chamber to a suction chamber formed in a rear housing without subjecting the cylinder block to special processing. The main challenge is to provide a machine.

  In order to achieve the above object, a variable capacity swash plate compressor according to the present invention includes a cylinder block in which a plurality of cylinder bores are formed, and a front housing that is assembled to the front side of the cylinder block to define a crank chamber. A rear housing which is assembled on the rear side of the cylinder block and has a suction chamber and a discharge chamber; a piston which is reciprocally disposed in each cylinder bore of the cylinder block; the front housing and the cylinder block A shaft that is rotatably supported by the shaft, a swash plate that is tiltably attached to the shaft, and that rotates as the shaft rotates, communicates with the crank chamber, and connects the crank chamber and the suction chamber. In a configuration having an oil release passage that is always in communication, the oil release passage is A bolt insertion hole formed in the cylinder block for inserting at least a fastening bolt for fastening the cylinder block and the rear housing in the axial direction; and a screw insertion of the fastening bolt in communication with the bolt insertion hole. The bolt receiving hole is formed in the rear housing, and the bolt receiving hole is formed by communication means for communicating with the suction chamber.

Therefore, the oil in the crank chamber flows through the bolt insertion hole formed in the cylinder block and then reaches the bolt receiving hole of the rear housing, and is guided from the bolt receiving hole to the suction chamber through the communication means. There is no need to newly form a hole or groove in the block, and the oil in the crank chamber can be guided to the suction chamber.
Further, since the existing bolt insertion hole of the cylinder block is used, the reliability of the compressor can be ensured without the lack of strength between the cylinder bores and the risk of refrigerant leakage.

  Here, in the compressor in which the suction chamber is formed inside the discharge chamber, the communication means may be a means for communicating with the suction chamber through a communication passage formed in the rear housing from a bolt receiving hole.

  Usually, the bolt receiving hole is formed in the vicinity of the peripheral edge of the rear housing. Therefore, in the compressor in which the suction chamber is formed inside the discharge chamber, the bolt receiving hole is provided adjacent to the discharge chamber. For this reason, it is necessary to form a tunnel-like communication path in the rear housing. However, since this communication path is formed by appropriately selecting a thick portion of the rear housing, it can be easily processed. .

  As an aspect of communicating the bolt receiving hole with the suction chamber via the communication passage, the end of the communication passage is opposed to the gasket or the discharge valve seat interposed between the cylinder block and the rear housing, and the gasket Or it is good to make it connect with the said suction chamber through the slit formed in the said valve seat.

  With such a configuration, it is possible to adjust the amount of oil discharged to the suction chamber through the oil release passage by adjusting the width of the slit formed in the gasket or valve seat, and the communication passage There is no need to form a diaphragm in the middle of the process.

  In addition, you may make it provide a filter in the middle in the communicating path, and remove the foreign material in oil.

  In the compressor in which the suction chamber is formed outside the discharge chamber, the communication means is formed in a gasket or a discharge valve seat interposed between the cylinder block and the rear housing, and the bolt receiving hole You may form by the slit connected to.

  Each of the above-described configurations, in addition to the oil release passage, is provided for a compressor provided with an extraction passage that constantly communicates the crank chamber and the suction chamber and allows the refrigerant gas in the crank chamber to escape to the suction chamber. This is effective when oil in the crank chamber is actively released to the suction chamber.

  As described above, according to the present invention, the oil release passage that always communicates the crank chamber and the suction chamber is inserted into the cylinder block in order to insert the fastening bolt that fastens at least the cylinder block and the rear housing in the axial direction. Formed by the formed bolt insertion hole, the bolt receiving hole formed in the rear housing for screwing the fastening bolt, and the communication means communicating the bolt receiving hole with the suction chamber. Therefore, it is not necessary to perform special processing on the cylinder block, and excess oil in the crank chamber can be guided to the suction chamber of the rear housing. For this reason, since no special processing is required for the cylinder block, it is possible to avoid insufficient strength of the cylinder block and a risk of refrigerant leakage, and it is possible to ensure the reliability of the compressor.

FIG. 1 is a cross-sectional view showing a configuration example of a compressor according to the present invention. FIG. 2 is an end view showing an end face of the cylinder block. FIG. 3 is an enlarged view showing a configuration example of communication means for communicating the bolt receiving hole of the rear housing and the suction chamber. FIG. 4A is an enlarged perspective view of a part of the rear housing showing a bolt receiving hole and a communication path formed in the rear housing, and FIG. 4B is a view in which a gasket is attached to FIG. It is a perspective view which shows the state which showed the state which formed the slit in this gasket. FIG. 5 is a view showing an example in which a slit is used in a discharge valve seat as a communication means between the bolt receiving hole of the rear housing and the suction chamber, and FIG. 5 (a) is a cross-sectional view thereof, and FIG. ) Is a plan view showing a part of a discharge valve sheet in which a slit is formed. FIG. 6 is a cross-sectional view showing an example of a compressor in which the suction chamber is disposed outside the discharge chamber. FIG. 7A is an enlarged cross-sectional view showing an example in which a slit provided in a gasket is used as communication means for communicating the bolt receiving hole of the rear housing and the suction chamber in the compressor shown in FIG. FIG. 7B is an enlarged cross-sectional view showing an example in which a slit provided in the discharge valve seat is used as a communication means for communicating the bolt receiving hole of the rear housing and the suction chamber in the compressor shown in FIG. 8A and 8B are diagrams showing a conventional example in which a crank chamber and a suction chamber of a compressor are communicated, where FIG. 8A is a side sectional view and FIG. 8B is an end surface of a cylinder block on the valve plate side. FIG. 9A and 9B are diagrams showing another conventional example in which a crank chamber and a suction chamber of a compressor are communicated, where FIG. 9A is a side sectional view thereof, and FIG. 9B is an end surface of a cylinder block on the valve plate side. FIG.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, the best embodiment of the invention will be described with reference to the accompanying drawings.

  In FIG. 1, the compressor is assembled so as to cover the cylinder block 1 and the front side of the cylinder block 1, and a front housing 3 that defines a crank chamber 2 between the cylinder block 1, and the cylinder block 1. And a rear housing 5 assembled via a valve plate 4 on the rear side. The front housing 3, cylinder block 1, valve plate 4, and rear housing 5 are fastened in the axial direction by fastening bolts 6.

  A crank chamber 2 defined by the front housing 3 and the cylinder block 1 accommodates a shaft 7 whose front end protrudes from the front housing 3. A drive pulley (not shown) is provided at a portion of the shaft 7 protruding from the front housing 3 so that rotational power applied to the drive pulley is transmitted to the shaft 7 via the clutch plate.

  Further, the front end side of the shaft 7 is hermetically sealed with the front housing 3 through a seal member 10 provided between the shaft 7 and the shaft 7 is rotatably supported by a radial bearing 11. The rear end side of the shaft 7 is rotatably supported via a radial bearing 13 that is accommodated in an accommodation hole 12 formed in the approximate center of the cylinder block 1. Here, the radial bearings 11 and 13 may be rolling bearings or plain bearings.

  As shown in FIG. 2, the cylinder block 1 includes the accommodation hole 12 in which the radial bearing 13 and the like are accommodated, and a plurality of cylinder bores arranged at equal intervals on a circumference around the accommodation hole 12. 14 is formed, and a piston 20 is inserted into each cylinder bore 14 so as to be slidable back and forth.

  A thrust flange 15 that rotates integrally with the shaft 7 is fixed to the shaft 7 in the crank chamber 2. The thrust flange 15 is rotatably supported on an inner wall surface of the front housing 3 formed substantially perpendicular to the shaft 7 via a thrust bearing 16. A swash plate 18 is connected to the thrust flange 15 via a link member 17.

  The swash plate 18 is held so as to be tiltable via a hinge ball 19 provided on the shaft 7, and rotates integrally with the rotation of the thrust flange 15. The thrust flange 15 and the swash plate 18 connected to the thrust flange 15 via a link member 17 constitute a power transmission mechanism that rotates in synchronization with the rotation of the shaft 7.

  The piston 20 is configured by joining a head portion 20a inserted into the cylinder bore 14 and an engaging portion 20b protruding into the crank chamber 2 in the axial direction. The engaging portion 20b is connected to a pair of shoes. The swash plate 18 is moored through the peripheral portion 21.

  Accordingly, when the shaft 7 is rotated, the swash plate 18 is rotated accordingly, and the rotational motion of the swash plate 18 is converted into the reciprocating linear motion of the piston 20 via the shoe 21, and the piston 20 and the valve in the cylinder bore 14. The volume of the compression chamber 25 defined between the plate 4 and the plate 4 is changed.

  The rear housing 5 is formed with a suction chamber 31 and a discharge chamber 32 formed outside the suction chamber 31. Further, the valve plate 4 includes a suction hole 26 that connects the suction chamber 31 and the compression chamber 25 via a suction valve (not shown), a discharge chamber 32, and a compression chamber 25, which are discharge valves (not shown). And a discharge hole 27 communicating with each other.

  In this configuration example, the rear housing 5 is provided with a pressure control valve 39 that adjusts the opening degree of an air supply passage (not shown) that connects the discharge chamber 32 and the crank chamber 2. The flow rate of the refrigerant flowing from the discharge chamber 32 to the crank chamber 2 through the air supply passage is adjusted, and the pressure in the crank chamber 2 is controlled.

  The shaft 7 is provided with an oil separation passage 43 described below. The crank chamber 2 and the suction chamber 31 are communicated with each other by the oil separation passage 43, a space 44 formed between the rear end of the shaft 7 and the valve plate 4, and an orifice hole 45 formed in the valve plate 4. A bleed passage 46 is formed.

  The oil separation passage 43 formed in the shaft 7 is connected to the shaft hole 43a formed on the shaft center of the shaft 7 from the rear end to the middle, and to the shaft hole 43a. And a side hole 43b that opens to the crank chamber 2 and has a function of separating and removing oil from the working fluid flowing from the side hole 43b by centrifugal force generated by the rotation of the shaft 7.

  That is, the bleed passage 46 separates and removes oil from the working fluid and allows the refrigerant gas to escape from the crank chamber 2 to the suction chamber, and can also be referred to as a gas release passage.

  As shown in FIG. 3, a suction valve seat 33 is overlaid on the end face of the valve plate 4 on the cylinder block 1 side, and the cylinder block 1 is overlaid on the suction valve seat 33 via a gasket 34. . A discharge valve seat 35 is overlaid on the end surface of the valve plate 4 on the rear housing side, and the rear housing 5 is overlaid on the discharge valve seat 35 via a gasket 36. The cylinder block 1, the gasket 34, the suction valve seat 33, the valve plate 4, the discharge valve seat 35, and the gasket 36 are positioned by a positioning pin (not shown) and are fastened to the cylinder block 1 by the fastening bolt 6 screwed into the rear housing 5. And the rear housing 5 are fixed in a pressed state.

In this compressor, an oil release passage 50 that communicates the crank chamber 2 and the suction chamber 31 is formed separately from the extraction passage 46.
The oil release passage 50 includes a bolt insertion hole 53 formed in the cylinder block 1 for inserting a fastening bolt 6 for fastening the front housing 3, the cylinder block 1 and the rear housing 5 in the axial direction, and the bolt insertion. A bolt receiving hole 54 formed in the rear housing 5 for communicating with the hole 53 and screwing the fastening bolt 6, and a communication path formed in a tunnel shape so as to communicate with the suction chamber 31 from the bolt receiving hole 54. 55. That is, the communication path 55 is one mode of communication means for communicating the bolt receiving hole with the suction chamber.

  In this example, seven bolt insertion holes 53 formed in the cylinder block 1 are arranged at substantially equal intervals in the vicinity of the peripheral edge of the cylinder block 1, and among these, the bolt insertion hole located at the lowest position with the compressor installed. The hole is used as the oil release passage 50. The inner diameter of the bolt insertion hole 53 is formed to be larger than the outer diameter of the cylindrical portion 6a of the fastening bolt 6 to be inserted, and when the fastening bolt 6 is inserted, the peripheral surface of the cylindrical portion 6a of the fastening bolt 6 and the bolt insertion. A gap is formed between the inner surface of the hole 53.

  The bolt receiving hole 54 is an alignment hole 4a, 34a, 36a, 33a formed at a position aligned with the bolt insertion hole 53 with respect to the valve plate 4, the gaskets 34, 36, the suction valve seat 33, and the discharge valve seat 35. , 35a and the bolt insertion hole 53. When the intake valve seat 33 and the discharge valve seat 35 are formed so as to avoid the fastening bolts 6, the alignment holes 4a of the valve plate 4 and the alignment holes formed in the gaskets 34 and 36 are used. The bolt insertion hole 53 and the bolt receiving hole 54 communicate with each other.

  The bolt receiving hole 54 is formed following the loose fitting portion 54a provided at a predetermined depth at the entrance of the bolt receiving hole 54, and the threaded portion 6b of the fastening bolt 6 is screwed. And a female screw portion 54b. The inner diameter of the loosely fitting portion 54a is formed larger than the outer diameter of the cylindrical portion 6a and the screw portion 6b of the fastening bolt 6. Thereby, when the screw part 6b of the fastening bolt 6 is screwed into the female screw part 54b, a gap is formed between the peripheral surface of the fastening bolt 6 and the inner surface of the loosely fitting part 54a.

One end of the communication path 55 opens to the loose fitting portion 54 a of the bolt receiving hole 54, and the other end opens to the end face of the rear housing 5 on the valve plate side so as to face the gasket 36.
In this example, as shown in FIG. 4, the communication passage 55 uses a pillar 5 a formed integrally with the rear housing 5 in order to press the gasket 36 and the discharge valve seat 35 against the valve plate 4. A vertical hole 55a formed along the axial direction of the shaft 7 from the top of 5a, and an inclined hole 55b that is formed obliquely from the loose fitting portion 54a of the bolt receiving hole 54 and communicates with the vicinity of the end portion of the vertical hole 55a. And is formed by.

The vertical hole 55a is formed by drilling or casting (casting) from the end surface of the rear housing 5 in a direction substantially perpendicular to the end surface, and is a portion that opens to the end surface of the rear housing 5 (opposite the gasket 36). In the portion), an enlarged portion 55a-2 having a slightly larger diameter is formed, and a filter 56 is detachably disposed on the enlarged portion 55a-2.
Further, the inclined hole 55 b is formed by inserting a drill obliquely from the opening end of the bolt receiving hole 54 of the rear housing 5.

  And the opening part (diameter enlarged part 55a-2) which opposes the gasket 36 of the communicating path 55 (vertical hole 55a) passes through the slit 36a provided in the gasket 36, as FIG.4 (b) shows. And communicates with the suction chamber 31.

  Therefore, the oil in the crank chamber 2 is caused by the pressure difference between the crank chamber 2 and the suction chamber 31, the bolt insertion hole 53 of the cylinder block 1, the gasket 34, the suction valve seat 33, the valve plate 4, the discharge valve seat 35, And the gasket 36 through the respective alignment holes (34a, 33a, 4a, 35a, 36a) to the bolt receiving hole 54 of the rear housing 5, and from the bolt receiving hole 54 through the communication passage 55 to the gasket 36. It reaches the oppositely enlarged diameter portion 55 a-2, passes through the filter 56, and is led to the suction chamber 31 through the slit 36 a formed in the gasket 36.

  In the above configuration, when the shaft 7 is rotated by the rotational power given to the drive pulley, the swash plate 18 is rotated, and the rotational motion of the swash plate 18 is converted into the reciprocating linear motion of the piston 20 via the shoe 21. 20 begins to reciprocate within the cylinder bore 14. The reciprocating motion of the piston 20 changes the volume of the compression chamber 25 formed between the piston 20 and the valve plate 4 in the cylinder bore 14, and from the suction chamber 31 through the suction hole 26 during the suction stroke. The working fluid is sucked into the compression chamber 25, and the compressed working fluid is discharged from the compression chamber 25 to the discharge chamber 32 through the discharge hole 27 during the compression stroke.

  The discharge capacity of the compressor is determined by the stroke of the piston 20, which is the pressure applied to the front surface of the piston 20, that is, the pressure in the compression chamber 25, and the pressure applied to the back surface of the piston 20, that is, the pressure in the crank chamber 2. It is determined by the differential pressure. Specifically, if the pressure in the crank chamber 2 is increased, the differential pressure between the compression chamber 25 and the crank chamber 2 is reduced, so that the inclination angle (swinging angle) of the swash plate 18 is reduced. If the stroke of the piston 20 is reduced and the discharge capacity is reduced. Conversely, if the pressure in the crank chamber 2 is reduced, the differential pressure between the compression chamber 25 and the crank chamber 2 is increased. (Swinging angle) is increased, and therefore, the stroke of the piston 20 is increased and the discharge capacity is increased.

During high speed operation such as acceleration, the amount of refrigerant gas supplied from the discharge chamber 32 to the crank chamber 2 via the air supply passage (not shown) by the pressure control valve 39 increases, and the crank chamber pressure is increased.
Accordingly, the swing angle of the swash plate 18 is reduced (the piston stroke is reduced), and the discharge capacity is reduced. In such a case, since the rotation of the shaft 7 is fast, the oil separation function by the oil separation passage 43 is increased, and the oil is easily collected in the crank chamber 2. However, since the oil release passage 50 is always in communication with the crank chamber 2, the oil accumulated in the crank chamber 2 is sucked into the suction chamber 31 via the oil release passage 50 due to a pressure difference between the crank chamber 2 and the suction chamber 31. The excess oil is prevented from being accumulated in the crank chamber 2.

  Further, according to the above-described configuration, the oil release passage of the cylinder block is formed using the bolt insertion hole 53, and thus no special processing is necessary. Further, there is no fear of insufficient strength or refrigerant leakage between adjacent cylinder bores, and the reliability of the compressor can be maintained.

  Further, the amount of oil discharged into the suction chamber 31 can be adjusted by adjusting the width of the slit 36 a formed in the gasket 36, so that the communication passage 55 constituting a part of the oil release passage 50. May be formed with a diameter that is easy to process, and there is no inconvenience that it is difficult to process the oil release passage.

  Further, in the above-described configuration, the oil release passage 50 opens on the inner peripheral surface of the bolt insertion hole 53 provided in the lower portion of the crank chamber 2, so that the oil accumulated in the crank chamber 2 is effectively discharged. It becomes possible to do. Further, since the existing bolt insertion hole 53 is used to form the oil release passage 50, it is not necessary to change the design of the position of the bolt insertion hole or the like in order to form the oil release passage.

  Moreover, the entrance of the oil release passage 50 becomes the opening end of the bolt insertion hole 53 into which the fastening bolt 6 is inserted (because it is a gap between the fastening bolt 6 and the inner peripheral surface of the bolt insertion hole 53). Even if the oil in the crank chamber is agitated and disturbed, the oil is prevented from being disturbed when flowing into the oil release passage, and the oil can be stably released to the suction chamber.

  Further, in the above-described configuration, since the oil release passage is provided separately from the extraction passage 46, the flow of the extraction gas and the oil release passage guided to the suction chamber 31 via the oil separation passage 43 (extraction passage 46). The flow of the oil guided to the suction chamber 31 via 50 can be made independent, and there is no inconvenience that one flow is obstructed by the other flow.

  In the above example, the end of the communication path 55 faces the gasket 36, and the conduction path 55 communicates with the suction chamber 31 through the slit 36a formed in the gasket 36. As shown in the figure, a through hole 36b is formed in the portion of the gasket 36 where the communication passage 55 faces, and the end of the communication passage 55 (the enlarged diameter portion 55a-2) faces the discharge valve seat 35. The communication path 55 may be communicated with the suction chamber 31 through the slit 35 a formed in the 35.

  In the above-described example, the vertical hole 55a is formed using the pillar 5a provided in the rear housing 5. However, the portion in contact with the gasket provided in the rear housing 5 is appropriately selected and connected. What is necessary is just to drill the channel | path 55, and is not limited to the said Example.

In the above example, the suction chamber 31 formed in the rear housing 5 is arranged inside the discharge chamber 32. However, as shown in FIG. Also in the compressor disposed outside, the oil in the crank chamber may be guided to the suction chamber after being guided to the rear housing using the bolt insertion hole and the bolt receiving hole.
In the example of the compressor shown in FIG. 6, the orifice 45 is disposed at a position corresponding to the suction chamber 31 disposed outside the discharge chamber 32 as the suction chamber 31 is disposed outside the discharge chamber 32. A groove 47 connecting the space 44 and the orifice 45 is formed on the end face of the cylinder block 1. Further, the positions of the suction holes 26 and the discharge holes 27 and the configurations of the corresponding suction valves and discharge valves are different from those in FIG. Since the rest is substantially the same as the configuration of FIG. 1, the same portions are denoted by the same reference numerals and description thereof is omitted.

In such a compressor, the communication path is not formed in the rear housing 5, and the loosely fitting portion 54a of the bearing hole 54 is provided with a slit 36c formed in the gasket 36 as shown in FIG. Alternatively, it may be communicated with the suction chamber 31 via the slit 35c or may be communicated with the suction chamber 31 via a slit 35c formed in the discharge valve seat 35, as shown in FIG.
Even in such a configuration, the same effects as those of the above-described embodiment can be obtained, and the formation of the communication passage is not necessary, so that the oil release passage 50 can be formed more easily.

  In the above example, the bolt insertion hole 53 that positions the oil release passage 50 (communication passage 51) on the lowermost side is used, and the bolt insertion hole 53 is formed at the lowermost part of the crank chamber 2 (perpendicular to the shaft). The oil release passage 50 is limited to the lowermost part of the crank chamber 2 as long as the oil release passage 50 communicates with the crank chamber 2 on the outer side in the radial direction with respect to the rotation locus of the swash plate 18. Is not to be done.

  The bolt insertion hole 53 used as the oil release passage is not necessarily formed in the lowermost part of the crank chamber 2 due to the installation location of the compressor and the convenience of the design, and a cylinder that supports the shaft 7 via the radial bearing 13. When the direction directly below the center of the housing hole 12 of the block 1 is defined as 0 °, from the viewpoint of preventing excessive oil from accumulating in the crank chamber 2 in any operation state, 90 ° ± 10 ° It is preferable that the position is lower than that, and if the start-up time is further taken into consideration, it is preferable to change the position from 45 ° ± 10 ° to a lower position.

DESCRIPTION OF SYMBOLS 1 Cylinder block 2 Crank chamber 3 Front housing 4 Valve plate 5 Rear housing 6 Fastening bolt 7 Shaft 14 Cylinder bore 18 Swash plate 20 Piston 25 Compression chamber 31 Suction chamber 32 Discharge chamber 35 Discharge valve seat 35a, 36a, 35c, 36c Slit 36 Gasket 50 Oil release passage 55 Communication passage 56 Filter

Claims (6)

A cylinder block formed with a plurality of cylinder bores;
A front housing assembled to the front side of the cylinder block to define a crank chamber;
A rear housing assembled on the rear side of the cylinder block and having a suction chamber and a discharge chamber;
A piston disposed in each cylinder bore of the cylinder block so as to be reciprocally movable;
A shaft rotatably supported by the front housing and the cylinder block;
A swash plate that is tiltably attached to the shaft and rotates with the rotation of the shaft;
In the variable capacity swash plate type compressor having an oil release passage that communicates with the crank chamber and constantly communicates with the crank chamber and the suction chamber.
The oil release passage communicates with the bolt insertion hole formed in the cylinder block for inserting a fastening bolt for fastening at least the cylinder block and the rear housing in the axial direction, and the fastening. 2. A variable capacity swash plate compressor, comprising: a bolt receiving hole formed in the rear housing for screwing a bolt; and a communication means for communicating the bolt receiving hole with the suction chamber. The suction chamber is formed inside the discharge chamber;
2. The variable capacity swash plate compressor according to claim 1, wherein the communication means is means for communicating with the suction chamber through a communication passage formed in the rear housing from the bolt receiving hole.   The end of the communication path is opposed to a gasket or discharge valve seat interposed between the cylinder block and the rear housing, and communicates with the suction chamber via a slit formed in the gasket or the valve seat. 3. The variable capacity swash plate compressor according to claim 2, wherein   The variable capacity swash plate compressor according to any one of claims 1 to 3, wherein a filter is provided in the communication path. The suction chamber is formed outside the discharge chamber;
2. The variable capacity according to claim 1, wherein the communication means is a slit formed in a gasket or a discharge valve seat interposed between the cylinder block and the rear housing, and is in communication with the bolt receiving hole. Swash plate compressor. 6. The bleed passage for always connecting the crank chamber and the suction chamber and allowing the refrigerant gas in the crank chamber to escape to the suction chamber is provided separately from the oil release passage. The variable capacity swash plate compressor according to claim 1.

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