JP2002031043A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable displacement compressor equipped with a single head piston, capable of performing the incline angle control of a cam plate accurately and smoothly and ensuring the lubricating performance of a seal mechanism (shaft seal device). SOLUTION: A suction chamber 13a and a discharge chamber 13b are formed in a rear housing 13, and a rotary shaft 14 is supported rotatably in such a way that its first end protrudes from the front housing 12, and a shaft seal chamber 29 is installed on the protruding side of the rotary shaft 14. The shaft seal chamber 29 is fitted with seal mechanisms 30 and 31 to generate sealing effect for inside the chamber 29 from the atmosphere and a seal member 32 to exert sealing effect for inside the chamber 29 from a crank chamber 12a. Via an external piping 35, the lubricating oil separated by an oil separator 28 is introduced into the chamber 29 from an inlet 29a, while an outlet 29b is coupled with a suction side piping 27b through another external piping 36.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor for moving a piston defining a compression chamber by rotation of a rotary shaft, and sucking and discharging refrigerant into and from the compression chamber by the operation of the piston. The present invention relates to a compressor characterized by a protective structure of a seal mechanism for preventing refrigerant leakage.

[0002]

2. Description of the Related Art As shown in FIG. 7, a variable displacement compressor as a compressor of this type generally comprises a front housing 71, a cylinder block 72 and a rear housing 73 which are fixedly connected to each other. The rotating shaft 74 is rotatably supported by the housing via a pair of radial bearings 75 and 76 on the first end side and the second end side such that the first end protrudes from the front housing 71. A shaft sealing device 78 for preventing the refrigerant gas from leaking from the crank chamber 77 to the atmosphere is disposed closer to the first end of the rotating shaft 74 than the first radial bearing 75 in the housing.

In a compressor, lubrication of a sliding portion such as a bearing is performed by lubricating oil present in a mist state in a refrigerant gas. In recent years, a compressor used in a refrigeration circuit that performs heat exchange including cooling a refrigerant in a supercritical region exceeding the critical temperature of the refrigerant, such as carbon dioxide, instead of carbon dioxide, has also been proposed. In the case where such a refrigerant is used, the pressure of the refrigerant becomes 10 times or more as high as the pressure in the case of using chlorofluorocarbon, and the load on the bearing and the shaft sealing device is increased.

In the compressor described in Japanese Patent Application Laid-Open No. 11-241681, a pressure reducing passage 79 is formed in a rotating shaft 74 as shown in FIG. Inlet 79a of decompression passage 79
However, the first radial bearing 75 makes the first
It is open at a position on the end side corresponding to the isolation chamber 80 in which the shaft sealing device 78 is housed.
b opens at the second end surface of the rotating shaft 74. A fan 81 is fitted and fixed to the second end of the rotating shaft 74.
When the fan 81 rotates integrally with the rotating shaft 74, the refrigerant in the pressure reducing passage 79 is pumped to the outlet 79b. The refrigerant pumped to the outlet 79b flows out of the radial bearing 76 into the crank chamber 77.

The isolation chamber 80 communicates with the crank chamber 77 via a gap in the radial bearing 75 and a gap in the thrust bearing 82. Radial bearing 7
The gap in 5 and the gap in thrust bearing 82 function as a lubricating oil supply passage.

Further, Japanese Patent Application Laid-Open No. 6-66252 discloses that
A configuration for supplying lubricating oil to a sealing device provided on the front side in a decompressed state in which the compression action on the front side is eliminated in a double-headed (double-headed) piston type variable displacement swash plate compressor is disclosed. In this configuration, in the decompression state, the refrigerant gas is guided from the rear suction chamber to the sealing chamber in which the sealing device is housed.

[0007]

Problems to be Solved by the Invention
In the device disclosed in Japanese Patent Publication No. 81, a part of the refrigerant gas in the crank chamber 77 is introduced into the pressure reducing passage 79 through the gap between the first radial bearing 75 or the thrust bearing 82 by the action of the fan 81 provided on the rotating shaft 74. And
After passing through the gap of the second radial bearing 76, the crank chamber 7
7 and the radial bearings 75, 7
6 and the lubrication of the shaft sealing device 78 are improved. However, a fan 81 for generating a flow to the pressure reducing passage 79 is required, and the structure becomes complicated.

Further, in the conventional variable displacement compressor, the crank chamber 77 through a hole formed in the front housing 71 through which the rotating shaft 74 is inserted, and the isolation chamber 80 in which the shaft sealing device 78 is accommodated. There is no configuration in which communication is positively blocked by providing a seal mechanism. Rather, the crank chamber 7 passes through the hole and the gap between the first radial bearing 75.
7 was used to supply a part of the refrigerant gas to the isolation chamber 80 side. However, in the variable displacement compressor, the inclination angle of the swash plate (cam plate) 83 changes depending on the magnitude of the difference between the pressure in the crank chamber 77 acting on the piston 84 and the suction pressure. Is controlled, the stroke amount of the piston 84, that is, the displacement of the compressor is changed. Therefore, it is not preferable from the viewpoint of capacity control to keep the crank chamber 77 and the isolation chamber 80 in communication with each other through the hole through which the rotating shaft 74 is inserted. In particular, a problem arises when a refrigerant having a higher pressure than conventional Freon refrigerant such as carbon dioxide is used as the refrigerant.

[0009] Japanese Patent Application Laid-Open No. 6-66252 discloses that
It is disclosed that refrigerant gas at a suction pressure is introduced from a suction chamber on the rear side into a seal chamber accommodating a seal device. However, this configuration is specific to a double-headed (double-headed) piston type variable displacement swash plate compressor. The configuration cannot be applied to a single-headed piston type compressor.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to accurately and smoothly control a tilt angle of a cam plate when applied to a variable displacement compressor having a single-headed piston. It is an object of the present invention to provide a compressor that can perform the lubrication of the sealing mechanism (shaft sealing device) in a satisfactory manner.

[0011]

In order to achieve the above object, according to the first aspect of the present invention, a housing having a suction chamber, a discharge chamber and a crank chamber, and a first end protruding from the housing. A rotating shaft rotatably supported by the housing, a shaft seal chamber provided on a protruding side of the rotating shaft of the housing, and a shaft seal chamber provided in the shaft seal chamber, and the shaft seal chamber and the atmosphere side. A single-headed piston reciprocally accommodated in a cylinder bore formed in the housing, and a reciprocating motion of the piston, which is accommodated in the crank chamber and rotates the rotation shaft. A compressor provided with a cam plate operatively connected to the piston to convert the shaft seal chamber into a crank chamber side. The shaft seal chamber is provided with an inlet and an outlet, lubricating oil separated from the refrigerant gas or a refrigerant gas in a suction pressure state is introduced from the inlet, and the outlet communicates with the suction pressure region. I let it.

According to the present invention, the seal between the shaft seal chamber and the atmosphere is secured by the seal mechanism, and the seal between the shaft seal chamber and the crank chamber is secured by the seal member. Then, lubricating oil separated from the refrigerant gas or refrigerant gas in a suction pressure state is introduced into the shaft seal chamber. Therefore, pressure reduction of the shaft seal chamber and lubrication of the sliding portion are performed favorably, and reliability is improved. In addition, since the refrigerant gas or the lubricating oil separated from the refrigerant gas is circulated, no heat is accumulated in the shaft seal chamber, the temperature rise in the shaft seal chamber is suppressed, and a longer life of the seal mechanism and the like can be expected.

According to a second aspect of the present invention, in the first aspect of the present invention, the cam plate is supported on the rotating shaft so that the inclination angle can be changed, and the compressor controls the pressure in the crank chamber. Tilt angle control means for changing the tilt angle of the cam plate to change the stroke of the piston. Note that the tilt angle of the cam plate means an angle formed between a virtual plane orthogonal to the rotation axis and the cam plate.

According to the present invention, the inclination angle of the cam plate is changed by the inclination control means to change the stroke of the piston. Unlike the conventional device, the seal member prevents the refrigerant gas in the crank chamber from leaking into the shaft seal chamber. Therefore, when the inclination of the swash plate is changed by changing the pressure in the crank chamber, it is easy to adjust the pressure in the crank chamber to a target pressure, and the inclination of the cam plate can be controlled accurately and smoothly.

According to a third aspect of the present invention, in the first or second aspect, the outlet is connected to the suction passage by an external pipe. According to the present invention, the configuration of the oil circulation passage can be simplified by the external piping.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the compressor includes an oil separating section for separating lubricating oil from refrigerant gas,
The lubricating oil separated by the oil separating section is introduced into the shaft seal chamber from the inlet.

According to the present invention, since the lubricating oil separated from the refrigerant gas is introduced into the shaft seal chamber, the supply amount of the lubricating oil to the shaft seal chamber increases, and the lubrication of the sliding portion is more effectively performed. .

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the oil separating section is an accumulator provided in an external refrigerant circuit for separating a liquid refrigerant and a refrigerant gas. According to the present invention, since lubricating oil having a low temperature can be supplied, the effect of lowering the temperature of the sliding portion of the shaft seal chamber is increased, and the durability of the seal mechanism and the like is further improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIG.

As shown in FIG. 1, the cylinder block 11
A front housing 12 and a rear housing 13 are joined and fixed to each other by tightening a plurality of bolts (only one is shown). Between the cylinder block 11 and the front housing 12, a crank chamber 12a is defined as an internal space. Cylinder block 1
A rotating shaft 14 is rotatably supported on the first housing 1 and the front housing 12 via radial bearings 15 and 16. Radial bearing 15 is front housing 1
2, the rotary shaft 14 is supported in an insertion hole 12b penetrating therethrough.
The rotary shaft 14 is supported in an insertion hole penetrated through the shaft. A disk-shaped rotary support 17 is fixed to the rotary shaft 14 in the crank chamber 12a, and a guide hole 17b is formed in a support arm 17a formed at a peripheral portion of the rotary support 17. .

A swash plate 18 as a cam plate is supported on the rotating shaft 14 so as to be tiltable and slidable in the axial direction of the rotating shaft 14. The swash plate 18 has a connecting portion 18a protruding therefrom, and a guide pin 19 is attached to a distal end of the connecting portion 18a.

The guide pin 19 is engaged with the guide hole 17b, and the guide hole 17b guides the tilt of the swash plate 18 via the guide pin 19. The swash plate 18 can swing in the direction of the rotating shaft 14 and can rotate integrally with the rotating shaft 14 by this guiding action and the supporting action of the rotating shaft 14.

A piston 20 is accommodated in a cylinder bore 11a provided through the cylinder block 11. The piston 20 partitions the compression chamber 11b inside the cylinder bore. The piston 20 is operatively connected to the swash plate 18 via a pair of hemispherical shoes 21 at a neck 20a.
Rotational movement of the swash plate 18 accommodated in the crank chamber 12a is converted into forward and backward reciprocating movement of the piston 20 via the shoe 21, and the piston 20 moves forward and backward in the cylinder bore 11a.

In the rear housing 13, a suction chamber 13a as a suction pressure area and a discharge chamber 13b are defined. A partition plate 22 and a pair of valve forming plates 23 and 24 are interposed between the cylinder block 11 and the rear housing 13, and the partition plate 22 is provided with a suction port 22a and a discharge port 22b. The suction port 22a is opened and closed by a suction valve 23a on the valve forming plate 23, and the discharge port 22b is opened and closed by a discharge valve 24a on the valve forming plate 24. The opening of the discharge valve 24a is regulated by the retainer 24b. The refrigerant in the compression chamber 11b is pushed out of the discharge valve 24a by the forward movement of the piston 20 to perform the discharge operation, and is discharged from the discharge port 22b to the discharge chamber 13b. The refrigerant in the suction chamber 13a is pushed back by the suction valve 23a due to the backward movement of the piston 20 which is the suction operation, and is sucked from the suction port 22a into the compression chamber 11b.

The stroke of the piston 20 is the crank chamber 1
Piston 20 between the pressure in compression chamber 11b and the pressure in compression chamber 11b
Swash plate 18, which changes according to the differential pressure across the crankshaft, that is, the differential pressure between the pressure in the crank chamber 12a and the suction pressure, and determines the discharge capacity.
Change the tilt angle of When the pressure in the crank chamber 12a increases, the inclination angle of the swash plate 18 decreases, and the discharge capacity decreases. When the pressure in the crank chamber 12a decreases, the inclination angle of the swash plate 18 increases, and the discharge capacity increases.

The rear housing 13 is equipped with a control valve 25. The control valve 25 controls the supply of the refrigerant gas from the discharge chamber 13b to the crank chamber 12a. The refrigerant gas in the crank chamber 12a is supplied to a bleed passage 26 having a throttle.
Through the suction chamber 13a. Crank chamber 12
The pressure in a is controlled by the refrigerant flowing out of the crank chamber 12a to the suction chamber 13a via the bleed passage 26 having a throttling function, and the refrigerant supply of the control valve 25.

The suction chamber 13a and the discharge chamber 13b are connected by an external refrigerant circuit 27. An oil separator 28 as an oil separating portion is provided in the middle of the discharge pipe 27a of the external refrigerant circuit 27. Oil separator 28
Is configured basically the same as that disclosed in, for example, JP-A-10-281060, in which a refrigerant gas is introduced into the oil separator 28 so as to rotate around a built-in separation cylinder, Lubricating oil is separated from the refrigerant gas by the centrifugal separation action. Then, the separated lubricating oil accumulates at the bottom of the oil separator 28.

A shaft seal chamber 29 is provided on the side of the housing where the rotary shaft 14 protrudes. The shaft seal chamber 29 is formed in the insertion hole 1 formed in the front housing 12.
2b. Between the inner wall surface of the front housing 12 of the insertion hole 12b and the rotating shaft 14, a sealing mechanism for sealing between the inside of the shaft seal chamber 29 and the atmosphere side is provided. The seal mechanism is a first seal mechanism 3
0 and a second seal mechanism 31. The first seal mechanism 30 has the insertion hole 12
b has a seal ring 30a in contact with the peripheral surface thereof, and the seal ring 30a is supported by the support ring 30b. Second
The seal mechanism 31 has a sliding ring that slides on the end face of the support ring 30b and rotates integrally with the rotating shaft 14.

Between the inner wall surface of the front housing 12 and the rotating shaft 14, a seal member 32 for sealing the inside of the shaft seal chamber 29 and the crank chamber 12a is interposed. The seal member 32 is formed of, for example, a rubber material or a fluororesin, has a substantially C-shaped cross section, and is disposed in contact with the peripheral surface of the insertion hole 12b and the peripheral surface of the rotary shaft 14. That is, the shaft seal chamber 29 isolated by the first seal mechanism 30 and the second seal mechanism 31 and the seal member 32 in the insertion hole 12b.
Are formed. The movement of the seal member 32 toward the first end of the rotary shaft 14 is restricted by a step (not shown).

The shaft seal chamber 29 is provided with an inlet 29a and an outlet 29b. The inlet 29a communicates with a supply passage 33 having one end opened at the lower part of the shaft seal chamber 29, and the outlet 29b communicates with a discharge passage 34 having one end opened at the upper part of the shaft seal chamber 29. The supply passage 33 is connected to the bottom of the oil separator 28 via the external pipe 35, and the discharge passage 34 is connected to the suction side pipe 27b of the external refrigerant circuit 27 via the external pipe 36.

Next, the operation of the compressor configured as described above will be described. The swash plate 18 is integrally rotated via the rotation support 17 and the like with the rotation of the rotating shaft 14, and the rotational motion of the swash plate 18 is converted to the reciprocating motion of each piston 20 via the shoe 21. With the continuation of the driving, the suction, compression and discharge of the refrigerant are sequentially repeated in the compression chamber 11b. The refrigerant supplied from the external refrigerant circuit 27 to the suction chamber 13a is sucked into the compression chamber 11b via the suction port 22a, subjected to a compression action by the movement of the piston 20, and then to the discharge port 22a.
The liquid is discharged to the discharge chamber 13b through the nozzle b. The refrigerant discharged into the discharge chamber 13b is sent out to the external refrigerant circuit 27 via the discharge passage.

The opening of the control valve 25 is controlled by a control device (not shown) in accordance with the cooling load.
The communication state between b and the crank chamber 12a is changed. When the cooling load is large, the discharge chamber 13b is moved from the crank chamber 12
a, the flow rate of the refrigerant gas supplied to the crank chamber 1 decreases.
The pressure of 2a is reduced, and the swash plate 18 is displaced to the maximum inclination angle side. Therefore, the stroke amount of the piston 20 increases,
The discharge capacity is increased. Conversely, when the cooling load decreases, the opening of the control valve 25 increases, and the flow rate of the refrigerant gas supplied from the discharge chamber 13b to the crank chamber 12a increases,
The pressure in the crank chamber 12a rises, and the swash plate 18 is displaced to the minimum inclination angle side. Therefore, the stroke amount of the piston 20 is reduced, and the discharge capacity is reduced.

The refrigerant gas sent from the discharge chamber 13b to the external refrigerant circuit 27 is sent to a condenser after lubricating oil is separated by an oil separator 28. The lubricating oil separated from the refrigerant gas is supplied to the shaft seal chamber 29 from the supply passage 33 via the external pipe 35. Then, the lubricating oil overflowing from the shaft seal chamber 29 is sent from the discharge passage 34 to the suction side pipe 27b via the external pipe 36.

This embodiment has the following effects. (1) The shaft seal chamber 29 is isolated from the crank chamber 12a by the seal member 32. Therefore, the crank chamber 12
When the pressure in the crank chamber 12a is changed to change the inclination angle of the swash plate 18, the pressure in the crank chamber 12a can be easily adjusted to a target pressure. The inclination angle of the swash plate 18 can be controlled accurately and smoothly.

(2) The shaft seal chamber 29 is sealed by the seal mechanism and the seal member 32 and the oil separator 2
The lubricating oil separated at 8 is always supplied to the shaft seal chamber 29. Accordingly, since the lubricating oil is reliably supplied to the sliding portions of the first seal mechanism 30 and the second seal mechanism 31 to improve lubrication, the life of the seal mechanism is extended.

(3) The lubricating oil is not supplied to the shaft seal chamber 29 in a state where the lubricating oil is dispersed in a mist state in the refrigerant gas. It is supplied to the chamber 29. Therefore, the supply amount of the lubricating oil to the shaft seal chamber 29 increases, and the lubrication of the seal mechanism and the like is performed well.

(4) The shaft seal chamber 29 is isolated from the crank chamber 12a by the seal member 32, and the pressure in the shaft seal chamber 29 is lower than that in the crank chamber 12a. Sealing mechanism 2
1 reduces the burden and extends the life. Further, the refrigerant gas in the crank chamber 12a having a relatively high temperature is supplied to the shaft seal chamber 29.
Therefore, the temperature rise of the shaft seal chamber 29 is suppressed, and the durability of the seal mechanism is improved.

(5) Since the outlet 29b is located above the axis of the rotary shaft 14, the lubricating oil stays in the shaft seal chamber 29, and the rotary shaft 14 is always immersed in the lubricating oil. There is no shortage of lubricating oil supply to the sliding portions of the mechanism 30 and the second seal mechanism 31, and the durability is further improved.

(6) The seal member 32 does not require a complete seal, so that a simple and inexpensive seal member can be used. (7) The refrigerant pressure is higher than the pressure of the refrigerant using Freon by 10
In a compressor using carbon dioxide as a refrigerant, the pressure of which is twice or more, the pressure reduction of the shaft seal chamber 29 by the seal member 32 is particularly effective.

(8) The shaft seal chamber 29 is connected to the oil separator 28 and the external pipes 35 and 36 to the suction side pipe 27b.
, The configuration of the lubricating oil circulation passage can be simplified.

(9) Since the oil separator 28 is provided outside the compressor, replacement is easy. (Second Embodiment) Next, a second embodiment will be described with reference to FIG. In this embodiment, the oil separator 28
Is greatly different from the above-described embodiment in that it is disposed in the housing. The same parts as those of the above-described embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The oil separator 28 is provided in the rear housing 1
The oil separator 28 is disclosed in Japanese Patent Application Laid-Open No. 10-281060, and another type of oil separator is used. The oil separator 28 is also configured so that lubricating oil is separated from the refrigerant gas while the refrigerant gas turns around the outer circumference of the separation cylinder 28a. The refrigerant gas from which the lubricating oil has been separated by the oil separator 28 is discharged into the discharge chamber 13b.

The bottom of the oil separator 28 and the inlet 29 a of the shaft seal chamber 29 are connected via a passage 37 and a supply passage 33 formed in the rear housing 13, the cylinder block 11 and the front housing 12. Outlet 29b of shaft seal chamber 29 and suction chamber 13a
Are connected via a passage 38 and a discharge passage 34 formed in the rear housing 13, the cylinder block 11, and the front housing 12.

Therefore, this embodiment has the following effects in addition to the effects (1) to (7) of the above embodiment. (10) The oil separator 28 (oil separating portion) is built in the rear housing 13 and the oil separator 2
The lubricating oil separated in 8 is circulated through passages 37, 38 formed in the wall of the housing. Therefore, the compressor is compact with no additional parts outside, and can be easily stored in the vehicle.

(Third Embodiment) Next, a third embodiment will be described with reference to FIG. This embodiment differs from the previous embodiments in that the lubricating oil is not separated from the refrigerant gas, and the refrigerant gas in the suction pressure region is introduced into the shaft seal chamber 29 and then returned to the suction pressure region again. Is different.

In this embodiment, the suction side pipe 27b serving as a refrigerant inflow path to the suction chamber 13a of the external refrigerant circuit 27
The supply external pipe 35 is branched from the
It is connected to. Further, the downstream side of the branch of the external pipe 35 and the discharge passage 34 are connected by an external pipe 36. Therefore, this embodiment has the following effects in addition to the effects (1), (4), (6), and (7) of the above-described embodiment.

(11) Since the refrigerant in the suction pressure region is circulated through the shaft seal chamber 29, lubrication of the seal mechanism and the like is favorably performed by the mist-like lubricating oil in the refrigerant gas. Further, since a low-temperature refrigerant constantly circulates in the shaft seal chamber 29, it is effective in reducing the heat generation of the seal mechanism, and the durability of the seal mechanism is improved.

(Fourth Embodiment) Next, a fourth embodiment will be described with reference to FIG. This embodiment is significantly different from the first and second embodiments in that an accumulator is provided in an external refrigerant circuit 27 instead of the oil separator 28 as an oil separating section.

The accumulator 39 is provided in the middle of the suction pipe 27b of the external refrigerant circuit 27. The accumulator 39 serves to prevent the liquid refrigerant from being supplied to the suction chamber 13a, and separates the refrigerant gas and the liquid refrigerant.
When the refrigerant gas and the liquid refrigerant are separated, the lubricating oil is also separated from the refrigerant gas, and is separated from the liquid refrigerant and accumulates at the bottom of the accumulator 39. Then, a part of the lubricating oil is mixed with the refrigerant gas and supplied to the suction chamber 13a. The bottom of the accumulator 39 is connected to a supply passage 33 through an external pipe 35.
It is connected to. The discharge passage 34 is connected to the suction-side pipe 27b via an external pipe 36.

Therefore, this embodiment has the following effects in addition to the same effects as (1) to (9) of the first embodiment. (12) Since the lubricating oil separated by the accumulator 39 has a low temperature, the lubricating oil separated by the oil separator 28 can be supplied at a lower temperature than the lubricating oil supplied to the shaft seal chamber 29. The effect of lowering the temperature of the sliding portion of the chamber 29 is increased, and the durability of the sealing mechanism and the like is further improved.

(Fifth Embodiment) Next, a fifth embodiment will be described with reference to FIG. This embodiment is the same as the third embodiment in that the refrigerant gas is circulated between the suction pressure region and the shaft seal chamber 29, but a part of the refrigerant gas circulation path is formed on the rotating shaft 14. Is different.

As shown in FIG. 5, the suction chamber 13a is formed on the center side of the rear housing 13, and the discharge chamber 13b is formed on the outside. The second end of the rotating shaft 14 is inserted into the housing hole 40 formed in the cylinder block 11. The accommodation hole 40 and the suction chamber 13a communicate with each other through a passage 41 formed in the partition plate 22 and the like. A seal member 42 is provided between the peripheral surface of the housing hole 40 and the peripheral surface of the rotating shaft 14. The rotary shaft 14 is formed with a communication hole 43 that connects the housing hole 40 and the shaft seal chamber 29. The opening of the communication hole 43 on the shaft seal chamber 29 side serves as an inlet 29 a of the shaft seal chamber 29. In addition, a lip seal 44 is provided as a seal mechanism. In this embodiment, a part of the suction refrigerant is introduced from the suction chamber 13a into the shaft seal chamber 29 through the communication hole 43, and is returned to the suction chamber 13a through the passage 38 in the outer wall of the compressor. Therefore, since the suction refrigerant can be circulated in the compressor, no external piping is required and the size can be reduced.

The embodiment is not limited to the above, and may be, for example, as follows. ○ A material other than the C-ring is used as the seal member 32. For example, an annular thin plate made of polytetrafluoroethylene (PTFE) as shown in FIG. 6 (a), an oil seal as shown in FIG. 6 (b), or as shown in FIG. 6 (c) You may use a simple corner ring etc. Similarly, a C-ring, a square ring, an oil seal, or the like may be used for the seal member 42.

In the embodiments other than the fifth embodiment, a lip-type seal may be used as the seal mechanism. In the first, third and fourth embodiments, instead of the external pipe 36, a passage 38 is formed in the outer wall of the compressor to return the refrigerant or the lubricating oil to the suction chamber 13a.
Also, when the external piping 36 is used, the suction side piping 27
It may be connected directly to the suction chamber 13a without being connected to b.

The outlet 29b of the shaft seal chamber 29 does not have to be above the shaft seal chamber 29. But,
If the outlet 29b is above the axis of the rotating shaft 14,
Lubricating oil stays in the shaft seal chamber 29, and there is no shortage of lubricating oil supply to the sliding portions of the first seal mechanism 30 and the second seal mechanism 31, thereby further improving durability.

The seal member 32 may be provided closer to the crank chamber 12a than the radial bearing 15. In this case, since the radial bearing 15 is arranged in the shaft seal chamber 29, the radial bearing 15 is well lubricated.

適用 Applied to a fixed capacity compressor. Instead of the configuration in which the cam plate (swash plate 18) rotates integrally with the rotary shaft 14, the present invention may be applied to a wobble type compressor in which the cam plate is supported so as to be rotatable relative to the rotary shaft and swings. .

The technical ideas other than those described in the claims grasped from each of the above embodiments will be described below. (1) In the invention according to any one of claims 1 to 5, the outlet of the shaft seal chamber is provided so as to be located above the axis of the rotation shaft.

(2) In the invention described in claim 1 or 2, a part of a passage communicating the shaft seal chamber and the suction pressure region is formed in the rotating shaft.

[0060]

As described in detail above, claims 1 to 5 are provided.
According to the invention described in (1), in the variable displacement compressor having the single-headed piston, the inclination angle of the cam plate can be controlled accurately and smoothly, and the seal mechanism (shaft sealing device) can be satisfactorily lubricated.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an entire compressor according to a first embodiment.

FIG. 2 is a side sectional view of the entire compressor showing a second embodiment.

FIG. 3 is a side sectional view of the entire compressor showing a third embodiment.

FIG. 4 is a side sectional view of the entire compressor showing a fourth embodiment.

FIG. 5 is a side sectional view of the entire compressor showing a fifth embodiment.

FIG. 6 is a schematic sectional view of a seal member according to another embodiment.

FIG. 7 is a side sectional view of the entire compressor according to the related art.

[Explanation of symbols]

11 ... Cylinder block constituting the housing, 12 ...
Similarly, a front housing, 13 ... Rear housing, 11a ... Cylinder bore, 12a ... Crankcase, 13
a ... suction chamber, 13b ... discharge chamber, 14 ... rotating shaft, 17a ...
Support arm constituting tilt control means, 17b Guide hole, 19 Guide pin, 25 Control valve, 18 Swash plate as cam plate, 20 Piston, 27 External refrigerant circuit, 27b Suction passage , An oil separator as an oil separating portion, 29, a shaft seal chamber, 30 a first seal mechanism constituting a seal mechanism, 31 a second seal mechanism, 32 a seal member, 35, 36 ... external piping, 39 ...
Accumulator as oil separation unit.

Claims (5)

[Claims] A housing provided with a suction chamber, a discharge chamber and a crank chamber; a rotation shaft rotatably supported by the housing such that a first end protrudes from the housing; and a rotation shaft of the housing. A shaft seal chamber provided on the protruding side of the shaft seal chamber; a seal mechanism provided in the shaft seal chamber for sealing between the shaft seal chamber and the atmosphere; and a reciprocally movable cylinder bore formed in the housing. A compressor comprising: a housed single-headed piston; and a cam plate housed in the crank chamber and operatively connected to the piston to convert a rotational movement of the rotating shaft into a reciprocating movement of the piston. In addition to providing a sealing member for sealing the shaft seal chamber and the crank chamber side, an inlet and a seal are provided to the shaft seal chamber. A compressor provided with an inlet and an outlet, introducing lubricating oil separated from the refrigerant gas or refrigerant gas in a suction pressure state from the inlet, and communicating the outlet with a suction pressure region. 2. The cam plate is supported with respect to the rotation shaft so that the inclination angle can be changed, and the compressor changes the inclination angle of the cam plate by controlling the pressure of the crank chamber to change the inclination angle of the piston. The compressor according to claim 1, further comprising an inclination control means for changing a stroke. 3. The compressor according to claim 1, wherein the outlet is connected to a suction passage by an external pipe. 4. The compressor according to claim 1, further comprising an oil separating section for separating lubricating oil from the refrigerant gas, wherein the lubricating oil separated by the oil separating section is introduced into the shaft seal chamber from the inlet. Item 4. The compressor according to any one of items 3 to 6. 5. The compressor according to claim 4, wherein said oil separation section is an accumulator provided in an external refrigerant circuit and separating liquid refrigerant and refrigerant gas.