JPH09209927A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate processing of a drive shaft, and achieve effective lubrication to peripheral mechanisms by forming axially extended linear grooves in an outer circumferential surface of the drive shaft. SOLUTION: Plural linear grooves 31 are formed in an outer circumferential surface of a drive shaft 17 to be parallel in axial line directions at a specified angular interval. In manufacturing this drive shaft 17 by cold forging, the grooves 31 are simultaneously formed. In addition, each radial bearing 18 is composed of a tubular plane bearing provided to an inner circumferential surface of a cylinder block 11. The groove 31 is formed to be extended to correspond to an inner circumferential surface of the radial bearing 18. In addition, the groove 31 is extended to correspond to an inner circumferential surface of a boss part 24a of a swash plate 24 as well. A front chamber and a back chamber of crank chambers 23 parted by the swash plate 24 are thus communicated with each other. In addition, the groove 31 is extended to a position where it corresponds to a lip seal 19. Peripheral mechanisms can thus be lubricated including a shaft support part of the drive shaft 17 through the grooves 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and more particularly to a structure for lubricating a drive shaft peripheral mechanism.

[0002]

2. Description of the Related Art Generally, in a compressor, a drive shaft is rotatably inserted and supported at the center of a housing. A plurality of cylinder bores are formed at predetermined intervals on the same circumference in a cylinder block forming a part of the housing. A piston is reciprocally accommodated in the cylinder bore. On the drive shaft,
A swash plate as a cam plate is fixed, and the piston is reciprocated through the swash plate as the drive shaft rotates.

In this type of compressor, it is particularly necessary to supply lubricating oil to the shaft support of the drive shaft for the cylinder block to lubricate the shaft support. Therefore, for example, in Japanese Patent Laid-Open No. 3-47488, a spiral groove is formed on the outer peripheral surface of the drive shaft from its end, and the lubricating oil dispersed in the refrigerant gas in the form of mist passes through the spiral groove. A compressor configured to be supplied to the shaft support has been proposed.

[0004]

However, in the compressor described in the above publication, it is necessary to form a spiral groove on the outer peripheral surface of the drive shaft, so that the machining is troublesome and the manufacturing cost is high. was there.

Further, in the single-head piston type variable displacement compressor, the pressure in the discharge pressure region is introduced into the crank chamber as needed, and the inclination angle of the swash plate is changed by the differential pressure acting between the two end faces of the piston. The discharge capacity can be changed. Therefore, it is necessary to accurately control the pressure in the crank chamber, and the crank chamber does not form a part of the refrigerant gas suction passage. Then, the lubricating oil is supplied to the crank chamber only when it is accompanied by the blow-by gas accompanying the compression operation of the piston and the refrigerant gas introduced from the discharge pressure region for changing the discharge capacity.
Therefore, the amount of lubricating oil in the crank chamber tends to be insufficient.
In particular, the thrust bearing, which forms a pivotal support for supporting the thrust load on the rear end side of the drive shaft, has a problem that the opening area of the passage from the crank chamber leading to the thrust bearing is small and the lubrication condition is extremely severe. there were.

The present invention has been made by paying attention to the problems existing in such conventional techniques. It is an object of the present invention to provide a compressor capable of easily manufacturing a drive shaft, reducing the manufacturing cost, and effectively lubricating a peripheral mechanism including a shaft support portion of the drive shaft. .

[0007]

In order to achieve the above object, in the invention of the compressor according to claim 1, a drive shaft is rotatably inserted and supported at the center of the housing, and a part of the housing is attached. A compressor in which a piston is reciprocally housed in a cylinder bore of a cylinder block, and a cam plate for reciprocating the piston is fixed on the drive shaft, wherein an axial line is provided on an outer peripheral surface of the drive shaft. A linear groove extending in the direction is formed.

According to a second aspect of the present invention, in the compressor according to the first aspect, the drive shaft is rotatably supported by the housing via a pair of radial bearings, and the groove corresponds to each radial bearing. It is formed so as to extend to the part to be opened.

According to a third aspect of the present invention, in the compressor according to the second aspect, the radial bearing is a plain bearing. According to a fourth aspect of the invention, in the compressor according to any of the first to third aspects, the groove is formed so as to extend to a fastening portion of the cam plate with respect to the drive shaft.

[0010] According to the fifth aspect of the present invention, the first to fourth aspects are provided.
In the compressor according to any one of items 1 to 3, the drive shaft is manufactured by forging. According to a sixth aspect of the present invention, in the compressor according to any of the first to fifth aspects, a lip is provided between the outer peripheral surface of the front end portion of the drive shaft and the inner peripheral surface of the housing facing the outer peripheral surface. A seal is provided and the groove is formed so as to extend to the vicinity of the lip seal.

Therefore, during the operation of the compressor according to the first aspect, the lubricating oil dispersed in the refrigerant gas in the form of mist in accordance with the rotation of the drive shaft is linearly extended on the drive shaft in the axial direction. Through the groove of the drive shaft to the peripheral mechanism including the shaft support of the drive shaft. For this reason, the groove on the drive shaft can be easily processed, the manufacturing cost can be reduced, and the peripheral mechanism including the shaft supporting portion of the drive shaft can be effectively lubricated. Moreover, the weight of the drive shaft is reduced by forming the groove in the drive shaft.

In the compressor according to the second aspect, the lubricating oil is sufficiently supplied to the pair of radial bearings supporting the drive shaft through the groove on the drive shaft. Therefore, each radial bearing can be effectively lubricated.

In the compressor according to the third aspect, the radial bearing is composed of a plain bearing. Therefore, the bearing structure can be simplified.
In the compressor according to the fourth aspect, the groove on the drive shaft extends to the fastening portion of the cam plate with respect to the drive shaft. Therefore, even if the crank chamber is divided into two chambers by the cam plate, the refrigerant gas containing lubricating oil can be smoothly circulated between the two chambers via the groove on the drive shaft. Then, the lubricating oil can be effectively supplied to each sliding portion in the crank chamber. Further, there is almost no risk of insufficient lubrication of only one of the radial bearings at both ends of the drive shaft, and stable relative rotation of the drive shaft with respect to the housing is ensured.

In the compressor according to the fifth aspect, the drive shaft is manufactured by forging. Therefore, when the drive shaft is manufactured, a linear groove extending in the axial direction can be simultaneously formed on the outer peripheral surface of the drive shaft, and the drive shaft can be manufactured easily and the cost can be reduced.

In the compressor according to the sixth aspect, the groove on the drive shaft is disposed between the outer peripheral surface of the front end portion of the drive shaft and the inner peripheral surface of the housing facing the outer peripheral surface. It extends close to the seal. For this reason,
Lubricating oil can be supplied also to the lip seal, and the lip seal can be effectively lubricated and cooled. Then, the durability of the lip seal can be improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) A first embodiment in which the present invention is embodied in a double-headed piston type compressor will be described in detail below with reference to FIGS. 1 and 2.

As shown in FIG. 1, a pair of cylinder blocks 11 forming a part of the housing are joined to each other at opposite end edges. The front housing 12, which also forms a part of the housing, is a cylinder block 1
1 is joined to the front end face via a valve plate 13. A rear housing 14, which also forms a part of the housing, is joined to the rear end surface of the cylinder block 11 via a valve plate 13. The cylinder block 11, the front housing 12, and the rear housing 14 are made of aluminum or aluminum alloy.

A plurality of through bolts 15 are screwed into the screw holes 16 of the rear housing 14 from the front housing 12 through both cylinder blocks 11 and the valve plate 13. The front housing 12 and the rear housing 14 are fastened and fixed to both end surfaces of the cylinder block 11 by these through bolts 15 to form a compressor housing.

The drive shaft 17 is rotatably supported at the center of the cylinder block 11 and the front housing 12 via a pair of radial bearings 18. A lip seal 19 is interposed between the outer peripheral surface of the front end portion of the drive shaft 17 and the inner peripheral surface of the front housing 12 facing the outer peripheral surface. The drive shaft 17 is operatively connected to an external drive source such as an engine (not shown) via a clutch (not shown), and is rotationally driven by the external drive source.

A plurality of cylinder bores 20 are provided so that each cylinder block 1 extends in parallel with the drive shaft 17.
1 are formed so as to penetrate between the two end portions on the same circumference at predetermined intervals. The double-headed piston 21 is attached to each cylinder bore 20.
A compression chamber 22 is formed in each of the cylinder bores 20 between the valve plate 13 and the both ends thereof so as to be reciprocally fitted and supported therein.

The crank chamber 23 is defined in the middle of the two cylinder blocks 11. In the crank chamber 23, a swash plate 24 as a cam plate is fitted and fixed to the drive shaft 17 at a boss portion 24a as a fastening portion thereof. The piston 21 is anchored to the outer peripheral portion of the swash plate 24 via a pair of hemispherical shoes 25. When the drive shaft 17 is rotated, the piston 21 reciprocates through the swash plate 24. The pair of thrust bearings 26 are interposed between both end surfaces of the boss portion 24 a of the swash plate 24 and the inner end surface of each cylinder block 11, and the swash plate 24 is interposed via the thrust bearings 26.
Are sandwiched and held between the two cylinder blocks 11.

The suction chamber 27 corresponds to the front housing 1
2 and an outer peripheral portion of the rear housing 14 are formed in an annular shape and are communicated with the crank chamber 23 via suction passages 11a formed in both the cylinder blocks 11. The crank chamber 23 is connected to the external refrigerant circuit via a suction port (not shown). The discharge chamber 28 is formed in an annular shape in the inner peripheral portions of the front housing 12 and the rear housing 14, and is connected to an external refrigerant circuit via a discharge muffler and a discharge port (not shown).

The suction valve mechanism 29 includes the above-mentioned valve plates 1
3, the piston 21 is reciprocally moved by the suction valve mechanism 29 from the suction chambers 27 to the cylinder bores 20.
Refrigerant gas is drawn into the compression chamber 22. Discharge valve mechanism 3
0 is formed on each valve plate 13, and when the piston 21 reciprocates, the discharge valve mechanism 30 discharges the refrigerant gas compressed in the compression chamber 22 of each cylinder bore 20 to both discharge chambers 28.

Next, the lubrication structure of the peripheral mechanism of the drive shaft 17 will be described in detail. As shown in FIGS. 1 and 2, the plurality of linear grooves 31 are formed on the outer peripheral surface of the drive shaft 17 at predetermined angular intervals and extend parallel to the axial direction. And in this embodiment, the drive shaft 1
7 is manufactured by cold forging, and a plurality of grooves 31 are simultaneously formed on the outer peripheral surface during the manufacturing.

Further, each of the radial bearings 18 is
The drive shaft 17 is composed of a circular tubular plain bearing interposed between the outer peripheral surface of the drive shaft 17 and the inner peripheral surface of the cylinder block 11 facing the outer peripheral surface. The groove 31 on the drive shaft 17 is formed so as to extend so as to correspond to the inner peripheral surfaces of the radial bearings 18. Further, the groove 31 on the drive shaft 17 is
4 is formed so as to correspond to the inner peripheral surface of the four boss portions 24a. Therefore, even if the swash plate 24 divides the crank chamber 23 into the front and rear chambers 23a and 23b, the chambers 23a and 23b are communicated with each other through the grooves 31. The groove 31 on the drive shaft 17 is
The extension is formed near the portion corresponding to the lip seal 19.

Next, the operation of the compressor configured as described above will be described. In this compressor, when the drive shaft 17 is rotated by an external drive source such as an engine (not shown), each piston 21 is reciprocated in the cylinder bore 20 via the swash plate 24. As a result, the refrigerant gas flows from the external refrigerant circuit (not shown) through the suction hole into the crank chamber 2
3, the refrigerant gas in the crank chamber 23 is supplied to both suction chambers 27 via the suction passage 11a. Both suction chambers 2
The refrigerant gas in 7 is sucked into the compression chamber 22 of each cylinder bore 20 via the suction valve mechanism 29, and is compressed in the compression chamber 22. The compressed refrigerant gas is discharged from the compression chamber 22 of each cylinder bore 20 to both discharge chambers 28 via the discharge valve mechanism 30. The high-pressure compressed refrigerant gas discharged into both discharge chambers 28 is supplied to the external refrigerant circuit via a discharge passage, a discharge muffler, and a discharge hole (not shown).

During operation of this compressor, the drive shaft 1
With the rotation of 7, the lubricating oil dispersed in the refrigerant gas in the form of mist is supplied to the sliding portions such as the radial bearings 18 and the lip seal 19 through the grooves 31 on the drive shaft 17. Therefore, both radial bearings 18 and lip seals 19 can be effectively lubricated.

The effects expected from the above embodiment will be described below. (A) In this compressor, a linear groove 31 extending in the axial direction is formed on the outer peripheral surface of the drive shaft 17. Therefore, unlike the conventional configuration in which the spiral groove is formed in the drive shaft, the drive shaft 17 can be easily processed and the manufacturing cost can be reduced. Further, by forming the plurality of grooves 31, the weight of the drive shaft 17 can be reduced, which in turn can reduce the weight of the compressor.

(B) In this compressor, the radial bearing 18 that supports the drive shaft 17 is composed of a plain bearing. Also, the drive shaft 1
The groove 31 formed on the 7 is formed on each radial bearing 18
Is formed so as to extend to a portion corresponding to. Therefore, although the bearing structure can be simplified,
Lubricating oil can be sufficiently supplied to each radial bearing 18 through the groove 31, and each radial bearing 18 is effectively lubricated. Therefore, the drive shaft 17
The wear of the shaft supporting portion is reduced, and a problem such as seizure in the shaft supporting portion is less likely to occur.

(C) In this compressor, the swash plate 24
The crank chamber 23 is divided into two front and rear chambers 23a and 23b. Here, the groove 31 on the drive shaft 17
Are extended along the inner peripheral surface of the boss portion 24 a of the swash plate 24. Therefore, the refrigerant gas containing the lubricating oil smoothly flows between the two chambers 23a and 23b through the groove 31 on the drive shaft 17 without being obstructed by the swash plate 24. Therefore, the lubricating oil can be effectively supplied to each sliding portion in the crank chamber 23. Also, the drive shaft 1
There is almost no risk of insufficient lubrication of only one of the radial bearings 18 at both ends of 7. Therefore, stable relative rotation of the drive shaft 17 with respect to both cylinder blocks 11 is ensured.

(D) In this compressor, the drive shaft 17 is manufactured by forging. Therefore, when manufacturing the drive shaft 17, the groove 31 extending in the axial direction can be simultaneously formed on the outer peripheral surface thereof. Therefore,
The drive shaft 17 can be manufactured easily and the cost can be reduced.

(E) In this compressor, the groove 31 on the drive shaft 17 extends to the vicinity of the portion corresponding to the lip seal 19 provided on the outer peripheral surface of the front end portion of the drive shaft 17. Therefore, the lubricating oil can be supplied also to the lip seal 19 and the lip seal 1
9 can be effectively lubricated and cooled. Therefore, the durability of the lip seal 19 can be improved, and the leakage prevention effect of the refrigerant gas in the crank chamber 23 can be secured for a longer period of time.

(Second Embodiment) Next, a second embodiment in which the present invention is embodied in a single-head piston type variable displacement compressor will be described with reference to FIG.

In the second embodiment, the drive shaft 17 is formed in the center of the cylinder block 11 and the front housing 12, and the radial bearing 33 is composed of a pair of rolling bearings having an outer race, an inner race and a plurality of rollers. It is rotatably supported via. A thrust bearing 3 for supporting the load in the thrust direction of the drive shaft 17 is provided at the rear end of the drive shaft 17.
4 are joined and arranged. This thrust bearing 34
Are supported by the valve plate 13 via springs 35.

Inside the front housing 12,
A crank chamber 23 is formed. This crank chamber 23
Inside the rotary support 36 is a boss portion 3 as a fastening portion thereof.
6a, it is supported on the drive shaft 17 so as to be integrally rotatable. A hinge mechanism 37 is attached to the rotary support 36.
The swash plate 38 can be tilted via the
It is supported so that it can rotate synchronously. A single-headed piston 39, which is reciprocally inserted into the cylinder bore 20 of the cylinder block 11 via a pair of hemispherical shoes 25, is anchored to the outer peripheral portion of the swash plate 38. That is,
The rotary support 36, the hinge mechanism 37, and the swash plate 38 form a cam plate.

The crank chamber 23 is communicated with a discharge chamber 28 in the rear housing 14 which constitutes a discharge pressure region via an air supply passage 40. A capacity control valve 41 for opening and closing the air supply passage 40 is disposed in the middle of the air supply passage 40. Then, the opening of the capacity control valve 41 is changed as necessary, the high-pressure refrigerant gas in the discharge chamber 28 is supplied into the crank chamber 23, and the pressure in the crank chamber 23 is controlled. Further, the pressure release passage for returning the refrigerant gas corresponding to the pressure higher than necessary in the crank chamber 23 to the suction chamber 27 includes the radial bearing 33 and the thrust bearing 3.
4, a bearing chamber 42 in the cylinder block 11, a valve plate 13, and a passage 43 formed in the rear housing 14. And the crank chamber 23
The tilt angle of the swash plate 38 is changed in accordance with the pressure difference between the pressure and the suction pressure to control the discharge capacity. In the compressor of the second embodiment, it is necessary to accurately control the pressure in the crank chamber 23, and the crank chamber 23 does not form part of the suction passage for the refrigerant gas from the external refrigerant circuit.

In the second embodiment as well, similar to the first embodiment described above, a plurality of linear grooves 31 are formed on the outer peripheral surface of the drive shaft 17 at predetermined angular intervals and extend parallel to the axial direction. ing. And when the compressor is running,
Lubricating oil dispersed in the refrigerant gas in the crank chamber 23 in the form of mist passes through these grooves 31 and the radial bearing 33, thrust bearing 34 and lip seal 19
It is supplied to.

Therefore, also in the second embodiment, as in the first embodiment described above, the drive shaft 17 can be easily processed, the manufacturing cost can be reduced, and the shaft support portion of the drive shaft 17 is included. The peripheral mechanism can be effectively lubricated.

Conventionally, for example, in order to lubricate the thrust bearing 34 at the rear end of the drive shaft 17 in which the lubrication condition is particularly severe among the shaft support portions, for example, the cylinder block 1 is used.
1, an oil supply mechanism such as an oil supply hole opened from the bearing chamber 42 into the crank chamber 23 is separately formed. However, this second
According to the embodiment, the thrust bearing 34 can be sufficiently lubricated without separately forming such an oil supply mechanism, and the structure can be simplified.

The present invention can be embodied with the following modifications. (1) In the compressor of the first embodiment, the radial bearing 18 is omitted, and the drive shaft 17 is directly rotatably supported in the support hole of the cylinder block 11 or the front housing 12.

(2) In the compressor of the first embodiment, the radial bearing 1 that supports the drive shaft 17
8 is composed of a rolling bearing having an outer race, an inner race and a plurality of rollers.

With this structure, it is possible to prevent the roller of the rolling bearing from falling into the groove 31 on the drive shaft 17. (3) In the compressors according to the first and second embodiments,
A radial bearing 18 for supporting the drive shaft 17,
33 is composed of a rolling bearing having an outer race and a plurality of rollers, and each roller is provided with a groove 31 on the drive shaft 17.
It should be rotatably housed in the room.

(4) In the compressor of the first embodiment, a key is inserted into the groove 31 on the drive shaft 17 to fix the boss portion 24a of the swash plate 24 serving as the cam plate to the drive shaft 17 while preventing it from rotating. To configure.

Next, a technical idea grasped from the embodiment will be described. (1) A discharge bearing is provided at a rear end of the drive shaft so as to support a thrust load of the drive shaft, and the discharge capacity is changed by changing an inclination angle of the cam plate. 2, 5,
The compressor according to any one of 6.

With such a structure, in the variable displacement compressor in which the thrust bearing is joined and arranged at the rear end of the drive shaft, the thrust bearing under extremely severe lubrication conditions is sufficiently lubricated through the groove on the drive shaft. Can be supplied. Therefore, it is not necessary to separately provide an oil supply mechanism, and the structure can be simplified.

[0046]

Since the present invention is constructed as described above, it has the following effects. According to the first aspect of the present invention, the groove on the drive shaft can be easily machined, the manufacturing cost can be reduced, and the peripheral mechanism including the shaft supporting portion of the drive shaft can be effectively lubricated. In addition, the drive shaft can be reduced in weight, which in turn leads to a reduction in the weight of the compressor.

According to the second aspect of the invention, the lubricating oil can be sufficiently supplied to the radial bearing through the groove on the drive shaft, and the radial bearing can be effectively lubricated.

According to the third aspect of the present invention, the radial bearing is composed of a plain bearing, so that the bearing structure can be simplified. According to the invention described in claim 4, even if the crank chamber is divided into two chambers by the cam plate, the crank chamber is divided between the two chambers via the groove on the drive shaft,
The refrigerant gas containing the lubricating oil can be smoothly circulated, and the lubricating oil can be effectively supplied to each sliding portion in the crank chamber. Further, there is almost no risk of insufficient lubrication of only one of the radial bearings at both ends of the drive shaft, and stable relative rotation of the drive shaft with respect to the housing is ensured.

According to the invention described in claim 5, when the drive shaft is manufactured by forging, a linear groove extending in the axial direction can be simultaneously formed on the outer peripheral surface of the drive shaft, and the drive shaft can be manufactured easily. Therefore, the cost can be reduced.

According to the sixth aspect of the present invention, the lubricating oil can be supplied also to the lip seal arranged on the outer periphery of the end portion of the drive shaft, and the lip seal can be effectively lubricated and cooled. be able to. The durability of the lip seal can be improved, and the effect of preventing refrigerant gas from leaking out of the crank chamber can be secured for a longer period of time.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a compressor of a first embodiment.

FIG. 2 is a partially enlarged sectional view taken along line 2-2 of FIG.

FIG. 3 is a cross-sectional view showing a compressor of a second embodiment.

[Explanation of symbols]

11 ... Cylinder block forming a part of housing
12 ... Front housing which constitutes a part of housing, 14 ... Rear housing which constitutes a part of housing, 17 ... Drive shaft, 18, 33 ... Radial bearing, 19 ... Lip seal, 20 ... Cylinder bore, 2
1, 39 ... Pistons, 23 ... Crank chambers, 24 ... Swash plates as cam plates, 24a, 36a ... Boss portions as fastening parts, 31 ... Grooves, 36 ... Rotation supports that form a part of cam plates, 37 ... a hinge mechanism forming a part of the cam plate, 38 a swash plate forming a part of the cam plate.

Continuation of the front page (72) Inventor Suzuko 2-chome Toyota-cho, Kariya city, Aichi prefecture Toyota Industries Corp.

Claims (6)

[Claims] 1. A drive shaft is rotatably inserted and supported in the center of a housing, a piston is reciprocally housed in a cylinder bore of a cylinder block forming a part of the housing, and a piston is provided on the drive shaft. In a compressor having a fixed cam plate for reciprocating, a compressor having a linear groove extending in the axial direction formed on the outer peripheral surface of the drive shaft. 2. The compressor according to claim 1, wherein the drive shaft is rotatably supported by the housing via a pair of radial bearings, and the groove extends to a portion corresponding to each radial bearing. 3. The compressor according to claim 2, wherein the radial bearing is a plain bearing. 4. The compressor according to claim 1, wherein the groove is formed so as to extend to a fastening portion of the cam plate with respect to the drive shaft. 5. The compressor according to claim 1, wherein the drive shaft is manufactured by forging. 6. A lip seal is provided between the outer peripheral surface of the front end portion of the drive shaft and the inner peripheral surface of the housing facing the outer peripheral surface, and the groove is formed to extend to the vicinity of the lip seal. The compressor according to any one of claims 1 to 5.