JPH0658250A - Rotary shaft supporting construction of swash plate type compressor - Google Patents

Abstract

PURPOSE:To provide a swash plate type compressor of which assembling work process is simple and application of preload can be stably controlled. CONSTITUTION:A swash plate 10 to reciprocate the double headed piston 15A in cylinder bores 13A, 14A is supported with a rotary shaft 7. The rotary shaft 7 is supported with valve plates 3, 4 through a pair of tapered roller bearings 8, 9. The outer rings 8a, 9a of the tapered roller bearings 8, 9 are slidably fitted into the supporting holes 3a, 4a. A preload applying spring 20 is provided between the presser projection 18a on a front housing 18 and the outer ring 8a so as to be flexibly deformed. The presser projection 19a on a rear housing 19 is brought in contact with the outer ring 9a. Rotary valves 27, 28 are supported with the rotary shaft 7 so as to enable to rotate in one body with the rotary shaft 7. Refrigerant gas in a swash plate chamber 11 is sucked into compression chambers Pa, Pb through the suction passages 29, 30 in the rotary valves 27, 28.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention accommodates double-headed pistons in a plurality of pairs of front and rear cylinder bores arranged around a rotary shaft, and the rotary movement of a swash plate supported by the rotary shaft is The present invention relates to a rotating shaft support structure in a swash plate compressor that converts reciprocating motion of a double-headed piston.

[0002]

2. Description of the Related Art A conventional swash plate compressor (e.g.
In Japanese Patent No. 92587), the refrigerant gas in the compression chamber is discharged into the discharge chamber by the forward movement of the double-headed piston, and the refrigerant gas in the suction chamber is sucked into the compression chamber by the backward movement of the double-headed piston. A plurality of double-headed pistons are used and housed in cylinder bores arranged at equal angular intervals around the rotary shaft. The compression chamber is connected to the discharge chamber via the discharge port, and is connected to the suction chamber via the suction port and the suction port. The discharge port is opened and closed by the discharge valve, and the refrigerant gas in the compression chamber is discharged to the discharge chamber while pushing the discharge valve away. The suction port is opened and closed by a suction valve, and the refrigerant gas in the suction chamber is sucked into the compression chamber while pushing the suction valve away.

[0003]

The rotation of the rotary shaft that supports the swash plate is supported by a pair of front and rear cylinder blocks via a pair of radial bearings. That is, the radial load on the rotary shaft is received by the cylinder block via the radial bearing. Further, the thrust load on the rotating shaft is received by the cylinder block via a pair of front and rear thrust bearer sandwiching the swash plate.

The thrust load on the rotary shaft fluctuates as shown by the curve C in FIG. That is, the maximum value Fmax of the thrust load with respect to the rotating shaft changes its direction alternately five times in the front-back direction of the swash plate. In this case, the swash plate compressor has five double-headed pistons. Although there is a thrust bearing between the cylinder block and the swash plate, the pair of races that sandwich the roller of the thrust bearing are flexibly deformed in advance. This flexural deformation is given in the joined state of the pair of front and rear cylinder blocks, and acts as a preload on the rotating shaft. This preload is set to exceed the maximum value of the thrust load. By such preload setting, rattling of the rotating shaft in the thrust direction is eliminated, and abnormal noise and abnormal vibration are suppressed.

However, the structure in which the radial load and the thrust load on the rotary shaft are received through the separate bearing members respectively complicates the assembly work process. It is an object of the present invention to provide a rotary shaft support structure in a swash plate compressor that can receive a radial load and a thrust load on a rotary shaft with a single bearing member and can apply an appropriate preload to the rotary shaft. To do.

[0006]

Therefore, according to the present invention,
A rotary shaft that supports the swash plate is rotatably supported by a pair of conical roller bearings, and a slidable fitting relationship is set between a support body that supports the outer ring of the conical roller bearings and the outer ring.
The spring force of the preloading spring for urging the thrust load in the conical roller bearing is applied to at least one outer ring of the conical roller bearing.

[0007]

The inner ring of the conical roller bearing is non-slideably fitted to the rotating shaft. The roller sandwiched between the inner ring and the outer ring is inclined with respect to the rotation axis, and the orbit of the roller is on a conical surface centered on the rotation axis. With such a configuration, both the thrust load and the radial load on the rotating shaft are received via the conical roller bearing. The spring force of the preloading spring acts on the outer ring from the small diameter side to the large diameter side of the conical surface. The outer ring is slidable with respect to its support, and the spring force of the preloading spring acts in the thrust direction on the rotating shaft via the outer ring, the roller, and the inner ring.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment embodying the present invention will now be described with reference to FIGS.
A description will be given based on FIG. As shown in FIG. 1, the pair of front and rear cylinder blocks 1 and 2 joined to each other are provided with accommodation holes 1a and 2a at the center thereof. Cylinder block 1, 2
The valve plates 3 and 4 are joined to the end face of the valve plate 3, and support holes 3a and 4a are formed through the valve plates 3 and 4, respectively. Annular positioning protrusions 3b and 4b are provided on the periphery of the support holes 3a and 4a, and the positioning protrusions 3b and 4b are provided.
Are fitted in the receiving holes 1a, 2a. Pins 5 and 6 are inserted into the valve plates 3 and 4 and the cylinder blocks 1 and 2, respectively, and the pins 5 and 6 prevent the valve plates 3 and 4 from rotating with respect to the cylinder blocks 1 and 2.

Support holes 3a, 4a of the valve plates 3, 4
A rotary shaft 7 is rotatably supported by conical roller bearings 8 and 9. Outer ring 8a of conical roller bearing 8,9,
9a is slidably fitted and supported in the housing holes 1a and 2a, and the inner rings 8b and 9b are stepped portions 7a and 7 on the rotary shaft 7.
It is fixed in contact with b. Outer rings 8a, 9a and inner ring 8
The rollers 8c and 9c sandwiched between b and 9b are inclined with respect to the rotation axis 7, and the orbits of the rollers 8c and 9c are on a conical surface. The large diameter sides of the conical surfaces, which are the orbits of the rollers 8c and 9c, face each other.

A swash plate 10 is fixedly supported on the rotary shaft 7. An inlet 12 is formed in each of the cylinder blocks 1 and 2 forming the swash plate chamber 11, and an external suction refrigerant gas pipe line (not shown) is connected to the inlet 12.

As shown in FIGS. 2 and 3, a plurality of cylinder bores 13, 1 are arranged at equidistant angular positions about the rotary shaft 7.
3A, 14 and 14A are formed. As shown in FIG. 1, a pair of front and rear cylinder bores 13, 14, 13A, 1
4A (5 pairs in this embodiment) have double-headed pistons 15 and 1
5A is housed so that it can reciprocate. Double-headed piston 1
Hemispherical shoes 16 and 17 are interposed between 5, 15A and the front and rear surfaces of the swash plate 10. Therefore, when the swash plate 10 rotates, the double-headed pistons 15 and 15A move back and forth in the cylinder bores 13, 14, 13A, and 14A.

A front housing 18 is joined to the end surface of the cylinder block 1, and a rear housing 19 is also joined to the end surface of the cylinder block 2. As shown in FIGS. 4 and 5, a plurality of pressing protrusions 18a and 19a are provided on the inner wall surfaces of both housings 18 and 19 so as to project therefrom.

An annular plate-shaped preloading spring 20 is interposed between the pressing protrusion 18a and the outer ring 8a of the conical roller bearing 8. The outer peripheral edge of the preload applying spring 20 is fitted into the pressing protrusion 18a. With this fitting configuration, the preload applying spring 20 is supported with respect to the front housing 18 so as not to be displaced. The end surface of the outer ring 8a of the conical roller bearing 8 projects from the end surface of the wall forming the support hole 3a of the valve plate 3, and the inner peripheral edge of the preloading spring 20 contacts the end surface of the outer ring 9a of the conical roller bearing 9. ing. The pressing protrusion 19a is the outer ring 9a of the conical roller bearing 9.
Is in contact with the end surface of.

The orbits of the rollers 8c and 9c of the conical roller bearings 8 and 9 are on the conical surface, and the large diameter sides of the conical surfaces, which are the orbits of the rollers 8c and 9c, face each other. Further, the inner rings 8b and 9b of the conical roller bearings 8 and 9 are the step portions 7 of the rotary shaft 7.
It is in contact with a and 7b. Therefore, the thrust load on the rotary shaft 7 from the front housing 18 side toward the rear housing 19 side is received by the rear housing 19 via the conical roller bearing 9. Also, the rear housing 19
The thrust load on the rotary shaft 7 from the side toward the front housing 18 is received by the front housing 18 via the conical roller bearing 8 and the preload applying spring 20.

The cylinder block 1, the valve plate 3 and the front housing 18 are fastened and fixed by bolts 21. The cylinder block 2, the valve plate 4, and the rear housing 19 are fastened and fixed by bolts 22. Tighten the bolt 21 with the ring race 2
0 is flexibly deformed, and this flexural deformation applies a preload to the rotating shaft 7 via the conical roller bearing 8.

A discharge chamber 2 is provided in both housings 18 and 19.
3, 24 are formed. Double-headed piston 15,15A
The compression chambers Pa and Pb defined by the cylinder bores 13, 14, 13A, and 14A are connected to the discharge chambers 23 and 24 via the discharge ports 3c and 4c on the valve plates 3 and 4, respectively. The discharge ports 3c and 4c are opened and closed by flapper valve type discharge valves 31 and 32. The opening degrees of the discharge valves 31 and 32 are regulated by the retainers 33 and 34. Discharge valve 3
1, 32 and retainers 33, 34 are fastened and fixed on the valve plates 3, 4 by bolts 35, 36. The discharge chamber 23 communicates with an external discharge refrigerant gas pipe line (not shown) via a discharge passage 25.

Reference numeral 26 is a discharge chamber 23 along the peripheral surface of the rotary shaft 7.
This is a lip seal that prevents refrigerant gas from leaking from the compressor to the outside of the compressor. Rotary valves 27, 28 are supported on the stepped portions 7 a, 7 b on the rotary shaft 7. Rotary valve 2
A seal ring 39, 40 is provided between the rotary shaft 7 and the rotary shaft 7.
Is intervening. The rotary valves 27, 28 are housed in the housing holes 1a, 2a so as to be rotatable integrally with the rotary shaft 7. The discharge refrigerant gas pressure of the discharge chambers 23 and 24 acts on one end of the rotary valves 27 and 28, and the suction refrigerant gas pressure of the swash plate chamber 11 acts on the other end. That is,
The rotary valves 27 and 28 shut off the discharge pressure region and the suction pressure region.

Intake passages 29, 30 are formed in the rotary valves 27, 28. The inlets of the suction passages 29, 30 are open above the swash plate chamber 11, and the suction passages 29, 30 are
The outlet of is opened on the inner peripheral surface of the accommodation holes 1a and 2a.

As shown in FIG. 2, the cylinder bores 13, 13 are formed on the inner peripheral surface of the accommodation hole 1a for accommodating the rotary valve 27.
The same number of suction ports 1b as A are arranged and formed at equal angular intervals. Suction port 1b and cylinder bores 13, 13
It is always in one-to-one communication with A, and each suction port 1b is connected to the circulation region of the outlet of the suction passage 29.

Similarly, as shown in FIG. 3, the cylinder bore 1 is formed on the inner peripheral surface of the accommodation hole 2a for accommodating the rotary valve 28.
The same number of suction ports 2b as 4, 14A are formed in an array at equal angular intervals. Suction port 2b and cylinder bore 1
4, 14A are always in one-to-one communication with each other, and each suction port 2b is connected to the circulation region of the outlet of the suction passage 30.

In the state shown in FIGS. 1, 2 and 3, the double-headed piston 15A is at the top dead center position with respect to one cylinder bore 13A and at the bottom dead center position with respect to the other cylinder bore 14A. In such a piston arrangement state, the outlet 29b of the intake passage 29 is immediately before being connected to the intake port 1b of the cylinder bore 13A, and the outlet 3 of the intake passage 30 is located.
0b is immediately after connecting to the suction port 2b of the cylinder bore 14A. That is, when the double-headed piston 15A enters the intake stroke from the top dead center position to the bottom dead center position with respect to the cylinder bore 13A, the intake passage 29 is provided with the intake passage 29.
It communicates with the compression chamber Pa of A. By this communication, the swash plate chamber 11
The refrigerant gas in the cylinder bore 1 passes through the suction passage 29.
It is sucked into the compression chamber Pa of 3A. On the other hand, double-headed piston 1
When 5A enters the discharge stroke from the bottom dead center position to the top dead center position with respect to the cylinder bore 14A, the suction passage 30
Is cut off from communication with the compression chamber Pb of the cylinder bore 14A. Due to this disconnection of communication, the compression chamber P of the cylinder bore 14A
Refrigerant gas in b pushes discharge valve 3 and discharge port 4
It is discharged from c to the discharge chamber 24.

The suction and discharge of such a refrigerant gas are similarly performed in the compression chambers P of the other cylinder bores 13, 14. One end of the rotary shaft 7 projects outward from the front housing 18, and the other end projects into the discharge chamber 24 on the rear housing 19 side. A discharge passage 37 is formed at the center of the rotary shaft 7. The discharge passage 37 is the discharge chamber 24.
It is open to. Discharge chamber 2 on the front housing 18 side
At the peripheral surface portion of the rotary shaft 7 surrounded by
8 is formed, and the discharge chamber 23 and the discharge passage 37 are connected by the outlet 38. Therefore, the front and rear discharge chambers 23, 24 communicate with each other through the discharge passage 37, and the refrigerant gas in the discharge chamber 24 joins the discharge chamber 23 from the discharge passage 37.

The thrust load on the rotating shaft 7 varies as shown by the curve C in FIG. The plus side of the vertical axis is the thrust load from the front housing 18 side toward the rear housing 19 side. The minus side of the vertical axis is the thrust load from the rear housing 19 side toward the front housing 18 side. The straight lines L ₁ and L ₂ represent the preload given by the bending deformation of the preload applying spring 20. The preload (+ F ₀ ) represented by the straight line L ₁ opposes the thrust load from the rear housing 19 side toward the front housing 18 side. The preload (-F ₀ ) represented by the straight line L ₂ opposes the thrust load from the front housing 18 side toward the rear housing 19 side. Preload F ₀ is the maximum thrust load Fma
It is set to slightly exceed x. By setting the preload F _{0 in} this way, no gap is formed in the thrust direction between the step portion 7a on the rotating shaft 7 and the pressing protrusion 18a and between the step portion 7b and the pressing protrusion 19a. That is, the rotating shaft 7 does not rattle, and no abnormal noise or vibration occurs.

Such a preload is determined by the spring characteristics and the amount of flexural deformation of the preload applying spring 20. The amount of flexural deformation of the preload applying spring 20 depends on the assembly error of the cylinder blocks 1 and 2, the valve plates 3 and 4, the front housing 18, the rear housing 19 and the preload applying spring 20. If there is no variation in the assembly error, the preload will be almost the same for all compressors. If the assembly error varies, the preload differs for each compressor. In such a case, a proper preload is applied by appropriately interposing a shim between the pressing protrusion 18a and the preload applying spring 20 or between the outer ring 9a of the conical roller bearing 9 and the pressing protrusion 19a. You can That is, the preload application in the swash plate compressor can be stably controlled, and the quality of the swash plate compressor with respect to noise and vibration is stabilized.

Further, since both the radial load and the thrust load on the rotary shaft 7 are received through the conical roller bearings 8 and 9, the number of bearing members for the rotary shaft 7 is reduced to half that of the conventional case. Therefore, the assembly work process is simplified.

In this embodiment, the rotary valves 27 and 28 are adopted as the intake valves, but this adopted structure brings the following advantages. In the case of a flapper valve type suction valve,
The lubricating oil increases the suction force between the suction valve and the close contact surface, and the suction valve delays the opening start timing of the suction valve. Due to this delay, the suction resistance due to the elastic resistance of the suction valve reduces the volumetric efficiency. However, when the rotary valves 27 and 28 that are forcibly rotated are used, there is no problem of the suction force due to the lubricating oil and the suction resistance due to the elastic resistance of the suction valve. If the pressure is slightly lower, the refrigerant gas will immediately become compressed chamber P.
It flows into a and Pb. Therefore, the rotary valves 27, 2
When 8 is adopted, the volumetric efficiency is significantly improved compared to when a flapper valve type suction valve is adopted.

In the conventional cylinder block, one intake passage is provided between adjacent cylinder bores, and the presence of such an intake passage reduces the strength of the cylinder block. The discharge passage is also provided in the cylinder block. Therefore, the arrangement interval of the cylinder bores can be widened to the extent that the strength of the cylinder block can be secured, and the arrangement interval of the cylinder blocks cannot be narrowed as long as the suction passage and the discharge passage exist in the cylinder block.

The suction refrigerant gas in the swash plate chamber 11 is sucked into the compression chambers Pa and Pb through the suction passages 29 and 30 in the rotary valves 27 and 28, respectively. No need for a suction passage. Further, the configuration in which the discharge refrigerant gas discharged into the discharge chamber 24 is guided to the discharge passage 25 via the discharge passage 37 in the rotary shaft 7 does not require the discharge passage in the cylinder block in the conventional swash plate compressor. By eliminating the suction passage and the discharge passage from the cylinder blocks 1 and 2, the arrangement interval of the cylinder bores 13, 13A, 14, 14A can be narrowed. The decrease in the arrangement interval of the cylinder bores 13, 13A, 14, 14A is caused by the cylinder bores 13, 13A, 14, 14
This leads to the reduction of the arrangement radius of A, and the cylinder block 1,
A reduction in diameter of the entire 2 is achieved. Therefore, it is possible to reduce the diameter and weight of the entire compressor.

The adoption of the rotary valves 27 and 28 eliminates the need for the conventional front housing and the suction chamber in the rear housing. Therefore, the conical roller bearings 8 and 9 can be arranged in the front housing 18 and the rear housing 19 instead of the suction chamber. That is, since the rotary valves 27 and 28 are used, it is not necessary to prepare an additional space for the bearing member, and the compactness of the compressor is not hindered.

The refrigerant gas in the swash plate chamber 11 is compressed in the compression chambers Pa, P.
When the pressure in b falls below the pressure in the swash plate chamber 11, the compression chamber P,
Inhaled in Pa and Pb. From the swash plate chamber 11 to the compression chambers P, P
If the flow path resistance in the refrigerant gas flow path reaching a and Pb, that is, the suction resistance is high, the pressure loss increases and the compression efficiency decreases. By adopting the rotary valves 27 and 28, the refrigerant gas flow path length from the swash plate chamber 11 to the compression chambers P, Pa and Pb is shortened, and the suction resistance is reduced as compared with the conventional case. Therefore, the loss is reduced and the compression efficiency is improved.

The present invention is of course not limited to the above-mentioned embodiment, and for example, in the above-mentioned embodiment, the preload applying spring 20 may be interposed between the rear housing 19 and the outer ring 9a of the conical roller bearing 9. .

Further, as shown in FIG. 6, a coil spring type preload applying spring 41 may be used. The adoption of the coil spring type preload applying spring 41 is more disadvantageous in terms of installation space than the annular leaf spring, but there is almost no variation in preload. That is, the preload application in the swash plate compressor can be managed more stably.

The present invention can also be applied to a swash plate type compressor as shown in FIGS. As shown in FIG. 7, a pair of front and rear cylinder blocks 43 tightened and joined by bolts 42,
A rotary shaft 45 is rotatably supported by 44 via conical roller bearings 46 and 47. Conical roller bearings 46, 4
7 is accommodated in the accommodation holes 43a and 44a. Outer rings 46a and 47a of the conical roller bearings 46 and 47 are accommodated in the receiving hole 43.
It is slidably fitted in the a and 44a. Inner rings 46b and 47b sandwiching the rollers 46c and 47c together with the outer rings 46a and 47a are fixed to the rotary shaft 45.

A swash plate 48 is fixedly supported on the rotary shaft 45. The cylinder blocks 43, 44 have inlets 49, 5
0 is formed, and an external suction refrigerant gas pipe line (not shown) is connected to the introduction ports 49 and 50. Inlet 49,
50 communicates with the swash plate chamber 66.

As shown in FIG. 8, a plurality of cylinder bores 51 and 52 are formed at equal angular positions about the rotary shaft 45. As shown in FIG. 7, a double-headed piston 53 is reciprocally housed in a pair of front and rear cylinder bores 51, 52, and a hemispherical shoe is provided between the double-headed piston 53 and both front and rear surfaces of the swash plate 48. 16, 17 are interposed.

A front cover 54 is fastened and joined to the end surface of the cylinder block 43 with bolts 55. A rear cover 56 is also fastened and joined to the end surface of the cylinder block 44 with bolts 57. An annular preloading spring 82 is interposed between the front cover 54 and the outer ring 46a of the conical roller bearing 46. The front cover 54 contacts the outer peripheral edge of the preload applying spring 82, and the outer ring 46 a contacts the inner peripheral edge of the preload applying spring 82. A rear cover 56 is in contact with an outer ring 47a of the conical roller bearing 47. The preload applying spring 82 is bent and deformed as in the first embodiment.

Discharge chambers 58, 5 are provided in both covers 54, 56.
9 is formed. The discharge chambers 58 and 59 are covers 54,
It is connected to the cylinder bores 51 and 52 via discharge ports 54a and 56a on 56. The discharge chamber 58 has the discharge passage 6
0 communicates with an external discharge refrigerant gas pipe line (not shown).

Reference numeral 61 denotes the discharge chamber 5 along the peripheral surface of the rotary shaft 45.
8 is a lip seal that prevents refrigerant gas from leaking from the compressor 8 to the outside of the compressor. A pair of suction chambers 6 are provided in the double-headed piston 53.
2, 63 are sectioned. The suction chambers 62 and 63 are connected to the swash plate chamber 6 through the inflow ports 64 and 65 on the double-headed piston 53.
6 and the refrigerant gas in the swash plate chamber 66 is connected to the inflow port 6
It is possible to flow into the suction chambers 62, 63 via 4, 65.

As shown in FIG. 9, a suction port 67 is formed through the front end face of the double-headed piston 53, and a suction valve 68 is interposed on the suction port 67. The suction valve 68 is a valve seat 6 fitted and fixed to the end surface of the head.
9 and a disk-shaped float valve 70 housed in the valve seat 69.
And a circlip type retainer 71 for accommodating and holding the float valve 70 in the valve seat 69.
A through hole 72 is formed in the valve seat 69, and the through hole 72 is formed.
Is opened and closed by the float valve 70.

A suction port 73 is also provided through the rear head end surface of the double-headed piston 53, and a suction valve 74 similar to the suction valve 68 is interposed on the suction port 73.
A discharge valve 75 is interposed on the discharge port 54a.
As shown in FIG. 9, the discharge valve 75 includes the front cover 54.
The valve seat 76 fitted and fixed in the valve seat 76, the disk-shaped float valve 77 accommodated in the valve seat 76, and the float valve 77.
And a retainer 78 for accommodating and holding therein. The valve seat 76, the float valve 77, and the retainer 78 have the same shape as the valve seat 69, the float valve 70, and the retainer 71 of the intake valve 68.

A discharge valve 79 similar to the discharge valve 75 is also interposed on the discharge port 56a. During the backward stroke of the double-headed piston 53 on the cylinder bore 51 side, the refrigerant gas in the suction chamber 62 pushes the float valve 70 away and is sucked into the compression chamber Pa between the double-headed piston 53 and the front cover 54. The opening of the float valve 70 is regulated by coming into contact with the retainer 71. During the forward stroke of the double-headed piston 53 on the cylinder bore 51 side, the refrigerant gas in the compression chamber Pa pushes the float valve 70 and is discharged to the discharge chamber 58. The opening of the float valve 77 is regulated by contacting the retainer 78.

On the compression chamber Pb side between the double-headed piston 53 and the rear cover 56, similar suction and discharge are performed via the suction valve 74 and the discharge valve 79. One end of the rotary shaft 45 projects outward from the front cover 54, and the other end projects into the discharge chamber 59 on the rear cover 56 side. A discharge passage 80 is formed at the center of the rotary shaft 45.
The discharge passage 80 opens into the discharge chamber 59.

Rotating shaft 45 surrounded by discharge chamber 58
A discharge port 81 is formed at the position of, and the discharge chamber 58 and the discharge passage 80 are connected by the discharge port 81.
The discharged refrigerant gas flowing from the discharge chamber 59 into the discharge passage 80 flows out from the outlet 81 to the discharge chamber 58. The discharge refrigerant gas in the discharge chamber 58 is discharged to the external discharge refrigerant gas pipeline via the discharge passage 60.

Also in this embodiment, the preload applying spring 82 is used.
The flexing deformation of the preloads the rotating shaft 45 via the conical roller bearings 46 and 47. Therefore, similarly to the first embodiment, the preload application in the swash plate compressor can be stably controlled, and the quality of the swash plate compressor regarding noise and vibration is stabilized.

Further, the refrigerant gas sucked into the swash plate accommodating chamber 66 passes through the suction chambers 62 and 63 in the double-headed piston 53, and then the compression chamber P.
The structure in which a and Pb are sucked does not require a plurality of suction passages in the cylinder block in the conventional swash plate compressor.
In addition, the discharge refrigerant gas discharged into the discharge chamber 59 is supplied to the rotary shaft 45.
The structure in which the discharge passage 60 is guided to the discharge passage 60 via the internal discharge passage 80 does not require the discharge passage in the cylinder block in the conventional swash plate compressor. Therefore, the diameter of the cylinder bores 51, 52 can be reduced, and the overall compressor can be reduced in diameter and weight.

Further, in the present embodiment, the suction chambers which are conventionally provided before and after the cylinder block are replaced with the suction chambers 62 and 63 in the double-headed piston 53, and this arrangement change also contributes to downsizing of the entire compressor.

[0047]

As described in detail above, the present invention rotatably supports the rotating shaft that supports the swash plate between the pair of conical roller bearings, and supports the outer ring of the conical roller bearing between the support and the outer ring. Is set to a slidable mating relationship, and the spring force of the preloading spring that biases the thrust load in the conical roller bearing is applied to the outer ring of at least one of the conical roller bearings. As a result, the number of bearing members is reduced, the assembling work process is simplified, and the preload application in the thrust direction to the rotating shaft can be stably controlled, which is an excellent effect.

[Brief description of drawings]

FIG. 1 is a side sectional view of an entire compressor showing an embodiment embodying the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

4 is a cross-sectional view taken along the line CC of FIG.

5 is a cross-sectional view taken along the line DD of FIG.

FIG. 6 is a side sectional view of the entire compressor showing another example.

FIG. 7 is a side sectional view of the entire compressor showing another example.

8 is a cross-sectional view taken along the line EE of FIG.

FIG. 9 is an enlarged side sectional view of an essential part.

FIG. 10 is a graph illustrating a preload.

[Explanation of symbols]

1, 2 ... Cylinder block serving as a support, 7 ... Rotating shaft,
8, 9 ... conical roller bearings, 8a, 9a ... outer ring, 10 ... swash plate, 20 ... preloading spring.

Claims (1)

[Claims] 1. A double-headed piston is housed in a plurality of pairs of front and rear cylinder bores arranged around a rotary shaft, and the rotary motion of a swash plate supported by the rotary shaft is converted into a reciprocating motion of the double-headed piston. In the swash plate compressor to be converted, the rotation shaft is rotatably supported by a pair of conical roller bearings, and a slidable fitting relationship is set between a support body that supports the outer ring of the conical roller bearings and the outer ring. A rotating shaft support structure in a swash plate compressor in which a spring force of a preloading spring that biases a thrust load in a conical roller bearing is applied to an outer ring of at least one of the conical roller bearings.