KR970001132B1 - Supporting mechanism of a driving shaft in a swash plate type compressor - Google Patents

Abstract

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Description

Rotating shaft support structure in swash plate compressor

1 is a longitudinal sectional view of the entire compressor, showing one embodiment embodying the present invention.

2 is a cross-sectional view taken along the line A-A of FIG.

3 is a cross-sectional view taken along the line B-B in FIG.

4 is a cross-sectional view taken along the line C-C in FIG.

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

6 is a graph showing the relationship between the temperature of the cylinder block and the amount of thermal expansion.

7 is a graph illustrating preload.

8 is a longitudinal sectional view of the entire compressor, showing a second embodiment of the present invention.

9 is a sectional view taken along the line E-E of FIG.

10 is an enlarged cross-sectional view of a main part.

11 is a side sectional view of the entire compressor, showing three embodiments embodying the present invention.

12 is a cross-sectional view taken along the line A-A of FIG.

13 is a cross-sectional view taken along the line B-B in FIG.

14 is a cross-sectional view taken along the line C-C in FIG.

FIG. 15 is a sectional view taken along the line D-D of FIG.

16 is a side cross-sectional view of the entire compressor, showing another example.

17 is a side cross-sectional view of the entire compressor, showing another example.

18 is a sectional view taken along the line E-E of FIG.

19 is an enlarged side cross-sectional view of the main portion.

* Explanation of symbols for main parts of the drawings

1,2: Cylinder block 3,4: Valve plate

3a, 4a: support 7 rotation axis

8,9,46,47: Conical roller bearing 8a, 9a, 46a, 47a: Outer ring

10: Saphan 18: Protohousing

18a: Pushing protrusions 19: rear housing

19a: Pushing protrusion 21,55: Through bolt

20,82: Preloaded plate spring 43,44: Cylinder block as a support

[Industrial use]

According to the present invention, a plurality of pairs of cylinder bores which are paired with each other in front and rear with respect to the cylinder block are formed in a plurality of places around the rotating shaft, and the front housing and the rear housing are joined and fixed to both front and rear sides of the cylinder block, and the two head pistons are respectively accommodated in the cylinder bore. At the same time, the present invention relates to a support structure of a rotating shaft in a swash plate type compressor that converts the rotational motion of the swash plate supported by the rotating shaft into a reciprocating motion of the double head piston.

[Prior art]

In a conventional inclined plate compressor (for example, see Japanese Patent Application Laid-Open No. 3-92587), the refrigerant gas in the compression chamber is discharged to the discharge chamber by the reciprocating operation of the double head piston, and the refrigerant gas in the suction chamber is introduced into the compression chamber by the reciprocating motion of the double head piston. Is inhaled. Two-headed pistons are used in plural and housed in cylinder bores arranged at equiangular intervals around the axis of rotation. The compression chamber is connected to the discharge chamber via the discharge port and is connected to the suction chamber via 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. The suction port is opened and closed by the suction valve and the refrigerant gas in the suction chamber is sucked into the compression chamber while pushing the suction valve.

Challenges to the Invention

Rotation of the rotating shaft supporting the swash plate is supported by a pair of front and rear cylinder blocks via a pair of radial bearings.

In other words, the radial load on the rotating shaft is taken from the cylinder block via the radial bearing. The thrust load on the rotating shaft is also taken from the cylinder block via a pair of front and rear thrust bearings with swash plates.

The thrust load on the axis of rotation fluctuates as shown by curve C in FIG. That is, the maximum value Fmax of the thrust load with respect to the rotating shaft alternates directions five times in the front-rear direction of the swash plate. In this case, there are five double head pistons in the swash plate compressor. There is a thrust bearing between the cylinder block and the swash plate, and the pair of races that intersect the rollers of the thrust bearing are deflected in advance. This deflection is given in the state of joining a pair of cylinder blocks before and after and acts as a preload for the axis of rotation.

The preload is set above the maximum value of the wing thrust load. This preload setting eliminates the vibration in the direction of the thrust of the rotating shaft and controls the abnormal noise and abnormal vibration.

However, the configuration in which the radial load and the thrust load on the rotating shaft are received through different bearing members, respectively, leads to the complexity of the assembly work process.

Therefore, the applicant of this application proposes the support structure of the rotating shaft as shown in patent 4-211164. That is, between the support and the outer ring which supports the rotating shaft rotatably by a pair of conical roller bearings and supports the outer ring of the conical roller bearing, a slidable coupling relationship in the trust direction is established and the pair of conical roller bearings A cross section of the outer ring is supported on the inner walls of the front housing and the rear housing, and a preload grant plate spring is provided to impart a thrust load of the conical roller bearing between the outer ring of the conical roller bearing and the inner wall of the housing.

However, in the above-described support structure of the rotating shaft, the coefficient of thermal expansion between the cylinder block and the rotating shaft is different from the cylinder block and the rotating shaft, such as a block made of aluminum and a steel made of steel, for example, so that the preloaded load can be appropriately applied by changing the discharge temperature. There is a new problem that cannot be granted. That is, during the high compression ratio operation of the compressor, the discharge temperature rises and the compressor temperature rises, so that the thermal expansion amount in the thrust direction of the cylinder block front housing and the rear housing becomes larger than the thermal expansion amount in the same direction of the rotation shaft. As a result, there is a new problem that the thrust load of the preloaded spring spring is lowered during the high compression ratio operation that requires the most preload, resulting in vibration and abnormal noise.

In addition, if the preload of the disc spring is set strongly in consideration of the above-mentioned effect of thermal expansion, the discharge temperature is lowered during the low compression ratio operation of the compressor and the temperature in the compression chamber is low, so the thrust load of the preload imparting disc spring acting on the rotating shaft. This is the most increase and there is a problem that the power loss occurs when rotating the rotary shaft.

The present invention relates to a swash plate compressor capable of receiving a radial load and a thrust load with respect to a rotating shaft with one bearing member, and also exerting an appropriate preload in the thrust direction with respect to the rotating shaft even at high compression ratio operation and suppressing power loss. It is an object to provide a support structure for a rotating shaft.

Means to solve the problem

To this end, in the present invention, a pair of cones is slidably established in the trust direction between the support and the outer ring which rotatably supports the rotating shaft by a pair of cone roller bearings and supports the outer ring of the cone roller bearing. Preload is provided to support the end face of the outer ring of the roller bearing by the front housing and the rear housing and to add a thrust load in the conical roller bearing between the outer ring of the at least one conical roller bearing and the inner wall of the housing. The cylinder block, the front housing and the rear housing were again tightened with a common through bolt through a spring.

Action

In the present invention, the inner ring of the conical roller bearing is coupled non-slip relative to the axis of rotation. The roller fitted between the inner ring and the outer ring is inclined with respect to the rotational axis, and the peripheral rotational trajectory of the roller is on the conical surface about the rotational axis. With this configuration, both thrust and radial loads on the rotating shaft are received via the cone roller bearings. 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 with respect to the axis of rotation via the outer ring, the roller and the inner ring.

In addition, in the present invention, the cylinder block, the front housing and the rear housing are tightened and fixed with a common through bolt.

For this reason, even if the compressor is in a high compression ratio operation and the cylinder block or the like is heated with a high-temperature compressed gas and tries to expand larger than the thermal expansion amount in the trust direction of the rotating shaft made of iron-based material, the through bolt thermal expansion in the trust direction of the cylinder block or the like. Amount is controlled.

Therefore, the load in the thrust direction of the preloading spring acting on the rotating shaft is properly maintained and vibration and abnormal noise are controlled.

Example

EMBODIMENT OF THE INVENTION Hereinafter, the 1st Example which actualized this invention is described based on drawing.

As shown in FIG. 1, accommodation holes 1a and 2a are formed in the center of the pair of front and rear cylinder blocks 1 and 2 joined together. The valve plates 3 and 4 are joined to the end faces of the cylinder blocks 1 and 2, and the support plates 3a and 4a as the support bodies are integrally formed on the valve plates 3 and 4. Ring-shaped positioning projections 3b and 4b protrude from the inner circumferential edges of the supports 3a and 2a, and the positioning projections 3b and 4b are fitted into the receiving holes 1a and 2a. The pins 5 and 6 are inserted into the valve plates 3 and 4 and the cylinder blocks 1 and 2, and the rotational movement of the valve plates 3 and 4 with respect to the cylinder blocks 1 and 2 is performed by the pins 5 and 6. 6) is blocked.

The support shafts 3a and 4a of the valve plates 3 and 4 are rotatably supported by the rotation shaft 7 via the cone roller bearings 8 and 9. The outer rings 8a, 9a of the conical roller bearings 8, 9 are slidably supported on the inner circumferential surfaces of the supports 3a, 4a, and the inner rings 8b, 9b are stepped portions 7a, on the suction 7. It is fixed in contact with 7b). The rollers 8c and 9c fitted between the outer rings 8a and 9a and the inner rings 8b and 9b are inclined with respect to the rotational shaft 7 and the peripheral rotational trajectories of the rollers 8c and 9c are on the conical surface. . The large diameter side of the conical surface of the periphery rotation locus of both rollers 8c and 9c opposes.

The swash plate 10 is fixedly supported by the rotation shaft 7.

Inlet ports 12 are formed in the cylinder blocks 1 and 2 that form the plate chamber 11, and external intake refrigerant gas pipes (not shown) are connected to the inlet ports 12.

As shown in FIG. 2 and FIG. 3, a plurality of cylinder bores 13, 13A, 14, 14A are formed at equally spaced angular positions around the rotation shaft 7. As shown in FIG. As shown in FIG. 1, the double head pistons 15 and 15A are reciprocally housed in the cylinder bores 13, 14, 14A and 13A (five pairs in this embodiment) which are paired in front and rear. Hemispherical shoes 16 and 17 are described between the double-headed pistons 15 and 15A and the front and rear surfaces of the swash plate 10. Therefore, as the swash plate 10 rotates, the double head pistons 15 and 15A move back and forth in the cylinder bores 13, 14, 13A and 14A.

The front housing 18 is joined to the front side of the valve plate 3, and the rear housing 19 is joined to the rear side of the valve plate 4. As shown in Figs. 4 and 5, a plurality of push protrusions 18a and 19a protrude from the inner wall surfaces of both housings 18 and 19. Figs.

An annular plate-shaped preload imparting spring 20 is interposed between the pressing projection 18a and the outer ring 8a of the conical roller bearing 8. With this configuration, the preloaded dish spring 20 is supported in a positional displacement impossible with respect to the front housing 18. The cross section of the outer ring 8a of the conical roller bearing 8 protrudes from the cross section of the support 3a of the valve plate 3, and the inner circumferential edge of the preloaded disc spring 20 has an outer ring of the conical roller bearing 8. It comes in contact with the cross section of (8a).

The peripheral rotational trajectories of the rollers 8c and 9c of the conical roller bearing 8 are on the conical surface, and the large diameter side of the conical surface of the peripheral rotational trajectories of the two rollers 8c and 9c is opposite. The inner rings 8b and 9b of the conical roller bearings 8 and 9 are in contact with the stepped portions 7a and 7b of the rotary shaft 7. Therefore, on the front housing 18 side, the thrust load on the rotating shaft 7 toward the rear housing 19 side is received by the rear housing 19 via the conical roller bearing 9. Moreover, the thrust load with respect to the rotating shaft 7 toward the front housing 18 side from the rear housing 19 side is taken in by the front housing 18 via the cone roller bearing 8 and the preloading plate spring 20. As shown in FIG. .

The cylinder blocks 1 and 2, the valve plates 3 and 4, the front housing 18 and the rear housing 19 are tightened and fixed at the place of the plurality (5 in this embodiment) by the through bolts 21. . The threaded portion 21a at the front end of each of the through bolts 21 is screwed into the screw hole 19b formed in the rear housing 19, and other than that is formed in each member 1, 2, 3, 4, 18. It is inserted into one insertion hole 1c, 2c, 3d, 4d, and 18b.

Tightening of the bolts 21 deflects the preloaded disc spring 20 and this deflection imparts a preload to the rotating shaft 7 via the cone roller bearing 8.

Discharge chambers 23 and 24 are formed in both housings 18 and 19. The compression chambers Pa and Pb, which are partitioned into the cylinder bores 13, 14, 13A, and 14A by the double head pistons 15 and 15A, are discharged through the discharge ports 3c and 4c on the valve plates 3 and 4, respectively. It is in communication with (23, 24). The discharge ports 3c and 4c are opened and closed by flapper valve type discharge valves 31 and 32. The opening degree of the discharge valves 31 and 32 is regulated by the retainers 33 and 34. The discharge valves 31 and 32 and the retainers 33 and 34 are fixed on the valve plates 3 and 4 by bolts 35 and 36. The discharge chamber 23 communicates with an external discharge refrigerant gas pipeline (not shown) via the discharge passage 25.

Reference numeral 26 denotes a lip seal which prevents refrigerant gas leakage from the discharge chamber 23 along the circumferential side of the rotary shaft 7 to the outside of the pressure gauge.

Rotary valves 27 and 28 are supported by the stepped portions 7a and 7b on the rotary shaft 7. Seal rings 39 and 40 are interposed between the rotary valves 27 and 28 and the rotary shaft 7. The rotary valves 27 and 28 are accommodated in the accommodation holes 1a and 2a so as to be rotatable integrally with the rotary shaft 7. Discharge refrigerant gas pressure of the discharge chambers 24 and 24 acts on one end of the rotary valves 27 and 28, while intake refrigerant gas pressure of the swash plate chamber 11 acts on the other end thereof.

That is, the rotary valves 27 and 28 block the discharge pressure region and the suction pressure region.

Suction passages 29 and 30 are formed in the rotary valves 27 and 28. Inlets of the suction passages 29 and 30 are opened on the swash plate chamber 11 and outlets of the suction passages 29 and 30 are opened on the inner circumferential surfaces of the receiving holes 1a and 2a.

As shown in FIG. 2, the cylinder bores 13 and 13A and the same number of suction ports 16 are arranged in the same equiangular angular position on the inner circumferential surface of the accommodation hole 1a which accommodates the rotary valve 27. As shown in FIG. The suction port 1b and the cylinder bores 13 and 13A are always in one-to-one communication, and each suction port 1b is connected to the peripheral rotation region of the outlet of the suction passage 29.

Similarly, as shown in FIG. 3, the cylinder bores 14 and 14A and the same number of suction ports 2b are arranged at equal intervals on the inner circumferential surface of the male hole 2a which accommodates the rotary valve 28. As shown in FIG.

The suction port 2b and the cylinder bores 14 and 14A are always in one-to-one communication, and each suction port 2b is connected to the peripheral rotation region of the outlet of the suction passage 30.

In the state shown in FIG. 1, FIG. 2, and FIG. 3, the double-headed piston 15A is at the top dead center position with respect to one cylinder bore 13A, and the bottom dead center position with respect to the other cylinder bore 14A. Is in. In such a piston arrangement, the outlet 29a of the suction passage 29 is immediately before connecting to the suction port 1b of the cylinder bore 13A, and the outlet 30a of the suction passage 30 is the cylinder bore 13A. Is immediately after connecting to the suction port 1b. That is, when the double head piston 15A enters the suction stroke from the top dead center position to the bottom dead center position with respect to the cylinder bore 13A, the suction passage 29 communicates with the compression chamber Pb of the cylinder bore 13A. . By this communication, the refrigerant gas in the swash plate chamber 11 is sucked into the compression chamber Pb of the cylinder bore 13A via the suction passage 29. On the other hand, when the double head piston 15A 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 communicates with the compression chamber Pb of the cylinder bore 14A. Is blocked. By this communication interruption, the refrigerant gas in the compression chamber Pb of the cylinder bore 14A is discharged from the discharge port 4c to the discharge chamber 24 while pushing out the discharge valve 32.

Such suction and discharge of the refrigerant gas are similarly performed in the compression chamber P of the other cylinder bores 13 and 14.

One end of the rotary shaft 7 protrudes outward from the front housing 18, and the other end protrudes into the discharge chamber 24 on the rear housing 19 side. The discharge passage 37 is formed in the shaft center portion of the rotary shaft 7. The discharge passage 37 is opened in the discharge chamber 24.

The discharge port 38 is formed in the peripheral part of the rotating shaft 7 surrounded by the discharge chamber 23 on the front housing 18 side, and the discharge chamber 23 and the discharge passage 37 communicate with each other by the discharge port 38. It is. Therefore, the front and rear discharge chambers 23 and 24 communicate with each other by 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 rotary shaft 7 fluctuates as shown by the curve c in FIG. The plus side of the vertical axis is a thrust load directed from the front housing 18 side to the rear housing 19 side. The negative side of the vertical axis is a thrust load directed from the rear housing 19 side to the front housing 18 side. The straight lines L1 and L2 represent preloads applied by the bending deformation of the preloading disc spring 20. The preload + Fo shown by the straight line L1 is opposed to the thrust load toward the front housing 18 side from the rear housing 19 side. The preload (-Fo) indicated by the straight line L2 is opposed to the thrust load directed from the front housing 18 side to the rear housing 19 side. The preload Fo is set to exceed the maximum thrust load Fmax for some time.

By setting such a preload Fo, a gap in the thrust direction occurs between the stepped portion 7a and the pressing projection 18a on the rotary shaft 7 and between the stepped portion 7b and the pressing projection 19a. There is no work. That is, the rotation shaft 7 does not rock, and abnormal noise and abnormal vibration do not occur.

This preload is determined by the spring characteristics of the preloaded dish spring 20 and the amount of deflection of the deflection. The bending deformation amount of the preload plate spring 20 is assembled by the cylinder blocks 1 and 2, the valve plates 3 and 4, the front housing 18, the rear housing 19 and the preload plate spring 20. It depends on the error. If there is no nonuniformity in the assembly error, the preload will be nearly equal for any compressor. In case of non-uniformity in assembly error, the preload is different for each compressor.

In such a case, a shim is appropriately interposed between the pressing projection 18a and the preloading plate spring 20 or between the outer ring 9a and the pressing projection 19a of the conical roller bearing 9. Therefore, an appropriate preload can be given. That is, the preloading can be stably managed in the swash plate compressor, and the quality of the swash plate compressor with respect to noise and vibration is stabilized.

In addition, when the compressor is operated at a high compression ratio, the temperature of the compressed gas increases. For this reason, the temperature in cylinder bore 13,13A, 14,14A also raises similarly. Accordingly, the cylinder blocks 1 and 2 of the aluminum-based metal have a thermal expansion in the trust direction of the front housing 18 which increases the thermal expansion of the rotating shaft 7 made of steel and presses the preloaded dish spring 20. The position of the pressing projection 18a is displaced in the unit of μm to the front side in FIG. 1. This amount of thermal expansion increases as the temperature of the cylinder blocks 1 and 2 rises. However, in this first embodiment, the cylinder blocks 1 and 2, the front housing 18 and the rear housing 19 are fastened and fastened with a plurality of through bolts 21, so that the cylinder blocks 1 and 2 are secured. The amount of thermal expansion in the trust direction is suppressed. For this reason, the load in the thrust direction of the preloading provision spring 20 is appropriately maintained, and vibration and noise are suppressed.

If the cylinder block 1 and the front housing 18, the cylinder block 2 and the rear housing 19 are fixed with different bolts, the cylinder blocks 1 and 2 are shown in FIG. When the temperature of is changed from 20 ° C. to 100 ° C., the thermal expansion amount is about 50 μm. In the first embodiment, this is about 12 mu m and 1/4 in the above temperature range. Therefore, the preload by the preload imparting spring 20 does not drop much with the temperature rise of the cylinder blocks 1 and 2.

In the first embodiment, it is not necessary to consider the attenuation of the preloading plate spring 20 at high temperature and to set the preload of the plate spring 20 at room temperature strongly.

This minimizes the preload in the thrust direction to the rotary shaft 7 and improves the durability of the conical roller bearings 8 and 9, while at the same time reducing the rotational torque in low-compression non-operating conditions with low rotational speeds and loss of power. Can be suppressed.

In addition, in the first embodiment, both the radial load and the thrust load on the rotary shaft 7 are received through the cone roller bearings 8 and 9, so that the number of bearing members of the rotary shaft 7 is reduced by half. Therefore, the assembly work process is simplified.

In the first embodiment, the rotary valves 27 and 28 are employed as the intake valves, but this configuration employs the following advantages.

In the case of the flapper valve type suction valve, the lubricating oil increases the suction force between the suction valve and its close contact surface, and the timing of opening the suction valve is delayed by the suction force. The delay and the suction resistance due to the elastic resistance of the suction valve lower the volumetric efficiency. However, with the rotary valves 27 and 28 being rotated forcibly, there is no problem of suction resistance due to lubricating oil and suction resistance due to elastic resistance of the suction valve, and the pressure in the compression chambers Pa and Pb is reduced. When the suction pressure is slightly below, the refrigerant gas immediately flows into the compression chambers Pa and Pb. Therefore, in the case of employing the rotary valves 27 and 28, the volumetric efficiency is greatly improved as compared with the case of employing the flapper valve type intake valve.

In the conventional cylinder block, one suction passage is provided in the gap between neighboring cylinder bores, and the presence of such suction 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 bore is widened to the extent that the strength of the cylinder block can be secured, and the arrangement interval of the cylinder block cannot be narrowed as long as the suction passage and the discharge passage exist in the cylinder block.

The inlet refrigerant gas of the swash plate chamber 11 is sucked into the compression chambers Pa and Pb via the suction passages 29 and 30 in the rotary valves 27 and 28. A plurality of suction passages are unnecessary. Moreover, the structure which guides the discharge refrigerant gas discharged | emitted to the discharge chamber 24 to the discharge passage 25 via the discharge passage 37 in the rotating shaft 7 is a discharge passage in the cylinder block in the conventional swash plate type compressor. It is unnecessary. By eliminating the suction passage and the discharge passage from the cylinder blocks 1, 2, the arrangement intervals of the cylinder bores 13, 13A, 14, 14A can be narrowed. The reduction in the spacing of the cylinder bores 13, 13A, 14, 14A is linked to the reduction of the arrangement radius of the cylinder bores 13, 13A, 14, 14A and the reduction of the entire shaft block 1, 2 is achieved. . Thus, reduction in diameter and weight of the entire compressor is achieved.

The adoption of the rotary valves 27 and 28 eliminates the need for a suction chamber in the conventional front housing and the rear housing. Therefore, instead of this suction chamber, conical roller bearings 8 and 9 can be arranged in the front housing 18 and in the rear housing 19. That is, due to the use of the rotary valves 27 and 28, it is not necessary to prepare an extra space for the bearing member, and does not impair compaction of the compressor.

The refrigerant gas in the swash plate chamber 11 is sucked into the compression chambers P, Pa, and Pb when the pressure in the compression chambers Pa and Pb falls below the pressure in the swash plate chamber 11.

If the flow path resistance in the refrigerant gas flow path from the swash plate chamber 11 to the compression chambers P, Pa, and Pb, that is, the suction resistance is high, the pressure loss increases and the compression efficiency decreases. By employing the rotary valves 27 and 28, the length of the refrigerant gas flow path from the swash plate chamber 11 to the compression chambers P, Pa, and Pb is shortened, and the suction resistance is reduced than before. Therefore, the loss is reduced and the compression efficiency is improved.

Next, a second embodiment in which this invention is embodied will be described with reference to FIGS.

As shown in FIG. 8, the rotating shaft 45 passes through the conical roller bearings 46 and 7 in a pair of cylinder blocks 43 and 44 fastened and joined by the through bolt 55 and the nut 55. It is rotatably supported. The cone roller bearings 46 and 47 are accommodated in the receiving holes 43a and 44a of the cylinder blocks 43 and 44 as the support. The outer races 46a and 47a of the conical roller bearings 46 and 47 are slidably fitted into the receiving holes 43a and 44a. In addition to the outer races 46b and 47b, the outer races 46 and 47b sandwiching the rollers 46c and 47c are fixed to the rotation shaft 45.

The swash plate 48 is fixed to the rotation shaft 45.

Inlet ports 49 and 50 are formed in the cylinder blocks 43 and 44, and external intake refrigerant gas pipes (not shown) are connected to the inlet ports 49 and 50. The introduction ports 49 and 50 communicate with the swash plate chamber 60.

As shown in FIG. 9, a plurality of cylinder bores 51 and 52 are formed at equally spaced angular positions around the rotational shaft 45. As shown in FIG. As shown in FIG. 8, the double-headed piston 53 is reciprocally accommodated in the cylinder bores 51 and 52 paired with each other in front and rear, and between the double-headed piston 53 and the front and rear surfaces of the swash plate 48. Hemispherical shoes 16 and 17 are interposed.

The front cover 54 is tightened and joined to the end surface of the cylinder block 43 by the through bolt 55 and the nut 57.

The rear cover 56 is also joined by a bolt 57 to the end face of the cylinder block 44. An annular preloading spring 82 is interposed between the front cover 54 and the outer ring 46a of the cone roller bearing 46. The front cover 54 abuts on the outer circumferential edge of the preloading spring 82, and the outer ring 46a abuts on the inner circumferential edge of the preloading spring 82. The rear cover 56 abuts on the outer ring 47a of the conical roller bearing 47.

The preloading spring 82 is warped and deformed like the first embodiment.

Discharge chambers 58 and 59 are formed in both covers 54 and 56. The discharge chambers 58 and 59 are connected to the cylinder bores 51 and 52 via the discharge ports 54a and 56a on the covers 54 and 56.

The discharge chamber 58 communicates with an external discharge refrigerant gas pipeline (not shown) via the discharge passage 60.

Reference numeral 61 denotes a lip seal that prevents leakage of refrigerant gas from the discharge chamber 58 along the main surface of the rotating shaft 45 to the outside of the compressor.

A pair of suction chambers 62 and 63 are formed in the double head piston 53. The suction chambers 62 and 63 communicate with the swash plate chamber 66 through the inlets 64 and 65 on the double head piston 53, and the refrigerant gas in the swash plate chamber 66 passes through the inlets 64 and 65. (62,63).

As shown in FIG. 10, the suction port 67 is provided in the front end face of the double-headed piston 53, and the suction valve 68 is interposed on the suction port 67. As shown in FIG. The suction valve 68 accommodates and retains the valve seat 69 and the disk-shaped float valve 70 and the float valve 70 accommodated in the valve seat 69 in the valve seat 69 which are fitted and fixed to the head end face. It consists of a retainer 71 of a circlip type. A valve port 69 is formed in the valve seat 69, and the port hole 72 is opened and closed by the float valve 70.

The suction port 73 is also provided in the rear end face of the double head piston 53 on the rear side, and the same suction valve 74 as the suction valve 68 is interposed on the suction port 73. The discharge valve 75 is described on the discharge port 54a. As shown in FIG. 10, the discharge valve 75 valves the float sheet valve 77 and the float 77 which are accommodated in the valve sheet 76 and the valve sheet 76 which are fitted into the front cover 54 and are fixed. It comprises the retainer 78 for accommodating and holding in the sheet | seat 76. As shown in FIG. The valve seat 76, the float valve 77, and the retainer 78 all have the same shape as the valve seat 69, the float valve 70, and the retainer 71 of the intake valve 68.

The discharge valve 79 similar to the discharge valve 75 is also interposed on the discharge port 56a.

During the reciprocating stroke of the cylinder bore 51 side of the double head piston 53, the refrigerant gas in the suction chamber 62 pushes the float valve 70 and compresses between the double head piston 53 and the front cover 54. It is sucked into the chamber Pa. The float valve 70 abuts against the retainer 71 so that the opening degree is regulated. During the reciprocating stroke of the cylinder bore 51 side of the double head piston 53, the refrigerant gas in the compression chamber Pa pushes the float valve 70 and is discharged to the discharge chamber 58.

The float valve 77 abuts against the retainer 78 so that the opening degree is regulated.

Similar suction and discharge are performed via the suction valve 74 and the discharge valve 79 also on the compression chamber pb side between the double head piston 53 and the rear cover 54.

One end of the rotary shaft 45 protrudes from the front cover 54 to the outside, and the other end protrudes into the discharge chamber 59 on the rear cover 56 side. The discharge passage 80 is formed in the shaft center portion of the rotating shaft 45. The discharge passage 80 is opened in the discharge chamber 59.

A discharge port 81 is formed in the bush of the rotary shaft 45 surrounded by the discharge chamber 58, and the discharge chamber 58 and the discharge passage 80 communicate with each other by the discharge port 81. The discharge coolant flowed into the discharge passage 80 from the discharge chamber 59 flows out from the discharge port 81 into the discharge chamber 58. The discharge refrigerant gas of the discharge chamber 58 is discharged to the external discharge refrigerant gas pipeline via the discharge passage 60.

Also in this second embodiment, the deflection of the preloading spring 82 imparts a preload to the rotating shaft 45 via the conical roller bearings 46 and 47. Therefore, as in the first embodiment, preloading in the swash plate type compressor can be stably managed, and the quality of the swash plate type compressor with respect to noise and vibration is stabilized.

In addition, the configuration in which the suction refrigerant gas to the swash plate accommodation chamber 55 is sucked into the compression chambers pa and Pb via the suction chambers 62 and 63 in the double head piston 53 is a cylinder block in the conventional swash plate type compressor. A plurality of suction passages in the interior are unnecessary. In addition, the discharge passage in the cylinder block of the conventional swash plate type compressor is constructed by guiding the discharge refrigerant gas discharged into the discharge chamber 59 to the discharge passage 60 via the discharge passage 80 in the rotary shaft 45. It is unnecessary. Therefore, the shaft radius of the arrangement bore of the cylinder bores 51 and 52 is reduced, and the shaft reduction and weight reduction of the whole compressor are obtained.

In addition, in the second embodiment, the suction chambers provided before and after the cylinder block replace the suction chambers 62 and 63 in the double head piston 53, and this arrangement change also contributes to the compactness of the entire compressor.

In addition, in the second embodiment, the cylinder blocks 43 and 44, the front cover 54 and the rear cover 56 are fastened and fixed with a plurality of through bolts 55 and nuts 57. The amount of thermal expansion in the trust direction of 44) is suppressed. For this reason, the load in the thrust direction of the preloading disc spring 82 is properly maintained, and vibration and abnormal noise are suppressed.

The present invention is, of course, not limited to the first and second embodiments described above, but for example, the preloading between the rear housings 19 and 56 and the outer races 9a and 47a of the conical roller bearings 9 and 47 in the four wing embodiment. The grant plate springs 20 and 82 may be interposed.

In the third embodiment, as shown in Fig. 11, accommodation holes 101a and 102a are formed in the center of the pair of front and rear cylinder blocks 101 and 102 joined together. The valve plates 103 and 104 are joined to the end faces of the cylinder blocks 101 and 102, and the support holes 103a and 104a are drilled through the valve plates 103 and 104, respectively. Annular positioning projections 103b and 104b protrude from the support edges 103a and 104a at their main edges, and positioning projections 103b and 104b are fitted into the receiving holes 101a and 102a.

Pins 105 and 106 are inserted into the valve plates 103 and 104 and the cylinder blocks 101 and 102, and rotational movements of the valve plates 103 and 104 relative to the cylinder blocks 101 and 102 are blocked by the pins 105 and 106.

The support shafts 103a and 104a of the valve plates 103 and 104 are rotatably supported by the rotation shaft 107 via the cone roller bearings 108 and 109. The outer races 108a and 109a of the conical roller bearings 108 and 109 are slidably inserted into the receiving holes 101a and 102a and the inner races 108b and 109b are supported by the stepped portions 107a and 107b on the rotary shaft 107. It is fixed in contact with it. The rollers 108c and 109c fitted between the outer rings 108a and 109a and the inner rings 108b and 109b are inclined with respect to the rotation axis 107 and the peripheral rotational trajectories of the rollers 108c and 109c are on the conical surface. . The large diameter side of the conical surface of the peripheral rotation locus of both rollers 108c and 109c opposes.

The swash plate 110 is fixed to the rotation shaft 107.

Inlet openings 112 are formed in the cylinder blocks 10 and 102 that form the swash plate chamber 111, and an external suction refrigerant gas pipeline (not shown) is connected to the inlet openings 112.

As shown in Figs. 12 and 13, a plurality of cylinder bores 113, 113A, 114 and 114A are formed at equally spaced angular positions around the rotating shaft 107. As shown in FIG. 11, the double head pistons 115 and 115A are accommodated in the cylinder bores 113, 114, 113A and 114A (five pairs in this embodiment) which are reciprocated in a forward and backward manner. Hemispherical shoes 116 and 117 are described between the double head pistons 115 and 115A and the front and rear surfaces of the swash plate 110. Thus, as the swash plate 110 rotates, both head pistons 115 and 115A move back and forth within the cylinder bores 113, 114, 113A, and 114A.

The front housing 118 is joined to the end face of the cylinder block 101, and the rear housing 119 is joined to the end face of the cylinder block 102. As shown in Figs. 14 and 15, a plurality of push protrusions 118a and 119a protrude from the inner wall surfaces of both housings 118 and 119. Figs.

An annular plate-shaped preloading spring 120 is interposed between the pressing projection 118a and the outer ring 118a of the cone roller bearing 118. The outer circumferential edge portion of the preloading spring 120 is fitted to the pressing projection 118a.

In this fitting configuration, the preloading spring 120 is supported with no positional displacement with respect to the front housing 118.

The cross section of the outer ring 108a of the conical roller bearing 118 protrudes from the cross section of the wall forming the support hole 103a of the valve plate 103, and the inner circumferential edge of the preloading spring 120 has a conical roller bearing ( It comes in contact with the end surface of the outer ring 108a of 118.

The end face of the push-out protrusion 119a and the outer ring 109a of the cone roller bearing 109 abut.

The peripheral rotational trajectories of the rollers 108c and 109c of the conical roller bearings 108 and 109 are on the conical surface and the large diameter sides of the conical surfaces of the peripheral rotational trajectories of the two rollers 108c and 109c face each other. In addition, the inner rings 108b and 109b of the conical roller bearings 108 and 109 abut against the stepped portions 107a and 107b of the rotary shaft 107. Therefore, on the front housing 118 side, the thrust load on the rotating shaft 107 toward the rear housing 119 side is received by the rear housing 119 via the conical roller bearing 109. Further, the thrust load on the rotating shaft 107 from the rear housing 119 side to the front housing 118 side is received by the front housing 118 via the conical roller bearing 108 and the preloading spring 120. .

The cylinder block 101, the valve plate 103, and the front housing 118 are fastened and fixed by the through bolts 121.

The cylinder block 102, the valve plate 104 and the rear housing 119 are tightened and fixed by the through bolts 122.

Tightening of the bolts 121 flexes and deforms the annular race 120, which deflects preload on the rotating shaft 107 via the cone roller bearing 108.

Discharge chambers 123 and 124 are formed in both housings 118 and 119. The compression chambers Pa and Pb, which are partitioned into the cylinder bores 113, 114, 113A and 114A by the double head pistons 115 and 115A, are connected to the discharge chambers 123 and 124 via the discharge ports 103c and 104c on the valve plates 103 and 104. have. The discharge ports 103c and 104c are opened and closed by flapper valve type discharge valves 131 and 132. The opening degree of the discharge valves 131 and 132 is regulated by the retainers 133 and 134.

The discharge valves 131 and 132 and the retainers 133 and 134 are tightened and fixed on the valve plates 103 and 04 by bolts 135 and 136. The discharge chamber 123 communicates with an external discharge refrigerant gas pipeline (not shown) via the discharge passage 125.

Reference numeral 126 denotes a lip seal which prevents refrigerant gas leakage from the discharge chamber 123 along the circumferential surface of the rotating shaft 107 to the outside of the pressure gauge.

Rotary valves 127 and 128 are supported by the stepped portions 107a and 107b on the rotary shaft 107. Sealing rings 139 and 140 are interposed between the rotary valves 127 and 128 and the rotary shaft 107.

The rotary valves 127 and 128 are accommodated in the receiving holes 101a and 102a so as to be integrally rotatable with the rotation shaft 107. Discharge refrigerant gas pressures of the discharge chambers 123 and 124 act on one end of the rotary valves 127 and 128, and suction refrigerant gas pressures of the swash plate chamber 111 act on the lower end thereof. That is, the rotary valves 127 and 128 block the discharge pressure region and the suction pressure region.

Suction passages 129 and 130 are formed in the rotary valves 127 and 128. Inlets of the suction passages 129 and 130 are opened on the swash plate chamber 111, and outlets of the suction passages 129 and 130 are opened on the inner circumferential surfaces of the receiving holes 101a and 102a.

As shown in FIG. 12, the cylinder bores 113 and 113A and the same suction port 101b are arranged in the same angular position on the inner peripheral surface of the accommodation hole 101a which accommodates the rotary valve 127. As shown in FIG.

The suction port 101b and the cylinder bores 113 and 113A are always in communication one-to-one, and each suction port 101b is connected to the peripheral rotation area of the outlet of the suction passage 129.

Similarly, as shown in FIG. 13, cylinder bores 114 and 114A and the same number of suction ports 102b are arranged at equal intervals on the inner circumferential surface of the receiving hole 102a for receiving the rotary valve 128. As shown in FIG.

The suction port 102b and the cylinder bores 114 and 114A are always in one-to-one communication, and each suction port 102b is connected to the peripheral rotation region of the outlet of the suction passage 130.

In the state shown in Figs. 11, 12 and 13, the double head piston 115A is at the top dead center position with respect to one cylinder bore 113A and at the bottom dead center position with respect to the other cylinder bore 114A. have. In such a piston arrangement state, the outlet 129a of the suction passage 129 is immediately before connecting to the suction port 101b of the cylinder bore 113A, and the outlet 130a of the suction passage 130 is the cylinder bore 114A. Is immediately after connecting to the suction port 102b. That is, when the double head piston 115A enters the suction stroke from the top dead center position to the bottom dead center position with respect to the cylinder bore 113A, the suction passage 129 communicates with the compression chamber Pa of the cylinder bore 113A. . By this communication, the refrigerant gas in the swash plate chamber 111 is sucked into the compression chamber Pa of the cylinder bore 113A via the suction passage 129. On the other hand, when the double head piston 115A enters the discharge stroke from the bottom dead center position to the top dead center position with respect to the cylinder bore 114A, the suction passage 130 communicates with the compression chamber Pb of the cylinder bore 114A. Is blocked. By this communication interruption, the refrigerant gas in the compression chamber Pb of the cylinder bore 114A is discharged from the discharge port 104c to the discharge chamber 124 while pushing the discharge valve 132.

Such suction and discharge of the refrigerant gas are similarly performed in the compression chamber P of the other cylinder bores 113 and 114.

One end of the rotary shaft 107 protrudes outward from the front housing 118, and the other end protrudes into the discharge chamber 124 on the rear housing 119 side. A discharge passage 137 is formed in the shaft center portion of the rotary shaft 107. The discharge passage 137 is opened in the discharge chamber 124. A discharge port 138 is formed at a peripheral portion of the rotary shaft 107 surrounded by the discharge chamber 123 on the front housing 118 side, and the discharge chamber 123 and the discharge passage 137 communicate with each other by the discharge port 138. It is. Accordingly, the front and rear discharge chambers 123 and 124 communicate with each other by the discharge passage 137, and the refrigerant gas in the discharge chamber 124 joins the discharge chamber 123 from the discharge passage 137.

The thrust load on the rotary shaft 7 fluctuates as shown by the curve c in FIG. The positive side of the vertical axis is a thrust load directed from the front housing 118 side to the rear housing 119 side. The negative side of the vertical axis is a thrust load directed from the rear housing 119 side to the front housing 118 side. The straight lines L ₁ and L ₂ represent the preloads applied by the bending deformation of the preloading disc spring 120. The preload + Fo represented by the straight line L ₁ is opposed to the thrust load directed from the rear housing 119 side to the front housing 118 side. The preload (-Fo) indicated by the straight line L ₂ is opposed to the thrust load directed from the front housing 118 side to the rear housing 119 side. The preload Fo is set to exceed the maximum thrust load Fmax for some time.

By setting such a preload Fo, a gap in the trust direction occurs between the stepped portion 107a and the pressing projection 118a on the rotation shaft 107 and between the stepped portion 107b and the pressing projection 119a. There is no work. That is, the rotation shaft 7 does not rock, and abnormal noise and abnormal vibration do not occur.

This preload is determined by the spring characteristics and bending deformation amount of the preloading spring 120. The bending deformation amount of the preloading spring 120 depends on the assembly errors of the cylinder blocks 101 and 102, the valve plates 103 and 104, the front housing 118, the rear housing 119 and the preloading spring 120. If there is no nonuniformity in the assembly error, the preload will be nearly equal for any compressor.

In case of non-uniformity in assembly error, the preload is different for each compressor. In such a case, the shim is appropriately interposed between the pressing projection 118a and the preloading spring 120 or between the outer ring 109a and the pressing projection 119a of the cone roller bearing 109. Appropriate preload can be given. That is, the preloading can be stably managed in the swash plate compressor, and the quality of the swash plate compressor with respect to noise and vibration is stabilized.

In addition, since both the radial load and the thrust load on the rotating shaft 107 are received via the cone roller bearings 108 and 109, the number of bearing members due to the rotating shaft 107 is halved than before. Therefore, the assembly work process is simplified.

In this embodiment, the rotary valves 127 and 128 are employed as the intake valves, but this configuration employs the following advantages.

In the case of the flapper valve type suction valve, the lubricating oil increases the suction force between the suction valve and its close contact surface, and the opening timing of the suction valve is delayed by the suction force. This delay and the suction resistance due to the elastic resistance of the suction valve lower the volumetric efficiency.

However, the adoption of the rotary valves 127 and 128, which are forcibly rotated, does not cause the problem of suction force due to lubricating oil and suction resistance due to elastic resistance of the suction valve, and the pressure in the compression chambers Pa and Pb is sucked in the swash plate chamber 111. When the pressure is slightly lower, the refrigerant gas immediately flows into the compression chambers Pa and Pb. Therefore, when the rotary valves 127 and 128 are employed, the volumetric efficiency is greatly improved as compared with the case of employing the flapper valve type intake valve.

In the conventional cylinder block, one suction passage is provided in the gap between neighboring cylinder bores, and the presence of such suction 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 bore is widened to the extent that the strength of the cylinder block can be secured, and the arrangement interval of the cylinder block cannot be narrowed as long as the suction passage and the discharge passage exist in the cylinder block.

The configuration in which the suction refrigerant gas of the swash plate chamber 11 is sucked into the compression chambers Pa and Pb via the suction passages 129 and 130 in the rotary valves 127 and 128 is a plurality of suction passages in the cylinder block in the conventional swash plate type compressor. Is unnecessary. Moreover, the structure which guides the discharge refrigerant gas discharged | emitted to the discharge chamber 124 to the discharge path 125 via the discharge path 137 in the rotating shaft 107 is a discharge path in the cylinder block in the conventional swash plate type compressor. It is unnecessary.

By excluding the suction passage and the discharge passage from the cylinder blocks 1 and 2, the arrangement interval of the cylinder bores 113, 113A, 114 and 114A can be narrowed.

The reduction in the arrangement intervals of the cylinder bores 113, 113A, 114 and 114A is linked to the reduction in the arrangement radius of the cylinder bores 113, 113A, 114 and 114A and the reduction in the overall diameter of the cylinder blocks 101 and 102 is achieved.

Thus, reduction in diameter and weight of the entire compressor is achieved.

The adoption of the rotary valves 127 and 128 eliminates the need for suction chambers in the conventional front and rear housings. Thus, instead of this suction chamber, conical roller bearings 108 and 109 can be arranged in the front housing 118 and in the rear housing 119. That is, due to the use of the rotary valves 127 and 128, it is not necessary to prepare an arrangement space for the bearing members in excess and does not impair compaction of the compressor.

The refrigerant gas in the swash plate chamber 111 is sucked into the compression chambers P, Pa, and Pb when the pressure in the compression chambers Pa and Pb falls below the pressure in the swash plate chamber 111. If the flow path resistance in the refrigerant gas flow path from the swash plate chamber 111 to the compression chambers P, Pa, and Pb, that is, the suction resistance is high, the pressure loss is increased and the compression efficiency is lowered. By employing the rotary valves 127 and 128, the length of the refrigerant gas flow path from the swash plate chamber 111 to the compression chambers P, Pa, and Pb is shortened, and the suction resistance is reduced than before. Therefore, the loss is reduced and the compression efficiency is improved.

The present invention is, of course, not limited to the above embodiment, and for example, in the above embodiment, the preloading spring 120 may be interposed between the rear housing 119 and the outer ring 109a of the cone roller bearing 109.

As shown in Fig. 16, a coil spring type preloading spring 141 may be used. Adoption of the preload spring 141 of the coil spring type is disadvantageous in terms of the installation space as compared with the annular leaf spring type, but the non-uniformity of the preload is almost eliminated. That is, preload provision in a swash plate type compressor can be managed more stably.

The present invention also applies to the swash plate compressor shown in FIGS. 17 to 19.

As shown in FIG. 17, the rotary shaft 145 is rotatably supported via the cone roller bearings 146 and 147 in the front and rear pairs of cylinder blocks 143 and 144 tightened and joined by bolts 142. The cone roller bearings 146 and 147 are accommodated in the receiving holes 143a and 144a. The outer races 146a and 147a of the conical roller bearings 146 and 14a are slidably fitted into the receiving holes 143a and 144a. The outer races 146 and 147b sandwiching the rollers 146c and 147c together with the outer races 146a and 147a are fixed to the rotation shaft 145.

The swash plate 148 is fixed to the rotating shaft 145. Inlet ports 149 and 150 are formed in the cylinder blocks 143 and 144, and external intake refrigerant gas pipelines (not shown) are connected to the inlet ports 149 and 150. Inlet ports 149 and 150 communicate with swash chamber 166.

As shown in FIG. 18, a plurality of cylinder bores 151 and 152 are formed at equally spaced angular positions around the rotation shaft 145. As shown in FIG. As shown in FIG. 17, the double-headed piston 153 is reciprocally accommodated in the cylinder bores 151 and 152 paired with each other in front and rear, and between the two-headed piston 153 and the front and rear surfaces of the swash plate 148, Shoe 116,117 is interposed.

The front cover 154 is fastened to the end surface of the cylinder block 143 by the through bolt 155. The rear cover 156 is also fastened to the end face of the cylinder block 144 by the bolt 157. An annular preloading spring 182 is interposed between the front cover 154 and the outer ring 146a of the cone roller bearing 146. The front cover 154 abuts on the outer circumferential edge of the preloading spring 182 and the outer ring 146a abuts on the inner circumferential edge of the preloading spring 182. The rear cover 156 is in contact with the outer ring 147a of the cone roller bearing 147. The preloading spring 182 is warped and deformed like the first embodiment.

Discharge chambers 158 and 159 are formed in both covers 154 and 156. The discharge chambers 158, 159 are connected to the cylinder bores 151, 152 via the discharge ports 154a, 156a on the covers 154, 156.

The discharge chamber 158 communicates with an external discharge refrigerant gas pipeline (not shown) via the discharge passage 160. Reference numeral 161 denotes a lip seal preventing leakage of refrigerant gas from the discharge chamber 158 along the main surface of the rotating shaft 145 to the outside of the compressor.

A pair of suction chambers 162 and 163 are formed in the double head piston 153. The suction chambers 162 and 163 communicate with the swash plate chamber 166 via the inlets 164 and 165 on the double head piston 153 and the refrigerant gas in the swash plate chamber 166 can enter the suction chambers 162 and 163 through the inlet ports 164 and 165. Do.

As shown in FIG. 19, the suction port 167 is perforated in the head end surface of the front head piston 153, and the suction valve 168 is interposed on the suction port 167. As shown in FIG. The suction valve 168 accommodates and holds the valve seat 169 and the disk-shaped float valve 170 and the float valve 170 accommodated in the valve seat 169 that are fitted and fixed to the head end face within the valve seat 169. It is composed of a retainer 170 of the circlip type. A valve hole 173 is formed in the valve seat 169, and the hole 172 is opened and closed by the float valve 170.

A suction port 173 is also provided in the rear end face of the double head piston 153, and a suction valve 174 similar to the suction valve 168 is interposed on the suction port 173.

The discharge valve 175 is described on the discharge port 154a. As shown in FIG. 19, the discharge valve 175 includes a valve seat 176 and a disk-shaped float valve 177 and a float valve 177 accommodated in the valve seat 176, which are fitted into the front cover 154 and are fixed. The retainer 178 for accommodating and holding in the valve seat 176 is comprised. The valve seat 176, the float valve 177, and the retainer 178 all have the same shape as the valve seat 169, the float valve 170, and the retainer 171 of the intake valve 168.

The discharge valve 179 similar to the discharge valve 175 is interposed on the discharge port 156a.

In the reciprocating stroke of the cylinder bore 151 side of the double head piston 153, the refrigerant gas in the suction chamber 162 pushes the float valve 170 and compresses between the double head piston 153 and the front cover 154. It is sucked into the chamber Pa. The float valve 170 abuts against the retainer 171 to regulate the opening degree. At the time of the reciprocating movement of the cylinder bore 151 side of the double head piston 153, the refrigerant gas in the compression chamber Pa pushes the float valve 170 and is discharged to the discharge chamber 158.

The float valve 177 abuts the retainer 178 so that the opening degree is regulated.

Similar suction discharge is also performed through the suction valve 174, the discharge valve 174, and the discharge valve 179 on the compression chamber Pb side between the double head piston 153 and the rear cover 154.

One end of the rotary shaft 145 protrudes from the front cover 154 to the outside, and the other end protrudes into the discharge chamber 159 on the rear cover 156 side. The discharge passage 180 is formed in the shaft center of the rotating shaft 145. The discharge passage 180 is opened in the discharge chamber 159.

A discharge port 181 is formed at a portion of the rotation shaft 145 surrounded by the discharge chamber 158, and the discharge chamber 158 and the discharge passage 180 communicate with each other by the discharge port 181. The discharge refrigerant gas flowing into the discharge passage 180 from the discharge chamber 159 flows out of the discharge port 181 into the discharge chamber 158. The discharge refrigerant gas of the discharge chamber 158 is discharged to the external discharge refrigerant gas pipe via the discharge passage 160.

In this embodiment as well, the bending deformation of the preloading spring 182 imparts a preload to the rotating shaft 145 via the cone roller bearings 146 and 147. Therefore, as in the first embodiment, preloading in the swash plate type compressor can be stably managed, and the quality of the swash plate type compressor with respect to noise and vibration is stabilized.

In addition, the configuration in which the suction refrigerant gas to the swash plate accommodation chamber 166 is sucked into the compression chambers Pa and Pb via the suction chambers 162 and 163 in the double head piston 153 is a plurality of cylinders in the conventional swash plate type compressor. The suction passage of the cable is unnecessary. In addition, the discharge passage in the cylinder block of the conventional swash plate type compressor is configured to lead the discharge refrigerant gas discharged to the discharge chamber 159 to the discharge passage 160 via the discharge passage 180 in the rotary shaft 145. It is unnecessary. Therefore, the shaft bore of the arrangement bore of the cylinder bores 151 and 152 can be reduced in diameter, and the shaft reduction and weight reduction of the whole compressor can be obtained.

In addition, the suction chamber, which has been provided before and after the cylinder block, replaces the suction chambers 162 and 163 in the double head piston 153 in the fourth embodiment, and this arrangement change also contributes to the compactness of the entire compressor.

Effects of the Invention

As described in detail above, the present invention rotatably supports the rotating shaft for supporting the swash plate with a pair of conical roller bearings, and establishes a slidable coupling relationship between the support and the outer ring for supporting the outer ring of the conical roller bearing. The spring force of the preloaded spring, which is applied in the direction of receiving the thrust load, is applied to the outer ring of the at least one conical roller bearing, thus reducing the number of bearing members on the rotating shaft, which simplifies the assembly process and furthermore the trust on the rotating shaft. The preloading of the direction also shows an excellent effect that it can be stably managed.

In addition, during high compression ratio operation, the thermal expansion amount of the cylinder block by the high-pressure compressed gas can be suppressed by the through bolts, and the preload to the rotating shaft by the preloading spring can be properly maintained, and the occurrence of vibration or abnormal noise can be suppressed. Can be. In addition, the present invention can set the load of the preloading spring to an appropriate load, so that the durability of the cone roller bearing can be improved and the power loss required to rotate the rotating shaft can be suppressed.

Claims (2)

It has a plurality of pairs of cylinder bores 13, 14, 13a, 14a arranged around the rotary shaft 7 and paired in front and rear, and accommodates the double-headed pistons 15, 15a in the bore, and on the rotary shaft 7. In the supporting structure of the rotary shaft in the swash plate type compressor which converts the rotational movement of the supported swash plate 10 into the reciprocating motion of the double head pistons 15 and 15a, the rotary shaft 7 is a pair of conical roller bearings 8, 9) is rotatably supported, and the contact portion between the supports 3a, 4a and the outer rings 8a, 9a for supporting the outer rings 8a, 9a of the cone roller bearings 8, 9 is formed by a slidable coupling. And the spring force of the preloading spring 20, which is added in the direction in which the conical roller bearing 8 receives the axial load, to the outer ring 8a of the at least one conical roller bearing. Support structure of the rotating shaft in the compressor. A plurality of pairs of cylinder bores 13, 14, 13a, and 14a are formed in a plurality of places around the rotation shaft 7 before and after the cylinder block 1, and the front and rear sides of the cylinder block 1 The swash plate (18) and the rear housing (19) are fixed to each other, and the two piston pistons (15, 15a) are accommodated in the cylinder bores (13, 14, 13a, 14a), respectively, and the swash plate supported on the rotating shaft ( In the support structure of the rotating shaft in the swash plate type compressor which converts the rotational movement of 10 into the reciprocating motion of the double head pistons 15 and 15a, the rotary shaft 7 is connected to a pair of conical roller bearings 8 and 9. Contact surfaces between the supports 3a, 4a and the outer rings 8a, 9a, which are rotatably supported by the support, and which support the outer rings 8a, 9a of the cone roller bearings 8, 9, are slidable in the axial direction. The front and rear housings 19 support the end faces of the outer races 8a and 9a of the pair of cone roller bearings 8 and 9. And a preload force for applying a spring force in a direction in which the cone roller bearing 8 receives the axial load between the outer ring 8a of the at least one cone roller bearing 8 and the inner wall of the housing 18. The cylinder block 1, the front housing 18 and the rear housing 19 are fastened by a common through-bolt 21 via a grant spring 20 to fix the rotary shaft in the swash plate type compressor. Support structure.