JPH08334085A - Reciprocating type compressor - Google Patents

Abstract

PURPOSE: To reduce manufacturing cost by eliminating the necessity of using an expensive rolling bearing as a radial bearing to support a rotary shaft. CONSTITUTION: A radial bearing 18 to support a rotary shaft 16 is composed of a sliding bearing. Its bearing 18 is composed of a shaft support hole 37, and a bearing part 38 of the rotary shaft 16 is supported in the hole 37. A recessed part 40 is formed so as to correspond to cylinder bores 20 where pistons 21 exist in the vicinity of the upper dead center on an outside surface of the bearing part 38 of the rotary shaft 16. Plural gas passages 41 are formed between the respective cylinder bores 20 and the bearing hole 37. When the respective pistons 21 are operated so as to be compressed according to rotation of the rotary shaft 16, the recessed part 40 communicates in order with the respective gas passages 41, and a high pressure refrigerant gas in the respective cylinder bores 20 is introduced into the recessed part 40. As a result, pressure of the recessed part 40 is increased, and its pressure is applied to the rotary shaft 16 as force in the opposite direction of radial directional component force P2 acting on the rotary shaft 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reciprocating compressor such as a swash plate compressor.

[0002]

2. Description of the Related Art As a reciprocating compressor of this type, one having a structure as shown in Japanese Utility Model Laid-Open No. 64-46480 is known. In this structure, the rotary shaft is supported in the housing via the radial bearing, and a plurality of cylinder bores accommodating the piston so as to reciprocate are formed around the rotary shaft. A swash plate is supported on the rotary shaft in the crank chamber of the housing, and the piston is reciprocated through the swash plate as the rotary shaft rotates.

[0003]

By the way, in this type of compressor, since the swash plate is inclined, the compression load generated during the compression operation of the piston, that is, the compression reaction force, is rotated via the swash plate. It acts on the shaft as a radial component of the rotary shaft, and a large load is applied to the radial bearing. The component force in the radial direction will be described in detail later. Therefore, in conventional compressors, rolling bearings such as needle bearings and ball bearings are used as radial bearings so that even if such a large radial load is applied, smooth rotation of the rotating shaft is not hindered. It was

However, since rolling bearings such as needle bearings and ball bearings are expensive, there is a problem in that the cost reduction of the compressor is hindered. The present invention has been made by paying attention to the problems existing in such conventional techniques. The purpose of the invention is to provide a compressor that can reduce the manufacturing cost without using expensive rolling bearings such as needle bearings and ball bearings as radial bearings that support the rotating shaft. is there.

[0005]

In order to achieve the above object, in the invention described in claim 1, the radial bearing is constituted by a sliding bearing, and between the sliding bearing and the rotating shaft, a piston is provided. A reaction force applying means is provided for applying a force in the opposite direction to the force acting in the radial direction to the rotary shaft via the swash plate during the compression operation.

According to a second aspect of the present invention, in the first aspect, the reaction force applying means is formed so that the piston corresponds to the cylinder bore near the top dead center on the outer surface of the rotary shaft facing the slide bearing. And a gas passage for introducing high-pressure gas into the recess.

According to a third aspect of the present invention, in the second aspect, the gas passage of the reaction force applying means is formed in the housing so as to connect each cylinder bore and the inner peripheral surface side of the sliding bearing, and the rotary shaft is provided. When the pistons are reciprocally moved in accordance with the rotation of, the recesses communicate with the gas passages in order, and the high-pressure gas in each cylinder bore is introduced into the recesses through the gas passages.

According to a fourth aspect of the present invention, in the third aspect, the recess of the reaction force applying means extends from the cylinder bore where the piston is near the top dead center to the cylinder bore side which is in the middle of the compression stroke from the cylinder bore. It is provided with the formed pressure action part.

According to a fifth aspect of the invention, in the fourth aspect, the recess is further connected to a pressure acting portion, and the gas passage of each cylinder bore in which the piston is moved to near the top dead center with the rotation of the rotating shaft. And a discharge pressure introducing groove that communicates with in order.

According to a sixth aspect of the present invention, in the fourth aspect, the recess is further connected to the pressure acting portion, and the piston communicates sequentially with the gas passages of the cylinder bores in the middle of the compression stroke as the rotary shaft rotates. The intermediate pressure introducing groove is provided.

According to a seventh aspect of the present invention, in the fourth aspect, the concave portion is further connected to the pressure acting portion, and the piston is connected to the gas passage of each cylinder bore immediately after the completion of the compression stroke in accordance with the rotation of the rotating shaft. It is provided with a communicating expansion gas introduction groove.

In the invention described in claim 8, claims 1 to 7 are provided.
In any one of the above, the piston is a single-headed piston.

[0013]

According to the invention described in claim 1, since the radial bearing for supporting the rotary shaft is constituted by the sliding bearing, it is less expensive than rolling bearings such as needle bearings and ball bearings. Further, when the piston is reciprocated through the swash plate due to the rotation of the rotary shaft to perform the compression operation, the compression load acts on the rotary shaft through the swash plate as a radial component force. , A large load is applied to the sliding bearing. That is, the rotary shaft is strongly pressed against the sliding bearing, and the sliding resistance between them increases. However, by the reaction force imparting means provided between the sliding bearing and the rotary shaft, a force in the opposite direction to the force acting on the rotary shaft in the radial direction is applied to the rotary shaft, and the radial direction is applied. The powers of are offset. Therefore, the rotary shaft is not strongly pressed against the sliding bearing, and even if the sliding bearing is used, smooth rotation of the rotating shaft is not hindered.

According to the second aspect of the present invention, when the piston reciprocates, the high pressure gas is introduced into the recess on the rotary shaft through the gas passage, and the pressure in the recess is increased. As a result, a force in the opposite direction to the radial force acting on the rotary shaft is applied to the rotary shaft, and the radial force is offset. Therefore, the radial force acting on the rotary shaft can be reliably canceled by the simple structure of the reaction force applying means.

According to the third aspect of the present invention, when the pistons are reciprocated along with the rotation of the rotary shaft, the recesses on the rotary shaft are communicated with the gas passages in order, and the high pressure gas in each cylinder bore is Are efficiently introduced into the recess through the gas passage.

According to the fourth aspect of the invention, the pressure acting portion of the concave portion provided on the rotary shaft extends from the cylinder bore where the piston is near the top dead center to the cylinder bore side which is in the middle of the compression stroke from the cylinder bore. Formed across. In other words, the position at which the resultant force of the compression loads from the multiple pistons arranged around the rotation axis acts as the largest radial force on the rotation axis is the position corresponding to the top dead center where the compression load becomes the largest. The position is slightly displaced toward the compression stroke side. Therefore, by providing the pressure acting portion corresponding to the position, the radial force acting on the rotary shaft can be effectively canceled.

According to the fifth aspect of the present invention, the discharge pressure introducing groove of the concave portion on the rotary shaft is only associated with the gas passage of each cylinder bore in which the piston is moved to the top dead center with the rotation of the rotary shaft. The high pressure gas in the cylinder bore is efficiently introduced into the pressure acting portion.

According to the sixth aspect of the present invention, as the rotary shaft rotates, the intermediate pressure introducing groove of the recess on the rotary shaft is communicated with only the gas passage of each cylinder bore in which the piston is in the middle of the compression stroke. Only the intermediate pressure gas lower than the discharge pressure is efficiently introduced into the pressure acting portion.

According to the invention as set forth in claim 7, as the rotary shaft rotates, the expansion gas introduction groove of the recess on the rotary shaft communicates only with the gas passages of the cylinder bores immediately after the piston completes the compression stroke. To be done. Therefore, only the gas that remains in the cylinder bore after the compression stroke and expands with the start of the suction stroke of the piston is efficiently introduced into the pressure acting portion.

According to the invention described in claim 8, when the present invention is applied to a compressor provided with a single-headed piston,
The radial force acting on the rotating shaft can be more effectively offset.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment in which the present invention is embodied in a single-head piston type swash plate compressor will be described in detail below with reference to FIGS.

As shown in FIGS. 1 and 3, the cylinder block 11 constitutes a part of the housing of the entire compressor, the front housing 12 is joined to the front end surface thereof, and the rear housing 13 is attached to the rear end surface thereof. Are joined via the valve plate 14. The plurality of through bolts 15 are screwed into the rear housing 13 from the front housing 12 through the cylinder block 11 and the valve plate 14, and the through bolts 15 fix the front housing 12 and the rear housing 13 to both end surfaces of the cylinder block 11. Has been done.

The rotary shaft 16 is the front housing 12
The cylinder block 11 is rotatably supported at the center of the cylinder block 11 via a pair of radial bearings 17 and 18, and a lip seal 19 is interposed between the outer periphery of the front end of the cylinder block 11 and the front housing 12. The front radial bearing 17 is a needle bearing, and the rear bearing 18 is a plain bearing (slide bearing). The rotary shaft 16 is operatively connected to a drive source such as a vehicle engine via a pulley and a belt (not shown), and is rotated by the drive source.

A plurality of cylinder bores 20 are provided on the rotary shaft 16
The cylinder block 11 is penetrated between both ends of the cylinder block 11 at predetermined intervals so as to extend in parallel therewith, and a single-headed piston 21 is reciprocally fitted and supported therein. The crank chamber 22 is the cylinder block 11
It is partitioned and formed inside the front housing 12 on the front side.

The lug plate 23 is integrally rotatably attached to the rotary shaft 16 in the crank chamber 22, and a thrust bearing 24 is interposed between the front surface of the lug plate 23 and the inner surface of the front housing 12. The support arm 25 is provided so as to project from the upper rear surface of the lug plate 23 toward the cylinder block 11 side, and a pair of guide holes 26 extending in a direction intersecting the axis of the rotary shaft 16 are formed at the tip thereof.

The swash plate 27 having a substantially disk shape is the rotary shaft 1
6 is slidably inserted in the axial direction,
A pair of spherical connecting bodies 28 are provided on the front surface so as to project.
The spherical connecting member 28 is pivotally and slidably engaged with the guide hole 26 of the supporting arm 25, so that the swash plate 27 is connected to the lug plate 23 so that the swash plate 27 can rotate integrally and the tilt angle can be changed. It

A pair of shoes 30 having hemispheres are slidably fitted to the base ends of the pistons 21 at the hemispheres. Sliding surfaces 29 are formed on both the front and rear sides of the outer peripheral portion of the swash plate 27, and the shoes 3 are formed on the sliding surface 29.
0 is slidably moored on its flat surface. When the rotary shaft 16 is rotated by the drive source, the swash plate 27 is rotated via the lug plate 23, and each piston 21 is reciprocated in the cylinder bore 20.

The spring 31 is interposed between the swash plate 27 and the lug plate 23 on the rotary shaft 16, and the spring 3
1, the swash plate 27 is biased rearward, that is, in the direction of decreasing the tilt angle. The stopper 32 is the rotary shaft 16
When the swash plate 27 is disposed in the middle portion of the swash plate 27 and is moved rearward as the tilt angle decreases, the stopper 32 engages with the swash plate 27 to regulate the minimum tilt angle position of the swash plate 27.

The suction chamber 33 is formed in an annular shape on the outer periphery of the rear housing 13 and is connected to an external refrigerant circuit via a suction opening (not shown). The discharge chamber 34 is defined in the center of the rear housing 13 and is connected to an external refrigerant circuit via a discharge opening (not shown). Then, depending on the pressure difference between the pressure in the crank chamber 22 via the piston 21 and the pressure in the cylinder bore 20, the swash plate 2
The inclination angle of 7 is changed.

The suction valve mechanism 35 is formed in the valve plate 14, and when the piston 21 is reciprocated in the cylinder bore 20, the suction valve mechanism 35 sucks the refrigerant gas from the suction chamber 33 into the compression chamber of each cylinder bore 20. To be done. The discharge valve mechanism 36 is formed on the valve plate 14, and when the piston 21 reciprocates in the cylinder bore 20, the discharge valve mechanism 36 discharges the refrigerant gas compressed in the compression chamber of each cylinder bore 20 to the discharge chamber 34. It

As shown in FIGS. 1 to 3, the rear radial bearing 18 comprises a shaft support hole 37 formed in the center of the cylinder block 11, and the rear end of the rotary shaft 16 is located in the shaft support hole 37. A large-diameter shaft support portion 38 formed in the above is rotatably fitted and supported. The reaction force application structure 39 as a reaction force application means is formed between the shaft support hole 37 of the radial bearing 18 and the shaft support portion 38 of the rotary shaft 16, and the piston 2
In the compression operation of No. 1, the force acting in the radial direction on the rotary shaft 16 via the swash plate 27 is applied to the rotary shaft 16 in the opposite direction.
6 is given.

That is, the concave portion 4 of the reaction force applying structure 39.
0 is formed on the outer surface of the shaft support portion 38 of the rotary shaft 16 facing the shaft support hole 37 so that the piston 21 corresponds to the cylinder bore 20 near the top dead center. Further, the recess 40 is formed in the pressure acting portion 40b formed from the cylinder bore 20 where the piston 21 is near the top dead center to the cylinder bore 20 side which is in the middle of the compression stroke from the cylinder bore 20, and the pressure acting portion 40b. It is provided with a discharge pressure introducing groove 40a that is connected and has the piston 21 extended in the axial direction so as to correspond to the cylinder bore 20 near the top dead center.

The plurality of gas passages 41 constituting the reaction force imparting structure 39 have a rear end of each cylinder bore 20 and a shaft support hole 37.
It is formed in the cylinder block 11 so as to extend between and. Then, as the rotary shaft 16 rotates, the swash plate 27
When each piston 21 is compressed through the recesses 4,
The introduction groove 40a of 0 communicates with the gas passage 41 of each cylinder bore 20 in which the piston 21 is moved to the vicinity of the top dead center in order. By this operation, the high pressure refrigerant gas in the compression chamber of each cylinder bore 20 is introduced into the pressure acting portion 40b of the recess 40 through the gas passage 41.

Next, the operation of the compressor configured as described above will be described. In the compressor of this embodiment, when the lug plate 23 is rotated by the drive source such as the vehicle engine via the rotary shaft 16, each piston 21 is reciprocated with a stroke corresponding to the tilt angle of the swash plate 27. It As a result, the refrigerant gas flows from the suction chamber 33 into each cylinder bore 2
0 is sucked into the compression chambers, compressed in the compression chambers, and then discharged into the discharge chamber 34. During this compression operation,
Since the swash plate 27 is inclined, as shown in FIGS. 1 and 3, the compressive load P1 from each piston 21 is reduced by the swash plate 27.
Acting on the rotary shaft 16 as a component force P2 in the radial direction of the rotary shaft 16 via. Therefore, the rotary shaft 16
Is the radial bearing 1 in the direction of the component force P2
The bearings 17, 18 are strongly pressed against the bearings 7, 18, and a large load is applied to the bearings 17, 18 in the radial direction.

However, at the time of compression operation of each piston 21, the discharge pressure introducing groove 40a of the recess 40 on the rotary shaft 16 is communicated with each gas passage 41 in order at the position corresponding to the rear radial bearing 18, so that each cylinder bore. The high-pressure refrigerant gas is introduced from the compression chamber 20 into the pressure acting portion 40b of the recess 40 through the gas passage 41. As a result, the pressure in the pressure acting portion 40b is increased, and the pressure is applied to the rotary shaft 16 as a force in the direction opposite to the radial component force P2 acting on the rotary shaft 16. As a result, the radial force P2 acting on the rotating shaft 16 is canceled.

Therefore, since the rotary shaft 16 is not strongly pressed against the rear radial bearing 18 and a large load is not applied to the bearing 18, the radial bearing 18 is inexpensive as in the present embodiment. Even if the sliding bearing is used, smooth rotation of the rotary shaft 16 is not hindered. Therefore, it is not necessary to use an expensive rolling bearing such as a needle bearing or a ball bearing as the radial bearing 18, and the manufacturing cost of the compressor can be reduced. In addition, there is no problem of noise that occurs when a rolling bearing is used, and the rollers and balls of the bearing are fatigued or deteriorated, so that the rotating shaft 16
There is no problem that it hinders the smooth rotation of the.

Further, in the compressor of this embodiment, the reaction force applying structure 39 as the reaction force applying means has the recess 40 formed on the outer surface of the rotary shaft 16 and the gas passage 41 formed in the cylinder block 11. It consists of Therefore, as a reaction force imparting means, the concave portion 40 is simply formed on the outer surface of the rotary shaft 16 and the gas passage 41 is formed through the cylinder block 11. The force P2 can be reliably offset.

Further, in the compressor of this embodiment, the pressure acting portion 40b of the concave portion 40 has the cylinder bore 20 where the piston 21 is near the top dead center on the outer surface of the rotary shaft 16.
From the cylinder bore 20 to the cylinder bore 20 side in the middle of the compression stroke. That is, at the position where the resultant force of the compression loads P1 from the plurality of pistons 21 arranged around the rotary shaft 16 acts as the largest radial component force P2 on the rotary shaft 16, the compression load P1 becomes the largest. It is a position slightly displaced to the compression stroke side from the position corresponding to the top dead center. For this reason, by providing the pressure acting portion 40b in such a manner as to correspond exactly to that position, the radial force P2 acting on the rotary shaft 16 can be more effectively offset.

Moreover, the concave portion 40 is the pressure acting portion 40b.
A discharge pressure introducing groove 40a connected to
0a indicates the gas passage 41 of each cylinder bore 20 in which the piston 21 is moved to the vicinity of the top dead center as the rotary shaft 16 rotates.
It is communicated with only in order. As a result, each cylinder bore 20
Only the refrigerant gas having a high pressure inside can be efficiently introduced into the pressure acting portion 40b of the recess 40 through the gas passage 41. Therefore, the pressure in the pressure acting portion 40b is
It can be sufficiently increased so as to be able to counter the radial force P2 acting on the rotating shaft 16.

In addition, in this embodiment, since the refrigerant gas is introduced into the recess 40 formed on the outer surface of the shaft supporting portion 38 of the rotary shaft 16, the lubricating oil contained in the refrigerant gas is supplied to the shaft supporting portion. 38 and the axial support hole 3 of the radial bearing 18
It can be efficiently supplied to the sliding portion between the sliding member and the sliding member. Therefore, it is possible to suppress the sliding resistance between the rotary shaft 16 and the radial bearing 18 and rotate the rotary shaft 16 more smoothly. Further, by providing such a recess 40, the pressure drop of the high-pressure refrigerant gas in the recess 40 can be suppressed, and a large load capacity can be secured.

In particular, when the present invention is embodied in a single-head piston type swash plate compressor having a single-head type piston 21 as in this embodiment, the radial force P2 acting on the rotary shaft 16 is applied. The invention can be more effectively offset, and the present invention is particularly effective.

[0042]

Another Embodiment Next, another embodiment of the present invention will be described with reference to FIGS.
It will be described with reference to FIG. First, a second embodiment shown in FIG. 4 is one in which the present invention is embodied in a double-headed piston type swash plate compressor, in which a pair of cylinder blocks 11 are jointly arranged, and the cylinder bores 2 of the cylinder blocks 11 are arranged.
A double-headed piston 21 is reciprocally fitted in and supported in 0. A front housing 12 and a rear housing 13 are joined and arranged at the front and rear ends of the cylinder block 11 via valve plates 14, respectively. A suction chamber 33 and a discharge chamber 34 are formed in the front housing 12 and the rear housing 13, respectively.
A suction valve mechanism 35 and a discharge valve mechanism 36 are formed in each valve plate 14 in correspondence with the valve 3 and the discharge chamber 34.

The pair of front and rear radial bearings 17 and 18 for supporting the rotary shaft 16 are both plain bearings (slide bearings). Similar to the first embodiment, each radial bearing 17, 18 is provided with a shaft support hole 37 formed in the cylinder block 11, and a large diameter shaft support portion 38 on the rotary shaft 16 is provided in the shaft support hole 37. It is rotatably fitted and supported. Each shaft support hole 37 and each shaft support 3
The reaction force imparting structure 39 is formed between each of them and the reaction force imparting structure 39, and each reaction force imparting structure 39 is composed of a concave portion 40 including a discharge pressure introducing groove 40a and a pressure acting portion 40b, and a plurality of gas passages 41. .

Therefore, in the second embodiment, it is not necessary to use expensive rolling bearings such as needle bearings and ball bearings for the radial bearings 17 and 18 that support the rotary shaft 16. Therefore, as described above, inexpensive sliding bearings can be used for both the radial bearings 17 and 18, and the manufacturing cost of the compressor can be reduced.

Next, in the third embodiment shown in FIG.
A cylindrical shaft support member 42 made of a metal material having wear resistance such as iron is fitted and arranged in the shaft support hole 37 of the radial bearing 18 supporting the rotary shaft 16. The shaft support 38 of the rotary shaft 16 is rotatably supported in the shaft support member 42. Therefore, in this third embodiment,
The wear resistance of the shaft support hole 37 of the cylinder block 11 made of aluminum alloy or the like can be enhanced.

Further, in the fourth embodiment shown in FIG. 6, an intermediate pressure introducing groove 40c is extended at the edge of the pressure acting portion 40b of the recess 40 in the reaction force applying structure 39, instead of the discharge pressure introducing groove 40a. Has been formed. This intermediate pressure introducing groove 40c
Is the gas passage 4 of the cylinder bore 20 in front of the top dead center during the compression stroke of the piston 21 as the rotary shaft 16 rotates.
1 are formed so as to communicate with each other in order. Therefore, during the compression operation of the piston 21, the intermediate pressure introducing groove 40c communicates with the gas passage 41, and only the refrigerant gas having an intermediate pressure lower than the discharge pressure is efficiently introduced into the pressure acting portion 40b.

Further, as shown by a chain line in FIG. 6, an expansion gas introducing groove 40d may be formed instead of the discharge pressure introducing groove 40a and the intermediate pressure introducing groove 40c. The expansion gas introduction groove 40d is connected to the gas passage 41 of the cylinder bore 20 that has passed the top dead center immediately after the completion of the compression stroke (in other words, immediately after the start of the suction stroke) as the rotation shaft 16 rotates. Has been formed. Therefore, the piston 21
At the time of the operation, the expansion gas introducing groove 40d communicates with the gas passage 41, the pressure acting portion 40b remains in the cylinder bore 20 after the compression stroke, and expands with the start of the suction stroke of the piston 21. Only are efficiently introduced.

Thus, the pressure acting portion 40b of the recess 40 is
How much pressure is introduced into the introduction groove 40a,
It can be easily selected by changing 40c and 40d. Further, which of the introduction grooves 40a, 40c, 40d should be selected or the size of the pressure acting portion 40b should be determined in consideration of the radial force P2 acting on the rotary shaft 16. Should be selected.

The present invention can be modified and embodied as follows. (1) In a compressor in which a rotary valve is disposed in a portion of the rotary shaft 16 corresponding to the radial bearing, as disclosed in, for example, Japanese Patent Application Laid-Open No. 5-126039, a reaction force applying structure 39 is provided on the rotary valve. To be installed. Incidentally, this rotary valve is provided so as to be rotatable integrally with the rotary shaft 16 and has an intake passage for introducing gas into each cylinder bore 20 in the intake stroke. Therefore, in the compressor provided with this rotary valve, the passage provided for communicating the intake passage on the rotary valve with each cylinder bore can be used as it is as the gas passage 41.

(2) A gas passage 41 for introducing high-pressure gas into the recess 40 is provided so as to connect the discharge chamber 34 and the inner peripheral surface side of the shaft support hole 37, and the high-pressure refrigerant in the discharge chamber 34 is provided. The gas is introduced into the recess 40.

(3) The present invention is applied to a single-head piston type swash plate compressor in which the inclination angle of the swash plate 27 is constant.

[0052]

Since the present invention is constructed as described above, it has the following effects. According to the invention described in claim 1, the force acting in the radial direction on the rotary shaft via the swash plate during the compression operation of the piston can be canceled by the reaction force applying means. Therefore, a large load does not act on the radial bearing that supports the rotating shaft, and it is not necessary to use an expensive rolling bearing such as a needle bearing or a ball bearing as the radial bearing, and even if an inexpensive sliding bearing is used, it does not rotate. The smooth rotation of the shaft is not hindered, so that the manufacturing cost of the compressor can be reduced.

According to the second aspect of the invention, the radial force acting on the rotary shaft can be reliably canceled by the simple structure of the reaction force applying means. According to the invention described in claim 3, the high-pressure gas in each cylinder bore can be efficiently introduced into the recess through the gas passage as the rotary shaft rotates.

According to the fourth aspect of the present invention, by providing the pressure acting portion at a position corresponding to the position where the greatest radial force acts on the rotary shaft, the radial direction acting on the rotary shaft is accurately provided. The power of can be offset more effectively.

According to the fifth aspect of the invention, only the refrigerant gas having a high pressure in each cylinder bore can be efficiently introduced into the pressure acting portion of the recess through the gas passage, and the pressure action is exerted. The pressure in the section can be sufficiently high so that it can counter the radial forces acting on the axis of rotation.

According to the sixth aspect of the invention, only the intermediate pressure gas lower than the discharge pressure can be efficiently introduced into the pressure acting portion as the rotary shaft rotates. According to the invention described in claim 7, only the gas that remains in the cylinder bore after the compression stroke and expands with the start of the suction stroke of the piston is efficiently transferred to the pressure acting portion due to the rotation of the rotary shaft. Can be introduced well.

According to the invention described in claim 8, the radial force acting on the rotary shaft can be more effectively offset,
The present invention is particularly effective.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a single-headed piston type swash plate compressor showing a first embodiment of the present invention.

FIG. 2 is a partial cross-sectional view showing a bearing portion of the rotary shaft.

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

FIG. 4 is a longitudinal sectional view of a double-headed piston type swash plate compressor showing a second embodiment of the present invention.

FIG. 5 is a partial vertical sectional view of a bearing portion showing a third embodiment of the present invention.

FIG. 6 is a partial transverse sectional view of a bearing portion showing a fourth embodiment of the present invention.

[Explanation of symbols]

11 ... Cylinder block that constitutes the entire housing of the compressor, 12 ... Front housing, 16 ... Rotating shaft, 17
... front radial bearing, 18 ... rear radial bearing, 20 ... cylinder bore, 21 ... piston, 22
... Crank chamber, 27 ... Swash plate, 37 ... Radial bearing shaft support hole, 38 ... Rotating shaft shaft support part, 39 ... Reaction force application structure as reaction force application means, 40 ... Recessed part, 40a ... Discharge pressure introduction groove, 40b ... Pressure acting part, 40c ... Intermediate pressure introducing groove, 4
0d ... Expansion gas introduction groove, 41 ... Gas passage.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hisakazu Kobayashi 2-chome, Toyota-cho, Kariya city, Aichi prefecture Toyota Industries Corporation

Claims (8)

[Claims] 1. A rotary shaft is supported in a housing through a radial bearing, a plurality of cylinder bores are arranged in the housing around the rotary shaft, and a piston is reciprocally housed in each cylinder bore. A reciprocating compressor in which a swash plate for reciprocating a piston is supported on a rotary shaft in a crank chamber of a housing, wherein the radial bearing is composed of a sliding bearing, and the radial bearing is provided between the sliding bearing and the rotating shaft. Is a reciprocating compression device provided with reaction force applying means for applying to the rotary shaft a force in the opposite direction to the force acting in the radial direction on the rotary shaft via the swash plate during the compression operation of the piston. Machine. 2. The reaction force imparting means introduces a high pressure gas into a recess formed so that the piston corresponds to the cylinder bore near the top dead center on the outer surface of the rotary shaft facing the slide bearing. The reciprocating compressor according to claim 1, wherein the reciprocating compressor comprises a gas passage for operating the compressor. 3. The gas passage of the reaction force imparting means is formed in the housing so as to communicate each cylinder bore with the inner peripheral surface side of the sliding bearing, and when each piston reciprocates as the rotating shaft rotates. 3. The reciprocating compressor according to claim 2, wherein the recess is communicated with each gas passage in order, and the high-pressure gas in each cylinder bore is introduced into the recess through the gas passage. 4. The recess of the reaction force applying means is provided with a pressure acting portion formed from a cylinder bore where the piston is near the top dead center to a cylinder bore side which is in the middle of the compression stroke from the cylinder bore. The reciprocating compressor according to item 3. 5. The recess further comprises a discharge pressure introducing groove that is connected to the pressure acting portion and sequentially communicates with the gas passage of each cylinder bore in which the piston is moved to the vicinity of the top dead center according to the rotation of the rotating shaft. The reciprocating compressor according to claim 4. 6. The recessed portion further comprises an intermediate pressure introduction groove connected to the pressure acting portion, and the piston sequentially communicating with the gas passages of the cylinder bores in the middle of the compression stroke as the rotary shaft rotates. The reciprocating compressor described in. 7. The expansion recess is further provided with an expansion gas introduction groove connected to the pressure acting part and sequentially communicating with the gas passage of each cylinder bore immediately after the completion of the compression stroke of the piston as the rotary shaft rotates. The reciprocating compressor according to item 4. 8. The reciprocating compressor according to claim 1, wherein the piston is a single-headed piston.