Compressor

Abstract

The invention provides a compressor which can reduce friction loss caused by a thrust bearing part bearing thrust from a piston side and abrasion amount of a shell compared with the prior art. A compressor (1) includes a conversion mechanism that converts rotation of a swash plate that rotates by rotation of a rotor (8) that rotates integrally with a drive shaft (7) into reciprocating motion of a piston, in which a first thrust receiving portion (31) that is provided between a front housing (3) and the rotor (8) and receives thrust from the piston side includes a thrust rolling bearing (311) and a thrust plate (312).

Description

Technical Field

[0001] The present invention relates to a compressor for compressing a refrigerant mainly in an air conditioning system for a vehicle. Background Art

[0002] As such a compressor, there is known a compressor configured to suck and compress refrigerant by converting the rotation of a swash plate rotated by a drive shaft into reciprocating motion of a piston in a cylinder bore. Patent Document 1 describes an example of such a compressor.

[0003] The compressor described in Patent Document 1 is a so-called swing plate type compressor, which includes: a rotor that rotates integrally with a rotating main shaft (drive shaft); a swash plate that rotates by utilizing the rotation of the rotor; and a swing plate that swings along with the rotation of the swash plate to cause the piston to reciprocate. The compressor described in Patent Document 1 is configured to change the displacement capacity by changing the swing amplitude of the swing plate by changing the inclination angle (tilt angle) of the swash plate relative to the drive shaft, thereby changing the stroke amount of the piston. In addition, the compressor described in Patent Document 1 is configured to receive the thrust from the piston side through a thrust bearing provided between the rotor and the front housing.

[0004] Patent Document 1: Japanese Patent Application Publication No. 2016-191347

[0005] In the above-mentioned compressor, the thrust bearing, which is a thrust bearing part that receives the thrust from the piston side, sometimes rotates and slides on the front housing while being pressed against the front housing. Therefore, depending on the combination of the materials of the thrust bearing and the front housing, there is a risk of increased friction loss and wear of the front housing. For example, in order to reduce weight, improve durability, etc., the material of the front housing is sometimes changed. In this case, the sliding state between the thrust bearing and the front housing changes, and the friction loss and wear of the front housing are sometimes increased compared to before the material of the front housing is changed. In this regard, it is also considered to harden the surface of the front housing by heat treatment or surface treatment of the front housing, but this will lead to increased costs and is therefore not preferred.

[0006] In addition, this problem is not limited to the wobble plate type compressor, and compressors having the same structure (so-called inclined plate type compressors, etc.) also face the same problem. Summary of the invention

[0007] Therefore, an object of the present invention is to provide a compressor capable of reducing the friction loss caused by a thrust receiving portion that receives the thrust from a piston side and the amount of wear of a casing as compared with the conventional technology.

[0008] According to one aspect of the present invention, a compressor is provided. The compressor includes: a housing having a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber inside; a piston disposed in the cylinder bore; a drive shaft rotatably supported by the housing; a rotor rotating integrally with the drive shaft; a swash plate rotating by utilizing the rotation of the rotor; a conversion mechanism converting the rotation of the swash plate into reciprocating motion of the piston; and a thrust bearing portion disposed between the rotor and the housing to bear thrust from the piston side, the thrust bearing portion including a thrust rolling bearing and a thrust plate.

[0009] According to the present invention, it is possible to provide a compressor capable of reducing the friction loss caused by a thrust receiving portion that receives the thrust from the piston side and the amount of wear of the casing as compared with the conventional technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic cross-sectional view of a compressor according to an embodiment. Figure 2 It is a diagram showing a front housing of a compressor according to an embodiment, a rotor fixed to a drive shaft, and a thrust receiving portion provided therebetween. DETAILED DESCRIPTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0012] Figure 1 1 is a schematic longitudinal sectional view of a compressor 1 according to an embodiment of the present invention. The compressor 1 according to the embodiment is a so-called swing plate type compressor (variable capacity compressor), and is mainly used in vehicle air conditioning systems. Figure 1 The left side in the figure is the front side of the compressor 1. Figure 1 The right side in the figure is the rear side of the compressor 1.

[0013] The compressor 1 has a generally cylindrical shape as a whole. Figure 1 The compressor 1 includes: a plurality of cylinder bores 2a ( Figure 1 Only one of them is shown in the figure) of the cylinder body 2; provided at one end side of the cylinder body 2 ( Figure 1 and disposed on the other end side of the cylinder body 2 ( Figure 1 The cylinder block 2, the front housing 3 and the cylinder head 4 are connected by fastening bolts, etc. to form a housing 5 of the compressor 1. In addition, a valve plate 6 is arranged between the cylinder block 2 and the cylinder head 4.

[0014] A crank chamber C1 is provided in the housing 5. The crank chamber C1 is defined by the cylinder block 2 and the front housing 3. The crank chamber C1 is communicated with each cylinder bore 2a. In addition, a suction chamber C2 and a discharge chamber C3 are formed in the cylinder head 4. Thus, the housing 5 has a plurality of cylinder bores 2a, a crank chamber C1, a suction chamber C2, and a discharge chamber C3 inside.

[0015] The suction chamber C2 is connected to each cylinder bore 2a via a suction hole 61 formed in the valve plate 6. The suction hole 61 is opened and closed by a suction valve (not shown) formed of a reed valve. In addition, the suction chamber C2 is connected to the refrigerant circuit (low-pressure side) of the vehicle air conditioning system via a suction passage (not shown).

[0016] The discharge chamber C3 communicates with the cylinder bore 2a via a discharge hole 62 formed in the valve plate 6. The discharge hole 62 is opened and closed by a discharge valve 63 formed of a reed valve. In addition, the discharge chamber C3 is connected to, for example, (the high-pressure side of) the refrigerant circuit of the vehicle air conditioning system via a discharge passage (not shown).

[0017] The compressor 1 has a drive shaft 7 for inputting a rotational driving force from an external driving source. The drive shaft 7 extends through the crank chamber C1 from the front to the rear. In the crank chamber C1, a rotor 8, a swash plate 9, and a swing plate 10 are arranged from the front to the rear.

[0018] The rotor 8 is fixed to the drive shaft 7. That is, the drive shaft 7 and the rotor 8 are integrated. The drive shaft 7 and the rotor 8 are supported in the radial direction by the first radial bearing 21 and the second radial bearing 22. The first radial bearing 21 is mounted on the front housing 3, and the second radial bearing 22 is mounted on the cylinder block 2. In other words, the drive shaft 7 is rotatably supported by the housing 5 by means of the first radial bearing 21 and the second radial bearing 22, and the rotor 8 rotates integrally with the drive shaft 7. In addition, in the present embodiment, the first radial bearing 21 and the second radial bearing 22 are composed of sliding bearings.

[0019] Furthermore, the drive shaft 7 and the rotor 8 are supported in the thrust direction by the first thrust receiving portion 31 and the second thrust receiving portion 32. The first thrust receiving portion 31 is provided between the front housing 3 and the rotor 8, and the second thrust receiving portion 32 is attached to the cylinder block 2.

[0020] The swash plate 9 is formed in a substantially disc shape. The swash plate 9 has a boss portion 9a protruding toward the rear side at a substantially central portion. The swash plate 9 rotates by the rotation of the drive shaft 7 and the rotor 8. The swash plate 9 is configured to be able to change its inclination angle relative to (the axis of) the drive shaft 7.

[0021] Specifically, the swash plate 9 is connected to the rotor 8 by means of a connection mechanism (connection mechanism) 11. The connection mechanism 11 includes: a swash plate side arm 111 protruding from the swash plate 9; a connection pin 112 fixed to the swash plate side arm 111; and a rotor side arm 113 protruding from the rotor 8, and a circular arc-shaped hole 113a is formed in the rotor side arm 113, into which the connection pin 112 can be inserted and through which the connection pin 112 can move.

[0022] A through hole 9b for passing the drive shaft 7 is formed substantially in the center of the swash plate 9. The through hole 9b is formed in a shape that allows the swash plate 9 to move in the axial direction of the drive shaft 7 and that allows the inclination angle of the swash plate 9 relative to (the axis of) the drive shaft 7 to be changed within a predetermined range.

[0023] In this embodiment, the inclined plate 9 is configured to be able to Figure 1 The state shown (hereinafter referred to as the "first state"), and Figure 1 The state shown changes between a state further to the rear side and substantially orthogonal to the drive shaft 7 (hereinafter referred to as a “second state”).

[0024] The swing plate 10 is formed in a substantially annular shape. The swing plate 10 is configured to swing along with the rotation of the swash plate 9 to reciprocate the pistons 12 disposed in the cylinder bores 2a. That is, the swing plate 10 functions as a conversion mechanism that converts the rotation of the swash plate 9 into the reciprocating motion of the pistons 12.

[0025] Specifically, the inner peripheral surface of the swing plate 10 is attached to the outer peripheral surface of the boss portion 9a of the swash plate 9 by means of the third radial bearing 41. In addition, a thrust bearing 42 is arranged between the rear surface of the swash plate 9 and the front surface of the swing plate 10. In the present embodiment, the third radial bearing 41 and the thrust bearing 42 are formed of rolling bearings. Moreover, the balance ring 13 is fixed to the top end side of the boss portion 9a of the swash plate 9 in a state where a predetermined gap is provided between the balance ring 13 and the swing plate 10. The balance ring 13 is a member that mainly achieves dynamic balance of the swash plate 9. That is, the swash plate 9, the swing plate 10, and the balance ring 13 are integrated in a state where the swing plate 10 can rotate relative to each other.

[0026] The swing plate 10 is prevented from rotating by an extended portion 10 a extending downward from the swing plate 10 and a rail member (rotation preventing member) 14 provided at a lower portion of the crank chamber C1 and extending from the front side to the rear side.

[0027] Furthermore, the wobble plate 10 is connected to a piston 12 via a connecting rod 15, and the piston 12 is disposed so as to be reciprocatingly movable in each cylinder bore 2a.

[0028] Thus, the swing plate 10 swings in the axial direction of the drive shaft 7 due to the rotation of the swash plate 9, and the piston 12 reciprocates in the cylinder bore 2a by means of the connecting rod 15. Therefore, when the swash plate 9 (and the swing plate 10) is in the second state substantially orthogonal to the drive shaft 7, the swing amplitude of the swing plate 10 becomes smaller, and the stroke amount of the piston 12 also becomes smaller. On the other hand, when the swash plate 9 (and the swing plate 10) is in the Figure 1 In the first state shown, the swing amplitude of the swing plate 10 becomes larger, and the stroke amount of the piston 12 also becomes larger.

[0029] The front side of the drive shaft 7 extends in a manner that penetrates the boss portion 3a of the front housing 3, and the front end of the drive shaft 7 is located outside the housing 5. In addition, an electromagnetic clutch 16 is installed on the boss portion 3a of the front housing 3. In addition, in the compressor 1 of the embodiment, by tightening the electromagnetic clutch 16, the rotational driving force from the external driving source is input to the front end portion of the drive shaft 7, thereby rotating the drive shaft 7 (and the rotor 8). In addition, a shaft seal device 17 is installed on the boss portion 3a to isolate the inside of the housing 5 from the outside.

[0030] The compressor 1 further includes a control valve 18. The control valve 18 is configured to control the amount of refrigerant pressure in the crank chamber C1 released to the suction chamber C2 by adjusting the opening of a pressure release passage for connecting the crank chamber C1 and the suction chamber C2. In the present embodiment, the control valve 18 is mounted on the cylinder block 2, and the pressure release passage includes a passage (internal passage) 7a formed inside the drive shaft 7. In addition, the discharge chamber C3 and the crank chamber C1 are connected by a pressure supply passage (not shown) having a throttle portion.

[0031] Here, an operation example of the compressor 1 will be briefly described.

[0032] If the drive shaft 7 and the rotor 8 rotate using the rotational driving force from the external drive source, the swash plate 9 rotates, and the swing plate 10 swings in the axial direction of the drive shaft 7 as the swash plate 9 rotates. As a result, the piston 12 connected to the swing plate 10 reciprocates in the corresponding cylinder bore 2a by means of the connecting rod 15. The refrigerant of the refrigerant circuit is introduced into the suction chamber C2 via the suction passage. Therefore, as the piston 12 reciprocates, the refrigerant in the suction chamber C2 is sucked into the cylinder bore 2a via the suction hole 61 and the suction valve and compressed. The compressed refrigerant is discharged to the discharge chamber C3 via the discharge hole 62 and the discharge valve 63, and the refrigerant discharged to the discharge chamber C3 (the compressed refrigerant) is sent to the refrigerant circuit via the discharge passage.

[0033] If the control valve 18 is closed, the pressure release passage for allowing the refrigerant in the crank chamber C1 to flow into the suction chamber C2 is cut off. In addition, the high-pressure refrigerant in the discharge chamber C3 is supplied to the crank chamber C1 via the pressure supply passage having the throttle portion. Therefore, the pressure in the crank chamber C1 rises. Then, if the pressure in the crank chamber C1 is higher than the pressure in the suction chamber C2, the inclined plate 9 and the swing plate 10 move toward the rear side while approaching the second state that is substantially orthogonal to the drive shaft 7. As a result, the swing amplitude of the swing plate 10 becomes smaller, the stroke amount of the piston 12 is reduced, and the discharge capacity of the compressor 1 is reduced.

[0034] On the other hand, if the control valve 18 is opened, the refrigerant in the crank chamber C1 flows out to the suction chamber C2 through the pressure release passage. In addition, although the high-pressure refrigerant in the discharge chamber C3 is supplied to the crank chamber C1 through the pressure supply passage having the throttle portion, the outflow amount of the pressure release passage is greater, so the pressure of the crank chamber C1 decreases as a result. Then, if the pressure of the crank chamber C1 is lower than the pressure of the suction chamber C2, the swash plate 9 and the swing plate 10 move forward while approaching the crank chamber C1. Figure 1 As a result, the swing amplitude of the swing plate 10 increases, the stroke amount of the piston 12 increases, and the discharge capacity of the compressor 1 increases.

[0035] However, in the compressor 1, the thrust from the piston 12 side is received by the first thrust receiving portion 31 provided between the front housing 3 and the rotor 8. The thrust from the piston 12 side is mainly a compression reaction force acting on the piston 12. Here, as in the prior art, if only a thrust bearing is used as the first thrust receiving portion 31, there is a risk of increased friction loss and wear of the front housing 3 as described above.

[0036] In order to alleviate or mitigate such a situation, the compressor 1 of the embodiment adopts the following structure. Figure 2 In addition, Figure 2 The diagram shows the front housing 3 (indicated by a two-dot chain line) in the compressor 1 , the rotor 8 fixed to the drive shaft 7 , and the first thrust receiving portion 31 provided therebetween.

[0037] Reference Figure 2 In the compressor 1 of the embodiment, the first thrust receiving portion 31 receiving the thrust from the piston 12 side includes a rolling bearing (hereinafter referred to as a "thrust rolling bearing") 311 disposed on the rotor 8 side, and a plate member (hereinafter referred to as a "thrust plate") 312 disposed on the front housing 3 side. The thrust rolling bearing 311 and the thrust plate 312 are mounted on the drive shaft 7.

[0038] The thrust rolling bearing 311 includes: a plurality of rolling elements 311a; an annular retainer 311b that retains the plurality of rolling elements 311a in a state where they are spaced apart in the circumferential direction; and an annular plate-shaped first thrust race 311c and a second thrust race 311d that sandwich the plurality of rolling elements 311a from both sides. The first thrust race 311c and the second thrust race 311d may be common components. The thrust rolling bearing 311 is arranged in such a manner that the first thrust race 311c is located on the rotor 8 side. A flat surface 8a that contacts the outer side surface of the first thrust race 311c is formed on the rotor 8. The size of the flat surface 8a is substantially the same as the size of the outer side surface of the first thrust race 311c, or is larger than the size of the outer side surface of the first thrust race 311c.

[0039] The thrust plate 312 is formed in a circular ring plate shape. The thrust plate 312 is arranged between the second thrust race 311d of the thrust rolling bearing 311 and the front housing 3. The thrust plate 312 has a radial dimension substantially the same as the radial dimension of the second thrust race 311d (and the first thrust race 311c) of the thrust rolling bearing 311. However, the thrust plate 312 is not limited thereto, and the outer diameter dimension of the thrust plate 312 may also be larger than the outer diameter dimension of the second thrust race 311d (and the first thrust race 311c) of the thrust rolling bearing 311.

[0040] One surface (the surface on the rear side) of the thrust plate 312 is located on the side of (the second thrust race 311d of) the thrust rolling bearing 311, and the other surface (the surface on the front side) of the thrust plate 312 is located on the side of the front housing 3. The front housing 3 is formed with a seat surface 3b that contacts the other surface of the thrust plate 312. The seat surface 3b is formed as a flat surface, and the area of ​​the flat surface is substantially the same as that of (the other surface of) the thrust plate 312, or is larger than the area of ​​(the other surface of) the thrust plate 312.

[0041] In the compressor 1, when a thrust is generated from the piston 12 side, the flat surface 8a of the rotor 8 contacts the outer side surface of the first thrust race 311c of the thrust rolling bearing 311, the outer side surface of the second thrust race 311d of the thrust rolling bearing 311 contacts the one surface of the thrust plate 312, and the other surface of the thrust plate 312 contacts the seat surface 3b of the front housing 3. Furthermore, the first thrust receiving portion 31 is pressed against the seat surface 3b of the front housing 3 as a whole.

[0042] Although not particularly limited here, in this embodiment, the same member as the first thrust race 311c or the second thrust race 311d of the thrust rolling bearing 311 is used as the thrust plate 312. This is because they are components of the thrust rolling bearing 311 and are therefore relatively easy to obtain, and have the physical properties required of the thrust plate 312.

[0043] Furthermore, the friction coefficient between the outer side surface of the second thrust race 311d of the thrust rolling bearing 311 and the one surface of the thrust plate 312 is set to be smaller than the friction coefficient between the other surface of the thrust plate 312 and the seat surface 3b of the front housing 3. This is because by effectively generating sliding between (the outer side surface of the second thrust race 311d of the thrust rolling bearing 311) and the thrust plate 312, the rotational sliding of the thrust plate 312 on the seat surface 3b of the front housing 3 is suppressed.

[0044] According to the compressor 1 of the embodiment, the following effects can be obtained.

[0045] The first thrust receiving portion 31 provided between the front housing 3 and the rotor 8 and receiving the thrust from the piston 12 side includes a thrust rolling bearing 311 arranged on the rotor 8 side and a thrust plate 312 arranged on the front housing 3 side.

[0046] In the above structure, the member that rotates and slides on the front housing 3 is the thrust plate 312, and sliding occurs between the thrust plate 312 and the thrust rolling bearing 311 arranged on the rotor 8 side. Therefore, compared with the prior art, the rotation speed (sliding speed) of the member that rotates and slides on the front housing 3 is reduced, and as a result, the friction loss caused by the first thrust receiving portion 31 and the wear of the front housing 3 can be reduced.

[0047] Specifically, the thrust rolling bearing 311 includes: a plurality of rolling elements 311a; an annular retainer 311b that retains the plurality of rolling elements 311a; and a first thrust race 311c and a second thrust race 311d that sandwich the plurality of rolling elements 311a from both sides, and the first thrust race 311c is arranged to be located on the side of the rotor 8. In addition, the thrust plate 312 is arranged between the second thrust race 311d of the thrust rolling bearing 311 and the seat surface 3b formed on the front housing 3.

[0048] Here, the seat surface 3b is formed as a flat surface having substantially the same area as or larger than (the other surface of) the thrust plate 312. In addition, the friction coefficient between the outer side surface of the second thrust race 311d of the thrust rolling bearing 311 and the one surface of the thrust plate 312 is set to be smaller than the friction coefficient between the other surface of the thrust plate 312 and the seat surface 3b of the front housing 3.

[0049] Therefore, deformation of the thrust plate 312 can be suppressed, and the sliding between the thrust rolling bearing 311 and the thrust plate 312 can be increased (more), which can effectively reduce the rotation speed (sliding speed) of the thrust plate 312, which is a member that rotates and slides on the front housing 3. Therefore, the friction loss caused by the first thrust receiving portion 31 and the wear of the front housing 3 can be further reduced.

[0050] In addition, the thrust plate 312 is the same as the first thrust race 311c or the second thrust race 311d of the thrust rolling bearing 311. Therefore, the friction loss caused by the first thrust receiving portion 31 and the wear of the front housing 3 can be reduced with a simple structure, and the cost increase can also be suppressed.

[0051] In the above embodiment, the thrust rolling bearing 311 is arranged on the rotor 8 side, and the thrust plate 312 is arranged on the front housing 3 side. However, this is not limiting. The thrust plate 312 may be arranged on the rotor 8 side, and the thrust rolling bearing 311 may be arranged on the front housing 3 side.

[0052] Furthermore, in the above-described embodiment, one thrust plate 312 is disposed between the thrust rolling bearing 311 and the front housing 3 , but a plurality of thrust plates 312 may be disposed, and the thickness of the thrust plate 312 may be increased.

[0053] Furthermore, the above embodiment describes a wobble plate type compressor, but the present invention can also be applied to other compressors (for example, a swash plate type compressor not having a wobble plate) that receive thrust from the piston side using the same structure as the above embodiment.

[0054] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it is apparent that deformation and modification can be made based on the technical concept of the present invention. Description of Reference Numerals

[0055] 1 compressor, 2 cylinder block, 2a cylinder bore, 3 front housing, 4 cylinder head, 5 housing, 7 drive shaft, 8 rotor, 9 swash plate, 10 swing plate, 11 connecting mechanism, 12 piston, 15 connecting rod, 31 first thrust receiving portion, 311 thrust rolling bearing, 311a rolling element, 311b retainer, 311c first thrust race, 311d second thrust race, 312 thrust plate, C1 crank chamber, C2 suction chamber, C3 discharge chamber.

Claims

1. A compressor, comprising: a housing having a cylinder bore, a crank chamber, a suction chamber, and a discharge chamber therein; A piston disposed in the cylinder bore; A drive shaft rotatably supported on the housing; a rotor that rotates integrally with the drive shaft; a swash plate that rotates by the rotation of the rotor; a conversion mechanism, converting the rotation of the swash plate into reciprocating motion of the piston; as well as The thrust receiving portion is provided between the housing and the rotor and receives the thrust from the piston side. The compressor is characterized in that The thrust bearing portion includes a thrust rolling bearing and a thrust plate.

2. The compressor according to claim 1, characterized in that The thrust rolling bearing comprises: a plurality of rolling elements; and The first and second thrust races in the form of annular plates sandwich the plurality of rolling elements from both sides. The first thrust race is configured to be located on the rotor side, The thrust plate is arranged between the second thrust race of the thrust rolling bearing and a seat surface formed in the housing.

3. The compressor according to claim 2, characterized in that The seat surface is formed as a flat surface, and an area of ​​the flat surface is the same as an area of ​​the second thrust race of the thrust rolling bearing, or is larger than an area of ​​the second thrust race of the thrust rolling bearing.

4. The compressor according to claim 2, characterized in that A friction coefficient between one surface of the thrust plate and the second thrust race of the thrust rolling bearing is smaller than a friction coefficient between the other surface of the thrust plate and the seat surface of the housing.

5. The compressor according to claim 2, characterized in that The same member as the first thrust race or the second thrust race of the thrust rolling bearing is used as the thrust plate.

Images