KR20060099453A - Variable displacement swash plate compressor - Google Patents

Abstract

A variable displacement swash plate compressor according to the present invention includes a rotating shaft, a swash plate fitted to the rotating shaft so as to slidably engage the rotating shaft and change an inclination with respect to the rotating shaft, and to rotate simultaneously with the rotating shaft, and the swash plate. A first spring for forcing in the direction of decreasing the inclination of the swash plate, a second spring for forcing a swash plate inclined close to the minimum inclination in the direction of increasing the inclination of the swash plate, and a swash plate inclined close to the minimum inclination. An attenuator is included to prevent the slope from fluctuating in short periods.

Description

Variable displacement swash plate compressor {VARIABLE DISPLACEMENT SWASH PLATE COMPRESSOR}

1 is a cross-sectional view of a variable displacement swash plate compressor according to a first preferred embodiment of the present invention.

2 is an enlarged cross-sectional view of an attenuator of a variable displacement swash plate compressor according to a first preferred embodiment of the present invention.

3 is an enlarged cross-sectional view of an attenuator of a variable displacement swash plate compressor according to a second preferred embodiment of the present invention.

4 is a structural diagram of an attenuator of a variable displacement swash plate compressor according to a third preferred embodiment of the present invention. FIGS. 4A and 4C are enlarged cross-sectional views, and FIGS. 4B and 4D are perspective views.

<Explanation of symbols for the main parts of the drawings>

10: axis of rotation

11: rotor

12: swash plate

13: link mechanism

14: first spring

15: second spring

16: Shu

17: piston

18: cylinder block

20: front housing

22: cylinder head

30: attenuator

31: cylindrical body

31a: floor wall

31b: peripheral sidewall

32: cover

The present invention relates to a variable displacement swash plate compressor.

Japanese Laid-Open Patent Publication No. 2001-002180 discloses a rotating shaft, a swash plate fitted to the rotating shaft so as to slide in engagement with the rotating shaft and to change an inclination with respect to the rotating shaft, and to rotate simultaneously with the rotating shaft; A variable displacement swash plate compressor comprising a first spring for forcing the swash plate in a direction of decreasing the inclination and a second spring for forcing a swash plate inclined close to the minimum inclination in the direction of increasing the inclination It is.

When the variable displacement swash plate compressor is operated with the swash plate inclined close to the minimum inclination, the load acting on the compressor becomes almost zero. As a result, the biasing force of the first spring and the biasing force of the second spring act on the swash plate, and due to the stretching action of these two springs, the inclination of the swash plate repeatedly increases and decreases in a short period near the minimum slope. If you do, the swash plate will be unstable. Such unstable operation of the swash plate results in wear and fatigue of the components of the compressor.

The present invention provides a rotating shaft, a swash plate which is slidably engaged with the rotating shaft and fitted to the rotating shaft so as to change an inclination with respect to the rotating shaft, and simultaneously rotates with the rotating shaft, forcing the swash plate in a direction of decreasing the inclination. A variable displacement swash plate type compressor comprising a first spring for fastening and a second spring for forcing a swash plate inclined close to the minimum inclination in the direction of increasing the inclination, the short inclination of the swash plate inclined near the minimum inclination in a short cycle. It is an object to provide a variable displacement swash plate type compressor which is prevented from increasing and decreasing.

According to the present invention, there is provided a rotating shaft, a swash plate which is slidably engaged with the rotating shaft and fitted to the rotating shaft so as to change an inclination with respect to the rotating shaft and rotates simultaneously with the rotating shaft, and the swash plate reduces the inclination of the swash plate. The first spring for forcing in the direction, the second spring for forcing the swash plate inclined close to the minimum inclination in the direction of increasing the inclination of the swash plate, and the inclination of the swash plate inclined near the minimum inclination in a short cycle. A variable displacement swash plate compressor is provided that includes an attenuator for preventing.

In the variable displacement swash plate compressor according to the present invention, in order to prevent the inclination of the swash plate inclined near the minimum inclination to increase and decrease in a short period, the inclination of the swash plate inclined near the minimum inclination varies in a short period. To prevent

In a preferred embodiment of the invention, the attenuator forms a case for receiving the second spring.

When the damper forms a case for accommodating the second spring, the compressor is downsized as compared with the case where the damper is disposed separately from the second spring.

In another preferred embodiment of the invention, the second spring is fitted on the axis of rotation, and the damper is of a cylindrical body having an annular bottom wall and peripheral sidewalls opposed to the swash plate and slidably fitted on the axis of rotation, and of the cylindrical body. A cover slidingly fitted at the open end and fitted to the rotary shaft, the second spring abuts the bottom wall of the cylindrical body at an end adjacent to the swash plate, abuts the cover at an end away from the swash plate, The cover is prevented from moving in a direction away from the swash plate.

When the second spring is fitted to the rotary shaft, the damper having the simple structure can prevent the inclination of the swash plate inclined near the minimum inclination to increase and decrease in a short period.

In another preferred embodiment of the present invention, the movement of the cover away from the swash plate is prevented by a snap ring fixed to the rotation shaft.

In another preferred embodiment of the present invention, the cover is pressed into the rotating shaft so as not to move in a direction away from the swash plate.

The cover can be prevented from moving in a direction away from the swash plate by a snap ring fixed to the rotating shaft or by being pressed into the rotating shaft.

In another preferred embodiment of the invention, the cylindrical body or cover may be provided with a hole.

The damping force of the damper against the increase and decrease of the inclination of the swash plate in a short period can be adjusted by adjusting the dimensions of the hole formed in the cylindrical body or the cover.

In another preferred embodiment of the present invention, the peripheral side wall of the cylindrical body is provided with a long hole extending in the longitudinal direction of the cylindrical body, the long hole overlaps the cover, the opening area of the long hole is the slope of the swash plate Decreases with decrease.

When the inclination of the swash plate is minimized, the opening area of the long hole is minimized in order to maximize the damping force against the increase and decrease of the inclination of the swash plate in a short period, thereby increasing the inclination of the inclined swash plate close to the minimum inclination in a short period. And effectively reduce.

In another preferred embodiment of the present invention, a protrusion is provided at the open end of the cylindrical body, which is in contact with the end face of the cover remote from the bottom wall of the cylindrical body.

The protrusion prevents the cylindrical body from detaching from the lid.

A variable displacement swash plate compressor according to a first preferred embodiment of the present invention is described.

As shown in FIG. 1, the variable displacement swash plate type compressor A has a rotary shaft 10, a rotor 11 fixed to the rotary shaft 10, and a rotary shaft 10 slidingly engaged with the rotary shaft 10. A swash plate 12 fitted to the rotating shaft 10 is provided to change the inclination with respect to 10). The swash plate 12 is connected to the rotor 11 via a link mechanism 13 so as to change the inclination with respect to the rotation shaft 10, and rotates simultaneously with the rotation shaft 10.

The first spring 14 is disposed between the rotor 11 and the swash plate 12 and fitted to the rotary shaft 10 to force the swash plate 12 in the direction of decreasing the inclination of the swash plate 12. The second spring 15 is fitted to the rotation shaft 10 to force the swash plate 12 in the direction of increasing the inclination of the swash plate. The first spring 14 and the second spring 15 are arranged to face opposite surfaces of the swash plate 12.

The plurality of pistons 17 are engaged with the swash plate 12 via a plurality of pairs of shoes 16 that slidably engage the outer periphery of the swash plate 12. The piston 17 is inserted into the cylinder bore 18a formed in the cylinder block 18.

A plurality of pairs of shoe 16, piston 17 and cylinder bore 18a are arranged at intervals from each other in the circumferential direction.

The rotor 11, the swash plate 12, the link mechanism 13, the shoe 16, and the piston 17 form a compression mechanism driven by the rotation shaft 10.

The cylindrical front housing 20 provided with the bottom wall forms a crank chamber 19 for accommodating the rotating shaft 10, the rotor 11, and the swash plate 12. The front end of the rotation shaft 10 penetrates the bottom wall of the front housing 20 and extends outside of the front housing 20.

The sealing member 21 is disposed in the annular space between the bottom wall of the front housing 20 and the rotation shaft 10.

Rotation force is transmitted from the power source (not shown) to the tip of the rotation shaft 10.

The cylinder head 22 is provided to form the suction chamber 22a and the discharge chamber 22b.

The valve plate 23 is disposed between the cylinder block 18 and the cylinder head 22. The valve plate 23 is provided with a suction hole 23a and a discharge hole 23b in communication with the cylinder bore 18a. The intake valve 24 and the discharge valve 25 are attached to the valve plate 23.

The front housing 20, the cylinder block 18, the valve plate 23 and the cylinder head 22 are integrally assembled by a plurality of through bolts 26 arranged at intervals from each other in the circumferential direction.

The rotary shaft 10 is rotatably supported by radial bearings 27 and 28 disposed in the front housing 20 and the cylinder block 18. The rotor 11 is rotatably supported by a thrust bearing 29 disposed in the front housing 20.

An attenuator 30 is arranged to receive the second spring 15.

As shown in FIG. 2, the attenuator 30 has a cylindrical body 31 having an annular bottom wall 31 a and a peripheral side wall 31 b facing the swash plate 12 and slidingly fitted to the rotational shaft 10. And a cover 32 which is slidably fitted to the cylindrical body 31 and slidably fitted to the rotary shaft 10. The second spring 15 is in contact with the bottom wall 31a of the cylindrical body 31 at the end adjacent to the swash plate 12 and in contact with the lid 32 at the end away from the swash plate 12. The lid 32 is restricted from moving in a direction away from the swash plate 12 by the snap ring 33 fixed to the rotation shaft 10.

The cylindrical body 31 is provided with the projection 31c at the open end. The projection 31c may abut the end face of the cover 32 away from the bottom wall 31a of the cylindrical body 31.

The variable displacement swash plate compressor A operates as follows.

Rotation force is transmitted from the external power source (not shown) to the rotation shaft 10, and rotation of the rotation shaft 10 is transmitted to the swash plate 12 through the rotor 11 and the link mechanism 13. When the swash plate 12 rotates, the peripheral portion of the swash plate 12 reciprocates in the longitudinal direction of the rotation shaft 10. The reciprocating motion of the peripheral part of this swash plate 12 is transmitted to the piston 17 through the shoe 16, and the piston 17 reciprocates in the cylinder bore 18a. Cooling gas enters the suction chamber 22a from the external cooling circuit through the suction port formed in the cylinder head 22. The cooling gas is sucked into the cylinder bore 18a through the suction hole 23a and the suction valve 24 and compressed in the cylinder bore 18a. The cooling gas compressed in the cylinder bore 18a flows out into the discharge chamber 22b through the discharge hole 23b and the discharge valve 25, and then flows out of the discharge chamber 22b to the cylinder head 22. It flows into the external cooling circuit through the discharge port formed.

In order to control the internal pressure of the crank chamber 19 and the inclination of the swash plate 12 to control the capacity of the variable displacement swash plate compressor A, the capacity control valve (not shown) is compressed and cooled in the discharge chamber 22b. The introduction of gas into the crank chamber 19 is controlled.

When the inclination of the swash plate 12 decreases, the first spring 14 extends to force the swash plate 12 toward the cylinder block 18. The swash plate 12 moves toward the cylinder block 18, and the inclination of the swash plate 12 decreases. When the inclination of the swash plate 12 decreases to a predetermined angle close to the minimum inclination angle, the swash plate 12 is in contact with the bottom wall 31a of the attenuator 30. If the inclination of the swash plate 12 further decreases, the swash plate 12 moves further toward the cylinder block 18 and forces the cylindrical body 31 toward the cover 32. The cylindrical body 31 slides toward the cover 32 and contracts the second spring 15, which is inhibited in the direction away from the swash plate 12 by the snap ring 33. In contact with the lid 32, rigid body movement is prevented.

When the inclination of the swash plate 12 is increased, the second spring 15 is extended to force the swash plate 12 toward the front housing 20. The projection 31c prevents the departure from the cover 32 of the cylindrical body 31.

When the variable displacement swash plate compressor A is operated with the swash plate 12 inclined close to the minimum inclination, the load acting on the compressor A becomes almost zero. As a result, the biasing force of the first spring 14 and the second spring 15 becomes the main force acting on the swash plate 12. Therefore, in general, due to the stretching movement of the springs 14 and 15, the inclination of the swash plate 12 is repeatedly increased and decreased in a short period near the minimum inclination, and the swash plate 12 is unstable in operation. Done. This unstable operation of the swash plate 12 leads to wear and fatigue of the components of the compressor A.

However, in the variable displacement swash plate type compressor A, when the inclination of the swash plate decreases close to the minimum inclination, the swash plate 12 is in contact with the bottom wall 31a of the attenuator 30. The inclination of the swash plate 12 repeatedly increases and decreases near the minimum inclination, the swash plate 12 alternately repeats the movement toward the cylinder block 18 and the movement toward the front housing 20, and at the same time the attenuator 30 In contact with the bottom wall 31a of the cylindrical body 31 alternately repeats the movement toward the cover 32 and the movement away from the cover 32 in the state of receiving the biasing force of the second spring 15. The space surrounded by the rotating shaft 10, the cylindrical body 31 and the lid 32 is filled with cooling gas and lubricant oil. When the cylindrical body 31 alternately repeats the movement toward the cover 32 and the movement away from the cover 32, between the rotating shaft 10 and the bottom wall 31a of the cylindrical body 31, the rotating shaft 10. Outflow of cooling gas and lubricating oil from the space and cooling into the space through a gap formed between the cover 32 and the sliding contact between the cover 32 and the peripheral side wall 31b of the cylindrical body 31. The intake of gas and lubricant is alternately repeated. When coolant gas and lubricating oil flow out of the space and are sucked into the space through the gap formed in the sliding contact portion, resistance force proportional to the flow rates of the cooling gas and the lubricating oil is generated due to the viscosity of the cooling gas and the lubricating oil. The resistive forces include cooling gas and lubricating oil flowing out of the space in a short cycle, cooling gas and lubricating oil being sucked into the space in a short cycle, the cylindrical body 31 and the swash plate 12 reciprocating in a short cycle, and the swash plate ( The inclination of 12) increases and decreases at short intervals, and prevents unstable movement of the swash plate 12.

The attenuator 30 forms a case for receiving the second spring 15. Therefore, the compressor A can be miniaturized as compared with the case where the damper 30 is disposed separately from the second spring 15.

When the second spring 15 is fitted to the rotary shaft 10, the damper 30 has the above simple structure for preventing the inclination of the swash plate 12 inclined close to the minimum inclination to increase and decrease in a short period. Can be.

As shown in FIG. 3, the cover 32 may be pressed into the rotation shaft 10. The cover 32 does not move in a direction away from the swash plate 12. Thus, the snap ring 33 can be removed, and the number of components is reduced.

The bottom wall 31a of the cylindrical body 31 may be provided with a small hole 31d as shown in FIGS. 4A and 4B. The peripheral side wall 31b of the cylindrical body 31 may be provided with a small hole 31e as shown in FIGS. 4C and 4D.

By adjusting the opening area of the small holes 31d and 31e, the resistance against the flow through the small holes 31d and 31e of the cooling gas and the lubricating oil can be adjusted, and the inclination of the swash plate 12 inclined close to the minimum slope. Can adjust the damping force of the attenuator 30 against increasing and decreasing in a short period.

The small hole 31e may extend in the longitudinal direction of the cylindrical body 31 to form the long hole 31e ', as shown in FIG. 4C. The long hole 31e 'can be overlapped with the lid 32, and the opening area thereof decreases as the inclination of the swash plate decreases. When the inclination of the swash plate 12 is minimized, the opening area of the long hole 31e 'is minimized to maximize the damping force against the increase and decrease of the inclination of the swash plate 12 in a short period, thereby approaching the minimum inclination. The inclination of the inclined swash plate 12 is effectively prevented from increasing and decreasing in a short period.

The lid 32 may be provided with a small hole 31f as shown in FIG. 4A. By adjusting the opening area of the small holes 31f, the resistance against the flow through the small holes 31f of the cooling gas and the lubricating oil can be adjusted, and the inclination of the swash plate 12 inclined close to the minimum inclination increases in a short period. And damping force of the attenuator 30 against decreasing.

While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that modifications and variations can be made without departing from the spirit and scope of the invention. It is intended that the scope of the invention only be determined by the appended claims.

The variable displacement swash plate compressor according to the present invention can be prevented from increasing and decreasing the inclination of the swash plate inclined close to the minimum inclination in a short period, and the unstable operation of the swash plate can be prevented, which is a component of the compressor Wear and fatigue can be avoided.

Claims (8)

A rotating shaft, a swash plate which is slidably engaged with the rotating shaft and fitted to the rotating shaft so as to change the inclination with respect to the rotating shaft, and rotates simultaneously with the rotating shaft; and a direction in which the swash plate reduces the inclination of the swash plate. A first spring for forcing the swash plate, a second spring for forcing the swash plate inclined close to the minimum inclination in the direction of increasing the inclination of the swash plate, and preventing the inclination of the swash plate inclined near the minimum inclination in a short cycle. Variable displacement swash plate compressor comprising an attenuator for. The variable displacement swash plate compressor of claim 1, wherein the damper forms a case for receiving the second spring. The cylindrical body of claim 2, wherein the second spring is fitted to the rotational shaft, and the damper is at the cylindrical body having an annular bottom wall and a peripheral sidewall opposed to the swash plate and slidingly fitted to the rotational shaft, and at the open end of the cylindrical body. A cover fitted slidingly and fitted to the rotational shaft, the second spring abuts the bottom wall of the cylindrical body at an end adjacent to the swash plate, abuts the cover at an end away from the swash plate, the cover being A variable displacement swash plate compressor in which movement in a direction away from the swash plate is prevented. The variable displacement swash plate compressor of claim 3, wherein a snap ring for preventing the lid from moving in a direction away from the swash plate is fixed to the rotating shaft. 4. The variable displacement swash plate compressor of claim 3, wherein the cover is press-fitted to the rotating shaft so as not to move in a direction away from the swash plate. The variable displacement swash plate compressor according to any one of claims 3 to 5, wherein the cylindrical body or the cover is provided with a hole. The peripheral side wall of the cylindrical body is provided with an elongated hole extending in the longitudinal direction of the cylindrical body, the elongated hole overlapping the lid, and the opening of the elongated hole. A variable displacement swash plate type compressor in which the area decreases as the inclination of the swash plate decreases. 6. A variable displacement swash plate compressor according to any one of claims 3 to 5, wherein a projection contacting the end face of the cover remote from the bottom wall of the cylindrical body is provided at the open end of the cylindrical body.

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