JP2006291749A - Variable displacement compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce contact pressure between a roller and a sliding contact object without increasing a diameter of a pin whole body constructing a connecting mechanism in a variable displacement compressor. <P>SOLUTION: A support hole 231 is formed to extend in a direction perpendicularly crossing a rotary shaft 231 on a support arm 23 formed on a swash plate 22. The pin 24 is press-fitted in the support hole 231. A cylinder 27 is press-fitted on the pin 24. A plane bearing 28 (sliding bearing) is rotatably fitted on an outer circumference of the cylinder 27. The roller 29 is rotatably fitted on an outer circumference of the plane bearing 28. A flange 291 is formed on an inner circumference side of one end part (an end part in a distal side of the support arm 23) of the roller 29. Inner diameter of the flange 291 is smaller than inner diameter of the plane bearing 28. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  In the present invention, the cam body is connected to a rotating support fixed to the rotating shaft via a connecting mechanism so that the tilt angle can be variably changed, and the tilt angle of the cam body is changed by adjusting the pressure of the control pressure chamber that houses the cam body. The present invention relates to a variable displacement compressor that controls the discharge capacity.

  In the coupling mechanism in the variable displacement compressor disclosed in Patent Document 1, pins are provided at predetermined positions on the front end face of the swash plate, and spherical portions are provided at both ends of the pin. A pair of long grooves are provided substantially in parallel on the rear end surface of the rotating member that rotates integrally with the rotating shaft, and the pair of spherical portions are guided in the pair of long grooves. The swash plate is tiltably supported by a hinge ball that is slidable along the peripheral surface of the rotation shaft. The guide of the spherical part by the long groove enables tilting of the swash plate around the hinge beer.

The structure which provided the spherical part which has entered into one of a pair of long groove so that rotation with respect to a pin was disclosed. When the swash plate tilts, the spherical portion (roller) rolls while engaging the surface of the long groove. The rotatable spherical portion (roller) is in the discharge stroke corresponding region (region in which the piston is moved from the bottom dead center side to the top dead center side) in the swash plate.
JP 2001-289159 A

  The surface pressure on the sliding contact surface between the spherical portion (roller) on the discharge stroke corresponding region side and the pin is preferably small in order to avoid premature wear. For this purpose, it is necessary to increase the diameter of the pin. However, the increase in the diameter of the entire pin results in an increase in the weight of the pin, and the support portion of the swash plate that supports the pin also becomes larger and the weight increases. The increase in the weight of the entire pin and the increase in the weight of the support portion of the swash plate that supports the pin work in the direction of increasing the inertial force accompanying the rotation of the swash plate and increasing the tilt angle of the swash plate. In particular, during high-speed rotation, the inclination of the swash plate tends to be excessive (discharge capacity is excessive), and when the inclination of the swash plate is excessive, control to reduce the discharge capacity (control to increase the pressure in the control pressure chamber) works. Is biased in the direction of decreasing the tilt angle. That is, there arises a problem that the swash plate hunts. That is, increasing the diameter of the entire pin results in a decrease in variable controllability.

Further, when the support portion is enlarged with the increase in the diameter of the entire pin, the control pressure chamber must be enlarged, and the compressor becomes large.
It is an object of the present invention to reduce the surface pressure between a roller and its sliding contact object without increasing the diameter of the entire pin constituting the coupling mechanism in the variable capacity compressor.

  In the present invention, the piston is interlocked with the rotation of the rotating shaft via a cam body that rotates integrally with the rotating shaft, and the cam body is connected to a rotating support fixed to the rotating shaft. And a variable displacement compressor that is connected in a variable manner through a tilt angle, the discharge angle of which is controlled by changing the tilt angle of the cam body by adjusting the pressure of a control pressure chamber that houses the cam body. In the first aspect of the invention, the coupling mechanism includes a pin supported by the cam body, a diameter-increasing portion provided in a part of the pin, a plain bearing fitted to the diameter-increasing portion, and the plain bearing. A roller fitted to the cam body, the roller being rotatably engaged with the rotary support, and the pin being held by the gripped portion having a smaller diameter than the increased diameter portion. It is supported by.

  Since the roller is fitted to the increased diameter part of the pin via a plain bearing (target of sliding contact with the roller), the surface pressure between the roller and the plain bearing and the surface pressure between the plain bearing and the pin are reduced. To do. Even when the increased diameter portion is integrated with the pin, only a part of the pin is increased in diameter, so that the weight increase of the pin is small. In addition, since the pin is supported by the cam body at the gripped portion having a smaller diameter than the increased diameter portion, the support portion of the cam body that supports the pin does not increase.

In a preferred example, the roller is provided on the discharge stroke corresponding area side.
The roller provided on the discharge stroke corresponding region side receives a majority of the compression reaction force. It is particularly necessary to reduce the surface pressure between the roller and the sliding contact target (plane bearing) and the surface pressure between the plain bearing and the pin. The roller and the plain bearing provided on the discharge stroke corresponding region side are particularly suitable as an application target of the present invention.

In a preferred example, the increased diameter portion is a cylinder that is fitted and fixed to the pin.
The configuration in which the cylinder is fitted to the pin to form the increased diameter portion is simple.
In a preferred example, the cylinder is press-fitted into the pin.

The press-fitting is convenient for fixing the cylinder to the pin.
In a preferred example, a flange is integrally formed on the inner peripheral side of the roller, and a circlip is attached to the pin, and the roller is engaged with the pin by the engagement of the flange and the circlip. Is restricted from moving in the axial direction.

In a preferred example, the engagement between the flange and the circlip is a configuration suitable for restricting the movement of the roller corresponding to the diameter increase of the roller.
The inner diameter of the flange is smaller than the outer diameter of the plain bearing, and the plain bearing is restricted from moving in the axial direction of the pin by engaging with the flange.

  The engagement between the plain bearing and the flange is a configuration suitable for the movement restriction of the plain bearing corresponding to the increased diameter of the plain bearing.

  The variable capacity compressor of the present invention has an excellent effect that the surface pressure between the roller and the sliding contact target can be reduced without increasing the diameter of the entire pin constituting the coupling mechanism.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 and 2.
As shown in FIG. 1A, a front housing 12 is connected to the front end of the cylinder block 11. A rear housing 13 is connected to the rear end of the cylinder block 11 via a valve plate 14 and a valve forming plate 15. The cylinder block 11, the front housing 12, and the rear housing 13 constitute an entire housing of the variable displacement compressor 10.

  A rotary shaft 18 is rotatably supported via radial bearings 19 and 20 on the front housing 12 and the cylinder block 11 forming the control pressure chamber 121. The rotating shaft 18 projecting outside from the control pressure chamber 121 obtains driving force from the vehicle engine E which is an external driving source.

  A rotary support 21 is fixed to the rotary shaft 18, and a swash plate 22 as a cam body is supported so as to be slidable and tiltable in the axial direction of the rotary shaft 18. The rotary shaft 18 is passed through a shaft hole 221 provided at the center of the swash plate 22, and the swash plate 22 can slide on the outer peripheral surface of the rotary shaft 18 through the peripheral wall of the shaft hole 221.

  A support arm 23 is integrally formed on the surface of the swash plate 22 that faces the rotary support 21. A support hole 231 (see FIG. 2B) is formed in the support arm 23 so as to extend in a direction perpendicular to the rotation shaft 18, and a pin 24 is press-fitted into the support hole 231. The pin 24 is supported by the support arm 23 of the swash plate 22 by the gripped portion 242.

  As shown in FIG. 2A, a spherical portion 241 is integrally formed at one end of the pin 24 extending in a direction orthogonal to the rotation shaft 18 (the end on the right side of the gripped portion 242 in the drawing). A guide arm 25 is integrally formed on the surface of the rotary support 21 facing the swash plate 22, and a guide groove 251 is formed in the guide arm 25. The direction of the guide groove 251 is a direction orthogonal to the pin 24 and inclined with respect to the rotation shaft 18. A spherical portion 241 is slidably fitted in the guide groove 251. The diameter of the portion of the pin 24 other than the spherical portion 241 is constant.

  As shown in FIG. 1B, a guide protrusion 26 is integrally formed on the opposite surface side of the rotary support 21 to the swash plate 22, and the distal end surface of the guide protrusion 26 is formed on an inclined guide surface 261. Is formed. The inclination angle of the guide surface 261 and the inclination angle of the guide groove 251 are the same.

  As shown in FIG. 2B, a cylinder 27 is press-fitted and fitted into the pin 24. A plain bearing 28 (sliding bearing) is rotatably fitted to the outer periphery of the cylinder 27, and a roller 29 is rotatably fitted to the outer periphery of the plain bearing 28. As the swash plate 22 tilts, the roller 29 rolls on the guide surface 261.

  A flange 291 is formed on the inner peripheral side of one end of the roller 29 (end far from the support arm 23). The inner diameter of the flange 291 is smaller than the inner diameter of the plain bearing 28. A circlip 30 is attached to the end of the pin 24 (the end opposite to the spherical portion 241). The outer diameter of the circlip 30 is larger than the inner diameter of the flange 291, and the circlip 30 and the flange 291 can be engaged with each other. The roller 29 is restricted by the circlip 30 from moving the pin 24 in the axial direction. Further, the roller 29 is restricted from moving in the axial direction of the pin 24 by one end face 232 of the support arm 23. That is, the position of the roller 29 is restricted between the circlip 30 and the support arm 23.

  The rotational force of the rotary support 21 that rotates integrally with the rotary shaft 18 is generated by engaging the wall surface 252 of the guide groove 251 with the spherical portion 241 (driving force receiving engagement portion) of the pin 24 through the swash plate 22. Is transmitted to. The swash plate 22 can rotate integrally with the rotary shaft 18 by the linkage between the wall surface 252 of the guide groove 251 and the spherical portion 241 of the pin 24.

  The guide arm 25, guide groove 251, pin 24, cylinder 27, plain bearing 28, and roller 29 are capable of changing the tilt angle of the swash plate 22 and transmitting torque from the rotary shaft 18 to the swash plate 22. The connecting mechanism 31 that connects the two is configured. The wall surface 252 of the guide groove 251 is a driving force transmission portion provided on the rotation support 21, and the pin 24 is a driving force receiving portion provided on the swash plate 22 so as to be engageable with the driving force transmission portion. .

  If the diameter center part of the swash plate 22 moves to the rotation support body 21 side, the inclination angle of the swash plate 22 increases. The maximum inclination angle of the swash plate 22 is regulated by the contact between the rotary support 21 and the swash plate 22, and the minimum inclination angle of the swash plate 22 is the contact between the circlip 32 attached to the rotary shaft 18 and the swash plate 22. Regulated by. The swash plate 22 shown by the solid line in FIG. 1A is in the maximum tilt state, and the swash plate 22 shown by the chain line is in the minimum tilt state. The minimum inclination angle of the swash plate 22 is larger than 0 °.

  Pistons 33 are accommodated in a plurality of cylinder bores 111 penetrating the cylinder block 11. The rotational movement of the swash plate 22 is converted into the back-and-forth reciprocating movement of the piston 33 via the shoe 34 moored to the swash plate 22, and the piston 33 reciprocates in the cylinder bore 111. That is, the piston 33 is interlocked with the rotation of the rotating shaft 18 through the swash plate 22 that rotates integrally with the rotating shaft 18.

  A suction chamber 131 and a discharge chamber 132 are defined in the rear housing 13. A suction port 141 is formed in the valve plate 14. A discharge port 142 is formed in the valve plate 14 and the valve forming plate 15. A suction valve 151 is formed on the valve forming plate 15, and a discharge valve 161 is formed on the valve forming plate 16 joined to the valve plate 14. The refrigerant in the suction chamber 131 flows into the cylinder bore 111 by pushing the suction valve 151 away from the suction port 141 by the suction operation of the piston 33 (movement from the right side to the left side in FIG. 1A). The gaseous refrigerant flowing into the cylinder bore 111 is discharged into the discharge chamber 132 by pushing the discharge valve 161 away from the discharge port 142 by the discharge operation of the piston 33 (movement from the left side to the right side in FIG. 1A). The discharge valve 161 is in contact with the retainer 17 and its opening degree is regulated.

  As shown in FIG. 2A, one half of the swash plate 22 divided by a virtual plane H orthogonal to the pin 24 so as to include the axis 181 of the rotating shaft 18 is the suction stroke corresponding region S, The half on one side is the discharge stroke corresponding region D. When viewed in the axial direction of the rotary shaft 18, the piston 33 corresponding to the suction stroke corresponding region S is in the suction stroke, and the piston 33 corresponding to the discharge stroke corresponding region D is in the discharge stroke. The spherical portion 241 of the pin 24 is on the suction stroke corresponding area S side, and the roller 29 is on the discharge stroke corresponding area D side.

The discharge chamber 132 and the suction chamber 131 are connected by an external refrigerant circuit (not shown). The refrigerant that has flowed out of the discharge chamber 132 into the external refrigerant circuit returns to the suction chamber 131.
A thrust bearing 35 is interposed between the rotary support 21 and the front housing 12. The thrust bearing 35 receives a compression reaction force acting on the rotary support 21 from the cylinder bore 111 via the piston 33, the shoe 34, the swash plate 22 and the coupling mechanism 31.

  The discharge chamber 132 and the control pressure chamber 121 are connected via a supply passage 36, and the control pressure chamber 121 and the suction chamber 131 are connected via a discharge passage 37. The refrigerant in the discharge chamber 132 is supplied to the control pressure chamber 121 through the supply passage 36. The refrigerant in the control pressure chamber 121 is discharged to the suction chamber 131 through the discharge passage 37.

  An electromagnetic capacity control valve 38 is interposed on the supply passage 36. The refrigerant supply amount from the discharge chamber 132 to the control pressure chamber 121 via the supply passage 36 increases and decreases according to the increase and decrease of the valve opening degree of the capacity control valve 38. Since the refrigerant in the control pressure chamber 121 flows out to the suction chamber 131 via the discharge passage 37, the control is performed according to the increase or decrease of the refrigerant supply amount from the discharge chamber 132 to the control pressure chamber 121 via the supply passage 36. The pressure in the pressure chamber 121 rises and falls. When the refrigerant supply amount increases, the pressure in the control pressure chamber 121 increases, and when the refrigerant supply amount decreases, the pressure in the control pressure chamber 121 decreases. Accordingly, the inclination angle of the swash plate 22 increases and decreases, and the discharge capacity increases and decreases.

  As the tilt angle of the swash plate 22 increases or decreases, the roller 29 rolls on the guide surface 261. The majority of the compression reaction force from the cylinder bore 111 on the discharge stroke corresponding region D side acts on the rotary support 21 through the engagement between the roller 29 and the guide surface 261.

In the first embodiment, the following effects can be obtained.
(1-1) The roller 29 is fitted to the cylinder 27 via the plain bearing 28, and the cylinder 27 is fitted and fixed to the pin 24. The cylinder 27 integrated with the pin 24 is a diameter-increasing part for increasing the diameter of the pin 24. The diameter of the plain bearing 28 and the diameter of the roller 29 fitted to the cylinder 27, which is the diameter-increasing part, are the plane. It becomes larger than the case where the bearing 28 is directly fitted to the pin 24. Therefore, the surface pressure between the roller 29 and the plain bearing 28 and the surface pressure between the plain bearing 28 and the cylinder 27 which is a part of the pin 24 are larger than those when the plain bearing 28 is directly fitted to the pin 24. Is also reduced.

  Since the cylinder 27 is fitted to only a part of the length of the pin 24, the weight increase of the pin 24 when the cylinder 27 is included as a part is small. The pin 24 is supported by a support arm 23 (a part of the swash plate 22) at a gripped portion 242 between the cylinder 27 and the spherical portion 241 (a portion having a smaller diameter than the outer diameter of the cylinder 27 which is an increased diameter portion). Therefore, the support arm 23 does not become large. Therefore, the problem of a decrease in capacity controllability due to an increase in weight of the coupling mechanism 31 does not occur.

  (1-2) The roller 29 is provided on the discharge stroke corresponding region D side. Reduction in surface pressure between the roller 29 and the plain bearing 28 provided on the discharge stroke corresponding region D side receiving the majority of the compression reaction force, and between the plain bearing 28 and the cylinder 27 which is a part of the pin 24. A reduction in surface pressure is particularly necessary. The roller 29 and the plain bearing 28 provided on the discharge stroke corresponding region D side are particularly suitable as an application target of the present invention.

  (1-3) The configuration in which the cylinder 27 is fitted to the pin 24 to form the increased diameter portion is simple in forming the increased diameter portion, and the configuration in which the cylinder 27 is press-fitted into the pin 24 is This is convenient for fixing to the pin 24.

  (1-4) The configuration in which the flange 291 integrally formed on the inner peripheral side of the roller 29 and the circlip 30 attached to the pin 24 can be engaged is that of the roller 29 corresponding to the diameter increase of the roller 29. This configuration is suitable for movement restriction (preventing the roller 29 from coming off the pin 24).

  (1-5) The configuration in which the inner diameter of the flange 291 is made smaller than the outer diameter of the plain bearing 28 so that the plain bearing 28 and the flange 291 can be engaged is the This configuration is suitable for movement restriction (preventing the plain bearing 28 from coming off the pin 24).

In the present invention, the following embodiments are also possible. In these embodiments, the same reference numerals are used for the same components as those in the first embodiment.
(1) In the embodiment shown in FIG. 3, the pin 24 </ b> A has a fitting portion 243 </ b> A having a smaller diameter than the gripped portion 242 of the pin 24 fitted into the support hole 231 of the support arm 23. The gripped part 242 is fitted in the support hole 231 without being fixed, and the cylinder 27A is press-fitted into the fitting part 243A so as to be in contact with the step 244 between the gripped part 242 and the fitting part 243A. Yes. The outer diameter of the cylinder 27 </ b> A is larger than the diameter of the gripped portion 242.

  In the embodiment of FIG. 3, the same effect as that of the first embodiment can be obtained. Further, since the cylinder 27A is press-fitted into the fitting portion 243A so as to contact the step 244, the cylinder 27A is accurately positioned with respect to the pin 24A, and the pin 24A does not come off from the support arm 23. Furthermore, since it is not necessary to press-fit the pin 24A into the support hole 231, the assembly of the coupling mechanism 31 is facilitated.

  (2) In the embodiment shown in FIG. 4, a flange 271 is formed on the outer peripheral side of the end of the cylinder 27B. The outer diameter of the flange 271 is larger than the inner diameter of the roller 29 so that the flange 271 and the roller 29 can be engaged with each other. The configuration in which the flange 271 integrally formed on the outer peripheral side of the end portion of the cylinder 27B and the roller 29 can be engaged with each other is that the movement of the roller 29 corresponding to the diameter increase of the roller 29 (the removal of the roller 29 from the pin 24). It is a structure suitable for stopping.

  (3) In the embodiment shown in FIG. 5, the pin 24 </ b> C has a gripped portion 242 </ b> C having a smaller diameter than the fitting portion 243 into which the cylinder 27 is fitted. A spherical portion 241C is press-fitted and fixed to the end portion of the gripped portion 242C. The gripped portion 242C is fitted in the support hole 231 without being fixed, and the cylinder 27 is press-fitted into the fitting portion 243.

  In the embodiment of FIG. 5, the same effect as that of the first embodiment can be obtained. In addition, since the diameter of the gripped portion 242C is smaller than the diameter of the fitting portion 243, the pin 24C is lighter than the pin 24 in the first embodiment.

(4) In the embodiment of FIG. 5, an increased diameter portion and a plain bearing may be interposed between the spherical portion 241C and the gripped portion 242C, and the spherical portion 241C may be used as a roller.
(5) In the embodiment of FIGS. 3 and 5, a circlip that can be engaged with the end surface of the support arm 23 (the right end surface in the figure) may be attached to the pin.

(6) Instead of the circlip in the item (5), a flange may be integrally formed on the peripheral surface of the pin.
(7) In the embodiment of FIG. 5, the cylinder 27 and the pin 24C may be integrally formed.

(8) The spherical portion in each of the embodiments may be a cylindrical driving force receiving engagement portion.
The technical idea that can be grasped from the embodiment described above will be described below.
[1] The variable capacity compressor according to any one of claims 1 to 6, wherein a driving force receiving engagement portion is separately formed on the pin.

1 shows a first embodiment, (a) is a side sectional view of the whole compressor. (B) is a fragmentary sectional view. (A) is a partial top view. (B) is a partial cross-sectional view incorporating an enlarged cross-sectional view. The fragmentary sectional view which shows another embodiment. The fragmentary sectional view which shows another embodiment. The fragmentary sectional view which shows another embodiment.

Explanation of symbols

  10: Variable capacity compressor. 121: Control pressure chamber. 18 ... Rotating shaft. 21 ... Rotating support. 22 ... A swash plate as a cam body. 24, 24A, 24C ... pins. 242, 242 C: gripped portion. 252 ... Wall surface. 27, 27A27B... Cylinder as an increased diameter portion. 28 ... Plain bearing. 29 ... Laura. 291 ... Flange. 31 ... Connection mechanism. 30 ... Circlip. 33 ... Piston. S: Inhalation stroke area. D: Discharge stroke area.

Claims (6)

The piston is interlocked with the rotation of the rotating shaft through a cam body that rotates integrally with the rotating shaft, and the cam body is inclined through a coupling mechanism with respect to the rotating support fixed to the rotating shaft. In a variable displacement compressor that is variably connected and the discharge capacity is controlled by changing the inclination angle of the cam body by adjusting the pressure of a control pressure chamber that houses the cam body,
The coupling mechanism includes a pin supported by the cam body, a diameter increasing portion provided in a part of the pin, a plain bearing fitted to the diameter increasing portion, and a roller fitted to the plain bearing. And
The roller is movably engaged with the rotary support, and the pin is supported by the cam body at a gripped portion having a smaller diameter than the increased diameter portion. Machine.   The variable displacement compressor according to claim 1, wherein the roller is provided on a discharge stroke corresponding region side.   The variable capacity compressor according to any one of claims 1 and 2, wherein the diameter-increasing portion is a cylinder that is fitted and fixed to the pin.   The variable capacity compressor according to claim 3, wherein the cylinder is press-fitted into the pin.   A flange is integrally formed on the inner peripheral side of the roller, and a circlip is attached to the pin. The roller is moved in the axial direction of the pin by the engagement of the flange and the circlip. The variable displacement compressor according to any one of claims 1 to 4, wherein movement is restricted.   6. The variable according to claim 5, wherein an inner diameter of the flange is smaller than an outer diameter of the plain bearing, and the plain bearing is restricted from moving in the axial direction of the pin by engagement with the flange. Capacity type compressor.

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