JP4439405B2 - Swing swash plate type variable capacity compressor - Google Patents

Description

  The present invention relates to a compressor used for refrigerant compression of a positive displacement pump and an air conditioner, and more particularly to a swing swash plate type compressor, and a swing swash plate type variable capacity that requires a large capacity such as a bus. It is suitable for a compressor.

  As a prior art, a structure in which a constant velocity joint is used as a detent mechanism for a swinging swash plate (wobble plate) and this is arranged at the center of the swinging swash plate is known in Patent Documents 1 to 3, etc. Each have various problems.

US Pat. No. 5,112,197 US Pat. No. 5,129,752 US Pat. No. 5,509,346

  For example, in Patent Document 1, a constant velocity joint is supported using a part of an extension sleeve fixed to a cylinder block. The drive shaft is rotatably supported by the extension sleeve via a needle bearing. Therefore, the constant velocity joint itself does not have an inner ring, and a part of the extension sleeve is an inner ring. For this reason, there exists a problem that the assembly | attachment to the sleeve of a constant velocity joint is difficult. Further, since the means for regulating the minimum capacity is a return spring that engages with the pin of the link portion, there is also a problem in rigidity.

  In Patent Document 2, the constant velocity joint itself has an inner ring, but the inner ring is not configured to be slidable in the axial direction, and a shaft member (center shaft) that supports the constant velocity joint. Is configured to be movable in the drive axis direction in the center of the cylinder block. However, this center shaft is configured to receive torque with a pin (key) sandwiched between it and the cylinder block, so there is a problem that the torque that can be received is limited. In order to improve this, means such as spline fitting of the fitting portion between the cylinder blot and the center shaft is conceivable. However, when the cylinder block is made of aluminum, there is a concern about wear. Further, when the cylinder block is made of iron, there is a problem of an increase in weight, and it is conceivable that only the spline portion is made of iron, but there is a problem that the number of parts increases. Further, since the center shaft moves back and forth, there is a problem that sliding occurs in the needle bearing portion that rotatably supports the drive shaft on the side opposite to the cylinder block, and the life of the bearing is reduced.

Further, in Patent Document 3, the center shaft is fixed to the cylinder block, and the problem caused by the movement of the center shaft in Patent Document 2 is solved. There is a problem that it is difficult to manufacture and assemble.
Further, in Patent Documents 1 and 3, since a journal that rotates integrally with the outer peripheral portion of the swing swash plate via the drive shaft and the link portion covers the outer periphery of the swash plate in order to balance during operation, compression is performed. There is also the problem that the physique of the machine grows.

  The present invention has been made in view of the above problems, and its purpose is particularly effective for a compressor having a large capacity, and is a small and well-balanced swash plate that is easy to manufacture and assemble. It is to provide a type variable capacity compressor.

The present invention provides a swing swash plate type variable displacement compressor according to each of the claims as means for solving the above-mentioned problems.
The swing swash plate type variable displacement compressor according to claim 1, wherein the rotation prevention mechanism for preventing the rotation of the wobble plate (swing swash plate) has an inner ring and is fixed to the housing. The anti-rotation mechanism can be moved in the axial direction by being supported by the shaft and moving the inner ring while restricting the rotation on the central axis in the axial direction, and is also in contact with the anti-rotation mechanism or the wobble plate to prevent the rotation. This is provided with a minimum capacity regulating part that regulates the axial movement of the compressor, so that when the compressor is assembled, the inner ring is pre-assembled to the non-rotating mechanism, and the non-rotating mechanism is assembled to the compressor. Since it is sufficient, the assembly is easy. Further, since the inner ring moves in the axial direction, the stroke sufficient for the variable capacity can be earned without increasing the outer ring and hence without increasing the size of the rotation preventing mechanism itself. Furthermore, since the central shaft is fixed, there is little play and rigidity is high, which is advantageous in terms of reliability, vibration and noise. Further, since the wobble plate does not tilt beyond the minimum capacity and there is no problem that the top of the piston hits the valve plate, high reliability can be obtained.

The swing swash plate type variable displacement compressor according to claim 2, wherein the rotation prevention mechanism for preventing the rotation of the wobble plate (swing swash plate) has an inner ring and is fixed to the housing. An urging member that is supported by the shaft and that is capable of moving the anti-rotation mechanism in the axial direction by restricting rotation in the axial direction on the central axis and moving the inner ring in the axial direction, and urging the anti-rotation mechanism in the axial direction The anti-rotation mechanism is installed on the front side and the rear side so that the front side urging member acts in the minimum capacity direction and the rear side urging member acts in the maximum capacity direction. Thus, the same effect as the compressor of claim 1 can be obtained, and the control at the time of capacity return can be assisted by the urging member that works on the maximum capacity side. Power of time can be reduced.

The compressor according to claim 3 is provided with a minimum capacity restricting portion that abuts against the inner ring that restricts the axial movement of the detent mechanism to determine the minimum capacity on the central axis. Since there is no problem of tilting beyond the minimum capacity and there is no problem that the top of the piston hits the valve plate, high reliability can be obtained.
The compressor according to claim 4 is constituted by a step having a smaller shaft diameter than a portion fixed to the housing of the central shaft so that the minimum capacity regulating portion of the central shaft is brought into contact with the inner ring. Thus, a step portion is provided as a minimum capacity regulating portion on the central axis, and the minimum capacity regulating portion can be easily formed.

The compressor according to claim 5 is configured such that the center of swing of the rotation prevention mechanism is arranged on the front side of the wobble plate, whereby the center of gravity of the drive unit and the center of rotation of the rotation stop mechanism are In general, the balance is generally good for any capacity. Moreover, there is no need to add a new balancer, nor will it cause an increase in physique.
The compressor according to claim 6 is a constant velocity joint including at least an inner ring, an outer ring, and a ball as a non-rotating mechanism. Thus, as a universal joint for connecting a wobble plate and a central shaft, By using a constant velocity universal joint such as a to-type, the wobble plate can be completely free of rotational motion components.

In the compressor according to claim 7 , the central shaft supporting the rotation preventing mechanism is cantilevered so that one end is a free end and the other end is fixed to a housing. By fixing the center axis to the center of the cylinder block, rigidity can be ensured even with cantilever support.
9. The compressor according to claim 8 , wherein the central shaft for supporting the rotation preventing mechanism is a double-sided support in which one end is supported by a bearing disposed on the drive shaft and the other end is supported non-rotatably by the housing. Thus, it is possible to maintain a load acting on the central axis, improve reliability, and reduce vibration and noise.

  A swing swash plate type variable capacity compressor according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing the overall structure of the swing swash plate type variable displacement compressor of the first embodiment in a motion state that provides the maximum discharge capacity (100% capacity). FIG. It shows the operating condition that provides the minimum discharge capacity (0% capacity) of the compressor. In these drawings, reference numeral 2 denotes a front housing of the compressor 1, and reference numeral 3 denotes a rear housing of the compressor 1. A cylinder serving as a middle housing is sandwiched between the front housing 2 and the rear housing 3. Blocks 4 are arranged and integrated by fastening means such as through bolts (not shown) to form a housing of the compressor 1. In the cylinder block 4, a plurality of (for example, five) cylinder bores 5 are formed so as to be substantially evenly arranged around the center line in the lateral direction (axial direction of a drive shaft described later) in FIG. 1. . A discharge chamber 6 is formed as a substantially annular space in the outer peripheral portion of the rear portion of the rear housing 3, and a suction chamber 7 is formed as a space in the center portion.

  Reference numeral 8 denotes a drive shaft for receiving rotational power from an external power source (for example, an engine), and a disc portion 9 is integrally formed so as to be orthogonal to the drive shaft 8. Further, the two arms 10 are formed so as to protrude rearward in parallel with a predetermined interval from a part near the outer periphery of the disc portion 9. The drive shaft 8 is supported by the front housing 2 which is a part of the housing via two radial bearings 11 and 12, and via a thrust bearing 13 which supports the back surface of the disk portion 9. It is also supported by the front housing 2 in the axial direction. A shaft seal device 14 is provided between the radial bearings 11 and 12 to prevent fluid from leaking from the periphery of the drive shaft 8 to the outside.

  Reference numeral 15 denotes a generally annular drive plate having an arm portion 16 protruding forward from a part thereof. The arm portion 16 is provided with a long hole 17 having a predetermined shape that operates as a cam, and a pin 18 attached between the two parallel arms 10 on the drive shaft 8 side so as to bridge. Is inserted into the long hole 17 and engaged therewith. The link mechanism 57 is constituted by these portions so that the drive plate 15 can rotate together with the drive shaft 8 and can be inclined with respect to the drive shaft 8 and its disk portion 9 in a variable angle state. A substantially annular wobble plate (swinging swash plate) 19 that is prevented from rotating by means described later and only swings is supported on the drive plate 15 via a radial bearing 20 and a thrust bearing 21. Needless to say, the link mechanism 57 can be replaced by other link mechanisms such as a slope and an arm, a ball seat and a sphere that perform the same function.

  A generally cylindrical outer ring (outer ring) 22 integrated therewith is fitted into the opening of the wobble plate 19, and the inner ring of the radial bearing 20 is supported by the small diameter portion 24. The outer ring of the radial bearing 20 is supported by the inner surface of the opening of the generally annular drive plate 15 and fixed by caulking or the like. A male screw portion 25 is formed at the left end portion of the small diameter portion 24 of the outer ring 22 in FIG. 1, and is attached to the outer ring 22 by a nut 26 and a washer 27 that are screwed to the male screw portion 25.

  In this manner, the radial bearing 20 couples the drive plate 15 to the outer ring 22 and the wobble plate 19 so as to be relatively rotatable, and the thrust bearing 21 is sandwiched between the drive plate 15 and the wobble plate 19. Therefore, although the wobble plate 19 and the outer ring 22 oscillate together with the drive plate 15 by these configurations, it is possible to stop without rotating regardless of the rotational motion of the drive plate 15. It is.

  In this embodiment, a known barfield type constant velocity joint 68 is used as a detent mechanism for preventing the rotational movement of the outer ring 22 and the wobble plate 19, but this detent mechanism and Since the peripheral configuration is characteristic of this embodiment, it will be described in detail later.

  A central shaft 32 that supports the drive plate 15 and the wobble plate is fixedly supported by the cylinder block 4 so as not to rotate on an extension line of the drive shaft 8. A spline is formed in the fitting portion between the center shaft 32 and the inner ring (inner ring) 74 of the constant velocity joint 68. Thus, in the present embodiment, the wobble plate 19 is prevented from rotating by the constant velocity joint 68 and the central shaft 32 that is prevented from rotating.

  In the periphery of the wobble plate 19, the same number of spherical depressions 34 as the above-described cylinder bore 5 are formed, and a spherical end 36 formed at one end of the same number of connecting rods 35 is engaged therewith. . A spherical recess 39 is also formed in each piston 38 slidably inserted into each cylinder bore 5, and a spherical end 40 formed at the other end of the connecting rod 35 is associated therewith. Match.

  The spherical recess 34 of the wobble plate 19 is secured by caulking around the spherical end 36 of the connecting rod 35. Similarly, the spherical recess 39 of the piston 38 is also The stopper is provided by caulking around the spherical end 40. In this embodiment, the wobble plate 19 and the piston 18 are connected to the spherical end portions 36 and 40 of the connecting rod 35 by caulking, but the connecting means of this portion in the present invention is only for “caulking”. It is not necessarily limited, and other connecting means may be used.

  Reference numeral 41 denotes a thick plate, and at least one discharge port 42 and one suction port 43 are opened so as to penetrate the valve plate 41 at positions corresponding to the cylinder bores 5. Each suction port 43 of the valve plate 41 is closed from the cylinder bore 5 side by a reed valve-like suction valve formed in each part of the suction valve 44 made of one thin spring steel plate. Each discharge port 42 is closed from the discharge chamber 6 side by a reed valve-like discharge valve 45 made of a thin spring steel plate disposed in each discharge port 42. When the cylinder block 4 and the rear housing 3 are fixed and integrated by means (not shown), the valve plate 41, the suction valve 44, and the discharge valve 45 are sandwiched and fixed therebetween. A stopper (not shown) for regulating the lift amount of the discharge valve 45 is attached to the valve plate 41 with bolts or the like.

  Reference numeral 48 denotes a control valve attached to the rear end portion of the rear housing 3, which is controlled by a control device such as an electronic control device (not shown), and the pressure of the fluid (refrigerant) in the suction chamber 7, that is, the suction pressure. Then, a fluid pressure having an arbitrary height between the pressure of the fluid (refrigerant) in the discharge chamber 6, that is, the discharge pressure, is generated and used as a control pressure to the control pressure chamber 49 where the drive plate 15 and the wobble plate 19 are provided. Supply. The inclination of the wobble plate 19 is controlled by the control pressure introduced into the control pressure chamber 49.

Next, the anti-rotation mechanism and the surrounding configuration, which are the features of this embodiment, will be described in detail. In the present embodiment, a constant velocity joint 68 for automobiles or industrial machines is used as a detent mechanism. Further, the outer ring 22 that is integrally fitted to the opening of the baffle plate 19 is used as an outer ring of the constant velocity joint. The constant velocity joint 68 includes an outer ring 22, a cage 70, an inner ring (inner ring) 74, and a plurality of balls 71. The constant velocity joint 68 is attached to the central shaft 32 so as to be movable in the axial direction. That is, the rear end portion of the central shaft 32 is fixed to the cylinder block 4 and does not rotate but also does not move in the axial direction. Therefore, the spline protrusion 73 formed on the outer peripheral surface of the center shaft 32 is spline-engaged with the spline groove 75 formed in the inner ring (inner ring) 74 of the constant velocity joint 68, so that the axial direction of the constant velocity joint 68 is increased. The wobble plate 19 is prevented from rotating through the inner ring 74.
The constant velocity joint 68 serving as the rotation preventing mechanism is disposed on the central shaft 32 so as to be positioned on the front side of the wobble plate 19. As a result, the center of gravity of the drive unit (the part that oscillates and rotates excluding the central axis) and the center of oscillation of the anti-rotation mechanism substantially coincide with each other, and the balance is substantially improved in any capacity.

  The central shaft 32 has a large diameter on the side fixed to the cylinder block 4 and a small diameter on the side on which the inner ring 74 of the constant velocity joint 68 is slidably fitted. A level difference 79 is formed in this, and this functions as a minimum capacity regulating portion 79. As a result, the inner ring 74 abuts against the minimum capacity regulating portion 79 to regulate the inclination angle of the wobble plate 19 and regulate the minimum capacity of the compressor.

  Further, an urging member 78 such as a spring is provided on the shaft, stopped on the large diameter portion of the central shaft 32 adjacent to the minimum capacity regulating portion 79, and urges the wobble plate 19 to the maximum capacity side. The urging member 78 assists the control when the capacity is restored. On the other hand, an urging member 77 such as a spring is provided on the shaft and is fixed to the end surface of the center shaft 32 on the free end opposite to the side fixedly supported by the cylinder block 4, and the inner ring of the constant velocity joint 68. 74 is pushed to the rear side. This urging member 77 assists in controlling the compressor capacity to the minimum side when the compressor is operating, and always keeps the wobble plate 19 on the side where the capacity is low when the compressor is stopped. Can be reduced.

  The operation of the swing swash plate type variable displacement compressor of the present embodiment having the above-described configuration will be described. Since the most suitable use of the compressor 1 is to be used as a refrigerant compressor of a vehicle air conditioner, it will be described that the compressor 1 is also used in a vehicle air conditioner.

  When the drive shaft 8 is driven to rotate by an external power source such as an internal combustion engine or a motor mounted on a vehicle via a belt transmission device or the like or directly, the disc portion 9 of the drive shaft 8 is driven. The drive plate 15 connected via the arm 10, the pin 18, the long hole 17, and the arm portion 16 rotates together with the drive shaft 8. However, the wobble plate 19 is connected to the drive plate 15 via the bearings 20 and 21 and the center portion is supported by the central shaft 32 that does not rotate via the constant velocity joint 68. If the drive plate 15 is inclined with respect to a virtual plane orthogonal to the drive shaft 8, only the swing motion having an amplitude corresponding to the inclination angle is performed. Accordingly, the plurality of pistons 38 connected to the wobble plate 19 via the connecting rod 35 reciprocate in the respective cylinder bores 5.

  As a result, among the working chambers 50 formed on the top surfaces of the plurality of pistons 38, those in the suction stroke are expanded to a low pressure, so that the refrigerant to be compressed in the suction chamber 7 enters the valve. The suction valve provided in the suction port 43 of the plate 41 is pushed open to flow in. On the contrary, the working chamber 50 formed on the top surface of the piston 38 in the pressure feed stroke is reduced, so that the refrigerant in the chamber is compressed to a high pressure and discharged from the discharge port 42 of the valve plate 41. The valve is pushed open and discharged into the discharge chamber 6. The discharge amount of the compressor 1 per rotation of the drive shaft 8 is generally proportional to the stroke length of the piston 38 determined by the inclination angle θ of the drive plate 15 and the wobble plate 19.

  As described above, when the inclination angle θ of the drive plate 15 and the wobble plate 19 is changed, the discharge capacity of the compressor 1 changes. Therefore, in order to control the discharge capacity, in the compressor 1 of the present embodiment, all the The pressure in the control pressure chamber (crank chamber) 49 serving as the back pressure of the piston 38 is changed to an arbitrary height commanded by a control device (not shown) by the control valve 48. As described above, the control pressure chamber 49 introduces from the control valve 48 a pressure having an arbitrary height between the high pressure in the discharge chamber 6 and the low pressure in the suction chamber 7.

  For example, when the pressure in the control pressure chamber 49, that is, the back pressure of the piston 38 is increased, the balance state with the pressure in the working chamber 50 formed on the top surface of each piston 38 changes, so that a new balance state is obtained. Until it is obtained, the position of the bottom dead center common to the plurality of pistons 38 moves toward the position close to the valve plate 41. Accordingly, the swing center of the wobble plate 19 also moves toward a position closer to the valve plate 41, so that the inclination angle θ of the wobble plate 19 and the drive plate 15 (definition of θ: a line perpendicular to the central axis (see FIG. In FIG. 1, θ = 0 is set for a vertical line), and therefore, when 100% capacity is reached, FIG. 1 shows a maximum θ and a minimum capacity FIG. 2 shows a minimum θ), and the strokes of all pistons 38 become all at once. Therefore, the discharge capacity of the compressor is continuously reduced.

  FIG. 2 shows that when the pressure in the control pressure chamber 49 is maximized, the bottom dead center of the piston 38 substantially coincides with the top dead center at the position closest to the valve plate 41, and the stroke of the piston 38 is substantially equal. As a result, the discharge capacity is substantially zero as a result. In this case, since the inclination angle θ of the drive plate 15 and the wobble plate 19 is substantially 0 degree, even if the drive plate 15 rotates with the drive shaft 8, the wobble plate 19 does not rotate but of course swings. If not, it is virtually stationary. Therefore, all the pistons 38 are substantially at the position of the top dead center and do not reciprocate substantially in the cylinder bore 5. However, in the present embodiment, the minimum capacity restriction portion 79 of the central shaft 32 is brought into contact with the inner ring (inner ring) 74 of the constant velocity joint 68 and the biasing member 78 is provided adjacent to the minimum capacity restriction portion 79. Further, the inclination angle θ is prevented from becoming strictly 0 degree, and the discharge capacity is not made completely zero (0% capacity), but is left slightly to enhance the response of the next control.

  On the other hand, when the control valve 48 is operated by a control device (not shown) to reduce the pressure in the control pressure chamber 49 to an arbitrary height up to the suction pressure, the back pressure acting on the piston 38 becomes small. Due to the compression reaction force generated by compressing the refrigerant in the working chamber 50, the bottom dead center of the reciprocating motion of all the pistons 38 is caused by the axial force due to the back pressure of the pistons 38 (pressure in the control pressure chamber 49). The valve plate 41 is moved away from the valve plate 41 to a position that balances the axial force generated by the compression reaction force. Along with this, the swing center moves away from the valve plate 41 as shown in FIG.

  As a result, since the inclination angle θ of the wobble plate 19 and the drive plate 15 increases and the amplitude of the swinging motion increases, the strokes of all the pistons 38 increase simultaneously, and the discharge capacity of the compressor 1 is stepless. Become bigger. In FIG. 1, by minimizing the pressure in the control pressure chamber 49, the inclination angle θ of the drive plate 15 and the wobble plate 19 is increased, and the stroke of the piston 38 and the discharge capacity of the compressor 1 are maximized (100%). (Capacity).

Next, the features of the present embodiment will be described together with the effects thereof.
In the present embodiment, the central shaft 32 that supports the constant velocity joint 68 that is a detent mechanism is fixed to the cylinder block 4, that is, the housing.
If the shaft that supports the constant velocity joint is not fixed, this shaft must move to the cylinder side during variable displacement, so the housing (when the load acting on the constant velocity joint is the largest at 100% capacity) The portion supported by the cylinder block 4) is shortened, an excessive load is generated at the shaft end, and the reliability of the sliding portion of the shaft cannot be ensured. Furthermore, when changing, since the shaft tries to move while an excessive load is applied to the shaft end, there is also a problem that the shaft end cuts the housing (cylinder block). In the present embodiment, since the central shaft 32 that supports the constant velocity joint 68 is fixed to the housing (cylinder block 4), such a problem can be avoided.

In the present embodiment, the constant velocity joint 68 itself, which is a detent mechanism, has an inner ring (inner ring) 74.
Since the constant velocity joint itself has an inner ring, when the compressor is assembled, the constant velocity joint may be assembled in advance and then assembled into the compressor, so that the assembly is easy. If the constant velocity joint itself does not have an inner ring, it is necessary to assemble the constant velocity joint at the same time as the compressor assembly.

Furthermore, in the present embodiment, the inner ring 74 of the constant velocity joint 68 that is a detent mechanism is slidable along the central axis 32.
If the constant velocity joint does not have an inner ring, a structure that moves along the axis in the constant velocity joint itself will increase the outer ring (outer ring) in the axial direction, leading to an increase in the size of the constant velocity joint. In this embodiment, since the inner ring moves in the axial direction, the outer ring does not increase, and therefore the piston stroke sufficient for the variable capacity can be achieved without increasing the physique of the constant velocity joint itself. Earn money.

  In this embodiment, since the wobble plate 19 is located on the rear side of the anti-rotation mechanism 68, the center of gravity of the drive unit and the rocking center of the anti-rotation mechanism substantially coincide with each other, and there is balance in any capacity. Generally better. Moreover, it is not necessary to add a new balancer, and the physique of the compressor is not increased. The center of swing is the center of swing of the constant velocity joint, and the center of gravity of the drive unit is the center of gravity of the rotating and swinging portion of the drive plate, wobble plate, constant velocity joint, and the like. The coincidence between the center of swing and the center of gravity is obtained as a coincident place on the three-dimensional CAD. That is, when the swing center of the constant velocity joint is moved from the center of the spherical seat of the wobble plate to the front side, a substantially coincident point is obtained.

In the present embodiment, the central shaft 32 that supports the drive plate 15 and the wobble plate 19 is press-fitted and fixed to the central portion of the cylinder block 4, so that the central shaft is movable in the axial direction. Since there is little backlash and high rigidity, it is advantageous in terms of reliability, vibration and noise.
Further, the central shaft 32 is provided with a minimum capacity regulating portion 79. By abutting with the inner ring 74 of the constant velocity joint 68, the inclination angle θ of the wobble plate 19 is regulated to reduce the minimum capacity of the compressor. It is regulated. For this reason, since the wobble plate 19 does not tilt beyond the minimum capacity, the top of the piston 38 does not hit the valve plate 41, so that the reliability can be improved.

Further, in the present embodiment, since the biasing member 78 such as a spring that biases toward the maximum capacity side is provided, it is possible to assist control when the capacity of the compressor is restored. Similarly, since the biasing member 77 such as a spring for biasing to the minimum capacity side is provided, the minimum capacity can be set when the engine is stopped, and the power when the compressor is started can be reduced.
In the present embodiment, it is preferable that HFC134a, which is a chlorofluorocarbon refrigerant, can ensure a capability equal to or higher than that of a compressor having a capacity of 300 cc / rev . Thereby, a large capacity compressor applicable to an air conditioner such as a bus can be obtained. For example, in the case of a CO ₂ refrigerant, it is equivalent to or better than a compressor having a capacity of 100 cc / rev when the refrigerant is HFC134a and has a capacity of 300 cc / rev .

  FIG. 3 is a longitudinal cross-sectional view showing the overall structure of the swing swash plate type variable displacement compressor of the second embodiment in an operating state that provides the maximum discharge capacity (100% capacity). In the second embodiment, a concave portion 81 is formed in the central portion of the drive shaft 8 facing the central shaft 32, and a radial bearing (slide bearing) 82 is disposed in the concave portion 81. The end is inserted and supported. That is, in the first embodiment, the central shaft 32 is a cantilever support in which only one end side is fixed and supported by the cylinder block (housing) 4, whereas in the second embodiment, the central shaft 32 has one end. This is a double-sided support structure in which the side is supported by the cylinder block 4 and the other end is supported by the drive shaft 8. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

By supporting the central shaft 32 at both ends in this way, the load acting on the central shaft 32 can be received on both sides, the rigidity is higher than the cantilever support, the reliability is further improved, and vibration / Noise can be further reduced.
The bearing (bearing) that supports the central shaft 32 may be a ball bearing (rolling bearing) instead of the radial bearing 82.

BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows the whole structure of the rocking | fluctuation swash plate type | mold variable capacity compressor of 1st Embodiment of this invention, The 100% capacity | capacitance is shown. It is a longitudinal cross-sectional view of the swing swash plate type variable capacity compressor of the first embodiment at the time of the minimum capacity. It is a longitudinal cross-sectional view in the time of 100% capacity | capacitance of the swing swash plate type variable capacity compressor of 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Oscillating swash plate type variable capacity compressor 4 Cylinder block 8 Drive shaft 15 Drive plate 19 Wobble plate (oscillating swash plate)
22 Outer ring (outer ring)
32 Center axis 68 Non-rotating mechanism (constant velocity joint)
70 Cage 71 Ball 73 Spline protrusion 74 Inner ring (inner ring)
75 Spline groove 77, 78 Energizing member 79 Minimum capacity restriction (step)
81 Concave portion 82 Radial bearing (slide bearing)

Claims (8)

A drive shaft that is supported by a housing via a bearing and receives rotational power from a power source;
A drive plate coupled to the drive shaft for rotation and tiltable with respect to the drive shaft;
A wobble plate coupled to the drive plate via a bearing, having the same inclination angle as the drive plate, but prevented from rotating by a detent mechanism;
A piston connected to the wobble plate to reciprocate in the axial direction of the drive shaft, and inserted into a cylinder bore formed in the housing to suck and compress fluid;
A central shaft supported by the housing on an extension line of the drive shaft to support the drive plate and the wobble plate;
In the swing swash plate type variable capacity compressor having
The anti-rotation mechanism has an inner ring that is movable in the axial direction along the central axis, and the inner ring is supported by the central axis and restricts rotation on the central axis in the axial direction. As the inner ring moves, the anti-rotation mechanism moves in the axial direction, and has a minimum capacity restricting portion that abuts against the anti-rotation mechanism or the wobble plate and restricts the axial movement of the anti-rotation mechanism. swash plate type variable displacement compressor, characterized by that. A drive shaft that is supported by a housing via a bearing and receives rotational power from a power source;
A drive plate coupled to the drive shaft for rotation and tiltable with respect to the drive shaft;
A wobble plate coupled to the drive plate via a bearing, having the same inclination angle as the drive plate, but prevented from rotating by a detent mechanism;
A piston connected to the wobble plate to reciprocate in the axial direction of the drive shaft, and inserted into a cylinder bore formed in the housing to suck and compress fluid;
A central shaft supported by the housing on an extension line of the drive shaft to support the drive plate and the wobble plate;
In the swing swash plate type variable capacity compressor having
The anti-rotation mechanism has an inner ring that is movable in the axial direction along the central axis, and the inner ring is supported by the central axis and restricts rotation on the central axis in the axial direction. When the inner ring moves, the rotation prevention mechanism moves in the axial direction, and a biasing member such as a spring that urges the rotation prevention mechanism in the axial direction includes a front side and a rear side across the rotation prevention mechanism. The swing swash plate type variable capacity compressor is characterized in that the urging member on the front side acts in the minimum capacity direction and the urging member on the rear side acts in the maximum capacity direction . Claim 1, wherein the central axis, determine the minimum capacity to regulate the axial movement of the detent mechanism, characterized in that it has the inner ring and the minimum capacity regulating portion abuts the detent mechanism Or the swing swash plate type variable capacity compressor of 2. The minimum capacity restricting portion of the central shaft is configured by a step having a smaller shaft diameter than a portion fixed to the housing of the central shaft in order to contact the inner ring. Item 4. The swing swash plate type variable capacity compressor according to item 3 . The swing swash plate type variable capacity compressor according to any one of claims 1 to 4 , wherein the center of swing of the rotation prevention mechanism is disposed on the front side of the wobble plate. The swing swash plate type variable capacity compressor according to any one of claims 1 to 5 , wherein the detent mechanism includes a constant velocity joint including at least the inner ring, an outer ring, and a ball. . Said central shaft which supports the detent mechanism, one end at the free end, the other end according to any one of claims 1 to 6, characterized in that a cantilever which is fixed to the housing Swing swash plate type variable capacity compressor. The center shaft that supports the detent mechanism is a double-sided support in which one end is supported by a bearing disposed on the drive shaft and the other end is supported non-rotatably by the housing. The swing swash plate type variable capacity compressor according to any one of claims 1 to 6 .

Images