JPH09133074A - Variable displacement compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of looseness in a screw member for fixing a pulley to a drive shaft, even in case that negative torque acts in the drive shaft, at minimum displacement operation time. SOLUTION: In a condition that a pulley 20 for operation connecting to an external drive source is fitted to a tip end of a drive shaft 16, a bolt 56 as a screw member is screwed to a screw hole 55 in the tip end of the drive shaft 16, the pulley 20 is fixed to the drive shaft 16. An elastic material 57 is interposed between a screw part 56a of the bolt 56 and the screw hole 55, looseness of the bolt 56 is locked by elastic deformation of this elastic material 57.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable displacement compressor used in, for example, a vehicle air conditioner.

[0002]

2. Description of the Related Art Generally, in a compressor such as a cam plate compressor, a pulley as a rotating body for operatively connecting an external drive source such as a vehicle engine to a tip of a drive shaft is a screw member such as a bolt. Is fixed by. Then, when the rotation is transmitted from the external drive source to the drive shaft via the pulley, with respect to the threaded member such as the bolt,
Rotational force in the tightening direction is applied.

[0003]

By the way, a compression reaction force is generated with the compression operation in each compression chamber of the compressor.
This compression reaction force is transmitted to the drive shaft to excite torque fluctuations in the drive shaft. Generally, in a variable displacement compressor in which the discharge capacity is changed, the resistance torque level with respect to the input torque from the external drive source that acts on the drive shaft during the compression operation at the minimum capacity becomes small. As shown in FIG. 3, when the resistance torque is extremely low and a torque fluctuation due to a compression reaction force is applied to the drive shaft, the negative value of the torque fluctuation exceeds the level of torque 0, and the drive shaft is driven. Negative torque may act on the shaft. For this reason, a rotational force in a direction opposite to the tightening direction is applied to the threaded member such as a bolt, and the threaded member may be loosened. Due to this looseness, the pulley rattles against the drive shaft, which may cause vibration and noise during operation.

Particularly, in the clutchless type variable displacement compressor in which the discharge capacity during the minimum capacity operation is made as small as possible and the pulley is directly operatively connected to the external drive source, the discharge capacity during the minimum capacity operation is It is extremely small.
The input torque level from the external drive source that acts on the drive shaft during this minimum displacement operation is close to zero. Therefore, a negative torque is likely to act on the drive shaft, and the screwing member may be more easily loosened.

An object of the present invention is to prevent loosening of a screwing member for fixing a pulley to a drive shaft even when a negative torque acts on the drive shaft during a minimum capacity operation. It is to provide a variable capacity compressor.

[0006]

In order to achieve the above object, according to the invention of claim 1, a rotating body is fitted to the end portion of the drive shaft, and a screw on the end surface of the drive shaft is screwed. In a variable displacement compressor in which a rotating body is fixed to a drive shaft by a screwing member that fits and the driving force of an external drive source is transmitted to the drive shaft via the rotating body, looseness is caused between the screwing member and the screw. It is provided with a stopping means.

According to a second aspect of the invention, in the variable displacement compressor according to the first aspect, in order to reduce the discharge capacity as much as possible, the supply of the refrigerant gas from the external refrigerant circuit is cut off. It is provided with a blocking means.

According to a third aspect of the present invention, in the variable displacement compressor according to the second aspect, the rotating body is directly operatively connected to an external drive source. According to a fourth aspect of the invention, in the variable displacement compressor according to any of the first to third aspects, a screw hole is formed at a tip of the drive shaft, and the screw member is screwed into the screw hole. The loosening prevention means is made of a deformable material interposed between the screw portion and the screw hole of the bolt.

According to a fifth aspect of the present invention, in the variable displacement compressor according to the fourth aspect, the elastic material is coated on the outer surface of the threaded portion of the bolt. According to a sixth aspect of the present invention, in the variable displacement compressor according to any of the first to third aspects, a threaded portion is formed at a tip of the drive shaft, and the screw member is screwed into the threaded portion. The loosening prevention means is composed of a thin-walled portion on the outer circumference of a plurality of slits formed in the inner circumference of the nut and extending in the axial direction, and a female screw portion adjacent to the slits.

According to a seventh aspect of the invention, in the variable displacement compressor according to the sixth aspect, the average inner diameter of the cylinder formed by the inner end surface of the female screw portion is the average outer diameter of the screw portion of the drive shaft. The diameter is slightly smaller than the diameter.

Therefore, in the variable displacement compressor according to the first to third aspects, the screwing member interposed between the pulley and the drive shaft is provided with the loosening prevention means. Therefore, in the state where the resistance torque level with respect to the input torque during the compression operation at the minimum capacity is small, a negative torque is generated due to the action of the torque fluctuation, and the torque in the direction opposite to the tightening direction is applied to the screw member. Even if applied, there is almost no risk of loosening the screwing member.

In the variable displacement compressor according to the fourth aspect, when the screw portion of the bolt as the screwing member is screwed into the screw hole at the tip of the drive shaft, it is interposed between the screw portion and the screw hole. The deformable material serving as the loosening prevention means is deformed by the tightening force. Due to the deformation of this material
The gap between the threaded hole of the drive shaft and the threaded portion of the bolt is almost completely filled. When the material is elastically deformed, the elasticity of the material alleviates the torque fluctuation acting on the drive shaft. Then, the loosening of the bolt due to the torque fluctuation during the minimum capacity operation is prevented. In other words, it is possible to reliably prevent the loosening by the loosening preventing means having a simple structure.

In the variable displacement compressor according to the present invention, the elastic material is firmly adhered to the outer surface of the threaded portion of the bolt, and the elastic material is peeled off even when the bolt is attached and detached a plurality of times. rare.

In the variable displacement compressor according to the sixth aspect and the seventh aspect, when the nut as the screwing member is screwed into the threaded portion at the tip of the drive shaft, the looseness extended in the axial direction is formed on the inner circumference of the nut. Along with the elastic deformation of the thin-walled portions on the outer periphery of the plurality of slits serving as the locking means, the female screw portion also serving as the locking means that is adjacent to the slits is expanded and deformed. Due to the impact resilience that acts on the nut due to this deformation, the threaded portion of the drive shaft is strongly clamped by the female threaded portion. Then, the loosening of the bolt due to the torque fluctuation during the minimum capacity operation is prevented. For this reason, the nut can be securely prevented from loosening by the loosening preventing means having a simple structure.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment) Hereinafter, a first embodiment in which the present invention is embodied in a clutchless type swash plate type variable displacement compressor will be described.
This will be described in detail with reference to FIGS.

As shown in FIG. 1, the cylinder block 11
Constitutes a part of the housing of the entire compressor. A front housing 12 is joined to the front end surface of the compressor and a rear housing 13 is joined to the rear end surface of the compressor through a valve plate 14. A plurality of through bolts 15 are screwed into the rear housing 13 from the front housing 12 through the cylinder block 11 and the valve plate 14, and the through bolts 15
Front housing 12 and rear housing 13
Are fastened and fixed to both end surfaces of the cylinder block 11.

The drive shaft 16 is supported by the cylinder block 11 and the front housing 12 via a pair of radial bearings 17 and 18. A lip seal 19 is provided between the outer periphery of the front end of the drive shaft 16 and the front housing 12. The pulley 20 as a rotating body is attached to the front end portion of the drive shaft 16 protruding from the front housing 12, and
1 is directly operatively connected to an external drive source such as a vehicle engine (not shown). Angular bearing 22
It is interposed between the pulley 20 and the front housing 12. The bearings 22 receive the thrust and radial loads acting on the pulley 20.

A plurality of cylinder bores 23 are formed through the cylinder block 11, and the piston 2 is provided inside them.
4 is inserted and supported. The crank chamber 25 is located on the front side of the cylinder block 11 and is located on the front housing 12.
It is partitioned inside. The rotary support 26 is integrally rotatably attached to the drive shaft 16 in the crank chamber 25, and is joined to the inner surface of the front housing 12 via a thrust bearing 27. Support arm 2
8 is provided on the rear side surface of the rotary support 26 so as to project, and a pair of guide holes 29 are formed at the tip thereof.

The swash plate 30 is tiltably fitted to the drive shaft 16 and has a pair of spherical connecting members 31 on its front side surface.
Is protruding. The spherical connecting member 31 is pivotally and slidably engaged with the guide hole 29 of the supporting arm 28, so that the swash plate 30 is hinge-connected to the rotating supporting member 26 so that the tilt angle can be changed. . The outer peripheral portion of the swash plate 30 is provided with a pair of hemispherical shoes 33, and each piston 24
It is articulated at the base end. And the drive shaft 16
When is rotated, the swash plate 30 is rotated via the rotation support 26, and each piston 24 is reciprocated in the cylinder bore 23.

The accommodating chamber 34 is formed through the cylinder block 11 so as to be located on the same axis as the drive shaft 16. The suction passage 35 is formed in the center of the rear housing 13 and the valve plate 14 so as to communicate with the accommodation chamber 34. The suction passage 35 is connected to the suction muffler 3
It is connected to the external refrigerant circuit 58 via 6.

The suction chamber 37 is formed in an annular shape in the center of the rear housing 13 and communicates with the accommodation chamber 34 through a communication port 38. The discharge chamber 39 is formed in an annular shape on the outer peripheral portion of the rear housing 13, and is connected to the external refrigerant circuit 58 via the discharge muffler 40 on the outer peripheral surface of the cylinder block 11.

The suction valve mechanism 41 and the discharge valve mechanism 42 are formed on the valve plate 14. Here, when the piston 24 is moved from the top dead center position in the cylinder bore 23 to the bottom dead center position in conjunction with the swing rotation of the swash plate 30, the suction chamber 37 is removed from the suction chamber 37 via the suction valve mechanism 41. Each cylinder bore 2
Refrigerant gas is drawn into the compression chamber of No. 3. Further, when the piston 24 is moved from the bottom dead center position in the cylinder bore 23 to the top dead center position, the refrigerant gas in the compression chamber of each cylinder bore 23 is compressed. Then, when the refrigerant gas reaches a predetermined pressure, it is discharged into the discharge chamber 39 via the discharge valve mechanism 42.

Cylindrical spool 43 which constitutes a breaking means
Is movably accommodated in the accommodation chamber 34 of the cylinder block 11 so as to be positioned on the same axis as the drive shaft 16. The spring 44 includes the spool 43 and the storage chamber 3
The spring 43 urges the spool 43 toward the swash plate 30. The rear radial bearing 18 described above is fitted in the spool 43, and the rear end of the drive shaft 16 is slidably fitted and supported in the radial bearing 18. As a result, the radial load acting on the drive shaft 16 with the rotation of the drive shaft 16 is received by the radial bearing 18.

The thrust bearing 45 is fitted on the drive shaft 16 between the spool 43 and the swash plate 30. The pair of protrusions 46 are formed on the rear surface of the swash plate 30 so as to contact the front race of the thrust bearing 45, and the outer surfaces thereof are spherical. The thrust bearing 45 receives the load in the thrust direction that acts on the spool 43 as the swash plate 30 tilts and rotates.

The throttle opening / closing portion 47 is formed on the rear end surface of the spool 43 so as to project so as to correspond to the suction passage 35.
The outer surface is almost spherical. And swash plate 3
When 0 is tilted to the minimum tilt angle state, the spool 43
Is moved to the rear closed position against the biasing force of the spring 44,
The throttle opening / closing portion 47 engages with the rear end edge of the suction passage 35. As a result, the introduction of the refrigerant gas from the external refrigerant circuit 58 into the suction chamber 37 is stopped. The minimum inclination angle of the swash plate 30 is set to be slightly larger than 0 degree (about 1 degree), and the minimum inclination angle is set to the spool 43.
Is regulated by being placed in the closed position.

When the swash plate 30 is tilted from the minimum tilt position to the maximum tilt position, the spool 43 is moved to the front open position by the urging force of the spring 44, and the throttle opening / closing section 4 is opened.
A gap is formed between 7 and the inner peripheral surface of the suction passage 35.
Thereby, the refrigerant gas is introduced from the external refrigerant circuit 58 into the suction chamber 37 through the suction passage 35, the accommodation chamber 34, and the communication port 38, and the normal compression operation including the maximum discharge capacity is accompanied by the rotation of the swash plate 30. Is done. The maximum inclination angle of the swash plate 30 is regulated by the contact between the regulation protrusion 48 formed on the front surface of the swash plate 30 and the rotary support 26.

The pressure release passage 49 is formed at the center of the drive shaft 16 and has a front end opened into the crank chamber 25 through the through hole 50 and a rear end opened into the spool 43. . The pressure release hole 51 is formed on the outer periphery of the rear end of the spool 43, and the inside of the spool 43 is communicated with the inside of the housing chamber 34 via the pressure release hole 51. And
The pressure in the crank chamber 25 is released into the suction chamber 37 through the through hole 50, the pressure release passage 49, the inside of the spool 43, the pressure release hole 51, the housing chamber 34, and the communication port 38.

The pressure supply passage 52 is formed continuously with the rear housing 13, the valve plate 14 and the cylinder block 11, and the discharge chamber 39 is connected to the crank chamber 25 via the pressure supply passage 52. The electromagnetic opening / closing valve 53 is attached to the rear housing 13 so as to be located in the middle of the pressure supply passage 52, and is closed or opened as the solenoid 54 is excited or demagnetized. And this solenoid on-off valve 5
When 3 is opened, the pressure in the discharge chamber 39 is supplied into the crank chamber 25 via the pressure supply passage 52, and the pressure in the crank chamber 25 is adjusted.

In the external refrigerant circuit 58, the condenser 5
9, the expansion valve 60 and the evaporator 61 are connected. The temperature sensor 62 is arranged near the evaporator 61. In addition, the control computer C controls the operation switch 6 of the air conditioner.
Based on the ON-OFF state of No. 3 and the detection information from the temperature sensor 62 and the rotation speed detector 64 that detects the rotation speed of the vehicle engine, the excitation / demagnetization of the solenoid 54 is commanded.

Next, the structure for fixing the pulley 20 to the drive shaft 16 and its peripheral structure will be described.
As shown in FIG. 1 and FIG.
Is formed in the center of. The sleeve 20b is the pulley 2
0 is fixed to the inner surface of the pin 0 by a pin 20c, a female screw 20d is formed on the inner peripheral surface thereof, and the outer end thereof is the through hole 20.
a. The sleeve 20b is screwed onto the male screw 16a on the outer periphery of the drive shaft 16.

The screw hole 55 is formed at the tip of the drive shaft 16 so as to extend in the axial direction. The bolt 56 as a screwing member is screwed into the screw hole 55, and the screw portion 56a and the head portion 5 are connected.
6b and a flange portion 56c. The flange portion 56c is pressed against the sleeve 20b while the bolt 56 is screwed. Based on this pressure contact, the pulley 2
The axial force acting on 0 is received by the angular bearing 22.

The elastic material 57 constituting the loosening prevention means is coated on the outer surface of the screw portion 56a of the bolt 56 and is formed of an elastically deformable film material such as polyamide resin or fluororesin. And pulley 2
When the screw portion 56a of the bolt 56 is screwed into the screw hole 55 while 0 is fitted to the outer periphery of the tip of the drive shaft 16,
The elastic material 57 is interposed between the outer periphery of the screw portion 56a and the inner periphery of the screw hole 55 in a crushed state, and is elastically deformed as the bolt 56 is tightened.

Next, the operation of the variable capacity compressor configured as described above will be described. In the state shown in FIG. 1, the solenoid opening / closing valve 53 is closed by the excitation of the solenoid 54, and the pressure supply passage 52 is closed. Therefore, the high-pressure refrigerant gas in the discharge chamber 39 is not supplied into the crank chamber 25 via the pressure supply passage 52, and the crank chamber 25
Only the refrigerant gas of the above flows into the suction chamber 37 through the pressure release passage 49 and the pressure release hole 51. Therefore, the pressure in the crank chamber 25 approaches the low pressure in the suction chamber 37, that is, the suction pressure, the swash plate 30 is held in the maximum inclination state, and the compression operation of the maximum discharge capacity is performed.

As described above, when the cooling operation is performed by performing the compression operation with the swash plate 30 in the maximum inclination state, the temperature of the evaporator 61 in the external refrigerant circuit 58 gradually decreases. Then, when the temperature of the evaporator 61 becomes equal to or lower than the set temperature at which frost starts to be generated, based on the detection of the temperature sensor 62,
A demagnetization command signal is output from the control computer C to the solenoid 54, and the electromagnetic opening / closing valve 53 is opened. As a result, the high-pressure refrigerant gas in the discharge chamber 39 is supplied into the crank chamber 25 via the pressure supply passage 52, and the pressure in the crank chamber 25 increases. Further, in the low cooling load state, the amount of the refrigerant gas vaporized in the evaporator 61 decreases and the suction chamber 3
The pressure of the refrigerant gas sucked into 7 decreases. For this reason,
The suction pressure acting on the head of the piston 24 decreases, and a differential pressure is generated between the suction pressure and the increased pressure in the crank chamber 25, so that the swash plate 30 quickly changes from the maximum inclination state to the minimum inclination state. Will be moved to.

When the tilt angle of the swash plate 30 is reduced in this way, a rearward moving force is applied to the spool 43 via the thrust bearing 45 with the tilt. As a result, the spool 43 is moved against the biasing force of the spring 44 from the front open position toward the rear closed position. Then, when the swash plate 30 is in the minimum inclination state, the spool 43 is arranged at the rear closed position, and the throttle opening / closing portion 47 enters and engages with the rear end edge of the suction passage 35. As a result, the suction passage 3
5 is closed, and the introduction of the refrigerant gas from the external refrigerant circuit 58 into the suction chamber 37 is blocked.

Since the minimum inclination angle of the swash plate 30 is set to be slightly larger than 0 degree, even when the swash plate 30 is in the minimum inclination angle, the compression chamber of the cylinder bore 23 is compressed into the discharge chamber 39. The refrigerant gas is continuously discharged, and the compression operation with the minimum discharge capacity is performed. And this discharge chamber 3
The refrigerant gas discharged into the inside 9 flows into the crank chamber 25 through the pressure supply passage 52. And crankcase 2
The refrigerant gas in 5 flows into the suction chamber 37 through the pressure release passage 49 and the pressure release hole 51, and is again sucked into the compression chamber of the cylinder bore 23. That is, in the minimum inclination state of the swash plate 30, the refrigerant gas passes through the circulation passage including the pressure supply passage 52 and the pressure release passage 49 inside the compressor, and the cylinder bore 23, the discharge chamber 39, the crank chamber 25, and the suction chamber 37. Is cycled to.

Next, when the cooling operation is increased by performing the compression operation in the minimum inclination state of the swash plate 30 as described above, the temperature of the evaporator 61 in the external refrigerant circuit 58 gradually rises. When the temperature of the evaporator 61 exceeds the set temperature,
Based on the detection of the temperature sensor 62, the control computer C
An excitation command signal is output from the solenoid 54 to the solenoid opening / closing valve 53. As a result, the high pressure refrigerant gas in the discharge chamber 39 passes through the pressure supply passage 52 and the crank chamber 25.
Will not be supplied within. Therefore, the pressure in the crank chamber 25 is only released into the suction chamber 37 via the pressure release passage 49 and the pressure release hole 51, and the pressure in the crank chamber 25 is gradually reduced. Further, when the cooling load increases, the amount of the refrigerant gas vaporized in the evaporator 61 in the external refrigerant circuit 58 increases, and the pressure of the refrigerant gas drawn into the suction chamber 37 rises. Therefore, the suction pressure acting on the head of the piston 24 rises and a pressure difference is generated between the suction pressure acting on the head of the piston 24 and the pressure reduced in the crank chamber 25 as described above, and the swash plate 30 changes from the minimum inclination state to the maximum inclination angle. It is transferred to the state.

When the tilt angle of the swash plate 30 is thus increased, the spool 43 is moved from the closed position at the rear to the open position at the front by the biasing force of the spring 44 in accordance with the tilt. Then, as shown in FIG. 1, when the swash plate 30 is in the maximum inclination state, the spool 43 is arranged at the front open position, and the throttle opening / closing portion 47 is withdrawn from the suction passage 35. As a result, the suction passage 35 is opened, and the external refrigerant circuit 58 is opened.
From this point, the introduction of the refrigerant gas into the suction chamber 37 is restarted, and the compression operation with the maximum discharge capacity is performed with the swash plate 30 in the maximum inclination state.

When the drive shaft 16 rotates, a compression reaction force is generated as the piston 24 reciprocates to perform a compression operation. This compression reaction force is transmitted to the drive shaft 16 via the swash plate 30 and the rotary support 26, and torque variation occurs in the drive shaft 16. As shown in FIG. 3, this torque fluctuation is caused by the drive shaft 16
The cylinder bore 23 of the compressor during one revolution of
It is a sine wave with a phase that repeats the number of displacements equal to the number of. It should be noted that FIG. 3 shows the case of, for example, a 10-cylinder type compressor.

During the compression operation of the above-mentioned minimum discharge capacity, the level of the resistance torque with respect to the input torque from the external drive source such as the vehicle engine becomes small and becomes close to zero. In this low resistance torque level state, when the torque fluctuation due to the compression reaction force is applied to the drive shaft, the negative value of the torque fluctuation exceeds the level of torque 0, and the negative torque is applied to the drive shaft 16. May occur. As a result, a rotational force in the direction opposite to the tightening direction is applied to the bolt 56, and the bolt 56 may be loosened.

However, in the variable displacement compressor of this embodiment, between the screw portion 56a of the bolt 56 and the screw hole 55 of the drive shaft 16 for fixing the pulley 20 in a state fitted to the outer periphery of the tip of the drive shaft 16. An elastic material 57 is interposed in the. Here, the elastic member 57 is elastically deformed to be in a crushed state, and the gap between the screw hole 55 of the drive shaft 16 and the screw portion 56a of the bolt 56 is almost completely filled. Therefore, resistance is generated against the rotational force in the direction opposite to the tightening direction of the bolt 56, and the bolt 56 is prevented from loosening in the screw hole 55 of the drive shaft 16.

According to the present embodiment constructed as described above, the following effects can be obtained. (A) As the loosening prevention means, the screw portion 56 of the bolt 56
The elastic member 57 is provided between the a and the screw hole 55 of the drive shaft 16.
Is interposed. Therefore, the elastic material 57 is elastically deformed by the tightening force when the pulley 20 is screwed onto the drive shaft 16. Then, the gap between the screw hole 55 of the drive shaft 16 and the screw portion 56a of the bolt 56 is almost completely filled, which serves as resistance against the rotational force in the direction opposite to the tightening direction of the bolt 56. Therefore, even if the negative torque fluctuation occurs during the operation at the minimum capacity, it is possible to prevent the bolt 56 from loosening and prevent the pulley 20 from rattling. Therefore, the pulley 20
Vibration and noise due to backlash can be prevented.

(B) Further, the elasticity of the elastic material 57 reduces the torque fluctuation acting on the drive shaft 16. Therefore, the rotational force in the direction opposite to the tightening direction of the bolt 56 due to the negative torque generated during the operation at the minimum capacity is also alleviated. Therefore, in combination with the effect described in the item (a), the bolt 56 can be more reliably prevented from loosening.

(C) The elastic material 5 as a loosening prevention means
7 is coated on the outer surface of the screw portion 56a of the bolt 56. The locking means has a simple structure and is firmly attached to the outer surface of the screw portion 56a of the bolt 56. Therefore, even if the bolt 56 is attached and detached a plurality of times, the coated elastic material 57 is used.
Hardly peels off. Therefore, the bolt 56 can be reliably prevented from loosening with a simple structure, and the bolt 56 can be repeatedly attached and detached for inspection and repair of the compressor.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
An embodiment will be described. As shown in FIGS. 4 to 6, in this second embodiment, the drive shaft 16
A screw portion 70 is formed so as to project from the tip of the. The nut 71 as a threaded member is provided with a threaded portion 70 in a state where the sleeve 20b of the pulley 20 is fitted to the outer periphery of the tip end of the drive shaft 16.
And a flange portion 71a is formed so as to project from the outer periphery of the base end thereof. The flange portion 71a is pressed against the sleeve 20b of the pulley 20 in the screwed state of the nut 71, and the pulley 20 is fastened and fixed to the drive shaft 16.

The plurality of slits 72 are formed in the inner peripheral surface of the nut 71 at predetermined intervals so as to extend in the axial direction. A portion of the slit 72 is a thin portion 73 that constitutes a locking device and is elastically deformable. The average inner diameter of the cylinder formed by the inner end surface of the female threaded portion 74 adjacent to the slit 72 and also constituting the loosening prevention means is slightly smaller than the average outer diameter of the threaded portion 70 of the drive shaft 16. Is formed in. Then, with the pulley 20 fitted to the outer periphery of the distal end of the drive shaft 16, the nut 71
When the threaded portion 70 is screwed into the threaded portion 70, the female threaded portion 74 is expanded and deformed along the outer peripheral surface of the threaded portion 70 due to the elastic deformation of the thin portion 73. This elastic deformation causes the nut 7
Due to the impact resilience acting on 1, the screw portion 70 of the drive shaft 16 is strongly clamped by the female screw portion 74. Then, the nut 71 is prevented from loosening with respect to the drive shaft 16.

Therefore, also in this embodiment, the nut 7 is operated even when a negative torque is generated during the operation of the minimum capacity.
It is possible to prevent the looseness of 1 from occurring. Further, in this embodiment, the plurality of slits 72 formed on the inner peripheral surface of the nut 71 constitute a loosening prevention means. For this reason, the nut 71 can be reliably prevented from loosening by the loosening prevention means having a simple structure.

(Third Embodiment) Next, the third embodiment of the present invention will be described.
An embodiment will be described. As shown in FIGS. 7 and 8, in the third embodiment, the nut 71 is not formed in the flange portion 71a, and the plurality of slits 72 are formed.
Only are formed. Therefore, when the nut 71 is screwed into the threaded portion 70 of the drive shaft 16, it is necessary to interpose a washer between the nut 71 and the sleeve 20b of the pulley 20. The operation of the third embodiment is similar to the operation of the second embodiment.

The present invention can be modified and embodied as follows. (1) Like the first embodiment, the drive shaft 1
In a fixing structure in which a bolt 56 is screwed into the screw hole 55 at the tip of the screw 6, and the pulley 20 is fixed to the drive shaft 16, the inner peripheral surface of the screw hole 55 is coated with an elastic material 57 to prevent loosening. Constitution of means.

(2) As in the second embodiment, in the fixing structure in which the nut 71 is screwed into the threaded portion 70 at the tip of the drive shaft 16 to fix the pulley 20 to the drive shaft 16, The elastic material 57 is attached to the outer surface of the screw portion 70.
To form a locking device.

(3) In the first to third embodiments, instead of the pulley 20 as a rotating body, a driving force from an external drive source such as a vehicle engine is applied to the drive shaft 16 via gears, sprockets and the like. Configure to communicate.

(4) Embodying the present invention in a variable displacement compressor with a clutch. (5) Embodying the present invention in a double-headed piston type variable displacement compressor.

[0053]

Since the present invention is constructed as described above, it has the following effects. According to the invention described in claims 1 to 3, in the state where the resistance torque level with respect to the input torque is small as in the compression operation of the minimum capacity, the torque fluctuation due to the compression reaction force acts, and the drive shaft and the rotating body are rotated. Even when a rotational force in a direction opposite to the tightening direction of the threaded member is generated, it is possible to prevent the threaded member from being loosened with respect to the drive shaft. Therefore, it is possible to prevent rattling of the rotating body, and to prevent vibration and noise due to rattling of the rotating body.

According to the invention described in claims 4, 6 and 7, the loosening preventing means having a simple structure can prevent the loosening of the screwing member. According to the invention described in claim 5, the bolt can be used repeatedly.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a variable displacement compressor according to a first embodiment.

FIG. 2 is an enlarged partial cross-sectional view showing a fixing structure of the pulley of FIG.

FIG. 3 is an explanatory diagram related to generation of negative torque.

FIG. 4 is a partial cross-sectional view illustrating a main part of a variable displacement compressor according to a second embodiment.

5 is a plan view of a nut used for fixing the pulley of FIG.

FIG. 6 is a front view of the nut.

FIG. 7 is a plan view showing a nut used for fixing a pulley according to a third embodiment.

FIG. 8 is a front view of the nut.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Cylinder block which comprises the housing of the whole compressor, 12 ... Front housing, 13 ... Rear housing, 16 ... Drive shaft, 20 ... Pulley as a rotating body, 43 ... Spool which comprises a cutoff means, 55 ... Screw hole, 56 ... Bolts as screwing members, 56a ... Screw parts,
57 ... Elastic material forming locking means, 70 ... Screw portion,
71 ... Nut as screwing member, 72 ... Slit, 73
... a thin portion that constitutes the loosening prevention means, 74 ... a female screw portion that constitutes the loosening prevention means.

[Procedure amendment]

[Submission date] November 22, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 4

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction contents]

According to a third aspect of the present invention, in the variable displacement compressor according to the second aspect, the rotating body is directly operatively connected to an external drive source. According to a fourth aspect of the invention, in the variable displacement compressor according to any of the first to third aspects, a screw hole is formed at a tip of the drive shaft, and the screw member is screwed into the screw hole. The loosening prevention means is made of an elastically deformable elastic material interposed between the screw portion and the screw hole of the bolt.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction contents]

In the variable displacement compressor according to the fourth aspect, when the screw portion of the bolt as the screwing member is screwed into the screw hole at the tip of the drive shaft, it is interposed between the screw portion and the screw hole. elastically deformable elastic as locking means which is
The material is deformed by the tightening force. Due to this deformation of the elastic material , the gap between the screw hole of the drive shaft and the screw portion of the bolt is almost completely filled. The torque fluctuation acting on the drive shaft by an elastic with the previous SL elastic material is relaxed. Then, the loosening of the bolt due to the torque fluctuation during the minimum capacity operation is prevented. In other words, it is possible to reliably prevent the loosening by the loosening preventing means having a simple structure.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0032

[Correction method] Change

[Correction contents]

The elastic member 57 constituting the locking means is coated on the outer surface of the threaded portion 56a of the bolt 56, for example a polyamide resin, a film-like bullet <br/> of deformable timber fees such as a fluorine resin Has been formed. Then, with the pulley 20 fitted to the outer periphery of the tip of the drive shaft 16,
When the threaded portion 56a of the bolt 56 is screwed into the threaded hole 55, the elastic material 57 is attached to the outer periphery of the threaded portion 56a and the threaded hole 55.
It is interposed in a crushed state between the inner periphery of the bolt and the inner periphery of and is elastically deformed as the bolt 56 is tightened.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shoho Sonobe 2-chome, Toyota-cho, Kariya city, Aichi Stock company Toyota Industries Corp.

Claims (7)

[Claims] 1. A rotary body is fitted to an end portion of a drive shaft, and the rotary body is fixed to the drive shaft by a screwing member that is screwed into a screw on an end surface of the drive shaft, so that a driving force of an external drive source is applied. A variable displacement compressor in which a drive shaft is transmitted via a rotating body, wherein a loosening prevention means is provided between a screw member and a screw. 2. In order to make the discharge capacity as small as possible,
The variable capacity compressor according to claim 1, further comprising a cutoff unit for cutting off the supply of the refrigerant gas from the external refrigerant circuit. 3. The variable displacement compressor according to claim 2, wherein the rotating body is directly operatively connected to an external drive source. 4. A screw hole is formed at the tip of the drive shaft, the screwing member is constituted by a bolt screwed into the screw hole, and the loosening prevention means is provided with a screw portion of the bolt and the screw hole. The variable capacity compressor according to any one of claims 1 to 3, which is made of a deformable material and is interposed between the variable capacity compressor and the variable capacity compressor. 5. The variable capacity compressor according to claim 4, wherein the elastic material is coated on the outer surface of the threaded portion of the bolt. 6. A threaded portion is formed at the tip of the drive shaft, the screwing member is constituted by a nut screwed into the threaded portion, and the locking means is axially provided on the inner circumference of the nut. 2. A thin-walled portion on the outer circumference of a plurality of extended slits and a female screw portion adjacent to the slits.
The variable capacity compressor according to any one of to 3. 7. The variable displacement compression according to claim 6, wherein an average inner diameter of the cylinder formed by the inner end surface of the female screw portion is slightly smaller than an average outer diameter of the screw portion of the drive shaft. Machine.