JP2003139160A - Motive power transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the overload on a rotating shaft 2 due to locking operation by giving a torque limiter function to a motive power transmission device. SOLUTION: A coupling 5 is mounted on the rotating shaft 2, a plurality of locked portions 523 protruded to the outer periphery side are provided on an external ring 52 thereof, and a plurality of locking portions 61 are provided on the inner periphery of a collar 6 axially movably supported on a pulley 4 via a supporting shaft 7. The locked portions 523 are pressed toward the pulley 4 by the locking portions 61, whereby each pair of the locking portions 61 and the locked portions 523 as well as the external ring 52 and the pulley 4 are press-contacted with predetermined frictional force. When the locking portions 61 are slid in the circumferential direction and removed from the locked portions 523 by the input of overtorque, the collar 6 is brought into an escape recessed portion 43 provided in the pulley 4 by a spring 8 externally inserted in the supporting shaft 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device used as a compressor for a vehicle interior air conditioner of an automobile or the like and functioning as a torque limiter when excessive torque is generated.

[0002]

2. Description of the Related Art In a refrigeration cycle of a vehicle interior air conditioner, a refrigerant compressor applies a rotational torque input from a crank pulley of an engine through a pulley belt to
It transmits to a rotating shaft via a power transmission device, and reciprocates a plurality of circumferential pistons that compress refrigerant gas through a swash plate provided on the rotating shaft.

FIG. 4 shows a conventional power transmission device. (A) is a half-cut front view, and (B) is a sectional view taken along line BB in (A). That is, as shown in FIG. 4, a conventional power transmission device includes a pulley 103 rotatably supported by a housing 101 of a refrigerant compressor via a ball bearing 102, and a rotary shaft inserted in a shaft hole of the housing 101. A coupling 105 that elastically connects 104 and the pulley 103 is provided. The coupling 105 is made of an annular rubber-like elastic material between a hub 105a attached to the shaft end of the rotary shaft 104 with a bolt 106 and an outer ring 105b attached to the end surface of the pulley 103 with a bolt 107. Ring rubber 1
It has a structure in which 05c is adhered by vulcanization, and transmits torque from the pulley 103 to the rotary shaft 104, and absorbs fluctuations and vibrations of the transmitted torque by shear deformation of the coupling rubber 105c.

By the way, in the case where the drive mechanism of the refrigerant compressor causes seizure or the like and the rotation shaft 104 thereof is locked, the pulley 103 is coupled through the coupling 105.
Since the rotation of the engine will also be locked, the pulley 1
The pulley belt (not shown) that transmits power to the motor 03 is damaged by excessive tension or friction. Moreover, once the pulley belt is damaged, other auxiliary equipment such as the engine cooling water circulation pump and alternator, which are powered by the engine by this belt, will also stop. There is a problem that causes such a situation.

Therefore, in order to avoid such a situation, when the rotary shaft 104 is locked due to seizure or the like of the operating portion of the refrigerant compressor, the power transmission device functions as a torque limiter and cancels the torque transmission. Therefore, it is necessary to hold the pulley 103 in a rotatable state and prevent the pulley belt from being damaged. As a conventionally known technique of such a power transmission device, for example, there is one disclosed in Japanese Patent Laid-Open No. 9-292003.

This known technique is interposed between an outer peripheral driving side holding member and an inner peripheral driven side holding member to transmit torque from the driving side to the driven side and absorb torsional vibration (torque fluctuation). Coupling rubber (elastic member) has a function as a torque limiter, that is, when the rotating shaft is locked due to seizure of the compressor and excessive torque is applied, the coupling rubber is deformed. The drive-side holding member slides with the engaging portion, whereby the engagement state with the drive-side holding member is released, and an overload is prevented.

However, according to the above-mentioned conventional technique, even if the engagement state between the coupling rubber and the driving side holding member is once released by the excessive torque, the driving side holding member is rotated by a predetermined angle after the engagement is released. At this point, the engagement is resumed, and when the torque increases, the coupling rubber is deformed and slips, which is repeated. Therefore, the torque transmission could not be completely cut off.

[0008]

The present invention has been made in view of the above problems, and its technical problem is to provide a power transmission device with a torque limiter function.
An object of the present invention is to provide a power transmission device capable of preventing the occurrence of overload due to locking of a rotating shaft and the like, and thus preventing a serious accident resulting from the occurrence of overload.

[0009]

The conventional technical problems can be effectively solved by the present invention. That is,
According to another aspect of the present invention, there is provided a power transmission device including a coupling fixed to a rotary shaft, wherein a plurality of locked portions projecting from the outer ring of the coupling at predetermined phase intervals rotate on a drive side. The locking portion, the locked portion, and the outer ring are pressed against the drive-side rotating body by a plurality of locking portions arranged in the body at a phase interval corresponding to the locked portion. When the drive-side rotating body is pressed into contact with a predetermined frictional force, and the locked portion and the locking portion are in completely different phases,
A biasing means is provided for holding one of the locked portion and the locking portion at an escape position that is not in contact with the other.

According to a second aspect of the present invention, in the power transmission device according to the first aspect, the locking portions are axially provided on a support shaft axially projectingly provided on the drive side rotating body at predetermined circumferential intervals. A relief recess is provided on a collar that is movably supported, and the escape position is recessed in the drive-side rotating body, and an urging means is externally inserted on the support shaft so that the locking portion is recessed into the escape recess. It consists of a spring that urges toward.

According to a third aspect of the present invention, in the power transmission device according to the first or second aspect, the urging means is made of a coupling rubber of the coupling, and the coupling rubber makes the engaged portion drive side. The force is applied in a direction away from the rotating body.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a preferred embodiment of a power transmission device according to the present invention. (A) is a half-cut front view, (B) is a sectional view taken along line BB in (A). 2A and 2B show a state in which the power transmission device of the present embodiment interrupts torque transmission. (A) is a half-cut front view, and (B) is (A).
6 is a sectional view taken along line BB in FIG. First, in FIG. 1, reference numeral 1 indicates a tubular end portion on the front side of the housing of a variable displacement compressor in a vehicle interior air conditioner of an automobile,
Reference numeral 2 is a rotary shaft that is inserted from the inner circumference of the tubular end portion 1 into the housing and operates the piston drive mechanism inside the compressor.

The variable displacement compressor is not shown here in its entirety, but as is well known, the stroke of the piston, the rotation of the rotary shaft 2 and the reciprocating piston for compressing the refrigerant are well known. By changing the inclination angle of the swash plate that is converted into stroke motion, the refrigerant discharge capacity is changed from 0 to 10
Since it can be controlled steplessly to 0%, the power transmission device of the present embodiment does not require an electromagnetic clutch for interrupting the power transmission to the rotary shaft 2.

The power transmission device according to the present embodiment includes a pulley 4 rotatably held on the outer periphery of a cylindrical end portion 1 of a housing of a variable displacement compressor via a ball bearing 3.
The rotary shaft 2 is provided with a coupling 5 mounted on the shaft end on the front side. Further, the coupling 5 has a shaft end 2a of the rotary shaft 2.
A hub 51 fixed to the hub 51, an outer ring 52 concentrically arranged on the outer periphery of the hub 51, and a coupling rubber 53 interposed between the outer ring 52 and the hub 51.

The pulley 4 corresponds to the drive side rotating body in claim 1, and is made of iron-based metal, and the poly V groove 41 is formed on the outer peripheral surface thereof. This poly V
A pulley belt (not shown) for transmitting a driving force from a crank pulley of the engine is wound around the groove 41 via a pulley of another auxiliary machine such as an engine cooling water circulation pump or an alternator. Further, on the front end surface of the pulley 4, a ridge 42 that is in contact with a flange portion 521 of an outer ring 52 described later is continuously formed in the circumferential direction.

The hub 51 of the coupling 5 is made of an iron-based metal material, is spline-fitted to the shaft end 2a of the rotary shaft 2, and is fixed by a bolt 54, and a boss portion 511 and its front end. From the above portion, a disk portion 512 is formed by expanding the front surface side of the housing tubular end portion 1 to the outer peripheral side, and a rim portion 513 that is provided around the outer peripheral edge of the disk portion 512 and projects to the front surface side. On the other hand, the outer ring 52 is manufactured by punching and pressing an iron-based metal plate, and has a flange portion 521 whose back surface contacts the protrusion 42 of the pulley 4.
And a sleeve portion 522 extending from the inner diameter of the flange portion 521 to the front side. Then, the coupling rubber 53 is continuously molded in the circumferential direction between the rim portion 513 of the hub 51 and the sleeve portion 522 of the outer ring 52 that is radially opposed to the rim portion 513 and is vulcanized and bonded. Are integrally joined by.

The flange portion 521 of the outer ring 52 of the coupling 5 has a plurality of locked portions 52 protruding outward.
3 are formed at a phase interval of 120 ° in the circumferential direction.
An outer diameter edge of the locked portion 523 is appropriately larger than the outer diameter of the protrusion 42 of the pulley 4.

An annular collar 6 is concentrically arranged on the front side of the pulley 4. The collar 6 is manufactured by punching and pressing an iron-based metal plate, and is capable of axially abutting the locked portion 523 of the outer ring 52 of the coupling 5 on the inner diameter edge. The locking part 61 is in the circumferential direction 1.
They are formed with a phase interval of 20 °. The inner diameter edge of the locking portion 61 is smaller than the outer diameter edge of the locked portion 523 and is appropriately larger than the outer diameter of the protrusion 42 of the pulley 4, and the portion between the locking portions 61 is The inner diameter edge 6a is formed to have a larger diameter than the outer diameter edge of the locked portion 523. In addition, each locked portion 52
The circumferential length of 3 is shorter than the circumferential length of the inner diameter edge 6a between the locking portions 61.

The collar 6 is located on the outer peripheral side of each locking portion 61 and is provided with mounting holes 6 formed at phase intervals of 120 ° in the circumferential direction.
It is supported in the axially movable state on the front side of the pulley 4 via the support shafts 7 that are respectively inserted in b. Specifically, the support shaft 7 is in the shape of a stepped bolt, the shaft portion of which is inserted into the mounting hole 6b of the collar 6, and the screw portion 7a at the tip of the shaft portion is formed on the front end surface of the pulley 4. It is screwed into the female screw hole.

Between the head portion 7b of each support shaft 7 and the collar 6, a coil spring 8 externally fitted to the shaft portion of each support shaft 7 is provided.
Intervenes in a completely compressed state. The coil spring 8 corresponds to the urging means in claim 1, and further corresponds to the spring in claim 2. The coil spring 8 is arranged on the outer peripheral side of the outer diameter edge of the locked portion 523 of the outer ring 52.

In the power transmission device of the present embodiment, in order to set the mounted state as shown in FIG. 1, first, the coupling 5 is arranged so that the locked portions 523 and the locking portions 61 are in the same phase. The outer ring 52 and the collar 6 are aligned with each other, and the support shaft 7 inserted into each mounting hole 6b of the collar 6 is screwed into the female screw hole of the pulley 4. As a result, the collar 6 pressed by the head portion 7b of the support shaft 7 via the coil spring 8 presses each locked portion 523 of the outer ring 52 of the coupling 5 at each locking portion 61 thereof, The rear surface of the flange portion 521 of the ring 52 is brought into pressure contact with the protrusion 42 of the pulley 4.
Then, the coil spring 8 is completely compressed by completely screwing the screw portion 7a of each support shaft 7, and the flange portion 521 of the outer ring 52 of the coupling 5, the protrusion 42 of the pulley 4, and the engagement of the collar 6 are engaged. Stop 61 and coupling 5
The locked portions 523 of the outer ring 52 are pressed against each other with a predetermined frictional force.

Therefore, in the mounted state shown in FIG. 1, when a torque larger than the set frictional force is input to the pressure contact surfaces of the pulley 4 and the collar 6 and the outer ring 52 of the coupling 5 with each other. Is a pulley 4 that rotates together
Of the ridge 42 and the locking portion 61 of the collar 6, the flange portion 521 of the outer ring 52 and the locked portion 5 of the coupling 5.
It is designed to slide in the circumferential direction with respect to 23.

The outer peripheral side of the ridge 42 of the pulley 4 is a groove-shaped relief recess 43 which is relatively recessed in the axial direction. The clearance recess 43 has a relative retreat distance from the tip end surface of the protrusion 42 larger than the axial wall thickness of the collar 6, and the inner peripheral surface of the recess recess 43 corresponding to the outer peripheral surface of the protrusion 42 is The diameter is smaller than the inner diameter edge of the locking portion 61 of the collar 6. That is, the escape recess 43 is formed by the collar 6
And the locking portion 61 thereof, the collar 6 and the locking portion 61 are accommodated in the escape recess 43, and the outer ring 52 of the coupling 5 and the locked portion 52 thereof are accommodated.
No contact with 3.

Therefore, when the excessive torque is input, the protrusion 42 of the pulley 4 and the locking portion 61 of the collar 6 are circumferentially moved with respect to the flange portion 521 and the locked portion 523 of the outer ring 52 of the coupling 5. Slide in the direction
As shown in FIG. 2A, when the locking portion 61 reaches a position where the locking portion 61 is completely disengaged from the locked portion 523, the locking portion 61 of FIG.
As shown in (B), the collar 6 is pushed out to the escape recess 43 of the pulley 4 by the urging force of the coil spring 8, and the outer ring 52 of the coupling 5 and the locked portion 5 thereof.
23 is held in a non-contact state.

According to the power transmission device configured as described above, the driving force of the engine is transmitted to the pulley 4 via the pulley belt (not shown) wound around the outer periphery of the pulley 4 to rotate. Further, this pulley belt is wound around the pulleys of other auxiliary machines such as an engine cooling water circulation pump and an alternator. Therefore, these auxiliary machines are also driven by a common pulley belt. ing.

The power transmission apparatus of this embodiment is normally in the state shown in FIG. 1, that is, the axial pressing force from the collar 6 causes the ridge 42 of the pulley 4 and the flange portion of the outer ring 52 of the coupling 5 to move. 521 are in pressure contact with each other with sufficient frictional force to transmit torque to the rotary shaft 2 for operating the piston drive mechanism inside the compressor. Therefore, the rotational torque input from the pulley belt to the pulley 4 is transmitted to the coupling 5 via the pressure contact surface between the protrusion 42 of the pulley 4 and the flange portion 521 of the outer ring 52, and the hub of this coupling 5 is further transmitted. 51 to rotating shaft 2
The rotation shaft 2 is rotated at the same speed as the pulley 4. Further, the torque fluctuation (torsional vibration) in the normal operation state is effectively absorbed by the shear deformation of the coupling rubber 53.

Further, for example, when the rotary shaft 2 is locked due to seizure of the internal mechanism of the compressor,
When an excessive torque is input between the pulley 4 and the pulley 4 that is forcibly rotated by receiving the power from the engine, the power transmission device of this embodiment functions as a torque limiter. That is, the protrusion 42 of the pulley 4 is
When a circumferential load larger than the frictional force acts on the pressure contact portion of the collar 6 and the locking portion 61, the coupling 5
Flange 521 and locked portion 52 of outer ring 52 in
3 slides in the circumferential direction and the locking portion 61 is disengaged from the locked portion 523 as shown in FIG.
As shown in FIG. 2 (B), the collar 6 is pushed out into the escape recess 43 of the pulley 4 by the urging force of the coil spring 8 and is not in contact with the outer ring 52 of the coupling 5 and the locked portion 523 thereof. Is held in the escape position. Therefore, the flange portion 521 of the outer ring 52 is released from the pressing force of the collar 6, and the surface pressure of the pulley 4 on the protrusion 42 is significantly reduced or comes into a non-contact state, and the pulley 4 moves to the coupling 5. Torque transmission is cut off.

When the torque transmission is cut off as described above, the coupling 5 stops rotating together with the locked rotating shaft 2, while the supporting shaft 7 screwed into the pulley 4 and the holding shaft The colored collar 6 and the coil spring 8 are rotated integrally with the pulley 4 by the driving torque continuously input to the pulley 4 from the pulley belt, but the pulley 4 is rotated by the urging force of the coil spring 8.
The collar 6 housed in the escape recess 43 of the
1 does not interfere with the locked portion 523 of the outer ring 52 of the coupling 5 during the rotation process. Further, since the support shaft 7 that holds the collar 6 and the coil spring 8 that is externally inserted in the support shaft 7 are also located on the outer peripheral side of the locked portion 523 of the outer ring 52, the locked portion 523 is rotated during the rotation process. There is nothing to interfere with.

Therefore, even if the rotary shaft 2 is locked, the pulley 4 does not enter the locked state and continues to rotate smoothly, so that when the rotary shaft 2 is locked, the pulley belt may be damaged by excessive torque. Since other auxiliary equipment such as the engine cooling water circulation pump and alternator that are operated by this pulley belt will continue to operate without preventing the occurrence of a situation where the engine stops and the vehicle cannot run. You can

FIG. 3 is a half cross-sectional view of another preferred embodiment of the power transmission device according to the present invention, taken along a plane passing through the axis, where (A) is a torque transmission state and (B) is a torque transmission. It shows a state in which the is cut off. This embodiment differs from the embodiment shown in FIG. 1 in that the end face of the pulley 4 is not formed with the protrusion 42 and the relief recess 43 as shown in FIG. 1, and the coupling rubber 53 is As shown in (B), in the free state, the outer periphery has a cross-sectional shape that protrudes toward the front side, and the flange portion 521 of the outer ring 52.
However, the distance from the end surface 4a of the pulley 4 is greater than the thickness of the collar 6. Other parts are basically the same as those in FIG.

That is, in order to obtain the mounted state as shown in FIG. 3A, the coupling 5 (the outer ring 52) is arranged so that the locked portions 523 and the locking portions 61 are in the same phase. ) And the collar 6 are aligned with each other, and the support shaft 7 inserted into each mounting hole 6b of the collar 6 is screwed into the female screw hole of the pulley 4. As a result, the collar 6 pressed by the head portion 7b of the support shaft 7 via the coil spring 8 causes the outer ring 52 to undergo the shearing deformation of the coupling rubber 53 in the axial direction.
Is displaced toward the pulley 4 side, the flange portion 521
The back surface of the press contact the end surface of the pulley 4. Then, by completely screwing the screw portion 7a of each support shaft 7, the coil spring 8 is completely compressed, and the flange portion 521 of the outer ring 52, the end surface of the pulley 4, and the locking portion 61 of the collar 6 are connected. Locked portion 523 of outer ring 52 of coupling 5
However, they are pressed against each other with a predetermined frictional force.

The power transmission device configured as described above is
When it functions as a torque limiter, it operates as follows. That is, due to an excessive torque input caused by the rotation shaft 2 locking due to seizure of the internal mechanism of the compressor, the frictional force is applied to the pressure contact portion between the protrusion 42 of the pulley 4 and the locking portion 61 of the collar 6. When a larger circumferential load is applied, the end surface of the pulley 4 and the locking portion 61 of the collar 6 are locked by the flange portion 521 and the locked portion 523 of the outer ring 52 of the coupling 5 as in FIG. 2A. With respect to the locked portion 523, the locking portion 61 disengages from the locked portion 523, so that, as shown in FIG.
The collar 6 moves to the contact position with the end surface of the pulley 4 by the urging force of the coil spring 8. On the other hand, the outer ring 52 of the coupling 5, which is released from the pressing by the locking portion 61 of the collar 6, is separated from the end surface of the pulley 4 by the restoring force of the coupling rubber 53, so that the torque from the pulley 4 to the coupling 5 is increased. Transmission is cut off.

In the state where the torque transmission is cut off as described above, the coupling 5 stops rotating together with the locked rotating shaft 2, while the supporting shaft 7 screwed into the pulley 4 and the holding shaft The formed collar 6 and the coil spring 8 rotate integrally with the pulley 4 by the driving torque input to the pulley 4 from the pulley belt. Then, due to the restoring force of the coupling rubber 53, the pulley 4
Since the locked portion 523 of the outer ring 52, which is separated from the end surface of the collar 6, is in the escape position which is not in contact with the locking portion 61 of the collar 6 that is brought into contact with the end surface of the pulley 4, the engagement of the rotating collar 6 is prevented. Stop 6
It does not interfere with 1. Further, since the support shaft 7 that holds the collar 6 and the coil spring 8 that is externally inserted in the support shaft 7 are also located on the outer peripheral side of the locked portion 523 of the outer ring 52, the locked portion 523 is rotated during the rotation process. There is nothing to interfere with.

Therefore, even if the rotary shaft 2 is locked, the pulley 4 is not locked and the smooth rotation is continued. Therefore, the same effect as that of the embodiment shown in FIG. 1 described above can be realized. it can.

Although the power transmission device of the variable displacement compressor which does not use the electromagnetic clutch has been described in the above-mentioned embodiment, the present invention can be applied to the power transmission device having the electromagnetic clutch.

[0036]

According to the power transmission device of the first aspect of the present invention, when an excessive torque is input, the locking portion slides off the locked portion, so that the outer ring of the coupling is released. The pressure contact state between the drive-side rotating body and the drive-side rotating body is released, torque transmission from the drive-side rotating body to the rotating shaft by the coupling is blocked, and one of the locked portion and the locking portion is biased by the biasing means. Since it is held in the escape position with respect to the other, it is possible to maintain the torque cutoff state, prevent the occurrence of overload due to the locking of the rotating shaft, and prevent a serious accident due to the occurrence of overload.

According to the power transmission device of the second aspect of the present invention, when the locking portion slides out of the locked portion due to the input of excessive torque, the locking portion rotates on the drive side. Due to the urging force of a spring that is externally attached to a support shaft that projects axially at a predetermined interval in the circumferential direction on the body, it moves to a relief recess recessed in the drive-side rotating body and escapes with the locked portion. Since it is held at the position, the effect according to claim 1 can be surely realized.

According to the power transmission device of the third aspect of the present invention, when the locking portion slides off the locked portion due to the input of excessive torque, the locked portion causes the coupling to occur. By the urging force of the coupling rubber of the above, it moves in the direction away from the driving-side rotating body and is held at the escape position with the locking portion, so that the effect according to claim 1 can be reliably realized.

[Brief description of drawings]

1A and 1B show a preferred embodiment of a power transmission device according to the present invention, where FIG. 1A is a half-cut front view, and FIG.
6 is a sectional view taken along line BB in FIG.

2A and 2B show a state in which the power transmission device of the present embodiment interrupts torque transmission, FIG. 2A being a front view in half-cutting, and FIG. 2B being a sectional view taken along line BB in FIG.

FIG. 3 is a half sectional view of another preferred embodiment of the power transmission device according to the present invention, taken along a plane passing through an axis,
(A) shows a torque transmission state, and (B) shows a state where the torque transmission is cut off.

FIG. 4 shows a power transmission device according to the prior art,
(A) is a front view of a half-cut, and (B) is a sectional view taken along line BB in (A).

[Explanation of symbols]

1 Housing tubular end 2 rotation axes 3 ball bearings 4 Pulley (rotating body on driving side) 4a end face 42 ridge 43 Escape recess 5 coupling 51 hub 52 outer ring 523 Locked part 53 coupling rubber 6 colors 61 Locking part 7 Support shaft 8 coil springs

Claims (3)

[Claims] 1. A power transmission device for transmitting a driving torque from a driving side rotating body (4) to a rotary shaft (2), comprising a coupling (5) attached to the rotary shaft (2).
A plurality of locked portions (523) protruding from the outer ring (52) of the coupling (5) at predetermined phase intervals are provided on the drive side rotating body (4). By being pressed toward the drive side rotating body (4) by a plurality of locking portions (61) arranged at a phase interval corresponding to, the locking portion (61) and the locked portion (523). And the outer ring (5
2) and the driving-side rotating body (4) are pressed against each other with a predetermined frictional force, and when the locked portion (523) and the locking portion (61) are on completely different phases, the locked A power transmission device comprising an urging means for holding one of the part (523) and the locking part (61) in an escape position that is not in contact with the other. 2. The driving side rotating body (4), wherein the locking portion (61) is
Support shafts (7) projecting in the axial direction at predetermined intervals in the circumferential direction
Is provided on a collar (6) that is axially movably supported on the drive shaft rotary body (4) and has an escape recess (43) recessed in the drive side rotating body (4). The power transmission device according to claim 1, further comprising a spring (8) that is externally attached to the locking member (6) and biases the locking portion (61) toward the escape recess (43). 3. The biasing means comprises a coupling rubber (53) of the coupling (5), and the coupling rubber (53) causes the locked portion (523) to move to the driving side rotating body (4).
The power transmission device according to claim 1 or 2, wherein the power transmission device is biased in a direction away from.