JP2006349057A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device capable of preventing occurrence of permanent distortion of a buffer member and obtaining sufficient damping effect for fluctuation of rotation by the buffer member. <P>SOLUTION: The buffer member 12 is formed by a spring member 12a and a rubber member 12b, compression deformation of the buffer member 12 is absorbed by elasticity of the spring member 12a, and damping force by elasticity of the rubber member 12b is given to compression deformation of the spring member 12a to prevent permanent distortion of the buffer member 12 by the spring member 12a, even if hardness of the rubber member 12b is reduced and increase damping effect by the rubber member 12b. Consequently, even when load is repeatedly applied by fluctuation of rotation, rupture strength of each connection part 11c of a transmission ring 11 is not reduced by fatigue by damping effect of the rubber member 12b, and each connection part 11c is always broken only when it reaches predetermined torque. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a power transmission device used in, for example, a compressor of a vehicle air conditioner.

  Generally, as a compressor used in an air conditioner for a vehicle, a compressor body formed in a hollow shape, a compression unit that compresses fluid sucked into the compressor body, and a drive shaft connected to the compression unit And the drive shaft is rotated by the power of the engine to drive the compression section to suck and discharge the refrigerant.

The power transmission device provided in the compressor includes a pulley that is rotated by power from the engine, a transmission member that is rotated by the pulley, and a hub that is coupled to the transmission member. A plurality of projecting portions provided at intervals in the direction are opposed to each other in the circumferential direction, and a block-shaped cushioning rubber is interposed between each projecting portion of the pulley and each projecting portion of the transmission member. The rotational force of the pulley is transmitted to the transmission member via the power transmission, and if a torque of a predetermined magnitude or more is generated between the pulley and the transmission member, the transmission of power is interrupted by breaking a part of the transmission member. What was made to do is known (for example, refer patent document 1).
JP 2002-54711 A

  By the way, in the power transmission device, when a rotational fluctuation occurs between the pulley and the transmission member, the buffer rubber between the projecting portions is elastically deformed in the compression direction, and an impact due to the rotational fluctuation is absorbed. However, since it is necessary to use a rubber material having high hardness in order to reduce permanent set, the buffer rubber cannot obtain a sufficient damping effect against rotational fluctuation. For this reason, when a load due to rotational fluctuation is repeatedly applied to the transmission member, the rupture strength of the transmission member is reduced due to fatigue, and breakage is likely to occur at a torque lower than a predetermined torque, and the function as a torque limiter is extended for a long period of time. There was a problem that it could not be maintained normally.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power that does not cause permanent deformation of the shock-absorbing member and that can obtain a sufficient damping effect against rotational fluctuation by the shock-absorbing member. It is to provide a transmission device.

  In order to achieve the above-mentioned object, the present invention includes a driving side rotating body that rotates by external power and a driven side rotating body that rotates by the driving side rotating body, each of the driving side rotating body and the driven side rotating body. A plurality of projecting portions provided at intervals in the circumferential direction are opposed to each other in the circumferential direction, and the circumference of each rotating body is between each projecting portion of the driving side rotating body and each projecting portion of the driven side rotating body. A plurality of buffer members that can be elastically deformed in the direction are interposed, and the rotational force of the driving side rotating body is transmitted to the driven side rotating body via each buffer member, and between the driving side rotating body and the driven side rotating body. In a power transmission device in which when a torque of a predetermined magnitude or more occurs, a part of the driven-side rotator is broken to interrupt power transmission, each of the buffer members and each of the protrusions is rotated. A spring member that urges the body in the circumferential direction, and a spring portion The variations in the compressing direction is formed from a rubber member for applying a damping force.

  As a result, when a variation in rotation occurs between the driving-side rotator and the driven-side rotator, the buffer members between the protrusions are elastically deformed in the compression direction, and the impact due to the variation in rotation is absorbed. At this time, the compression deformation of the buffer member is absorbed by the elasticity of the spring member, and a damping force is applied to the compression deformation of the spring member by the elasticity of the rubber member. Can be prevented by the spring member.

  According to the power transmission device of the present invention, even if the hardness of the rubber member is lowered, permanent deformation of the buffer member can be prevented by the spring member, so that the damping effect by the rubber member can be enhanced. As a result, even when a load due to rotational fluctuation is repeatedly applied, the breaking strength of the driven side rotating body does not decrease due to fatigue due to the damping effect of the rubber member, and some members of the driven side rotating body are always subjected to a predetermined torque. It can be broken only when Therefore, it is possible to reliably prevent generation of harmful vibrations and noise due to rotational fluctuations, maintain the function as a torque limiter normally over a long period of time, and improve reliability. .

  1 to 6 show an embodiment of the present invention. FIG. 1 is a side sectional view of a power transmission device, FIG. 2 is a sectional view in the direction of arrows AA in FIG. 1, and FIG. 4 is a front view of the buffer member, FIG. 5 is a perspective view thereof, and FIG. 6 is an exploded perspective view thereof.

  This power transmission device is used in a compressor of a vehicle air conditioner, and transmits power to a rotating shaft 2 protruding from one end of a compressor body 1.

  The power transmission device of the present embodiment includes a pulley 10 as a driving side rotating body that rotates by power from the outside, a transmission ring 11 as a driven side rotating body that rotates by the pulley 10, and a pulley 10 and a transmission ring 11. A plurality of buffer members 12 interposed therebetween and a hub 13 for connecting the transmission ring 11 and the rotary shaft 2 are provided, and the rotational force of the pulley 10 is transmitted to the transmission ring 11 via the buffer members 12. ing.

  The pulley 10 is configured such that a V belt (not shown) is wound around the outer peripheral surface, and is rotatably supported by the compressor main body 1 via a bearing 10 a disposed between the inner peripheral surface and the compressor main body 1. Has been. A recess 10b in which the transmission ring 11 is disposed is provided on one end surface of the pulley 10, and a plurality of projecting portions 10c projecting radially inward from each other on the inner peripheral surface side of the recess 10b at intervals in the circumferential direction. Is provided.

  The transmission ring 11 includes an outer peripheral portion 11a to which a rotational force is input from the pulley 10 side, and an inner peripheral portion 11b to which the hub 13 is connected from one axial end side. The outer peripheral portion 11a and the inner peripheral portion 11b are in the circumferential direction. They are integrally formed with each other via connecting portions 11c provided at a plurality of locations. The outer peripheral portion 11a is provided with a plurality of protruding portions 11d protruding radially outward at intervals in the circumferential direction, and each protruding portion 11d is spaced apart from each protruding portion 10c of the pulley 10 in the circumferential direction. They are alternately arranged one by one. Each of the connecting portions 11c is formed so that a part thereof is narrowed in the width direction, and is broken when a torque of a predetermined magnitude or more is generated between the outer peripheral portion 11a and the inner peripheral portion 11b. In this case, in order to increase the breaking accuracy of each connecting portion 11c with respect to the magnitude of torque, it is preferable to use a material having a low breaking strength for the transmission ring 11. Further, the other end side of the transmission ring 11 is covered with a cover member 14.

  Each buffer member 12 is disposed between the protruding portion 10 c of the pulley 10 and the protruding portion 11 d of the transmission ring 11, and is formed to be elastically deformable in the circumferential direction of the pulley 10 and the transmission ring 11. The buffer member 12 includes a spring member 12a that urges the protrusions 10c and 11d outward in the circumferential direction, and a rubber member 12b that applies a damping force to the deformation of the spring member 12a in the compression direction. The spring member 12a is formed to bend alternately in the radial direction of the pulley 10 and the transmission ring 11, and both ends thereof are in contact with the projecting portions 10c and 11d, respectively. The rubber member 12b includes a bottom surface portion 12c that curves along the inner peripheral surface of the recess 10b of the pulley 10 and the outer peripheral portion 11a of the transmission ring 11, and a plurality of block portions 12d that are integrally formed on the bottom surface portion 12c. Each block portion 12d is interposed between the bent portions of the spring member 12a. That is, the spring member 12a is fitted in the gap 12e between the block portions 12d, and when the buffer member 12 is compressed in the circumferential direction of the pulley 10 and the transmission ring 11, each block of the rubber member 12b together with the spring member 12a. The portion 12d is elastically deformed.

  The hub 13 is formed in a disk shape and is connected to the inner peripheral portion 11 b of the transmission ring 11. One end of the hub 13 is provided with a connecting portion 13a to which the rotary shaft 2 of the compressor is connected. The rotary shaft 2 is fastened to the connecting portion 13a by a nut 13b that is screwed from the other end of the hub 13.

  In the power transmission device configured as described above, when engine power is input to the pulley 10, the transmission ring 11 rotates integrally with the pulley 10. At that time, the rotational force of the pulley 10 is transmitted to the transmission ring 11 via each buffer member 12. Here, if an excessive rotational load is applied to the pulley 10 due to, for example, seizure of the compressor, each connecting portion 11c of the transmission ring 11 is broken, and power is transmitted from the pulley 10 to the rotary shaft 2 of the compressor. Is cut off.

  Further, in a normal rotational operation, when a rotational fluctuation occurs between the pulley 10 and the transmission member 11, the buffer member 12 between the protrusions 10c and 11d is elastically deformed in the compression direction, and the shock due to the rotational fluctuation is absorbed. Is done. At this time, the compression deformation of the buffer member 12 is absorbed by the elasticity of the spring member 12a, and a damping force due to the elasticity of the rubber member 12b is applied to the compression deformation of the spring member 12a.

By the way, if the natural frequency of a predetermined part (pulley 10 or a rotating part on the compressor side) rotated by the engine is fn [Hz] and the engine frequency is f [Hz], the engine frequency f is the natural frequency. When it becomes equal to fn, resonance occurs and vibration increases. Here, assuming that the engine speed at idling is 700 [rpm], the engine frequency f is 23.3 [Hz] when the number of explosions per engine revolution is two (secondary). . On the other hand, if the spring constant of each buffer member 12 is k [kgf · m / rad] and the inertial mass of a predetermined part rotating together with each buffer member 12 is m [kg · m ² ], the natural frequency fn is It can be obtained from equation (1).

fn = 1 / 2π · (k / m) ^1/2 (1)
At this time, since the condition for starting the damping is generally f / fn> 2 ^1/2 , the natural frequency fn is expressed by the following equation in order to prevent resonance above the engine speed at idling. The condition (2) must be satisfied.

fn <f / 2 ^1/2 (2)
In this case, since f = 23.3 [Hz],
fn <16.5 [Hz] (3)
It becomes. Therefore, from the equations (1) and (3), if the spring constant k of each buffer member 12 is set so that the natural frequency fn is smaller than 16.5 [Hz], the predetermined component that is rotated by the engine. However, resonance does not occur when the engine speed exceeds the idling speed.

  As described above, according to the power transmission device of this embodiment, the buffer member 12 is formed of the spring member 12a and the rubber member 12b, and the compression deformation of the buffer member 12 is absorbed by the elasticity of the spring member 12a. Since the damping force due to the elasticity of the rubber member 12b is applied to the compression deformation of the rubber member 12a, the spring member 12a can prevent permanent deformation of the buffer member 12 even if the hardness of the rubber member 12b is lowered. The attenuation effect by 12b can be heightened. As a result, even if a load due to rotational fluctuation is repeatedly applied, due to the damping effect of the rubber member 12b, the breaking strength of each connecting portion 11c of the transmission ring 11 does not decrease due to fatigue, and each connecting portion 11c is always subjected to a predetermined torque. It can be broken only when Accordingly, it is possible to reliably prevent the generation of harmful vibrations and noise due to rotational fluctuations, and to maintain the function of each connecting portion 11c as a torque limiter normally over a long period of time, thereby improving reliability. Can be achieved.

  Further, since the spring member 12a is formed to bend alternately in the radial direction of the pulley 10 and the transmission ring 11, and the rubber member 12b is interposed between the bent portions of the spring member 12a, the spring member 12a is bent. Thus, the rubber member 12b can be reliably elastically deformed, and the shock-absorbing member 12 with high attenuation can be formed.

  In this case, since the plurality of block portions 12d are formed in the rubber member 12b and the spring member 12a is fitted into the gap 12e of each block portion 12d, the spring member 12a can be assembled integrally with the rubber member 12b. And the assembly work with other parts can be performed very easily.

  Further, since each buffer member 12 is formed so that the natural frequency fn of a predetermined component that rotates together with each buffer member 12 by the engine is smaller than 16.5 [Hz], the rotation of the engine when the rotating component is idling. Resonance does not occur when the number is more than a few, and excessive vibration due to resonance can be reliably prevented.

  In the above embodiment, the block portions 12d of the rubber member 12b are formed integrally with the bottom surface portion 12c. However, a plurality of rubber members arranged between the bent portions of the spring member 12a are separated from each other. You may make it form.

  7 to 11 show another embodiment of the present invention. FIG. 7 is a cross-sectional view taken along line AA in FIG. 1, FIG. 8 is a front view of the buffer member, FIG. 9 is a plan view thereof, FIG. 10 is a perspective view thereof, and FIG. 11 is an exploded perspective view thereof. In addition, the same code | symbol is attached | subjected and shown to the component equivalent to the said embodiment.

  The buffer member 15 shown in the figure is disposed between the protruding portion 10 c of the pulley 10 and the protruding portion 11 d of the transmission ring 11, and is formed so as to be elastically deformable in the circumferential direction of the pulley 10 and the transmission ring 11. The buffer member 15 includes a spring member 15a that urges the protrusions 10c and 11d outward in the circumferential direction, and a rubber member 15b that applies a damping force to deformation of the spring member 15a in the compression direction. The spring member 15a has bent portions 15c that are bent in a circular shape on both ends, and both ends thereof are in contact with the protruding portions 10c and 11d, respectively. That is, when the spring member 15a receives a compressive force in the circumferential direction of the pulley 10 and the transmission ring 11 between the protrusions 10c and 11d, the bent portions 15c are elastically deformed radially inward as shown in FIG. It is supposed to be. The rubber member 15b includes a bottom surface portion 15d that curves along the inner peripheral surface of the recess 10b of the pulley 10 and the outer peripheral portion 11a of the transmission ring 11, and a pair of columnar block portions 15e formed on both ends of the bottom surface portion 15d. Each block portion 15e is disposed inside each bent portion 15c of the spring member 15a. That is, each bent portion 15c of the spring member 15a is fitted to each block portion 15e, and when the buffer member 15 is compressed in the circumferential direction of the pulley 10 and the transmission ring 11, each bent portion 15c of the spring member 15a. At the same time, each block portion 15e of the rubber member 15b is elastically deformed radially inward.

  According to the present embodiment, when a rotational fluctuation occurs between the pulley 10 and the transmission member 11, the buffer member 15 between the projecting portions 10c and 11d is elastically deformed in the compression direction, and the shock due to the rotational fluctuation is absorbed. The At that time, the compression deformation of the buffer member 15 is absorbed by the elasticity of the spring member 15a, and a damping force by the elasticity of the rubber member 15b is applied to the compression deformation of the spring member 15a. Therefore, as in the above-described embodiment, even if the hardness of the rubber member 15b is lowered, permanent deformation of the buffer member 15 can be prevented by the spring member 15a, and the damping effect by the rubber member 15b can be enhanced.

  Further, the spring member 15a is formed so that both end sides thereof are bent in a circular shape, and each block portion 15e of the rubber member is disposed in the bent portion 15c, so that the bent portion 15c is contracted inward in the radial direction. Each block portion 15e of the rubber member 15b can be reliably elastically deformed, and the buffer member 15 with high attenuation can be formed.

  In this case, since the pair of block portions 15e are formed in the rubber member 15b and the spring member 15a is fitted to each block portion 15e, the spring member 15a can be assembled integrally with the rubber member 15b. Assembling work with these parts can be performed very easily.

  In the above embodiment, the block portions 15e of the rubber member 15b are integrally formed with the bottom surface portion 15d. However, the pair of rubber members disposed inside the bent portion 15c of the spring member 15a are separated from each other. You may make it form in.

  Also in the above-described embodiment, each buffer member 15 is formed such that the natural frequency fn of a predetermined component that rotates together with each buffer member 15 by the engine is smaller than 16.5 [Hz]. Can be prevented.

Side surface sectional drawing of the power transmission device which shows one Embodiment of this invention AA arrow direction sectional view of FIG. Main part exploded perspective view of power transmission device Front view of cushioning member Perspective view of buffer member Exploded perspective view of buffer member FIG. 1 is a cross-sectional view taken along line AA in FIG. 1 showing another embodiment of the present invention. Front view of cushioning member Top view of cushioning member Perspective view of buffer member Exploded perspective view of buffer member

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Pulley, 10c ... Projection part, 11 ... Transmission ring, 11c ... Connection part, 11a ... Projection part, 12 ... Buffer member, 12a ... Spring member, 12b ... Rubber member, 15 ... Buffer member, 15a ... Spring member, 15b ... rubber member.

Claims (5)

A plurality of drive-side rotators that are rotated by power from the outside and driven-side rotators that are rotated by the drive-side rotator, and are provided at intervals in the circumferential direction on each of the drive-side rotator and the driven-side rotator. A plurality of cushioning members that are elastically deformable in the circumferential direction of each rotating body between each projecting part of the driving side rotating body and each projecting part of the driven side rotating body. When the torque of a predetermined magnitude or more is generated between the driving side rotating body and the driven side rotating body while transmitting the rotational force of the driving side rotating body to the driven side rotating body via each buffer member, In the power transmission device in which a part of the driven-side rotator is broken to interrupt the transmission of power,
Each of the buffer members is formed of a spring member that urges each protrusion in the circumferential direction of each rotating body, and a rubber member that applies a damping force to deformation of the spring member in the compression direction. apparatus. The said spring member is formed so that it may bend alternately in the radial direction of each rotary body, The rubber member was formed so that at least one part might interpose between the bending parts of a spring member. Power transmission device. The spring member is formed such that at least one end side in the circumferential direction of each rotating body is bent in a circle, and the rubber member is formed so that at least a part thereof is disposed inside the circular bent portion of the spring member. The power transmission device according to claim 1. The power transmission device according to claim 1, wherein the spring member and the rubber member are formed so as to be fitted to each other. The said buffer member was formed so that the natural frequency of the predetermined component which rotates with each buffer member with the power from the outside might become smaller than 16.5Hz. Power transmission device.

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