JP2007040403A - Power transmission system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission system which can prevent the entry of water from the clearance in the axis direction between a pulley and the equipment on the driven side into the bearing side, and which does not cause an increase in manufacturing costs caused by cutting work. <P>SOLUTION: Since the clearance between one end of the inner peripheral part 10c of the pulley 10 in the axis direction and a compressor 1 is covered with a cylindrical part 51f of a retaining member 51 from outside in the radial direction, there is a clearance in the axis direction between one end of the inner peripheral part 10c of the pulley 10 in the axis direction and the compressor 1. Even when the clearance is expanded outward by the curved surface part 10d of one end of the inner peripheral part 10c in the axis direction, the clearance between one end of the inner peripheral part 10c in the axis direction and the compressor 1 can be reduced by the cylindrical part 51f. Thus, the water entering from the clearance in the axis direction between the pulley 10 and the compressor 1 into the bearing 11 side can be prevented. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

Conventionally, as this type of power transmission device, as shown in FIG. 17, a cylindrical outer peripheral portion 101a around which a belt for transmitting external power is wound, and a radially inner side from the inner peripheral surface side of the outer peripheral portion 101a. A pulley 101 having a radially extending portion 101b extending in the axial direction, a cylindrical inner peripheral portion 101c extending in the axial direction from the inner peripheral surface side of the radially extending portion 101b, and an inner peripheral portion 101c of the pulley 101. The bearing 102 is fixed to a part of the driven device 100 disposed on one end side of the shaft 101 and rotatably supports the inner peripheral surface of the inner peripheral portion 101c, and the rotational force of the pulley 101 is used to rotate the driven device 100. A shut-off mechanism 103 that cuts off the rotational force transmitted from the pulley 101 to the rotary shaft 100a when a torque greater than a predetermined magnitude is generated between the pulley 101 and the rotary shaft 100a. Those with is known (see Patent Document 1.).
Japanese Patent No. 3421619

  By the way, in the said power transmission device, since the pulley 101 is shape | molded by the rolling process which bends and rolls a rolled steel plate, the outer side and the inner side of the bending part which bent the rolled steel plate become a curved surface shape without becoming an acute angle shape. . Further, since one end in the axial direction of the inner peripheral portion 101c of the pulley 101 is bent radially inward in order to fix the bearing 102 in the axial direction, a curved surface portion 101d is formed on the outer peripheral surface at one axial end of the inner peripheral portion 101c. Will occur. For this reason, since the axial gap between one axial end of the inner peripheral portion 101c and the driven device 100 is widened outward, water easily enters the gap from the outside, and water is likely to enter the bearing 102 side. Intruded to cause rusting inside the bearing 102.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a power transmission device that can prevent water entering the bearing side from a gap in the axial direction between the pulley and the driven device. It is to provide.

  In order to achieve the above object, the present invention provides a cylindrical outer peripheral portion around which a belt for transmitting power from the outside is wound, a radially extending portion extending radially inward from the inner peripheral surface side of the outer peripheral portion, A pulley having a cylindrical inner peripheral portion extending in the axial direction from the inner peripheral surface side of the radially extending portion, and a part of the driven side device disposed on one axial end side of the pulley inner peripheral portion A bearing that is fixed and rotatably supports the inner peripheral surface of the pulley inner peripheral portion, and transmits the rotational force of the pulley to the rotating shaft of the driven device, and has a predetermined size or more between the pulley and the rotating shaft. In a power transmission device having a shut-off mechanism that cuts off the rotational force transmitted from the pulley to the rotating shaft when a rotational force is generated, a radially outer portion is provided between one axial end of the pulley inner peripheral portion and the driven device. The cover part which covers from is provided.

  Thus, the cover portion covers the space between the axial end of the pulley inner peripheral portion and the driven device from the radially outer side, so that the outer peripheral surface side of the axial end of the pulley inner peripheral portion is curved by rolling. Even when molded, the cover portion can reduce the axial gap between the axial end of the pulley inner peripheral portion and the driven device.

  According to the present invention, even when one axial end of the pulley inner peripheral portion is formed into a curved surface by rolling, the axial gap between the axial one end of the pulley inner peripheral portion and the driven device is defined by the cover portion. Since it can be made small, the water which penetrates into the bearing side from the axial gap between the pulley and the driven device can be prevented, and rusting inside the bearing can be prevented.

  1 to 12 show a first embodiment of the present invention. FIG. 1 is a side sectional view of a power transmission device, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line C-C in FIG. 3, FIGS. 5 and 6 are explanatory views of the operation of the power transmission device, FIG. 7 is a front view of the elastic member, and FIG. 8 is a front view of the pressing member. 9 is a front view of the hub, FIG. 10 is a front view of the holding member, FIG. 11 is a sectional view taken along the line DD in FIG. 10, and FIG. 12 is a sectional side view of the main part of the power transmission device showing a state where water is applied. is there.

  The power transmission device of the present embodiment is fixed to one end side in the axial direction of the housing of a pulley 10 to which power from an engine (not shown) is transmitted and the compressor 1 as a driven device, and rotates on the inner peripheral surface of the pulley 10. A bearing 11 for freely supporting, a hub 20 disposed axially opposite to the pulley 10, an elastic member 30 disposed between the pulley 10 and the hub 20, and a part of the elastic member 30 A pressing member 40 for pressing against the hub 20 and a connecting mechanism 50 provided on the pulley 10 and connecting the elastic member 30 to the pulley 10 are provided.

  The pulley 10 has a cylindrical outer peripheral portion 10a around which a V belt (not shown) is wound on the outer peripheral surface, a radially extending portion 10b extending radially inward from the inner peripheral surface side of one end side in the axial direction of the outer peripheral portion 10a, and a diameter. And a cylindrical inner peripheral portion 10c extending in the axial direction on the compressor 1 side from the inner peripheral surface side of the direction extending portion 10b. The pulley 10 is formed by rolling a rolled steel plate. Further, one axial end of the inner peripheral portion 10c on the compressor 1 side is bent inward in the radial direction in order to fix the bearing 11. Accordingly, the curved surface portion 10d is formed on the outer peripheral surface on the one axial end side of the inner peripheral portion 10c by rolling. An inner peripheral portion 10 c of the pulley 10 is supported by a bearing 11. An annular groove 10e extending in the circumferential direction is formed on the compressor 1 side of the pulley 10 by the outer peripheral portion 10a, the radially extending portion 10b, and the inner peripheral portion 10c of the pulley 10.

  The bearing 11 is fixed to the outer peripheral surface of the housing of the compressor 1 and rotatably supports the inner peripheral surface of the pulley 10.

  The hub 20 is formed integrally with the connecting portion 21 and the cylindrical connecting portion 21 for connecting to the shaft 2 of the compressor 1, and is radially from the axial end side of the connecting portion 21 opposite to the pulley 10. And a disk-like flange portion 22 extending outward.

  The inner peripheral surface of the connecting portion 21 engages with a spline 2 a provided at the tip of the shaft 2 in the rotational direction, and the connecting portion 21 is fixed to the shaft 2 by a nut 2 b that is screwed to the tip of the shaft 2.

  One end surface in the axial direction of the flange portion 22 faces the one end surface in the axial direction of the pulley 10 in the axial direction, and a predetermined gap is provided between the flange portion 22 and the pulley 10. The flange portion 22 is provided with a plurality of rivet holes 22a spaced from each other in the circumferential direction. A plurality of protrusions 22 b are provided on the outer peripheral surface of the flange portion 22 at intervals in the circumferential direction, and each protrusion 22 b extends radially outward from the outer peripheral surface of the flange portion 22.

  The elastic member 30 is made of a spring steel plate and has an annular main body portion 31 and a plurality of extending portions 32 extending from the outer peripheral surface side of the main body portion 31 in the circumferential direction of the main body portion 31. The base end side of each extending portion 32 is integral with the outer peripheral surface of the main body portion 31. In addition, an inclined portion 32 a that is inclined from the pulley 10 toward the flange portion 22 of the hub 20 is provided at a central portion in the extending direction of each extending portion 32. Further, a mounting hole 32 b is provided on the base end side of each extending portion 32. In addition, a protruding portion 32 c that protrudes toward the pulley is provided on the distal end side of each extending portion 32.

  The pressing member 40 is made of a spring steel plate and has a disk shape. The pressing member 40 has a plurality of rivet holes 40a spaced from each other in the circumferential direction. In addition, a plurality of protruding portions 40 b are provided on the outer peripheral surface of the pressing member 40 at intervals in the circumferential direction, and each protruding portion extends radially outward from the outer peripheral surface of the pressing member 40. Each protrusion 40b is provided with an engagement hole 40c inserted in the axial direction. A rivet 41 is inserted into each of the rivet holes 22 a and 40 a of the hub 20 and the pressing member 40, and the pressing member 40 is fixed to the hub 20 by each rivet 41. At this time, the distal end side of each extending portion 32 of the elastic member 30 is pressed to the hub 20 side by each projecting portion 40b of the pressing member 40, and the distal end side of each extending portion 32 is elastically deformed to the hub 20 side. Further, the distal end side of each projecting portion 32 is pressed against one end surface in the axial direction of the flange portion 22, and the distal end side of each extending portion 32 is sandwiched between each projecting portion 40 b and the flange portion 22. Furthermore, the protrusion 32c of each extension part 32 engages with the engagement hole 40c of each protrusion 40b in the rotation direction of the pulley 10.

  The coupling mechanism 50 is disposed in the groove portion 10b of the pulley 10 and a plurality of holding members 51 provided along the groove portion 10b and held by the holding member 51 and spaced apart from each other in the circumferential direction of the pulley 10. And a damper 52 as a buffer member.

  The holding member 51 is made of a plastic material, and includes an annular holding member main body 51a provided along the groove 10b of the pulley 10, and a cylindrical portion 51b extending from the holding member main body 51a in the axial direction on the compressor 1 side. . The cylindrical portion 51 b has a damper 52 disposed inside, and holds the damper 52 in the rotation direction of the pulley 10. In addition, the holding member main body 51a at the portion where the cylindrical portion 51b is provided is provided with an opening hole 51c penetrating in the axial direction. Further, a through hole 10 f that penetrates in the axial direction is provided in the radially extending portion 10 b of the pulley 10 so as to correspond to the opening hole 51 c of the holding member main body 51. Further, the cylindrical portion 51b is reinforced by a plurality of ribs 51d. Furthermore, the holding member 51 is fixed to the pulley 10 by a plurality of rivets 51e provided at intervals in the circumferential direction of the pulley 10. The holding member 51 has a cylindrical cylindrical portion 51f extending in the axial direction along the outer peripheral surface of the inner peripheral portion 10c of the pulley 10 from the inner peripheral surface side of the holding member main body 51a. A part of the cylindrical part 51f is integral with a part of each cylindrical part 51b. The end of the extended cylindrical portion 51f is positioned closer to the compressor 1 than the axial end of the inner peripheral portion 10c of the pulley 10. That is, the cylindrical portion 51 f covers the space between the axial end of the inner peripheral portion 10 c of the pulley 10 and the compressor 1 from the radially outer side.

  Each damper 52 includes a cylindrical screw member 52a having an inner peripheral surface provided with a female screw, and a damper rubber 52b provided between the outer peripheral surface of the screw member 52a and the inner peripheral surface of the cylindrical portion 51b. And have. Bolts 52c inserted through the attachment holes 32b of the elastic member 30 are screwed into the screwing members 52a of the dampers 52, respectively. That is, the elastic member 30 is connected to the pulley 10 via each damper 52 and the holding member 51.

  In the power transmission device configured as described above, when power is transmitted to the pulley 10 from an engine (not shown), the rotational force of the pulley 10 is transmitted to the hub 20 via the elastic member 30. Further, since the elastic member 30 is coupled to the pulley 10 via the coupling mechanism 50, the rotational fluctuation of the rotational force transmitted from the pulley 10 to the hub 20 is reduced by each damper 52 of the coupling mechanism 50.

  Here, since the compressor 1 is mounted on the vehicle, as shown in FIG. 12, water is applied from below while the vehicle is running. Further, since there is a gap in the axial direction between the axial end of the inner peripheral portion 10c of the pulley 10 and the compressor 1, water enters the bearing 11 when water enters from this gap. Furthermore, since the curved surface part 10d is shape | molded in the outer peripheral surface of the axial direction end in the inner peripheral part 10c of the pulley 10, the said clearance gap spreads outside and it is in the state which water tends to penetrate | invade into a clearance gap. However, since the space between the axial end of the inner peripheral portion 10c of the pulley 10 and the compressor 1 is covered by the cylindrical portion 51f of the holding member 51 from the radially outer side, the axial end of the inner peripheral portion 10c of the pulley 10 is covered. The gap between the compressor 1 and the compressor 1 can be reduced by the cylindrical portion 51f. Thereby, the water which penetrate | invades into the bearing 11 side from the clearance gap of the axial direction of the pulley 10 and the compressor 1 can be blocked | prevented.

  On the other hand, for example, when the compressor 1 is seized and the rotation of the shaft 2 is restricted so that a rotational force of a predetermined magnitude or more is generated between the pulley 10 and the hub 20, the tip of the extending portion 32. The side is separated from between each protrusion 40b and the flange 22. Specifically, as shown in FIGS. 5 and 6, each extending portion 32 moves against the pressing force of the pressing member 40 due to the rotational force generated between the pulley 10 and the hub 20. That is, each protrusion 40b of the pressing member 40 is bent toward the pulley 10 by the movement of each extending portion 32, and the engagement between each protrusion 32c and each engagement hole 40c is released.

  Further, the distal end side of each extending portion 32 that is detached from between each projecting portion 40b and the flange portion 22 moves to the pulley 10 side by a restoring force. On the other hand, each protrusion 40b also moves to the flange portion 22 side by a restoring force. Thereby, after each extended part 32 detach | leaves, the elastic member 30, the holding member 40, and the hub 20 do not interfere, but the rotational force transmitted to the hub 20 from the pulley 10 can be interrupted | blocked reliably.

  Thus, according to the present embodiment, the space between the axial end of the inner peripheral portion 10c of the pulley 10 and the compressor 1 is covered by the cylindrical portion 51f of the holding member 51 from the radially outer side. Even if there is an axial gap between one axial end of the inner peripheral portion 10c and the compressor 1, and the gap is widened outward by the curved surface portion 10d at one axial end of the inner peripheral portion 10c, A gap between the axial end of the peripheral portion 10c and the compressor 1 can be reduced by the cylindrical portion 51f. Thereby, the water which penetrate | invades into the bearing 11 side from the axial gap of the pulley 10 and the compressor 1 can be blocked | prevented, and the rusting inside the bearing 11 can be prevented.

  Further, there is a method in which the outer peripheral surface at one end in the axial direction of the inner peripheral portion 10c of the pulley 10 is formed into an acute angle shape by cutting, but this is not preferable because the manufacturing cost increases by the amount of cutting. According to the present embodiment, it is not necessary to form the outer peripheral surface at one axial end of the inner peripheral portion 10c of the pulley 10 in an acute angle shape by cutting or the like, so that the manufacturing cost is not increased by the cutting.

  Further, the elastic member is connected to the shaft 2 of the compressor 1, and the one end surface in the axial direction of the flange portion 22 is connected to the one end surface in the axial direction of the pulley 10 and the one end surface in the axial direction of the pulley 10. A member 30; and a pressing member 40 that elastically deforms each extending portion 32 of the elastic member 30 toward the hub 20 and presses it against the flange portion 22. Each extending portion is provided between the pressing member 40 and the flange portion 22. When the rotational force is transmitted from the pulley 10 to the hub 20 via the elastic member 30 by pinching 32, and a rotational force of a predetermined magnitude or more is generated between the pulley 10 and the hub 20, each extending portion 32 is separated from between the pressing member 40 and the flange portion 22 and moved to the pulley 10 side by a restoring force. For example, when the compressor 1 is seized and the rotation of the shaft 2 is restricted. , Wound around pulley 10 It is possible to prevent the damage of kicked the belt.

  Further, the holding member 51 is provided with a cylindrical portion 51f extending in the axial direction along the outer peripheral surface of the inner peripheral portion 10c of the pulley 10, and the cylindrical portion 51f covers one end in the axial direction of the inner peripheral portion 10c of the pulley 10. Therefore, there is no need to separately provide a dedicated part to prevent water from entering through the gap in the axial direction between the pulley 10 and the compressor 1, which is extremely advantageous in that the number of parts does not increase. .

In the present embodiment, the cylindrical portion 51f of the holding member 51 is shown so that one end in the axial direction of the inner peripheral portion 10c is covered from the outside in the radial direction. However, as shown in FIG. It is also possible to form the tip end side of the portion 51f so as to extend radially inward and cover one axial end of the inner peripheral portion 10c from the radially outer side and the axial direction. Also in this case, water that enters the bearing 11 side from the axial gap between the pulley 10 and the compressor 1 can be blocked, and the number of parts does not increase to prevent water from entering. FIG. 15 shows a second embodiment of the present invention, FIG. 14 is a side sectional view of an essential part of the power transmission device, and FIG. 15 is a front view of the coupling mechanism. In addition, the same code | symbol is attached | subjected and shown to the component equivalent to 1st Embodiment.

  The power transmission device of this embodiment is provided in the pulley 10, the bearing 11, the hub 20, the elastic member 30 and the pressing member 40, and the elastic member 30 elastically supported by the pulley 10 as in the first embodiment. And a connecting mechanism 60.

  The coupling mechanism 60 is disposed in the groove 10 b of the pulley 10. The connection mechanism 60 includes a plurality of dampers 52 similar to those in the first embodiment, a holding member 61 provided along the groove 10b, and a connection member 62 for connecting the dampers 52 to each other. .

  The holding member 61 is made of a plastic material and includes an annular holding member main body 61a provided along the groove 10b of the pulley 10 and a cylindrical portion 61b extending from the holding member main body 61a in the axial direction on the compressor 1 side. . The cylindrical portion 61 b has a damper 52 disposed on the inner side, and holds the damper 52 in the rotation direction of the pulley 10. Further, an opening hole 61c penetrating in the axial direction is provided in a portion of the holding member main body 61a where the cylindrical portion 61b is provided. Further, the cylindrical portion 61b is reinforced by a plurality of ribs 61d. Furthermore, the holding member 61 is fixed to the pulley 10 by a plurality of rivets 61e that are spaced apart from each other in the circumferential direction of the pulley 10.

  The connecting member 62 has a cylindrical shape, and one axial end side of the connecting member 62 extends in the axial direction along the outer peripheral surface of the inner peripheral portion 10 c of the pulley 10. The leading end of the extended connecting member 62 is located closer to the compressor 1 than the axial end of the inner peripheral portion 10 c of the pulley 10. That is, the connecting member 62 covers one end in the axial direction of the inner peripheral portion 10 c of the pulley 10 and the compressor 1 from the radially outer side. Further, the other axial end of the connecting member 62 is integrated with each damper 52 by welding.

  As a result, the dampers 52 are connected to each other at the hub 20 side by the connecting member 62, and the compressor 1 side is connected by the elastic member 30. That is, when a rotational force is generated between the pulley 10 and the elastic member 30, the bending moment applied to each damper 52 and the elastic member 30 can be reduced, and the durability of each damper 52 and the elastic member 30 is improved. can do. That is, connecting the dampers 52 by the connecting member 62 is extremely advantageous in improving the durability of the dampers 52 and the elastic members 30.

  Thus, according to the present embodiment, the space between the axial end of the inner peripheral portion 10c of the pulley 10 and the compressor 1 is covered by the connecting member 62 from the radially outer side. Even if there is an axial gap between one axial end of the compressor 10c and the compressor 1, and the gap is spread outward by the curved surface portion 10d at one axial end of the inner peripheral portion 10c, the inner peripheral portion 10c A gap between the one end in the axial direction and the compressor 1 can be reduced by the connecting member 62. Thereby, the water which penetrate | invades into the bearing 11 side from the axial gap of the pulley 10 and the compressor 1 can be blocked | prevented, and the rusting inside the bearing 11 can be prevented.

  In addition, since one end in the axial direction of the inner peripheral portion 10c of the pulley 10 is covered by the connecting member 62 that connects each damper 52, it is exclusively used to prevent water from entering from the gap between the pulley 10 and the compressor 1. This is extremely advantageous in that it is not necessary to separately provide these parts and the number of parts does not increase.

  In the present embodiment, the connecting member 62 is configured to cover one end in the axial direction of the inner peripheral portion 10c from the outside in the radial direction. However, as shown in FIG. 16, the distal end of the extending connecting member 62 is provided. Can be formed so as to extend radially inward, and one axial end of the inner peripheral portion 10c can be covered from the radially outer side and the axial direction. Also in this case, water that enters the bearing 11 side from the axial gap between the pulley 10 and the compressor 1 can be blocked, and the number of parts does not increase to prevent water from entering.

Side surface sectional drawing of the power transmission device which shows the 1st Embodiment of this invention AA line sectional view in FIG. BB sectional view in FIG. CC sectional view in FIG. Operation explanatory diagram of power transmission device Operation explanatory diagram of power transmission device Front view of elastic member Front view of pressing member Front view of hub Front view of holding member DD sectional view in FIG. Cross-sectional side view of the main part of the power transmission device showing a state where water is applied Side surface sectional drawing of the principal part of the power transmission device which shows the modification of the holding member in 1st Embodiment. Side surface sectional drawing of the principal part of the power transmission device which shows the 2nd Embodiment of this invention. Front view of coupling mechanism Side surface sectional drawing of the principal part of the power transmission device which shows the modification of the connection member in 2nd Embodiment. Side sectional view showing a conventional power transmission device

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Shaft, 10 ... Pulley, 10a ... Outer peripheral part, 10b ... Radially extending part, 10c ... Inner peripheral part, 10d ... Curved surface part, 11 ... Bearing, 20 ... Hub, 22 ... Flange part, 22b ... Projection, 30 ... Elastic member, 31 ... Main body, 32 ... Extension, 32a ... Inclination, 32c ... Projection, 40 ... Pressing member, 41b ... Projection, 41c ... Engagement hole, 50 ... Connection Mechanism: 51 ... Holding member, 51f ... Cylindrical part, 52 ... Damper, 60 ... Connection mechanism, 61 ... Holding member, 62 ... Connection member, 100 ... Compressor, 101 ... Pulley, 101a ... Outer peripheral part, 101b ... Radial extension Installation part, 101c ... inner peripheral part, 101d ... curved surface part, 102 ... bearing, 103 ... blocking mechanism.

Claims (6)

A cylindrical outer periphery around which a belt for transmitting power from the outside is wound, a radially extending portion extending radially inward from the inner peripheral surface side of the outer peripheral portion, and an inner peripheral surface side of the radially extending portion A pulley having a cylindrical inner peripheral portion extending in the axial direction, and an inner peripheral surface of the pulley inner peripheral portion fixed to a part of the driven device disposed on one axial end side of the pulley inner peripheral portion The rotational force of the pulley and the rotating shaft of the driven device is transmitted to the rotating shaft of the driven device, and when a rotational force of a predetermined magnitude or more is generated between the pulley and the rotating shaft, the pulley rotates to the rotating shaft. In a power transmission device having a shut-off mechanism that cuts off the transmitted rotational force,
A power transmission device comprising: a cover portion that covers a space between one axial end of the pulley inner peripheral portion and a driven side device from a radially outer side. A hub connected to the rotating mechanism of the driven device and having one end surface in the axial direction opposed to one end surface in the axial direction of the pulley in the axial direction, an elastic member connected to one end surface in the axial direction of the pulley, A pressing member that elastically deforms a part of the member toward the hub and presses it against one end surface in the axial direction of the hub;
By sandwiching a part of the elastic member between the pressing member and one axial end surface of the hub, a rotational force is transmitted from the pulley to the hub via the elastic member, and a predetermined size is established between the pulley and the hub. If more torque is generated, a part of the elastic member will be detached from between the pressing member and the hub, and will return to a predetermined position on the pulley side by elasticity, and the torque transmitted from the pulley to the hub will be cut off. The power transmission device according to claim 1, wherein the power transmission device is configured as described above. An elastic member having a plurality of buffer members arranged at intervals in the circumferential direction of the pulley and fixed to the elastic member, and holding members fixed to the pulley and holding the buffer members on the pulley, respectively. Including a coupling mechanism that couples the pulley to each other via the buffer member and the holding member,
The power transmission device according to claim 2, wherein the cover portion is formed by extending a part of the holding member in the axial direction along the outer peripheral surface of the pulley inner peripheral portion. The power transmission device according to claim 3, wherein a distal end side of the extended holding member is formed to extend radially inward. A plurality of buffer members arranged at intervals in the circumferential direction of the pulley, each fixed to an elastic member, a connecting member for connecting the buffer members to each other in the circumferential direction of the pulley, and fixed to each pulley A holding member for holding the member on each pulley, and a connecting mechanism for connecting the elastic member to the pulley via each buffer member and the holding member,
The power transmission device according to claim 2, wherein the cover portion is formed by extending a part of the connecting member in the axial direction along the outer peripheral surface of the pulley inner peripheral portion. The power transmission device according to claim 5, wherein a distal end side of the extending connecting member is formed to extend radially inward.

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