JP4476197B2 - Power transmission device - Google Patents

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 kind of power transmission device, there are a pulley to which power from the outside is transmitted, an outer ring arranged on the inner side in the radial direction of the pulley, an elastic member for transmitting a rotational force from the pulley to the outer ring, an outer The inner ring is provided on the inner side in the radial direction of the ring and is fixed to the drive shaft of the driven device and rotated by the rotational force transmitted from the outer ring, and the outer ring and the inner ring are spaced apart from each other in the circumferential direction. And a plurality of connecting members that transmit rotational force from the outer ring to the inner ring, and when a rotational force of a predetermined magnitude or more is generated between the pulley and the drive shaft, each connecting member is connected to the pulley. Break due to the rotational force between the drive shaft and cut off the rotational force transmitted from the outer ring to the inner ring Ones are known (e.g., see Patent Document 1.).
JP 2003-314660 A

  By the way, in the power transmission device, since the breaking torque at which the rotational force is cut off is set by the breaking strength of each connecting member, it is necessary to stabilize the breaking strength of each connecting member in order to stabilize the breaking torque. However, since the bending moment and the shearing force act on each connecting member in a complicated manner, it is difficult to stabilize the breaking strength of each connecting member, and there is a problem that the breaking torque varies.

  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 always break a connecting member that transmits a rotational force with a predetermined breaking torque. .

The present invention has a first rotating body that is rotated by power from the outside, a second rotating body that is rotated by a rotational force transmitted from the first rotating body, and a predetermined spring constant in the rotational direction of the first rotating body. And an elastic member that transmits a rotational force from the first rotating body to the second rotating body, and a radial inner side of the second rotating body, is fixed to the drive shaft of the driven device, and is transmitted from the second rotating body. A third rotating body that is rotated by the rotating force that is generated, and a connecting member that is provided between the second rotating body and the third rotating body and transmits the rotating force from the second rotating body to the third rotating body, A power transmission device that cuts off the rotational force transmitted from the second rotating body to the third rotating body by breaking the connecting member when a rotational force of a predetermined magnitude or more is generated between the first rotating body and the drive shaft. And provided in the vicinity of the connecting member. A protrusion projecting radially inward from the inner peripheral surface of the second rotating body, and provided on the first rotating body side, wherein the first rotating body and the second rotating body are opposed to each other in the rotational direction against the elastic member. A contact portion that, when displaced by a predetermined angle or more, hits the protruding portion of the second rotating body from the inside in the radial direction to deform the second rotating body to the outside in the radial direction and breaks the connecting member by the deformation of the second rotating body; I have.

As a result, when a rotational force of a predetermined magnitude or more is generated between the first rotating body and the drive shaft, the first rotating body and the second rotating body are opposed to the elastic member by a predetermined angle in the rotational direction. Displacement is as described above.

Thereby , the contact part of a 1st rotary body contacts a protrusion part from a radial inside, and deforms a 2nd rotary body toward a radial direction outer side. Moreover, since the protrusion part of the 2nd rotary body is provided in the vicinity of the connection member, a connection member will fracture | rupture when a 2nd rotary body deform | transforms toward a radial direction outer side.

That is, by setting the torque necessary for displacing the first rotating body and the second rotating body by a predetermined angle or more to a predetermined breaking torque, the connecting member can be always broken at the predetermined breaking torque. .

  According to the present invention, since the connecting member can always be broken at a predetermined breaking torque, a rotational force that does not satisfy the predetermined breaking torque can be reliably transmitted, and a rotational force exceeding the predetermined breaking torque can be reliably cut off. can do.

  1 to 4 show a first embodiment of the present invention. FIG. 1 is a side sectional view of a power transmission device, FIG. 2 is a front view of the power transmission device, and FIG. 3 is an operation explanatory view of the power transmission device. FIG. 4 is a perspective view of main parts of the contact portion and the connecting member.

  The power transmission device according to the present embodiment includes a pulley 10 as a first rotating body to which power from an engine (not shown) is transmitted, a hub 20 disposed radially inside the pulley 10, and a metal fixed to the pulley 10. A ring 30 and a buffer rubber 40 as an elastic member that transmits a rotational force from the metal ring 30 to the hub 20 are provided.

  The pulley 10 can wind a V-belt (not shown) around its outer peripheral surface, and is rotatably supported by a housing of the compressor 1 as a driven device via a bearing 11.

  The hub 20 is made of a metal material, and a ring-shaped outer ring 21 serving as a second rotating body, and a boss 22 serving as a third rotating body provided on the radially inner side of the outer ring 21 and fixed to the drive shaft 2 of the compressor 1. And a plurality of connecting members 23 that connect the outer ring 21 and the boss 22.

  The boss 22 has a cylindrical portion 22a connected to the drive shaft 2 of the compressor 1, and a disk-shaped flange portion 22b extending radially outward from the outer peripheral surface of the cylindrical portion 22a. The inner peripheral surface of the cylindrical portion 22a engages with a spline 2a provided at the tip of the shaft 2 in the rotational direction, and the cylindrical portion 22a is fixed to the shaft 2 by a nut 2b that is screwed to the tip of the shaft 2.

  Each connecting member 23 is provided at intervals in the circumferential direction, and connects the inner peripheral surface of the outer ring 21 and the outer peripheral surface of the flange portion 22 b of the boss 22.

  The metal ring 30 is provided with a cylindrical ring portion 31 and a plurality of flange portions 32 that are spaced apart from each other in the circumferential direction and extend radially outward from one axial end side of the ring portion 31. It has a plurality of radially extending portions 33 provided at intervals and extending radially inward from the other axial end of the ring portion 31. Each flange portion 32 is provided with a mounting hole 32a. The metal ring 30 is fixed to the pulley 10 by a plurality of bolts 32b inserted through the mounting holes 32a. Abutting portions 33 a are provided on the radially inner side of the respective radially extending portions 33, and each abutting portion 33 a is disposed between the inner peripheral surface of the outer ring 21 and the outer peripheral surface of the flange portion 22 b of the boss 22. Yes. As shown in FIG. 2, when the metal ring 30 and the outer ring 21 rotate with respect to each other by a predetermined angle α, one end surface in the circumferential direction of each contact portion 33 a hits each connecting member 23 in the circumferential direction. As shown in FIG. 4, one end surface in the circumferential direction of the contact portion 33a is planar.

  The buffer rubber 40 has a ring shape, and the inner peripheral surface is vulcanized and bonded to the outer peripheral surface of the outer ring 21 of the hub 20, and the outer peripheral surface is vulcanized and bonded to the inner peripheral surface of the ring portion 31 of the metal ring 30. Further, when a predetermined torque is generated between the metal ring 30 and the hub 20, the spring constant of the buffer rubber 40 is set so that the metal ring 30 and the hub 20 are displaced by an angle α or more.

  In the power transmission device configured as described above, when power is transmitted from the engine (not shown) to the pulley 10, the rotational force of the pulley 10 is transmitted to the hub 20 via the metal ring 30 and the buffer rubber 40. At this time, rotational fluctuations input from the engine to the pulley 10 are reduced by the buffer rubber 40.

  Here, for example, when the predetermined torque is generated between the pulley 10 and the drive shaft 2 due to the seizure of the compressor 1 and the rotation of the shaft 2 being restricted, the metal ring 30 and the outer ring 21 are angled. Displaces more than α. Thereby, the circumferential direction one end surface of each contact part 33a of the metal ring 30 hits each connection member 23 in the circumferential direction, and each connection member 23 breaks when each contact part 33a hits. That is, by setting the torque necessary for displacing the metal ring 30 and the outer ring 21 with respect to each other by an angle α or more to a predetermined breaking torque, it is possible to always break the connecting members 23 with the predetermined breaking torque.

  As described above, according to the present embodiment, when a predetermined torque is generated between the pulley 10 and the drive shaft 2, one end surface in the circumferential direction of each contact portion 33 a of the metal ring 30 hits each connecting member 23 in the circumferential direction. Since each contact member 33a hits each connecting member 23, the torque required to displace the metal ring 30 and the outer ring 21 from each other by an angle α or more is set to a predetermined cutoff torque. Thus, each connecting member 23 can always be broken at a predetermined breaking torque. Accordingly, it is possible to reliably transmit a rotational force that does not satisfy the predetermined cutoff torque, and it is possible to reliably interrupt a rotational force that exceeds the predetermined cutoff torque.

  Further, since a plurality of connecting members 23 are provided at intervals in the circumferential direction, and a plurality of abutting portions 33a corresponding to the connecting members 23 are provided, each contact when the metal ring 30 and the outer ring 21 are displaced from each other by an angle α or more. Each connecting member 23 is reliably broken by the contact portion 33a, and a rotational force exceeding a predetermined breaking torque can be reliably cut off.

  Further, since the metal ring 30 is fixed to the pulley 10 and each contact portion 33a is formed by extending a part of the metal ring 30 radially inward, each contact portion 33a is provided with a simple configuration. This is advantageous in reducing the manufacturing cost.

  In the present embodiment, a plurality of connecting members 23 are provided. However, only one connecting member 23 may be provided.

  Further, in the present embodiment, the one end surface in the circumferential direction of the abutting portion that hits the connecting member 23 is shown to be planar, but the one end surface in the circumferential direction of the abutting portion 33a is curved as shown in FIG. It is also possible to make it project. Moreover, as shown in FIG. 6, it is also possible to make the one end surface of the contact part 33a protrude in an acute angle shape. Moreover, as shown in FIG. 7, it is also possible to provide a level | step difference in the circumferential direction one end surface of the contact part 33a. Moreover, as shown in FIG.8 and FIG.9, it is also possible to provide an inclined surface in the circumferential direction one end surface of the contact part 33a. Moreover, as shown in FIG. 10, it is also possible to form the axial direction edge part of the contact part 33a in acute angle shape. Moreover, as shown in FIG. 11, it is also possible to form the axial direction edge part of the contact part 33a in the shape of a curved surface.

  In this embodiment, a ring-shaped buffer rubber 40 is provided which is vulcanized and bonded to the outer peripheral surface of the outer ring 21 of the hub 20 and vulcanized and bonded to the inner peripheral surface of the ring portion 31 of the metal ring 30. However, as shown in FIGS. 12 to 14, it is also possible to provide a plurality of cushioning rubbers 50 between the pulley 10 and the outer ring 21 of the hub 20.

  In this case, a plurality of radial protrusions 21 a are provided on the outer peripheral surface of the outer ring 21 at intervals in the circumferential direction, and each radial protrusion 21 a protrudes radially outward from the outer peripheral surface of the outer ring 21. The pulley 10 is provided with a plurality of axial projecting portions 10a spaced from each other in the circumferential direction, and each axial projecting portion 10a faces each radial projecting portion 21a in the circumferential direction.

  Each shock absorbing rubber 50 has a pair of shock absorbing rubber main bodies 51 formed in a block shape, and a connecting portion 52 that connects each shock absorbing rubber main body 51. Each buffer rubber 50 is attached between the pulley 10 and the outer ring 21 so that the buffer rubber body 51 is disposed between each axial protrusion 10a and each radial protrusion 21a. Further, the spring constant of each buffer rubber 50 is set so that when a predetermined torque is generated between the pulley 10 and the outer ring 21, the pulley 10 and the outer ring 21 are displaced by an angle α or more.

  That is, when the predetermined torque is generated between the pulley 10 and the drive shaft 2, the pulley 10 and the outer ring 21 are displaced by an angle α or more. Thereby, the circumferential direction one end surface of each contact part 33a of the metal ring 30 hits each connection member 23 in the circumferential direction, and each connection member 23 breaks when each contact part 33a hits.

  15 to 18 show a second embodiment of the present invention. FIG. 15 is a side sectional view of the power transmission device, FIG. 16 is a front view of the power transmission device, and FIGS. 17 and 18 are views of the power transmission device. It is operation | movement explanatory drawing. Note that the same components as those in the first embodiment are denoted by the same reference numerals.

  The power transmission device of the present embodiment includes a pulley 10 and a buffer rubber 40 equivalent to those of the first embodiment, a hub 60 disposed on the radially inner side of the pulley 10, and a metal ring 70 fixed to the pulley 10. I have.

  The hub 60 is made of a metal material, and has a ring-shaped outer ring 61 as a second rotating body, and a boss 62 as a third rotating body provided on the radially inner side of the outer ring 61 and fixed to the drive shaft 2 of the compressor 1. And a plurality of connecting members 63 that connect the outer ring 61 and the boss 62.

  A plurality of protrusions 61 a are provided on the inner peripheral surface of the outer ring 61 at intervals in the circumferential direction, and each protrusion 61 a protrudes radially inward from the inner peripheral surface of the outer ring 61. In addition, each protrusion 61 a is disposed in the vicinity of each connecting member 63.

  The boss 62 has a cylindrical portion 62a connected to the drive shaft 2 of the compressor 1, and a disk-shaped flange portion 62b extending radially outward from the outer peripheral surface of the cylindrical portion 62a. The inner peripheral surface of the cylindrical portion 62a is engaged with a spline 2a provided at the tip of the shaft 2 in the rotational direction, and the cylindrical portion 62a is fixed to the shaft 2 by a nut 2b that is screwed to the tip of the shaft 2. A plurality of protruding portions 62c are provided on the outer peripheral surface of the flange portion 62b at intervals in the circumferential direction, and each protruding portion 62c protrudes radially outward from the outer peripheral surface of the flange portion 62b. Each protrusion 62c is opposed to each protrusion 61a of the outer ring 61 in the circumferential direction.

  The respective connecting members 63 are provided at intervals in the circumferential direction, and connect the inner peripheral surface of the outer ring 61 and the outer peripheral surface of the flange portion 62 b of the boss 62.

  The metal ring 70 includes a ring portion 71 having a cylindrical shape, and a plurality of flange portions 72 that are spaced apart from each other in the circumferential direction and extend radially outward from one axial end side of the ring portion 71. There are a plurality of radially extending portions 73 provided at intervals and extending radially inward from the other axial end of the ring portion 71. Each flange portion 72 is provided with a mounting hole 72a. The metal ring 70 is fixed to the pulley 10 by a plurality of bolts 72b inserted through the mounting holes 72a. Abutting portions 73 a are provided on the radially inner side of the respective radially extending portions 73, and each abutting portion 73 a is disposed between the inner peripheral surface of the outer ring 61 and the outer peripheral surface of the flange portion 62 b of the boss 62. Yes. Each contact portion 73a has a width dimension larger than the radial gap between the protruding portion 61a and the protruding portion 62c. As shown in FIGS. 17 and 18, when the metal ring 70 and the outer ring 61 are rotated by a predetermined angle α or more, the protrusions 62c of the boss 62 abut against the contact portions 73a from the inside in the radial direction. The contact portion 73a hits each protruding portion 61a of the outer ring 61 from the inside in the radial direction.

  In the power transmission device configured as described above, when a predetermined torque is generated between the pulley 10 and the drive shaft, the metal ring 70 and the outer ring 61 are displaced by an angle α or more. Thereby, each contact part 73a of the metal ring 70 hits each protrusion part 61a, 62c, and each contact part 73a hits each protrusion part 61a of the outer ring 61 from the radial inner side, so that the outer ring 61 moves radially outward. Deforms toward. Moreover, since each protrusion part 61a of the outer ring | wheel 61 is provided in the vicinity of each connection member 63, when the outer ring | wheel 61 deform | transforms toward a radial direction outer side, each connection member 63 will fracture | rupture. That is, by setting the torque necessary for displacing the metal ring 70 and the outer ring 61 relative to each other by an angle α or more to a predetermined breaking torque, each connecting member 63 can always be broken at the predetermined breaking torque. On the other hand, each protrusion 62c of the boss 62 hits each contact portion 73a from the inside in the radial direction, and each contact portion 73a is restricted from moving radially inward by each protrusion 62c.

  As described above, according to the present embodiment, when a predetermined torque is generated between the pulley 10 and the drive shaft 2, each contact portion 73 a of the metal ring 70 hits each projection portion 61 a of the outer ring 61 from the inside in the radial direction. The outer ring 61 is deformed radially outward by the contact of each contact portion 73a, and each connecting member 63 is broken by the deformation of the outer ring 61. Therefore, the metal ring 70 and the outer ring 61 are displaced from each other by an angle α or more. By setting the torque necessary for this to be a predetermined breaking torque, each connecting member 63 can always be broken at the predetermined breaking torque. Accordingly, it is possible to reliably transmit a rotational force that does not satisfy the predetermined cutoff torque, and it is possible to reliably interrupt a rotational force that exceeds the predetermined cutoff torque.

  Further, when each protrusion 62c is provided on the outer peripheral surface of the flange portion 62b of the boss 62 and the metal ring 70 and the outer ring 61 are displaced by an angle α or more, each protrusion 62c is radially directed to each contact portion 73a of the metal ring 70. Since the contact is made from the inside, the movement of each contact portion 73a inward in the radial direction is restricted, and the outer ring 61 can be reliably deformed by each contact portion member 73a.

  In the present embodiment, as shown in FIGS. 16 to 18, the protrusions 61 a and 62 c are formed in a substantially rectangular shape, but the protrusions 61 a and 62 c are formed in a semicircular shape. Is also possible.

  19 to 20 show a third embodiment of the present invention. FIG. 19 is a side sectional view of the power transmission device, and FIG. 20 is a front view of the power transmission device. In addition, the same code | symbol is attached | subjected and shown to the component equivalent to 1st Embodiment.

  The power transmission device of the present invention includes a hub 20 and a buffer rubber 40 according to the first embodiment, a pulley 80 as a first rotating body to which power from an engine (not shown) is transmitted, and a metal ring fixed to the pulley 80. 90.

  The pulley 80 can wind a V-belt (not shown) around the outer peripheral surface, and is rotatably supported on the housing of the compressor 1 via a bearing 81. The pulley 80 is made of a resin material and has a bearing support member 82 on the radial center side. The bearing support member 82 is made of a metal material and has a cylindrical shape. A plurality of contact portions 82a are provided at one end surface in the axial direction of the bearing support member 82 at intervals in the circumferential direction, and each contact portion 82a extends from one end surface in the axial direction of the bearing support member 82 in the axial direction. Yes. Each contact portion 82 a is disposed between the inner peripheral surface of the outer ring 21 and the outer peripheral surface of the flange portion 22 b of the boss 22. As shown in FIG. 20, when the pulley 80 and the outer ring 21 rotate with respect to each other by an angle α or more, one end surface in the circumferential direction of each contact portion 82 a hits each connecting member 23 in the circumferential direction.

  The metal ring 90 includes a ring portion 91 having a cylindrical shape and a plurality of flange portions 92 that are provided at intervals in the circumferential direction and extend radially outward from one axial end side of the ring portion 91. Each flange portion 92 is provided with a mounting hole 92a. The metal ring 90 is fixed to the pulley 80 by a plurality of bolts 92b inserted through the mounting holes 92a.

  In the power transmission device configured as described above, when a predetermined torque is generated between the pulley 80 and the drive shaft 2, the pulley 80 and the outer ring 21 are displaced by an angle α or more. Thus, one end surface in the circumferential direction of each abutting portion 82a of the pulley 80 hits each connecting member 23, and each connecting member 23 is broken by hitting each abutting portion 82a. That is, by setting the torque necessary for displacing the pulley 80 and the outer ring 21 by an angle α or more to a predetermined breaking torque, each connecting member 23 can always be broken at the predetermined breaking torque.

  As described above, according to the present embodiment, when a predetermined torque is generated between the pulley 80 and the drive shaft 2, one end surface in the circumferential direction of each contact portion 82 a of the pulley 80 hits each connecting member 23, and Since each connecting member 23 is broken by contact with the contact portion 82a, the torque necessary for displacing the pulley 80 and the outer ring 21 from each other by an angle α or more is set to a predetermined breaking torque. The member 23 can always be broken at a predetermined breaking torque. Accordingly, it is possible to reliably transmit a rotational force that does not satisfy the predetermined cutoff torque, and it is possible to reliably interrupt a rotational force that exceeds the predetermined cutoff torque.

  In addition, since each abutment portion 82a is formed by extending the bearing support member 82 of the pulley 80 in the axial direction, providing the abutment portions 82a does not increase the size of the entire apparatus, thereby saving space. It is advantageous in planning.

Side surface sectional drawing of the power transmission device which shows the 1st Embodiment of this invention Front view of power transmission device Operation explanatory diagram of power transmission device The principal part perspective view of a contact part and a connection member The principal part perspective view of the contact part which shows the 1st modification of an contact part, and a connection member The principal part perspective view of the contact part and connecting member which show the 2nd modification of an contact part The principal part perspective view of the contact part and connecting member which show the 3rd modification of an contact part The principal part perspective view of the contact part and connection member which show the 4th modification of an contact part. The principal part perspective view of the contact part and connecting member which show the 5th modification of an contact part The principal part perspective view of the contact part and connecting member which show the 6th modification of an contact part The principal part perspective view of the contact part and connecting member which show the 7th modification of an contact part Front view of power transmission device showing modified example of shock absorbing rubber Front view of shock absorbing rubber showing a modification of shock absorbing rubber Top view of shock absorbing rubber showing a variation of shock absorbing rubber Side surface sectional drawing of the power transmission device which shows the 2nd Embodiment of this invention. Front view of power transmission device Operation explanatory diagram of power transmission device Operation explanatory diagram of power transmission device Side surface sectional drawing of the power transmission device which shows the 3rd Embodiment of this invention. Front view of power transmission device

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Drive shaft, 10 ... Pulley, 11 ... Bearing, 20 ... Hub, 21 ... Outer ring, 22 ... Boss, 23 ... Connecting member, 30 ... Metal ring, 31 ... Ring part, 32 ... Flange part, 33 ... Radial extension part, 33a ... Contact part, 40 ... Buffer rubber, 50 ... Buffer rubber, 60 ... Hub, 61 ... Outer ring, 61a ... Projection part, 62 ... Boss, 62c ... Projection part, 63 ... Connecting member , 70 ... Metal ring, 71 ... Ring part, 72 ... Flange part, 73 ... Radially extending part, 73a ... Contact part, 80 ... Pulley, 81 ... Bearing, 82 ... Bearing support member, 82a ... Contact part, 90 ... Metal ring, 91 ... Ring part, 92 ... Flange part.

Claims (5)

A first rotating body that is rotated by power from the outside, a second rotating body that is rotated by a rotational force transmitted from the first rotating body, and a predetermined spring constant in a rotating direction of the first rotating body, An elastic member that transmits rotational force from the rotating body to the second rotating body, and a rotational force that is provided on the radially inner side of the second rotating body and that is fixed to the drive shaft of the driven device and transmitted from the second rotating body A third rotating body that is rotated by the first rotating body, and a connecting member that is provided between the second rotating body and the third rotating body and transmits a rotational force from the second rotating body to the third rotating body. In the power transmission device that cuts off the rotational force transmitted from the second rotating body to the third rotating body when the rotational force of a predetermined magnitude or more is generated between the rotating shaft and the drive shaft,
A protrusion that is provided in the second rotating body, is disposed in the vicinity of the connecting member, and protrudes radially inward from the inner peripheral surface of the second rotating body;
Provided on the first rotating body side, when the first rotating body and the second rotating body are displaced from each other by a predetermined angle in the rotational direction against the elastic member, they contact the projecting portion of the second rotating body from the radially inner side. A power transmission device comprising: a contact portion that deforms the second rotating body radially outward and breaks the connecting member by deformation of the second rotating body. A plurality of the connecting members are provided at intervals in the circumferential direction, a plurality of the projecting portions corresponding to each connecting member are provided, and a plurality of the abutting portions corresponding to each projecting portion are provided. The power transmission device according to 1 . The first rotating body and the second rotating body are arranged so as to protrude radially outward from the outer peripheral surface of the third rotating body and to face the protruding portion of the second rotating body, and against the elastic member. 3. The power transmission device according to claim 1, further comprising: a projecting portion that hits the contact portion from the radially inner side when displaced by a predetermined angle or more in the rotation direction. Wherein the contact portion, a power transmission device according to claim 1, 2 or 3, characterized in that formed by extending a portion radially inside the fixed metal ring to the pulley. Wherein the contact portion, a power transmission device according to claim 1, 2 or 3, characterized in that formed by extending the radially inward of the pulley in the axial direction.

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