JP2005273676A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device, in which a connected state of a drive unit to a driven body is released when a load torque of driving force exceeds a prescribed value to eliminate rupture for making it reusable. <P>SOLUTION: In this power transmission device, the driven body 10 and the drive unit 4 to drive the driven body 10 are connected to each other to transmit driving force, while transmission of driving force is disconnected when the load torque to the driven body 10 exceeds the prescribed value. It is provided with a leaf spring 12 connected to the drive unit 4 at one end, and connected to the driven body 10 at the other end, in such a way that one end or the other end is released from the connected state when the load torque exceeds the prescribed value, a damper 30 comprising an elastic body installed on the drive unit 4, and a transmission member 20 inserted to the damper 30 at one end to be engaged, and detachably engaged with the other end of the leaf spring 12 at the other end. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a power transmission device that transmits a driving force of a driving body to a driven body.

  When a driven body and a drive body that drives the driven body are connected to the compressor of the vehicle air conditioner to transmit the driving force, and the load torque to the driven body exceeds a predetermined value A power transmission device for interrupting transmission of driving force is incorporated.

  FIG. 11 is a cross-sectional view of a conventional power transmission device described in Japanese Patent Application Laid-Open No. 2002-54711. A boss portion 102 is formed in the housing 101 of the compressor, and a pulley 104 as a driving body is rotatably supported by the boss portion 102 via a bearing 103. A belt (not shown) from the crankshaft of the engine is stretched around the pulley 104, and the pulley 104 is driven to rotate by driving the engine.

  The housing 101 is provided with a rotation shaft 105 protruding outward from the boss portion 102 so as to be coaxial with the boss portion 102. An output disk 106 as a driven body is fixed to the rotating shaft 105. The output disk 106 includes an outer hub 107 disposed on the outer peripheral side and an inner hub 108 coupled to the rotating shaft 105.

  A plurality of holes 104a are formed in the pulley 104 at a plurality of locations in the circumferential direction, and rubber dampers 109 are fitted into the holes 104a. A pin 110 is inserted into the rubber damper 109, and the driving force of the pulley 104 is transmitted to the outer hub 107 by engaging the pin 110 with the outer hub 107.

  The inner hub 108 includes an outer ring 108a inserted into the outer hub 107, an inner ring 108b that is screwed to the rotary shaft 105, and a bridge 108c that connects the outer ring 108a and the inner ring 108b. The bridge 108c is formed with a damaged portion 111 that is preferentially damaged when an overload overload torque is applied.

  In such a structure, when the engine is driven, the pulley 104 rotates and power is transmitted to the rotating shaft 105 via the rubber damper 109, the pin 110, the outer hub 107, and the inner hub 108.

When an abnormality such as burn-in occurs in the compressor, the rotary shaft 105 is locked, and the pulley 104 continues to rotate while the output disk 106 stops rotating, so the load torque exceeds a predetermined value. In this case, the damaged portion 111 of the inner hub 108 breaks preferentially and breaks. As a result, the inner hub 108 and the outer hub 107 are separated from each other and the transmission of power from the pulley 104 to the rotating shaft 105 is cut off, so that the pulley 104 rotates idle.
JP 2002-54711 A

  In the above power transmission device of the prior art, when the load torque exceeds a predetermined value, the inner hub 108 breaks and cannot be reused. The inner hub 108 and the outer hub 107 into which the inner hub 108 is inserted It is necessary to replace at least the output disk 106 consisting of Further, readjustment is necessary at the time of assembling this exchange, and the exchange work is troublesome.

  The present invention has been made in consideration of such problems. When the load torque exceeds a predetermined value, the structure is configured to be disconnected from the connected state, so that it is not necessary to break and can be reused. It is an object to provide a simple power transmission device.

  In the first aspect of the present invention, the driven body 10 is connected to the driving body 4 that drives the driven body 10 to transmit the driving force, and the load torque to the driven body 10 exceeds a predetermined value. A power transmission device that interrupts transmission of driving force in the case where one end is connected to the driving body 4 side and the other end is connected to the driven body 10 side, and the load torque exceeds a predetermined value. One end or the other end of the leaf spring 12 is removed from the connected state, the damper 30 is made of an elastic body attached to the driving body 4, and one end is inserted into the damper 30 to be engaged with the other end. And a transmission member 20 detachably engaged with the end.

  The invention according to claim 2 is the power transmission device according to claim 1, wherein the storage space 38 is partitioned inside the drive body 4, and the damper 30 is placed in the storage space 38. It is inserted.

  The invention according to claim 3 is the power transmission device according to claim 1 or 2, wherein the damper 30 has a spring constant on the upstream side in the driving force direction D with the insertion part at one end of the transmission member 20 as a boundary. The spring constant is larger than the downstream spring constant.

  According to the first aspect of the present invention, one end of the transmission member 20 is engaged with the damper 30 attached to the drive body 4, and the other end of the transmission member 20 is engaged with the leaf spring 12. Is transmitted to the leaf spring 12 via the damper 30 and the transmission member 20, the damper absorbs or attenuates unnecessary vibration and the like, and only the driving force can be reliably transmitted to the driven body 10. . In addition, the leaf spring 12 is connected to the driving body 4 side and the driven body 10 side, and when the load torque exceeds a predetermined value, one end or the other end is detached from the connected state, so that the driving is not broken. Since the power can be interrupted, no replacement is required and reassembly can be easily performed.

  Since the damper 30 is inserted into the storage space 38 provided in the drive body 4 in a partitioned state, the damper 30 is compressed in the storage space 38 when the driving force is transmitted. Thus, the driving force can be reliably transmitted to the transmission member 20.

  According to the third aspect of the invention, since the spring constant on the upstream side in the driving force direction of the damper 30 is large, the damper 30 does not sag and the durability can be improved.

  1 is an exploded perspective view of a power transmission device according to an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, and FIGS. FIG. 8 shows a transmission shaft in the transmission member, and FIG. 9 shows a damper and a transmission shaft.

  1 to 3, reference numeral 1 denotes a housing of a clutchless compressor, and a pulley 4 as a driving body is rotatably supported by a boss portion 2 via a bearing 3. The housing 1 is coaxially arranged with respect to the boss portion 2 and accommodates a rotating shaft 7 protruding outward from the boss portion 2, and a driven body via a bolt 8 at the end thereof. A disk-shaped hub 10 is fixed.

  A plurality of pin insertion holes 11 are formed in the hub 10 along the circumference. Four pin insertion holes 11 are formed at equal intervals of 90 ° on the same circumference around the rotation shaft 7, and pins (projections) 13 are fixed in a through state in each pin insertion hole 11. The penetrating ends of the respective pins 13 are engaged with the leaf springs 12. The engagement of the pin 13 with the leaf spring 12 is performed by caulking the penetrating end of the pin 13 penetrating the leaf spring 12.

  The leaf spring 12 connects the pulley 4 as a driving body and the hub 10 as a driven body to transmit the rotational driving force of the pulley 4 to the hub 10, and the leaf driving force 12 is transmitted by the rotational driving force transmitted to the hub 10. The rotating shaft 7 rotates. Further, the leaf spring 12 acts so as to cut off the transmission of the driving force when the load torque to the hub 10 exceeds a predetermined value.

  Four leaf springs 12 are arranged so as to correspond to the pins 13, and each leaf spring 12 has the same shape and size. The leaf spring 12 is provided with wear resistance, whip and good tensile strength by using bearing steel such as “SUJ”. Further, the leaf spring 12 is provided with a rust preventive film such as a phosphate coating, and it is possible to prevent fluctuations in torque load due to rusting. Further, the torque transmission portion of the leaf spring 12 is subjected to a surface treatment to prevent performance deterioration.

  The leaf spring 12 has a bifurcated shape in which one ends of a pair of side pieces 12a having a distance 16 are connected to each other so as to be openable and closable. A penetrating engagement hole 14 to be engaged is formed. Further, a protrusion (pin) 22 of a transmission shaft 21 (described later) is inserted and held on the open end side of the leaf spring 12 so as to be detachably engaged with the protrusion 22 of the transmission shaft 21. A surface 15 is formed.

  The transmission shaft 21 is a constituent member of the transmission member 20, and the transmission member 20 has a circular ring-shaped location plate 23 as a transmission plate, and the transmission shaft 21 is attached to the location plate 23. In the location plate 23, insertion holes 24 penetrate in the thickness direction at four equal positions on the circumference around the rotation shaft 7, and the protrusions 22 of the transmission shaft 21 penetrate the respective insertion holes 24. doing. The penetrating end of the protrusion 22 is detachably held by the holding surface 15 of the leaf spring 12.

  The transmission shaft 21 includes a protruding portion 22 on the leaf spring 12 side and a shaft plate 25 that is coaxial with the protruding portion 22 and extends integrally to the pulley 4 side. The shaft plate 25 has a flat shaft shape, and the shaft plate 25 is connected to the pulley 4 via the damper 30.

  As shown in FIG. 8, the transmission shaft 21 is formed with a fixing portion 27 having a serration on the outer surface between the protrusion 22 and the shaft plate 25. On the other hand, the insertion hole 24 of the location plate 23 is formed with a serration that fits with the fixing portion 27. Accordingly, by inserting the transmission shaft 21 into the insertion hole 24 of the location plate 23 and serration-coupling them, the transmission shaft 21 is fixed to the location plate 23 in a rotation-stopped state. Thereby, the transmission shaft 21 and the location plate 23 can be securely fastened, and the driving force to the transmission shaft 21 can be transmitted to the location plate 23 without waste.

  As shown in FIGS. 1 and 4 to 7, the damper 30 includes a pair of damper main bodies 31 and 32 formed in a substantially square columnar block shape, and a connection band 33 that connects the pair of damper main bodies 31 and 32. The entirety is formed of an elastic body such as rubber or soft resin. The connecting band 33 connects the damper main bodies 31 and 32 on one side in the height direction of the pair of damper main bodies 31 and 32. Further, in a connected state by the connecting band 33, an insertion space 34 in which the shaft plate 25 of the transmission shaft 21 is inserted is provided between the pair of damper main bodies 31 and 32.

  The damper 30 is inserted and housed inside the pulley 4 to transmit the driving force of the pulley 4 to the transmission shaft 21. Inside the pulley 4, a plurality of rib portions 36 extending radially inward from the inner wall thereof are formed, and a step portion 37 protruding in a step shape between the rib portions 36 is formed. The damper 30 is inserted and stored in a storage space 38 surrounded by the rib portion 36 and the step portion 37. At the time of storage, it is inserted into the storage space 38 from the connecting band 33 side, and thereby the insertion space 34 is positioned on the transmission member 20 side.

  As shown in FIG. 9, by inserting the shaft plate 25 into the insertion space 34 with respect to the damper 30 inserted into the storage space 38, the pulley 4 and the transmission member 20 are connected via the damper 30 and the transmission shaft 21. Are concatenated. Then, the protrusion 22 of the transmission shaft 21 is fitted and engaged with the holding surface 15 of the leaf spring 12 attached to the hub 10 by the pin 13. Thereby, the pulley 4 and the hub 10 are connected via the damper 30, the transmission member 20, and the leaf spring 12. As shown in FIG. 2, the leaf spring 12 is assembled so as to be substantially perpendicular to a straight line connecting the center of the rotating shaft and the pin 13 of the hub 10. In such assembling, the space for arranging the leaf springs 12 can be reduced, the size can be reduced, and the arm of the load torque to be transmitted can be lengthened.

  The holding surface 15 of the leaf spring 12 is formed with a curvature that matches the outer peripheral portion of the protruding portion 22 of the transmission shaft 21, so that the holding surface 15 can securely hold the protruding portion 22. It has become. On the other hand, when the protruding portion 22 moves toward the open end side along the holding surface 15, the protruding portion 22 can come out from the open end side of the leaf spring 12. As a result, the connection between the leaf spring 12 and the transmission member 20 is released, and the leaf spring 12 is released from the connected state between the pulley 4 and the hub 10.

  In such a structure, when the load torque from the compressor side is a predetermined value or less, the driving force of the engine applied to the pulley 4 via a belt (not shown) is transmitted via the damper 30, the transmission member 20, and the pin 13. Is transmitted to the hub 10 and the rotary shaft 7 rotates.

  A damper 30 made of an elastic member is disposed in the driving force transmission path, and the damper 30 absorbs or attenuates unnecessary vibration or the like, so that only the driving force of the pulley 4 is transmitted to the hub 10 and the rotary shaft 7. The rotating shaft 7 can rotate smoothly.

  Further, the damper 30 is inserted into the storage space 38 partitioned by the rib portion 36, and when the driving force is transmitted, the damper 30 is compressed in the storage space 38, so that the driving force is reliably transmitted to the transmission member 20. Can communicate.

  When seizure or the like occurs inside the compressor and the load torque exceeds a predetermined value, the protrusion 22 held on the holding surface 15 of the leaf spring 12 is detached from the open end side. As a result, transmission of power from the pulley 4 to the rotating shaft 7 is interrupted, so that the pulley 4 idles. Thus, in the structure in which the leaf spring 12 is detached from the connected state, the leaf spring 12 is not broken. For this reason, it is not necessary to replace the leaf spring 12, the transmission member 20, and the like, and reassembly can be easily performed.

  As shown in FIGS. 4 and 7, groove portions 31 a and 32 a are formed in the pair of damper main bodies 31 and 32, respectively. The groove portions 31 a and 32 a are open in a direction intersecting with the width direction of the damper main bodies 31 and 32 and have a depth along the height direction of the damper main bodies 31 and 32. Thereby, when the driving force D (refer FIG. 4) from the pulley 4 acts, the groove parts 31a and 32a can be elastically compressed and the driving force D can be transmitted to the shaft plate 25 in the insertion space 34.

  In this embodiment, the upstream groove 31a in the direction of the driving force D is larger than the downstream groove 32a. Thereby, the spring constant of the damper main body 31 in which the groove part 31a is formed is larger than the spring constant of the damper main body 32 in which the groove part 32a is formed. That is, the pair of damper main bodies 31 and 32 is set so that the upstream damper main body 31 in the direction of the driving force D has a larger spring constant than the downstream damper main body 32 with the insertion portion of the shaft body 25 as a boundary. Is. By setting in this way, the damper 30 reliably pushes the shaft body 25 and transmits the driving force, so that the driving force can be reliably transmitted to the hub 10 via the leaf spring 12. Moreover, since the damper 30 does not sag, the durability of the damper 30 can be improved.

  As the pin 13 of the hub 10 and the transmission shaft 21 of the transmission member 20, durability of these members can be improved by using a metal material having high wear resistance and shear resistance.

  As shown in FIG. 3, the bearing 3 is attached to the pulley 4 via an insert fitting 9 inserted into the pulley 4. In other words, the outer race of the bearing 3 is inserted into the insert fitting 9, and the insert fitting 9 is crimped in this inserted state to be fixed to the pulley 4 via the insert fitting 9. By setting the position of the insert fitting 9 to a position on the circumference that coincides with the rib portion 36 of the inner wall of the pulley 4, the strength of the crimped portion can be improved.

  As shown in FIG. 3, a gap G is formed between the location plate 23 and the leaf spring 12, and the gap G avoids contact between the leaf spring 12 and the location plate 23. By providing the gap G in this way, there is no need to provide a gap adjusting shim between the leaf spring 12 and the location plate 23, so that the number of parts can be reduced and the assembly can be facilitated.

  FIG. 10 shows another embodiment of the present invention, and the same members as those in the above-described embodiment are given the same reference numerals and correspond to each other.

  In the transmission member 20 of this embodiment, the shaft plate 25 is formed on the location plate 23, and the protrusion 22 is separated from the shaft plate 25 and is fixed to the location plate 23. The shaft plate 25 is integrally formed so as to rise from the surface of the location plate 23 on the pulley 4 (damper 30) side. Further, the shaft plate 25 is formed at four equal positions on the circumference around the rotation shaft 7.

  In this case, the insertion hole 24 of the protrusion 22 and the shaft plate 25 are formed at different positions on the circumference, and the projection 22 and the shaft plate 25 are located at different positions on the circumference. Protrudes from both sides. Even in such a structure, the driving force from the pulley 4 can be transmitted to the hub 10 by inserting the shaft plate 25 into the damper 30 and holding the protrusion 22 on the holding surface 15 of the leaf spring 12.

  In such a structure, as shown in FIG. 1, it is not necessary to assemble the transmission shaft 21 to the location plate 23, and the assembly is easy. Note that the number of the shaft plates 25 and the protrusions 22 may be the same or different.

  The present invention is not limited to the above embodiments, and various modifications can be made. For example, the leaf spring 12 may be detached from the connected state by detaching the O pin 13 on the hub 10 side from the leaf spring 12. Further, in the damper 30, the thickness of the damper main body 31 on the upstream side in the driving force direction is made thicker than the thickness of the damper main body 32 on the downstream side, or the damper main body 31 is formed of a material harder than the damper main body 32. Thus, the spring constants on the upstream side and the downstream side may be different.

It is a disassembled perspective view of the power transmission device in one Embodiment of this invention. It is a side view of a power transmission device. It is the sectional view on the AA line of FIG. It is a top view of a damper. It is a front view of a damper. It is a bottom view of a damper. It is the BB sectional view taken on the line of FIG. It is a side view of a transmission shaft. It is a front view which shows the state which attaches a transmission shaft to a damper. It is a partial exploded perspective view of the power transmission device in another embodiment of the present invention. It is sectional drawing of the conventional power transmission device.

Explanation of symbols

1 Housing 3 Bearing
4 Pulley (Driver)
7 Rotating shaft 10 Hub (driven body)
12 Leaf spring 13 Pin 20 Transmission member 21 Transmission shaft 22 Projection portion 23 Location plate 25 Shaft plate 30 Damper 31a, 32a Damper body 36 Rib portion 37 Step portion 38 Storage space

Claims (3)

The driven body (10) and the driving body (4) for driving the driven body (10) are connected to transmit the driving force, and the load torque to the driven body (10) exceeds a predetermined value. A power transmission device that interrupts transmission of driving force in the case of
A leaf spring having one end connected to the drive body (4) side and the other end connected to the driven body (10) side, and when the load torque exceeds a predetermined value, the one end or the other end is disconnected from the connected state. (12), a damper (30) made of an elastic body attached to the drive body (4), one end (25) is inserted into the damper (30) and engaged, and the other end (22) is a leaf spring ( 12) A power transmission device comprising a transmission member (20) detachably engaged with the other end of 12).   The storage space (38) is formed in the drive body (4) in a partitioned state, and the damper (30) is inserted into the storage space (38). The power transmission device described. In the damper (30), the upstream spring constant in the driving force direction (d) is larger than the downstream spring constant at the insertion part of one end (25) of the transmission member (20). The power transmission device according to claim 1 or 2, characterized in that

Images