JP4664183B2 - Power transmission device - Google Patents

Description

  The present invention relates to a power transmission device used for a car air conditioner compressor and the like, and particularly, when an overload is applied to a rotating shaft of a driven device, the connection between the driving side rotating member and the driven side rotating member is released. The present invention relates to a power transmission device.

  As a conventional power transmission device of this type used in a compressor for a car air conditioner, for example, the one described in Patent Document 1 is known. The power transmission device disclosed in FIGS. 36 to 38 of Patent Document 1 will be schematically described with reference to FIGS. 6 to 8. Reference numeral 2 denotes a compressor for a car air conditioner (driven device), and reference numeral 3 denotes a housing of the compressor 2. 4 is a pulley (drive-side rotating member) rotatably mounted on the cylindrical portion 3A of the housing 3 via a bearing 5, 6 is a rotating shaft of the compressor 2, and 7 is a hub (driven side) mounted on the rotating shaft 6. (Rotating member) 8 is a torque limiter mechanism that connects the pulley 4 and the hub 7, and constitutes a power transmission device 1 of the compressor 2 for a car air conditioner.

The torque limiter mechanism 8 includes a rotation transmission member 10 that is an elastic member interposed between the pulley 4 and the hub 7, a set screw 11 that fixes the rotation transmission member 10 to the pulley 4, and the rotation transmission member 10. The connecting portion 10D is detachably held together with the hub 7 so as to be detachable.

  As shown in FIG. 7A, the rotation transmitting member 10 is formed in a substantially disc shape as a whole by a spring steel plate. By providing three slits 13, an annular main body 10A and the main body 10A are provided. It is composed of three connecting pieces 10B that are elastically deformable in the axial direction and are provided on the outside at equal intervals in the circumferential direction. And the base end part of the connection piece 10B forms the fixed part 10C, and the front-end | tip part forms the connection part 10D. The fixing portion 10C integrally connects the main body 10A and the connecting piece 10B. The fixing portion 10C has an attachment hole 14 through which the set screw 11 is inserted, and is fixed to the disc portion 4A of the pulley 4. The connecting portion 10D has an engaging portion 15 protruding on the back surface side, is in close contact with the back surface of the hub 7 by elastic deformation of the connecting piece 10B, and is detachably held by the hub 7 and the holding plate 12. The holding portion of the holding plate 12 is provided with a groove-shaped locking portion that engages with the engaging portion 15 and prevents the connecting piece 10B from being detached in the circumferential direction.

  In such a power transmission device 1, when the rotating shaft 6 stops due to overload, the coupled state of the pulley 4 and the hub 7 by the torque limiter mechanism 8 is released by the power of the automobile engine (drive side device). That is, even if the rotating shaft 6 stops, the pulley 4 continues to rotate, so that the rotation transmitting member 10 continues to rotate. For this reason, the connecting portion 10D is separated from both the members 7 and 12 against the holding force between the hub 7 and the holding plate 12, the coupling between the pulley 4 and the hub 7 is released, and the connecting piece 10B is elastically restored. Then, the connecting portion 10D is moved to the rear of the holding plate 12. As a result, power transmission from the pulley 4 to the rotating shaft 6 is interrupted.

Japanese Patent No. 3421619

  However, in the above-described conventional power transmission device 1, stress is concentrated on the base end portion 16 of the connection piece 10 </ b> B because a repeated load of tension and compression acts on the connection piece 10 </ b> B of the rotation transmission member 10 during braking or activation. In particular, there is a problem that it is easily broken from the hatched portion A in FIG. 8 and lacks durability and reliability. That is, the portion where the stress concentrates when an external force is applied to the object is often a portion where the cross-sectional area changes, for example, a hole, a notch, or a step. In the case of the connecting piece 10B, as shown in FIG. 8, the closing end 13a of the slit 13 is positioned at the base end portion 16 of the connecting piece 10B, that is, the boundary portion with the fixed portion 10C, thereby connecting the connecting piece 10B to the base end portion. 16, the inner end edge P of the base end portion 16 of the connecting piece 10B (the point where it intersects with the inner edge of the closed end 13a) becomes a portion where the cross section changes suddenly, and stress is applied thereto. Most concentrated and maximum. When the maximum stress becomes a certain value or more, a crack occurs in the inner edge P, and the connecting piece 10B may break from here.

  The present invention has been made in order to solve the above-described conventional problems. The object of the present invention is to prevent the breakage of the connecting piece due to the concentration of stress and improve the durability and reliability of the rotation transmission member. Another object is to provide a power transmission device.

In order to achieve the above object, the present invention provides a driving side rotating member that rotates by external power, a rotating shaft of a driven device, a driven side rotating member provided on the rotating shaft, and the driven side rotating member. And a rotation transmission member that is interposed between the rotation member and the drive side rotation member to connect the two members and release the connection when an overload is applied to the rotation shaft. The transmission member is formed in a disc shape and is formed so as to surround the outer periphery of the annular main body by forming a plurality of connecting piece forming slits at equal intervals in the circumferential direction near the outer periphery. A plurality of connecting pieces elastically deformable in the axial direction, each connecting piece having a fixing portion fixed to the driving side rotating member on the base end side and holding the driven side rotating member on the tip end side Is removably held by the member Be one having a connection part, in particular a closed end of the connecting piece forming slit, positioned inside the central portion of the fixing portion serving as the connecting piece of the base rotating direction side end portion than end, the connecting piece The base end is inclined by being bent at a required angle toward the driven side rotating member, and the connecting portion of the connecting piece is bent at a required angle in a direction opposite to the connecting piece .

  In the present invention, the fixed portion of each connecting piece is fixed to the driven side rotating member instead of the driving side rotating member, and the connecting portion is detachably connected to the driving side rotating member instead of the driven side rotating member. is there.

  In the present invention, the closed end of the connecting piece forming slit is positioned in the vicinity of the inside of the center portion of the fixed portion, so that stress is not concentrated on the closed end of the slit due to repeated loading of tension and compression. On the other hand, stress concentrates on the base end of the connecting piece due to the above repeated load, but since the closed end of the slit is not located at this base end, a portion where the cross-sectional area changes rapidly is not formed. , Prevent stress from concentrating on one point. Therefore, there is no possibility that the connecting piece breaks from the base end.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.
FIG. 1 is a front view showing a part of a power transmission device according to an embodiment in which the present invention is applied to a compressor for a car air conditioner, FIG. 2 is a sectional view taken along line II-II in FIG. 1, and FIG. FIG. 4 is a front view of the transmission member, FIG. 4 is a view showing a positional relationship between the stress generation location and the closed end of the slit, and FIGS. 5A and 5B are a front view and a sectional view of the holding member. It should be noted that the same components and parts as those in the prior art are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  In these drawings, a power transmission device generally indicated by reference numeral 20 includes a pulley 4 rotatably mounted on a projection 3A of a housing 3 of a compressor 2 for a car air conditioner 2 via a bearing 5, and a rotating shaft of the compressor 2. 6, a hub 7 mounted on the rotary shaft 6, a torque limiter mechanism 8 that connects the hub 7 and the pulley 4, a damper mechanism 22 that connects the torque limiter mechanism 8 and the pulley 4, and the like. I have.

  The pulley 4 includes a disc portion 4A, and an outer cylindrical portion 4B and an inner cylindrical portion 4C that are integrally projected on the side surface of the driven device of the disc portion 4A. A plurality of V grooves 23 are formed, and the power from the automobile engine is transmitted to the outer cylindrical portion 4B via the V belt. On the other hand, the inner cylindrical portion 4 </ b> C is rotatably supported by the bearing 5.

  One end portion of the rotating shaft 6 protrudes from the protruding portion 3 </ b> A of the housing 3, and the hub 7 is fixed to the protruding end portion. In addition, three gripping portions 7C are integrally projected on the outer periphery of the flange portion 7B at equal intervals in the circumferential direction.

  The hub 7 is composed of a boss portion 7A splined to the shaft end of the rotating shaft 6 and a disk-shaped flange portion 7B extending radially from the boss portion 7A. It is fixed to the end face.

  The torque limiter mechanism 8 includes a rotation transmission member 21 interposed between the pulley 4 and the hub 7 to connect these members, a set screw 11 for fixing the rotation transmission member 21 to the damper mechanism 22, A part of the rotation transmission member 21 is elastically deformed, and is constituted by a holding member 12 or the like that is detachably held together with the hub 7.

  In FIG. 3, the rotation transmission member 21 is formed in a substantially disk shape by a spring steel plate. By providing three connection piece forming slits 30, an annular main body 21 </ b> A and the main body 21 </ b> A are provided. It is composed of three connecting pieces 21B that are elastically deformable in the axial direction and are provided on the outside at equal intervals in the circumferential direction. Then, the base end portion (rotation direction side end portion of the rotation transmitting member 21) of the coupling piece 21B forms a fixing portion 21C fixed to the pulley 4, and the distal end portion (counter rotation direction side end portion) is the hub 7. And the holding member 12 form a connecting portion 21D that is detachably held.

  The connecting piece 21B is inclined by being bent at a required angle on the hub 7 side. When the connecting portion 21D is clamped between the hub 7 and the clamping member 12, the hub 7 side is elastically deformed by a predetermined amount. Thus, the main body 21A and the connecting portion 21D are made substantially parallel. There are two bent portions of the connecting piece 21B, ie, a base end 31a of the connecting piece 21B, that is, a boundary portion between the fixed portion 21C and a boundary portion 31b between the connecting piece 21B and the connecting portion 21D.

  The fixing portion 21C forms the same plane as the main body 21A and integrally connects the main body 21A and the connecting piece 21B, and has a mounting hole 14 through which the set screw 11 is inserted at the center of the portion. . The main body 21 </ b> A and the fixing portion 21 </ b> C are fixed to the front end surface of the nut member 44 by screwing the set screw 11 into the nut member 44 of the damper mechanism 22 using the mounting hole 14.

  The connecting portion 21D is located in a direction opposite to the rotation direction (arrow direction) of the rotation transmitting member 21 with respect to the fixed portion 21C, and is close to and opposed to the fixed portion 21C on the counter-rotating direction side. Further, the connecting portion 21D is bent at a required angle in the opposite direction to the connecting piece 21B, and a hemispherical engaging portion 33 projects from the center of the back surface.

  The connecting piece forming slit 30 is a slit for integrally forming the main body 21A and the connecting piece 21B, and its closed end 30a is inside the center portion O of the fixing portion 21C as shown in FIG. It is positioned inside the head of the set screw 11. In the drawing, the center portion O of the fixing portion 21 </ b> C indicates the center of the mounting hole 14. The closed end 30a of the slit 30 is formed in a semicircular shape that is convex in the rotation direction of the rotation transmitting member 21, and the end on the side of the connecting portion 21D is open.

In FIG. 5, the holding member 12 is also formed of a spring steel plate, and has a disc portion 12A and three holding portions that are integrally projected on the outer periphery of the disc portion 12A at equal intervals in the circumferential direction. It consists of the part 12B. The disc portion 12A has three attachment holes 34, and is fixed to the rear surface side of the flange portion 7B of the hub 7 by rivets 35 inserted through these attachment holes 34. Each holding portion 12B is a portion that removably holds the connecting portion 21D of the rotation transmitting member 21 together with the holding portion 7C of the hub 7, and the engaging portion 33 of the connecting portion 21D is engaged in the center of the connecting piece 21B. A locking hole 36 is provided for preventing separation in the circumferential direction.

  In FIG. 2, the damper mechanism 22 includes a damper holding member 41 disposed in an annular space 40 provided between the cylindrical portions 4 </ b> B and 4 </ b> C of the pulley 4, and a circumferential direction in the damper holding member 41. And three damper rubbers 42 incorporated at equal intervals. The damper holding member 41 includes a disk-shaped main body 41A and three cylindrical portions 41B that are integrally projected on the surface of the main body 41A on the compressor 2 side at equal intervals in the circumferential direction. A plurality of rivets 43 are fixed to the inner surface of the disc portion 4 </ b> A of the pulley 4. The damper rubber 42 is formed in a cylindrical body, and is incorporated in each cylindrical portion 41 </ b> B together with the nut member 44. The nut member 44 is formed in a cylindrical body with a flange having an internal thread, and the damper rubber 42 is fitted on the outer periphery thereof. The set screw 11 is screwed through the mounting hole 14 of the rotation transmission member 21. Thus, the damper rubber 42 is pressed against the inner surface of the disk portion 4A.

  In the power transmission device 20 having such a structure, when power from the engine is transmitted to the pulley 4 via the V-belt, the rotation of the pulley 4 is performed via the damper mechanism 22, the rotation transmission member 21 and the hub 7. It is transmitted to the rotating shaft 6.

  The damper rubber 42 of the damper mechanism 22 effectively buffers or absorbs torque fluctuation transmitted from the pulley 4 to the hub 7. Therefore, the tension applied to the connecting portion 21D of the rotation transmitting member 21 due to an impact during power transmission or torque fluctuation during power transmission is reduced, and the connecting portion 21D does not come out from between the hub 7 and the holding member 12. .

  In the present invention, even when a repeated load of tension and compression is applied to the connecting piece 21B of the rotation transmitting member 21 during braking, a large stress is not generated at the base end portion of the connecting piece 21B compared to the conventional device. Breakage of the connecting piece 21B can be prevented. That is, in the present invention, unlike the conventional apparatus shown in FIGS. 6 to 8, the closed end 30a of the connecting piece forming slit 30 of the rotation transmitting member 21 is positioned near the inside of the center portion O of the fixed portion 21C. The base end 31a is not formed at a portion where the cross-sectional area changes rapidly, and therefore the stress generated at the base end of the connecting piece 21B spreads in the longitudinal direction and the width direction of the connecting piece 21B, and the stress concentration point A Becomes a wide area, and the maximum stress generated at the inner end edge P of the base end 31a is reduced. Therefore, no crack occurs in the inner edge P of the base end 31a, and the breakage of the connecting piece 21B from here can be prevented.

  Further, even if the connecting piece 21B is elastically deformed, the fixing portion 21C is firmly fixed to the nut member 44 by the set screw 11 and is not deformed, so that the stress generated at the closed end 30a of the slit 30 can be reduced. Therefore, there is no fear that the closed end 30a cracks and the fixing portion 21C is broken, and the reliability and durability of the power transmission device 20 can be improved.

  In the above-described embodiment, the example in which the fixing portion 21C of the rotation transmitting member 21 is fixed to the driving-side rotating member 4 and the connecting portion 21D is detachably connected to the driven-side rotating member 7 is shown. The present invention is not limited to this, and may be a structure in which the fixing portion 21C is fixed to the driven-side rotating member 7 and the connecting portion 21D is detachably connected to the driving-side rotating member 4. .

It is a front view which fractures | ruptures and shows a part of power transmission device which shows one Embodiment which applied this invention to the compressor for car air conditioners. It is the II-II sectional view taken on the line of FIG. It is a front view of a rotation transmission member. It is a figure which shows the positional relationship of the generation | occurrence | production location of stress, and the obstruction | occlusion end part of a slit. (A), (b) is the front view and sectional drawing of a clamping member. It is sectional drawing of the conventional power transmission device. (A), (b) is the front view and sectional drawing of a rotation transmission member. It is a figure which shows the positional relationship of the generation | occurrence | production location of stress, and the obstruction | occlusion end part of a slit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Power transmission device, 2 ... Compressor, 3 ... Housing, 4 ... Pulley (drive side rotation member), 6 ... Rotating shaft, 7 ... Hub, 8 ... Torque limiter mechanism, 12 ... Gripping member, 20 ... Power transmission device, DESCRIPTION OF SYMBOLS 21 ... Rotation transmission member, 21A ... Main body, 21B ... Connection piece, 21C ... Fixed part, 21D ... Connection part, 30 ... Slit, 30a ... Closed end of slit.

Claims (2)

A drive-side rotating member that is rotated by power from the outside, a rotating shaft of a driven device, a driven-side rotating member provided on the rotating shaft, and an intermediate between the driven-side rotating member and the driving-side rotating member. In a power transmission device comprising a rotation transmission member that is mounted and connects these members and releases the connection when an overload is applied to the rotating shaft,
The rotation transmission member is formed in a disc shape and is formed so as to surround the outer periphery of the annular main body by forming a plurality of connecting piece forming slits at equal intervals in the circumferential direction near the outer periphery. A plurality of connecting pieces elastically deformable in the axial direction,
Each of the connecting pieces has a fixed portion fixed to the driving side rotating member on the base end side, and a connecting portion that is detachably held by the driven side rotating member and the holding member on the distal end side. The closed end of the connecting piece forming slit is positioned inside the center portion of the fixed portion that is the rotational direction side end from the base end of the connecting piece ,
The connecting piece is inclined by being bent at a required angle on the driven side rotation member side at the base end,
The power transmission device according to claim 1, wherein the connecting portion of the connecting piece is bent at a required angle in a direction opposite to the connecting piece .   The fixed portion of the rotation transmitting member is fixed to the driven side rotating member instead of the driving side rotating member, and the connecting portion is detachably connected to the driving side rotating member instead of the driven side rotating member. The power transmission device described.

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