JP2009250303A - Power transmission device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission device offering high operation reliability by inhibiting entering of foreign substance. <P>SOLUTION: The power transmission device comprises a boss section 22 connected to a shaft 4 projecting from a driven device, an inner ring 23 annularly provided about the boss section 22, an inner hub 21 equipped with a connection section 24 connecting the inner ring 23 and the boss section 22, an elastic member 26 arranged on an outer peripheral side of the inner hub 21 and a pulley 1 rotating unitedly with the elastic member 26, wherein a plurality of circular holes 25a are annularly provided at predetermined intervals in the connection section 24. The power transmission device is fixed to at least one of the boss section 22 and the inner ring 23, has a cover 3 covering the plurality of circular holes 25a so that they can not be seen in an axial direction, and the cover 3 is equipped with a tool engagement section 34 for engagement with a tool 100. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a power transmission device having a torque limiter function, and is particularly suitable for application to a refrigerant compressor of a vehicle air conditioner operated from an external power source such as an engine via a belt or the like. It is about.

  A power transmission device described in Patent Document 1 is known as a power transmission device that transmits power from an engine or an electric motor to a refrigerant compressor via a belt or the like. This type of power transmission device is usually provided with a torque limiter that cuts off excessive torque that occurs when the rotating shaft of the refrigerant compressor is locked. The torque limiter described in Patent Document 1 is a rotating shaft of the compressor. The narrow-diameter portion is configured to be preferentially broken when it receives excessive torque.

  On the other hand, a power transmission device in which a torque limiter is provided in the disk-shaped part of the hub is also conceivable. In such a case, the easily breakable part is formed by making a through hole in the disk-shaped part of the hub. 11 and 12 are views showing a state in which the hub drop prevention plate 303 is assembled to such a power transmission device. 11 is a view as seen from the front side of the refrigerant compressor, and FIG. 12 is a longitudinal sectional view taken along the line CC of FIG. 11 and 12 includes a pulley 301 around which a belt is wound, and a hub 302 that transmits torque from the pulley 301 to the rotating shaft 304 of the refrigerant compressor. The hub 302 is fixed in the axial direction by a fixing bolt 309 that is spline-fitted with the rotating shaft 304 at the center boss portion 322 and screwed into the rotating shaft 304. The hub 302 is provided with a torque limiter portion 325 including three arc-shaped holes 325a and easily breakable portions 325b between the holes. When excessive torque is applied to the hub 302, the torque limiter portion 325 is provided. The easily breakable portion 325b is broken so that the torque transmission path is cut off. Further, when the easily breakable portion 325b is broken, a drop-off preventing plate 303 that suppresses the movement of the hub 302 is fixed to the hub 302 so that the outer peripheral side of the hub 302 does not drop off.

  By the way, when the fixing bolt 309 is tightened to fix the hub 302 to the rotating shaft, it is necessary to stop the rotation of the rotating shaft 304 and the hub 302. For this purpose, a rotation preventing jig 100 as shown in FIG. 4 is used. It is done. For example, when the fixing bolt 309 is manually tightened using a box wrench (not shown), the tip of the box wrench is attached to the head of the fixing bolt 309 through the center hole 104 of the anti-rotation jig 100, while the anti-rotation treatment. By inserting the three pins 102 of the tool 100 into three holes 334 provided as torque support portions on the drop-off prevention plate 303, the rotational force generated when the fixing bolt 309 is tightened is prevented from rotating. And the rotation of the hub 302 and the rotating shaft 304 is stopped.

JP 2004-239186 A

  In the type of power transmission device shown in FIGS. 11 and 12, for example, the bearing 305 or the rotation inside the hub 302 through the three arc-shaped holes 325 a of the torque limiter unit 325 through the three holes 334 of the drop-off prevention plate 303. There is a possibility that foreign matters such as dust and water may enter the shaft sealing device 308 of the shaft and cause a failure of the bearing 305 or the shaft sealing device 308.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide power that provides high operational reliability by suppressing the intrusion of foreign matter from an arc-shaped hole forming a limiter. It is to realize a transmission device.

  The present invention provides a power transmission device according to each of the claims as technical means for achieving the above object.

  The invention described in claim 1 is a boss part coupled to a shaft protruding from a driven device, an inner ring provided annularly around the boss part, and a connection connecting the inner ring and the boss part. A power transmission device comprising: an inner hub including a portion; an elastic member disposed on an outer peripheral side of the inner hub; and a pulley that rotates integrally with the elastic member, wherein the connecting portion includes a plurality of arcuate shapes. The cover is fixed to at least one of the boss part or the inner ring and covers the plurality of arc-shaped holes so as not to be seen from the axial direction, The cover is provided with a jig engaging portion with which a jig can be engaged.

  According to the first aspect of the present invention, since the plurality of arc-shaped holes are covered with the cover so as not to be seen from the axial direction, foreign matters such as dust and water enter inside through the arc-shaped holes. It can be suppressed.

  According to a second aspect of the present invention, in the first aspect of the invention, the cover includes a cylindrical portion fixed to the boss portion and a flange portion extending in a radial direction from the cylindrical portion, and is engaged with a jig. The portion is provided on the flange portion. This also enables a simple fixing structure in which the cylindrical portion of the cover is press-fitted into the boss portion, and the arc-shaped hole can be covered with the flange portion.

  In the invention according to claim 2, the jig engaging portion can be constituted by a plurality of concave portions provided on the axial end face of the flange portion, and further can be constituted by one provided on the outer periphery of the flange portion. Good.

  In the invention according to any one of claims 2 to 4, the flange portion extends outward in the radial direction from the plurality of arc-shaped holes. Accordingly, the plurality of arc-shaped holes are covered with the flange portion so as not to be seen from the axial direction.

  The invention according to claim 6 is a boss part coupled to a shaft protruding from a driven device, an inner ring provided in an annular shape around the boss part, and a connecting part that connects the inner ring and the boss part. An inner hub, an elastic member disposed on the outer peripheral side of the inner hub, and a pulley that rotates integrally with the elastic member. And a cover that is fixed to either the boss portion or the inner ring and covers the plurality of arc-shaped holes so as not to be seen from the axial direction. The boss portion or the inner ring The other of the rings is provided with a jig engaging portion capable of fitting a jig.

  According to the invention described in claim 6, since the plurality of arc-shaped holes are covered with the cover so as not to be seen from the axial direction, foreign matters such as dust and water enter inside through the arc-shaped holes. It can be suppressed.

  In addition, the code | symbol in the bracket | parenthesis of each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a preferred first embodiment of the present invention will be described with reference to the drawings. The power transmission device of the present invention is suitable for use in a compressor of a vehicle air conditioner. In the following description, the power transmission device will be described as being assembled to a compressor. Can be used as appropriate for rotating devices other than compressors. 1 is a side view of a power transmission device according to an embodiment of the present invention as viewed from the front side of a compressor, FIG. 2 is a longitudinal sectional view taken along a line AA in FIG. 1, and FIG. It is an enlarged view of the center part.

  The power transmission device of the present invention includes a pulley 1 that is a driving-side rotating member that obtains a driving force from an engine or an electric motor, and a hub 2 that is a driven-side rotating member that transmits torque from the pulley 1 to the rotating shaft 4 of the compressor. And a cover 3 fixed to the hub 2. The pulley 1, the hub 2, and the cover 3 are provided coaxially with the rotating shaft 4.

  As shown in FIG. 2, the pulley 1 includes a rim portion 11 that receives power when a belt (not shown) is hung on an outer peripheral portion thereof, and a bearing that extends in an annular shape in an annular shape on the inner peripheral side to hold the bearing 5. An annular rib portion projecting annularly from the pulley coupling portion 13 to the distal end side of the rotary shaft 4 to couple the holding portion 12, the pulley coupling portion 13 that couples the rim portion 11 and the bearing holding portion 12, and the hub 2. 14. The pulley 1 is rotatably mounted on a boss portion 61 provided on one end side of the casing 6 of the compressor via a bearing 5 and a retaining ring 7 with a sleeve ring. The pulley 1 is preferably formed of a thermosetting synthetic resin. Normally, the pulley 1, the retaining ring 7 with the sleeve ring, and the bearing 5 are integrated by insert molding. Moreover, the casing 6 and the rotating shaft 4 are sealed by the shaft seal device 8, and it is prevented that a refrigerant | coolant, oil, etc. leak outside.

  In the case of this embodiment, in order to concavo-convexly fit the hub 2 on the inner peripheral side of the annular rib portion 14 of the pulley 1, as shown in FIG. 1, a series of 20 convex portions arranged in an annular shape 15 is formed.

  The front end portion of the rotary shaft 4 of the compressor protrudes from the casing 6 to the front side of FIG. 2, the front end shaft portion 41 formed as a spline shaft in order from the front end side, It has a base end shaft portion 43 having a smooth surface with a diameter larger than that of the portion 42 and the tip end shaft portion 41 and to which a shaft seal device is attached.

  The hub 2 includes an inner hub 21 and an elastic member 26 for torque transmission and buffering made of an elastic material such as rubber. The inner hub 21 includes a spline hole 22a that fits into the spline shaft of the distal end shaft portion 41 of the rotary shaft 4, and a boss portion 22 that has a recess 22b that is formed on the distal end side and larger diameter than the spline hole 22a. It is formed from a ring portion 23 that is a peripheral wall coupled to the elastic member 26, and a disk-like connecting portion 24 that extends in the radial direction between the boss portion 22 and the ring portion 23 and connects them. Yes. The connecting portion 24 of the inner hub is provided with a torque limiter portion 25 that cuts off a force transmission path when an excessive torque is applied, and the torque limiter portion 25 is approximately 115 degrees on one circumference. Are formed with three arc-shaped holes 25a provided at equal intervals and an easily breakable portion 25b which is a narrow region left between the arc-shaped holes 25a. The portion 25b is sheared when subjected to excessive torque.

  The elastic member 26 is formed in a relatively thick disk shape having a thickness substantially equal to the height of the annular rib portion 14 of the pulley 1, has a center hole coupled to the inner hub 21 at the center, and has an outer peripheral portion. Are formed with 20 concave portions 27 for engaging with the 20 convex portions of the annular rib portion 14 of the pulley 1. In the present embodiment, the elastic member 26 is coupled to the inner hub 21 by adhesion.

  The hub 2 is concavo-convexly fitted with the pulley 1 on the outer peripheral side, while the spline hole 22a is concavo-convexly fitted with the spline shaft of the tip shaft portion 41 of the compressor rotary shaft 4 on the center side, whereby the pulley 1 and the rotary shaft are fitted. Allows transmission of torque between 4. The hub 2 is attached to the rotating shaft 4 and fastened by a fixing bolt 9 screwed into a female screw hole 44 formed along the central axis from the tip surface of the rotating shaft 4. At this time, the boss portion 22 is sandwiched between the shoulder portion formed by the large-diameter shaft portion of the rotating shaft 4 and the spacer 91 pressed by the fixing bolt 9 and is fixed in the axial direction.

  The cover 3 is formed of a cap portion 31 that is fitted and fixed to the tip end side of the boss portion 22 of the inner hub 21 by press-fitting, and a flange portion 32 that extends radially outward from the end of the cap portion 31. The outer diameter of the flange portion 32 is formed to be slightly smaller than the inner diameter of the ring portion 23 of the inner hub 21, and thus the arc-shaped hole 25 a formed in the torque limiter portion 25 of the inner hub 21 is the flange portion 32. Covered by.

  Further, a clearance hole 33 for a tool such as a box wrench for tightening the fixing bolt 9 is provided in the center of the cap portion 31 of the cover 3 in order to avoid interference with the head of the fixing bolt 9 and a flange. Three circular recesses 34 arranged at equiangular intervals are formed on the outer surface of the portion 32. The three circular recesses 34 are circular recesses formed one step lower than the front side end face of the flange portion 32. When the hub 2 is attached to the rotation shaft 4 and fastened with the fixing bolt 9, the rotation shaft 4 functions as a jig engaging portion 34 that supports torque to the detent jig 100 for stopping the rotation of 4.

  The anti-rotation jig 100 is used when assembling the power transmission device according to the first embodiment of the present invention, and as shown in FIG. 4 showing a front view and a left side view thereof, a substantially circular plate-shaped main body. Part 101, three cylindrical pins 102 projecting from one surface of body part 101, lever part 103 extending radially from body part 101 so as to be gripped by a human hand, and body plate And a center hole 104 opened at the center of the center. The three pins 102 are formed and arranged with dimensions that can be fitted into three circular recesses 34 provided in the cover 3.

  FIG. 5 is a vertical cross-sectional view of the center portion of the power transmission device of the present embodiment and the anti-rotation jig 100 showing a case where the fixing bolt 9 is tightened with a box wrench 200 as an example. As shown in this figure, the box portion 201 at the tip of the box wrench 200 is attached to the head of the bolt through the center hole 104 of the rotation prevention jig 100 and the relief hole 33 of the cover 3, while the rotation prevention jig. Three pins 102 of 100 are inserted into three circular recesses 34 provided on the cover 3. As a result, the rotational force transmitted to the cover 3 as the fixing bolt 9 is tightened is supported by the three pins 102 of the detent jig 100 in the three circular recesses 34 of the cover 3. The rotation of the hub 2 and the rotating shaft 4 can be stopped. Further, in the present embodiment, the cap portion 31 of the cover 3 and the boss portion 22 of the inner hub 21 are connected by press-fitting, but the press-fitting portion has a sufficient rotational force generated by tightening the fixing bolt 9 described above. It is formed so that it can be transmitted.

  By the way, when excessive torque acts and the easily breakable portion 25b of the torque limiter portion 25 is broken, the outer peripheral side portion of the hub 2, more specifically, the outer peripheral side portion of the easily breakable portion 25b is unevenly fitted with the pulley 1. Since it is held by the pulley 1 only by the frictional force of the shaft, it can move to the tip side due to vibration or the like and drop off. However, the flange portion 32 of the cover 3 is large enough to reach the ring portion 23 of the inner hub 21 as described above. Thus, although a slight distance of movement until the connecting portion 24 of the inner hub 21 abuts on the flange portion 32 of the cover 3 is allowed, dropping from the pulley 1 is prevented. Thus, the cover 3 of the present embodiment has a function of preventing the hub 2 from falling off.

(Second Embodiment)
FIG. 6 is an enlarged view of the central portion of the longitudinal sectional view taken along the line BB in FIG. 6 and FIG. 6, which is a side view of the power transmission device according to the second embodiment of the present invention as viewed from the front side. This will be described with reference to FIG. The power transmission device of the second embodiment differs from that of the first embodiment in that the arrangement configuration of the jig engaging portions 34 provided on the cover 3 is different. The cover 3 of the second embodiment has a cap portion 31 and a flange portion 32 similar to those of the first embodiment. However, the jig engaging portion 34 is different from that of the first embodiment, and is the three semicircular recesses 34 formed in a notch shape radially inward from the outer peripheral edge of the flange portion 32. . Further, as the anti-rotation jig 100 corresponding to the cover 3, it is possible to use a type in which the radial positions of the three pins 102 in FIG. 4 are shifted outward.

(Third embodiment)
The power transmission device according to the third embodiment of the present invention is different from those of the first and second embodiments in that the arrangement configuration of the jig engaging portions 34 provided on the cover 3 is different. The cover 3 of the third embodiment has cap portions 31 and 32 similar to those of the above-described embodiment, but as shown in FIG. This is different because the flange portion 32 has a pair of straight edges. As the anti-rotation jig 100 corresponding to the cover 3, it is possible to use a non-rotating jig 100 having a pair of arcuate cross-sections having opposed flat portions instead of the three pins 102 shown in FIG. 4.

(Fourth embodiment)
A power transmission apparatus according to a fourth embodiment will be described with reference to FIG. 9 which is a front view thereof and FIG. 10 which is an enlarged vertical sectional view of a central portion taken along a line CC in FIG. In the power transmission device of the fourth embodiment, the cover 203 is fixed to the ring portion 223 of the inner hub 221, and the rotation stopper jig (not shown) is engaged with the boss portion 222 during assembly. It differs from that of the embodiment. Therefore, the cover 203 covers the cylindrical portion 231 formed with a size that is press-fitted and fixed to the ring portion 223 of the inner hub 221 and the arc-shaped hole 225a provided in the connecting portion 224 when viewed in the axial direction. As described above, the flange portion 232 extends radially inward from the end of the cylindrical portion 231. As shown in FIG. 9, the boss portion 222 has a hexagonal jig engaging portion 234 with which an anti-rotation jig can be engaged. Moreover, the rotation prevention jig | tool applied to the assembly of the power transmission device of this embodiment can utilize a hexagon spanner, for example.

(Fifth other embodiment)
In the fifth embodiment, a cover attached to the boss portion is used as in the first to third embodiments described above, but the cover does not include a jig engaging portion, and instead of the inner hub. The ring part includes a jig engaging part. The jig engaging part of the ring part can be formed, for example, by providing a protrusion radially inward from the ring part, or by forming the inner peripheral side of the ring part into a polygonal shape such as a hexagon.

It is a side view of the front side of the power transmission device according to the first embodiment of the present invention. It is a longitudinal cross-sectional view of the said power transmission device by the AA cutting line of FIG. It is an enlarged view of the center part of FIG. It is the front view and left view of a rotation prevention jig used when assembling the power transmission device of 1st Embodiment. It is a longitudinal cross-sectional view which shows the state by which the said jig | tool etc. were applied to the power transmission device of 1st Embodiment. It is a side view of the front side of the power transmission device which concerns on the 2nd Embodiment of this invention. It is an expanded longitudinal cross-sectional view of the center part of the power transmission device of 2nd Embodiment by the BB cutting line of FIG. It is a side view of the front side of the power transmission device which concerns on the 3rd Embodiment of this invention. It is a side view of the front side of the power transmission device which concerns on the 4th Embodiment of this invention. It is a longitudinal cross-sectional view of the said power transmission device by the CC cut line of FIG. It is a side view of the front side of the power transmission device by a prior art. It is a longitudinal cross-sectional view of the power transmission device of the prior art by the DD cut line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pulley 2 Hub 3 Cover 4 Rotating shaft 5 Bearing 6 Casing 9 Fastening member 25 Torque limiter part 25a Arc-shaped hole 25b Easily breakable part 34 Jig engaging part

Claims (6)

An inner hub including a boss portion coupled to a shaft projecting from the driven device, an inner ring provided in an annular shape around the boss portion, and a connecting portion connecting the inner ring and the boss portion;
An elastic member disposed on the outer peripheral side of the inner hub;
A power transmission device comprising a pulley that rotates integrally with the elastic member,
The connecting portion is provided with a plurality of arc-shaped holes in an annular shape with a predetermined interval,
A cover fixed to at least one of the boss part or the inner ring and covering the plurality of arc-shaped holes so as not to be seen from the axial direction;
The power transmission device according to claim 1, wherein the cover includes a jig engaging portion with which a jig can be engaged. The cover is composed of a cylindrical portion fixed to the boss portion, and a flange portion extending in a radial direction from the cylindrical portion,
The power transmission device according to claim 1, wherein the jig engaging portion is provided in the flange portion.   The power transmission device according to claim 2, wherein the jig engaging portion is a plurality of concave portions provided on an axial end surface of the flange portion.   The power transmission device according to claim 2, wherein the jig engaging portion is provided on an outer periphery of the flange portion.   The power transmission device according to any one of claims 2 to 4, wherein the flange portion extends radially outward from the plurality of arc-shaped holes. An inner hub including a boss portion coupled to a shaft protruding from the driven device, an inner ring provided annularly around the boss portion, and a connecting portion connecting the inner ring and the boss portion;
An elastic member disposed on the outer peripheral side of the inner hub;
A power transmission device comprising a pulley that rotates integrally with the elastic member,
The connecting portion is provided with a plurality of arc-shaped holes in an annular shape with a predetermined interval,
A cover that is fixed to either the boss portion or the inner ring and covers the plurality of arc-shaped holes so as not to be seen from the axial direction;
A power transmission device comprising a jig engaging part capable of fitting a jig on the other of the boss part or the inner ring.

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