JP4106557B2 - Torque transmission device - Google Patents

Description

  The present invention relates to a torque transmission device used for driving torque transmission means in a power window of a vehicle, torque transmission means in an industrial device, or the like and having a function of absorbing torque fluctuation (torsional vibration) and impact input.

  The driving torque of a rotating device, whether it is due to an internal combustion engine or an electric motor, causes a periodic torque fluctuation with rotation. FIG. 6 shows a typical prior art of a torque transmission device that absorbs such torque fluctuations and smoothes the transmission torque, or absorbs an impact when the rotation is locked for some reason. 7 is a side view of the elastic body 103 shown in FIG. 6 viewed from the outer peripheral side, and FIG. 8 is a side view of the elastic body of another prior art viewed from the outer peripheral side.

  First, in FIG. 6, reference numeral 101 is a driving side rotating body, 102 is a driven side rotating body, and 103 is an elastic body made of a rubber-like elastic material. In a state where the driving side rotating body 101 and the driven side rotating body 102 are coupled via the elastic body 103, a plurality of driving side protrusions 101 a formed at the end of the driving side rotating body 101 and the driven side rotating body 102. A plurality of driven-side protrusions 102a formed at the end of each are alternately arranged in the circumferential direction. The elastic body 103 has a plurality of damper portions 103a and 103b interposed between the projections 101a and 102a via bridge portions 103c and 103d that alternately straddle the tips of the projections 101a and 102a in order to improve the assemblability. Are formed into a ring-like shape.

  That is, in this type of torque transmission device, the damper 103a or 103b of the elastic body 103 is subjected to compression deformation between the driving side protrusion 101a of the driving side rotating body 101 and the driven side protrusion 102a of the driven side rotating body 102. Thus, this torque is transmitted from the driving side rotating body 101 to the driven side rotating body 102 while absorbing the torque fluctuation.

As a similar torque transmission device, for example, the one described in Patent Document 1 below is known. The torque transmission device according to Patent Document 1 is obtained by connecting portions corresponding to the above-described damper portion as one set.
JP 2002-206564 (see FIGS. 4 and 5)

  However, according to the above-described conventional torque transmission device, the side surface tip portion of the driving-side protrusion 101a abuts on the base of the bridge portion 103c and shear stress is applied to this portion, and the side surface tip portion of the driven-side protrusion 102a is the bridge portion. Abutting on the base of 103d, a shear stress is applied to this portion. For this reason, there has been a problem that cracks C as shown in FIG. 7 occur at the bases of the bridge portions 103c and 103d due to long-term use. The shear stress can be alleviated by forming the tips of the protrusions 101a and 102a in a round shape, but it has not reached a fundamental measure.

  Further, by forming R-shaped concave portions 103e and 103f as shown in FIG. 8 at the base portions of the bridge portions 103c and 103d, it is possible to relieve the shear stress and prevent the generation of the crack C. . However, in this case, in the molding of the elastic body 103, the presence of the recesses 103e and 103f becomes an undercut, so that it becomes difficult to release the mold after molding, and the feasibility of the countermeasure is low.

  The present invention has been made in view of the above points, and a technical problem thereof is that a plurality of intervening between a plurality of drive-side protrusions and driven-side protrusions arranged alternately in the circumferential direction. In a torque transmission device having a damper part and a bridge part connecting the damper part, it is effective that cracks occur in the base part of the bridge part in the damper part due to repeated torque input between the driving side protrusion and the driven side protrusion. There is to prevent.

  As means for effectively solving the above technical problem, a torque transmission device according to the invention of claim 1 includes a plurality of driving side protrusions formed on the driving side rotating body at predetermined intervals in the circumferential direction, and a driven side. A damper portion made of a rubber-like elastic material is interposed between the driving-side protrusions and the plurality of driven-side protrusions alternately arranged in the circumferential direction, and is formed on the rotating body at predetermined intervals in the circumferential direction. The damper part is formed integrally with the bridge part made of a rubber-like elastic material straddling the driving side protrusion or (and) the tip part of the driven side protrusion, and among the damper part, the driving side protrusion and the driven side protrusion In the damper part on the side subjected to compression by the input torque between them, a recess is formed which is located at the end part on the bridge part side and whose axial depth is larger than the axial thickness of the bridge part. is there.

  According to the torque transmission device of the first aspect of the present invention, the recess formed in the damper portion at least on one side in the circumferential direction of the bridge portion has a shear stress at the contact portion with the side surface tip portion of the protrusion. Since generation | occurrence | production of this is prevented or relieve | moderated, generation | occurrence | production of a crack can be prevented or suppressed effectively and durability can be improved significantly. The concave portion has a non-linear characteristic such that when the torsion angle (transmission torque) between the driving side rotating body and the driven side rotating body is small, the spring constant of the damper portion is reduced, and the spring constant increases as the torsion angle increases. Because of this, it also has the function of achieving both a function of absorbing torque fluctuation (torsional vibration) and a sufficient torque transmission function, and since it does not cause undercutting during molding, it does not become difficult to release after molding. .

  Hereinafter, a preferred first embodiment in which a torque transmission device according to the present invention is applied to, for example, a drive torque transmission unit in a power window of a vehicle will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing the first embodiment, FIG. 2 shows an assembled state of the torque transmission device according to the first embodiment, and (A) is a cross section cut by a plane perpendicular to the axis. FIG. 3B is a cross-sectional view taken along line II-II in FIG. 3A, FIG. 3A shows an elastic body in the first embodiment, FIG. 3A is a view seen from the axial direction, and FIG. It is a III direction arrow directional view.

  First, in FIG. 1, reference numeral 10 is a driving side rotating body, and 20 is a driven side rotating body arranged concentrically with the driving side rotating body 10. A cylindrical housing 11 and a columnar inner peripheral protrusion 12 are formed concentrically at the end of the driving side rotating body 10 facing the driven side rotating body 20. Three drive-side protrusions 13 extending in the axial direction and the radial direction are formed between the protrusions 12 at intervals of 120 degrees in the circumferential direction.

  On the other hand, three driven projections 21 extending in the axial direction and in the radial direction are formed at intervals of 120 degrees in the circumferential direction at the end of the driven side rotating body 20 facing the driving side rotating body 10. Further, as shown in FIG. 2A, the circumscribed circle with respect to the outer peripheral end of each driven-side protrusion 21 is slightly smaller than the inner diameter of the housing 11 of the driving-side rotating body 10, and each driven-side protrusion The inscribed circle with respect to the inner circumferential end of 21 is slightly larger in diameter than the outer diameter of the inner circumferential projection 12 of the driving side rotating body 10, that is, the driven side protrusion 21 in the driven side rotating body 20 is The drive-side rotating body 10 is inserted between the housing 11 and the inner peripheral projection 12. In this state, the driving side protrusions 13 and the driven side protrusions 21 are alternately arranged in the circumferential direction.

The housing 11 and the inner peripheral projection 12 are formed to have the same axial height h ₁ , the drive side projection 13 and the driven side projection 21 have the same axial height h ₂ , and the housing 11 and the inner projection 12 It is formed lower than the axial height h ₁ of the peripheral projection 12.

  Reference numeral 30 in FIG. 1 is an elastic body formed into a ring shape by a rubber-like elastic material. This elastic body 30 is interposed between the driving side rotating body 10 and the driven side rotating body 20 and elastically couples them. In the assembled state shown in FIG. Between the drive-side protrusions 13 and the driven-side protrusions 21 that are alternately present, damper portions 301 and 302 that are alternately interposed in the circumferential direction, and as shown in FIG. Three bridge portions 303 straddling the tip portion 13a and three bridge portions 304 straddling the tip portion 21a of each driven-side projection 21 are integrally formed. In other words, the elastic body 30 has a structure in which the damper portions 301 and 302 are alternately connected in the circumferential direction via the bridge portions 303 and 304 positioned on the opposite sides in the axial direction.

As shown in FIGS. 1 and 3, the portion surrounded by the bridge portion 303 on one side in the axial direction and the damper portions 301 and 302 on both sides in the circumferential direction is an engagement groove 305 into which the drive side protrusion 13 is inserted. The portion surrounded by the bridge portion 304 on the other side in the axial direction and the damper portions 302 and 301 on both sides in the circumferential direction is an engagement groove 306 into which the driven projection 21 is inserted. The axial depths d ₁ of these engaging grooves 305 and 306 are substantially equal to the axial height h _{2 of the} driving side protrusion 13 and the driven side protrusion 21 shown in FIG. The groove width is substantially equal to the width of the driving side protrusion 13 and the driven side protrusion 21.

Each of the damper portions 301 and 302 in the elastic body 30 has a recess extending in a direction parallel to the radial direction, positioned at one end in the axial direction on the bridge portion 303 side and on the other end in the axial direction on the bridge portion 304 side. 307, 308 are formed, in other words, a pair of recesses 307 are formed on both sides of the bridge portion 303 in the circumferential direction, and a pair of recesses 308 are formed on both sides of the bridge portion 304 in the circumferential direction. Yes. As shown in FIG. 3, the axial depths d ₂ of the recesses 307 and 308 are formed larger than the axial thickness t ₁ of the bridge portions 303 and 304. Therefore, the bridge portions 303 and 304 have a substantially bend-like bent shape due to the concave portions 307 and 307 or the concave portions 308 and 308.

The axial thickness t ₁ of the bridge portions 303 and 304 is the axial height h ₁ of the housing 11 and the inner peripheral protrusion 12 in the driving side rotating body 10 and the axial height of the driving side protrusion 13 and the driven side protrusion 21. it is substantially equal to the difference between _{h 2 (h 1 -h 2)} . Therefore, in the assembled state shown in FIG. 2, the bridge portions 303 and 304 are formed between the tip end portion 13 a of the driving side protrusion 13 and the axially opposed surface of the driven side rotating body 20 and the tip end portion 21 a of the driven side protrusion 21. It is interposed between the axially facing surfaces of the driving side rotating body 10.

Further, when the assembly state is set, the overlap amount of the driving-side protrusion 13 and the driven-side protrusion 21 and the recesses 307 and 308 existing on both sides thereof, in other words, d ₂ −t ₁ in FIG. Is about 1 mm, and the width w of the concave portion 307 (and 308) shown in FIG. 3A is that of the damper portion 301 or 302 due to the variation in the transmission torque between the driving side projection 13 and the driven side projection 21. About the maximum value of the compression stroke.

  The elastic body 30 is formed in a split shape such that a mold for vulcanizing and molding the elastic body 30 is released in the axial direction of the elastic body 30 so that the recesses 307 and 308 are not undercut. For this reason, the difficulty of mold release after molding does not occur.

  In the above-described configuration, the elastic body 30 includes the damper portions 301 and 302 that are alternately interposed in the circumferential direction between the driving-side protrusion 13 and the driven-side protrusion 21 in an annular manner via the bridge portions 303 and 304. Therefore, first, the engaging groove 305 (or 306) facing in the axial direction is inserted into each driving-side protrusion 13 (or each driven-side protrusion 21 in the driven-side rotating body 20) of the driving-side rotating body 10 and locked. Then, by inserting each driven-side protrusion 21 (or each driving-side protrusion 13 in the driving-side rotating body 10) in the driven-side rotating body 20 into the engagement groove 306 (or 305) facing the other in the axial direction, The assembling work to the state shown in FIG. 2 can be easily performed.

  In this assembled state, when the driving side rotating body 10 rotates in the direction of arrow R in FIG. 1, the driving torque is transferred from the driving side protrusion 13 to the driven side protrusion 21 via the damper portion 301 in the elastic body 30. As a result, the driven-side rotator 20 rotates in the same direction. For this reason, when the transmission torque increases, the damper portion 301 receives a circumferential compression force between the driving side protrusion 13 and the driven side protrusion 21.

  At this time, since both ends of the damper portion 301 have a reduced axial thickness due to the recesses 307 and 308, the circumferential compression spring constant is low. Both end portions are compressed and deformed in the circumferential direction. Therefore, the low spring characteristic can effectively absorb the fluctuation (torsional vibration) of the transmission torque during rotation and smoothen the rotation of the driven side rotating body 20.

  Further, at this time, the side end portions of the drive side projection 13 and the driven side projection 21 are in contact with the bases of the bridge portions 303 and 304 in the elastic body 30, but overlap the side end portions in the axial direction. Since the recesses 307 and 308 are formed, no shear stress is generated near the roots of the bridge portions 303 and 304. For this reason, it can prevent effectively that the crack of the circumference direction by shearing stress generate | occur | produces in the root of the bridge parts 303 and 304. FIG.

  Then, as the torsional angle (transmission torque) of the driving side rotating body 10 and the driven side rotating body 20 further increases and the amount of compressive deformation at both ends of the damper portion 301 increases, the damper portion 301 Since the portion having a large axial thickness between the recesses 307 and 308 is also compressed, the circumferential compression spring constant increases nonlinearly. For this reason, for example, it is possible to ensure a transmission force for a large driving torque such as at the time of start-up and to ensure a required durability against a circumferential compression load due to the torque. Such a nonlinear characteristic makes it possible to achieve both a function of absorbing torque fluctuation (torsional vibration) and a sufficient torque transmission function. In addition, because of such non-linear characteristics, the buffering ability is also excellent, so that a protection function for the gear and the rotating body at the time of impact input can be exhibited.

  In addition, the displacement to the outer peripheral side of the damper parts 301 and 302 by the centrifugal force at the time of rotation is restrict | limited by the cylindrical housing 11 in the drive side rotary body 10. FIG.

  Further, according to this embodiment, since the concave portions 307 and 308 are formed on both sides in the circumferential direction of the bridge portions 303 and 304, respectively, the drive side rotating body 10 is rotated in the direction opposite to the arrow R in FIG. Even when the damper portion 302 in the elastic body 30 receives the circumferential compressive force between the driving side protrusion 13 and the driven side protrusion 21, the same effect as described above is realized.

  Next, FIG. 4 is an exploded perspective view showing a second preferred embodiment in which the torque transmission device according to the present invention is applied to, for example, a drive torque transmission portion in a vehicle power window, and FIG. 5 is an elastic segment in the second embodiment. It is a perspective view which shows 31 alone.

  In the second embodiment, the difference from the first embodiment described above is that, in the first embodiment, damper portions 301 and 302 arranged alternately in the circumferential direction are integrated via bridge portions 303 and 304. In contrast to the use of the formed annular elastic body 30, the second form has a pair of two damper portions 311 and 312 adjacent in the circumferential direction as shown in FIG. In this embodiment, a plurality of (three in the illustrated example) elastic body segments 31 integrated through the bridge portion 313 are used.

  The driving side rotating body 10 and the driven side rotating body 20 are configured in the same manner as in FIG.

  Each elastic body segment 31 is formed of a rubber-like elastic material, and the damper portions 311 and 312 are arranged between the drive-side protrusions 13 and the driven-side protrusions 21 that exist alternately in the circumferential direction in the assembled state. The bridge portions 313 are formed on one side in the axial direction between the damper portions 311 and 312 so as to straddle the front end portion 13a of the drive side protrusion 13. In this assembled state, the end portions of the damper portions 311 and 312 opposite to the bridge portion 313, in other words, the circumferential end portions 311 a and 312 a of the elastic body segment 31 are in contact with the side surface of the driven side protrusion 21. It has come to be.

The portion surrounded by the bridge portion 313 and the damper portions 311 and 312 on both sides in the circumferential direction is an engaging groove 314 into which the driving side protrusion 13 or the driven side protrusion 21 is inserted. The axial depth of the engaging groove 314 is equal to the axial height h _{2 of the} driving-side protrusion 13 shown in FIG. 2B described above, and the groove width of the engaging groove 314 is the driving width. The width of the side protrusion 13 is substantially equal.

The damper portions 311 and 312 in each elastic body segment 31 have a pair of recesses 315 located on both ends of the bridge portion 313, in other words, on both sides in the circumferential direction of the bridge portion 313 and extending in a direction parallel to the radial direction. 315 is formed. The axial depth d ₃ of the recess 315 is formed to be larger than the axial thickness t _{2 of} the bridge portion 313, so that the bridge portion 313 is substantially bent and bent by the recesses 315 and 315. A shape will be exhibited.

Axial thickness t ₂ of the bridge portion 313, an axial height h ₁ of the housing 11 and the inner circumferential projection 12 of the driving-side rotator 10 shown in FIG described above 2 (B), the drive-side protrusions It is substantially equivalent to the difference (h ₁ −h ₂ ) from the axial height h _{2 of} 13. Therefore, in the assembled state, the bridge portion 313 is interposed between the tip end portion 13a of the driving side protrusion 13 and the axially opposed surface of the driven side rotating body 20.

Further, the overlap amount of the driving-side protrusion 13 and the concave portions 315 and 315 existing on both sides in the assembled state, in other words, d ₃ -t ₂ in FIG. 5 is about 1 mm, and the width of the concave portion 315 Is about the maximum value of the compression stroke of the damper portion 311 or 312 due to fluctuations in the transmission torque between the driving side protrusion 13 and the driven side protrusion 21.

  In the second embodiment having the above-described configuration, when the elastic body segment 31 is assembled, the elastic groove 31 is inserted in the state where the engaging groove 314 of each elastic body segment 31 is inserted into each driving-side protrusion 13 in the driving-side rotating body 10. The body segment 31 is held between the housing 11 and the inner circumferential protrusion 12, and the driven-side protrusion on the driven-side rotator 20 is inserted into the gap G between both end portions 311 a and 312 a of the elastic body segment 31 adjacent in the circumferential direction. By inserting 21, it can be assembled easily.

  Also in this embodiment, the same operations and effects as the first embodiment described above are exhibited. In other words, since the concave portion 315 is not undercut during the molding of the elastic segment 31, there is no difficulty in releasing after molding, and the concave portion 315 has shear stress due to torque and the root of the bridge portion 313. Due to the non-linear characteristic that the spring constant increases as the torsion angle (transmission torque) between the driving side rotating body 10 and the driven side rotating body 20 increases. A function of absorbing torque fluctuation (torsional vibration) and a sufficient torque transmission function can be achieved at the same time. In addition, because of such non-linear characteristics, the buffering ability is also excellent, so that a protection function for the gear and the rotating body at the time of impact input can be exhibited.

  In the first and second embodiments described above, it has been described that the housing 11 is provided on the drive-side rotator 10 side, but conversely, a housing is formed on the driven-side rotator 20 side to drive-side rotation. The body 10 may have no housing. That is, in the description of the first and second embodiments described above, the driving side rotating body is read as the driven side rotating body, and the driven side rotating body is replaced with the driving side. It may be read as a rotating body.

  Further, in the first embodiment described above, the recesses 307 and 308 are formed on both the damper portions 301 and 302, in other words, on both sides in the circumferential direction of the bridge portions 303 and 304. 315 is formed on both of the damper portions 311 and 312, in other words, on both sides of the bridge portion 313, but when the rotation direction is constant, compression by the input torque between the driving side protrusion 13 and the driven side protrusion 21 is performed. In the case of rotating only in the R direction in the receiving side, for example, in FIG. 1, the concave portions 307 and 308 may be formed only in the damper portion 301 that receives compression.

1 is an exploded perspective view showing a first preferred embodiment of a torque transmission device according to the present invention. The assembly state of a 1st form is shown, (A) is sectional drawing cut | disconnected and shown by the plane orthogonal to an axial center, (B) is II-II sectional drawing in (A). The elastic body 30 in the form of FIG. 1 is shown, (A) is the figure seen from the axial direction, (B) is the III direction arrow line view in (A). It is a separation perspective view showing a desirable second form of a torque transmission device concerning the present invention. It is a perspective view which shows the elastic body segment 31 in a 2nd form. It is an isolation | separation perspective view which shows the typical prior art of a torque transmission device. It is the side view which looked at the elastic body 103 shown by FIG. 6 from the outer peripheral side. It is the side view which looked at the elastic body 103 in another prior art from the outer peripheral side.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Drive side rotary body 11 Housing 12 Inner peripheral protrusion 13 Drive side protrusion 13a, 21a Tip part 20 Drive side rotary body 21 Drive side protrusion 30 Elastic body 31 Elastic body segment 301,302,311,312 Damper part 303,304, 313 Bridge portion 305, 306, 314 Engagement groove 307, 308, 315 Recess

Claims (1)

A plurality of drive-side protrusions (13) formed at predetermined intervals in the circumferential direction on the drive-side rotator (10) and the drive-side protrusions (13) formed at predetermined intervals in the circumferential direction on the driven-side rotator (20). 13) and a plurality of driven-side protrusions (21) arranged alternately in the circumferential direction, damper portions (301, 302, 311 and 312) made of rubber-like elastic material are respectively interposed between the damper portions ( 301, 302, 311, 312) are bridge portions (303, 304) made of a rubber-like elastic material straddling the tip end portions (13 a, 21 a) of the drive side projection (13) or (and) the driven side projection (21). , 313) of the damper portion (301, 302, 311, 312) on the side subjected to compression by the input torque between the driving side projection (13) and the driven side projection (21). In the damper section, Tsu located on the edge portion of the di portion (303,304,313) side, the axial thickness of the axial depth _(d 2, _{d 3)} said bridge portion (303,304,313) _(t 1, torque transmission device, characterized in that t ₂₎ greater recesses than (307,308,315) are formed.

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