JP6947287B2 - Torque transmission fittings and electric power steering device - Google Patents

Torque transmission fittings and electric power steering device Download PDF

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JP6947287B2
JP6947287B2 JP2020506518A JP2020506518A JP6947287B2 JP 6947287 B2 JP6947287 B2 JP 6947287B2 JP 2020506518 A JP2020506518 A JP 2020506518A JP 2020506518 A JP2020506518 A JP 2020506518A JP 6947287 B2 JP6947287 B2 JP 6947287B2
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transmission
circumferential
end transmission
teeth
axial
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JPWO2019176871A1 (en
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哲英 藤田
哲英 藤田
信幸 西村
信幸 西村
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NSK Ltd
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
    • F16D3/54—Couplings comprising a chain or strip surrounding two wheels arranged side by side and provided with teeth or the equivalent
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
    • F16D3/72—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members with axially-spaced attachments to the coupling parts
    • F16D3/74—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members with axially-spaced attachments to the coupling parts the intermediate member or members being made of rubber or other rubber-like flexible material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
    • B62D—MOTOR VEHICLES; TRAILERS
    • B62D5/00—Power-assisted or power-driven steering
    • B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
    • B62D5/0409—Electric motor acting on the steering column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D3/00—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive
    • F16D3/50—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members
    • F16D3/64—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members comprising elastic elements arranged between substantially-radial walls of both coupling parts
    • F16D3/68—Yielding couplings, i.e. with means permitting movement between the connected parts during the drive with the coupling parts connected by one or more intermediate members comprising elastic elements arranged between substantially-radial walls of both coupling parts the elements being made of rubber or similar material

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Power Steering Mechanism (AREA)

Description

本発明は、各種機械装置に組み込まれ、駆動軸と被駆動軸との間でトルクを伝達するためのトルク伝達用継手、および、該トルク伝達用継手が組み込まれた電動式パワーステアリング装置に関する。 The present invention relates to a torque transmission joint incorporated in various mechanical devices for transmitting torque between a drive shaft and a driven shaft, and an electric power steering device incorporating the torque transmission joint.

図２３および図２４は、特開２００４−３０６８９８号公報などに記載された従来の電動式パワーステアリング装置の１例を示す。この電動式パワーステアリング装置は、後端部にステアリングホイール１が取り付けられたステアリングシャフト２と、ステアリングシャフト２の前端部を回転自在に支持するハウジング３と、ステアリングシャフト２により回転駆動される部分に固定されたウォームホイール４と、ウォームホイール４と噛合するウォーム歯５を軸方向中間部に有し、電動モータ６により回転駆動されるウォーム７とを備える。 23 and 24 show an example of a conventional electric power steering device described in Japanese Patent Application Laid-Open No. 2004-306988. This electric power steering device includes a steering shaft 2 having a steering wheel 1 attached to a rear end portion, a housing 3 that rotatably supports the front end portion of the steering shaft 2, and a portion that is rotationally driven by the steering shaft 2. The worm wheel 4 is fixed, and the worm tooth 5 that meshes with the worm wheel 4 is provided in the intermediate portion in the axial direction, and the worm 7 is rotationally driven by the electric motor 6.

ウォーム７の軸方向両端部は、深溝型玉軸受などの１対の転がり軸受８、９により、ハウジング３内に回転自在に支持されている。ウォーム７の先端部で転がり軸受８よりも突出した部分に、押圧駒１０が外嵌されており、押圧駒１０とハウジング３との間に、コイルばね１１などの付勢機構が配置されている。コイルばね１１は、押圧駒１０を介して、ウォーム７のウォーム歯５を、ウォームホイール４に向け付勢する。このような構成により、ウォーム歯５とウォームホイール４との間のバックラッシュに起因する歯打ち音の発生が抑えられている。 Both ends of the worm 7 in the axial direction are rotatably supported in the housing 3 by a pair of rolling bearings 8 and 9 such as deep groove ball bearings. A pressing piece 10 is externally fitted to a portion of the tip of the worm 7 that protrudes from the rolling bearing 8, and an urging mechanism such as a coil spring 11 is arranged between the pressing piece 10 and the housing 3. .. The coil spring 11 urges the worm teeth 5 of the worm 7 toward the worm wheel 4 via the pressing piece 10. With such a configuration, the generation of rattling noise due to backlash between the worm teeth 5 and the worm wheel 4 is suppressed.

従来の電動式パワーステアリング装置では、ウォーム歯５とウォームホイール４との噛合部における歯打ち音の発生は抑えられるが、電動モータ６の出力軸１２の先端部とウォーム７の基端部との結合部で発生する異音を抑える面から、改良の余地がある。この点について、以下に説明する。 In the conventional electric power steering device, the generation of rattling noise at the meshing portion between the worm teeth 5 and the worm wheel 4 is suppressed, but the tip end portion of the output shaft 12 of the electric motor 6 and the base end portion of the worm 7 There is room for improvement in terms of suppressing abnormal noise generated at the joint. This point will be described below.

従来の電動式パワーステアリング装置では、電動モータ６の出力軸１２の先端部とウォーム７の基端部とをトルクの伝達を可能に結合するために、ウォーム７の基端部に設けられたスプライン孔１３と、出力軸１２の先端部に設けられたスプライン軸部１４とをスプライン係合させている。スプライン軸部１４とスプライン孔１３とが、周方向隙間をゼロにした状態、すなわち、バックラッシュが存在しない状態でスプライン係合していれば、
出力軸１２の先端部とウォーム７の基端部とのスプライン係合部で、異音が発生することはない。しかしながら、実際には、スプライン係合部にはバックラッシュが存在している。特に、ウォーム歯５とウォームホイール４との間のバックラッシュを抑える構造では、ウォーム７を揺動変位させる必要上、スプライン係合部のバックラッシュを完全になくすことはできない。このため、電動モータ６の出力軸１２の回転方向を反転させる際に、当該バックラッシュの存在に基づいて異音が発生する可能性がある。 In the conventional electric power steering device, a spline provided at the base end portion of the worm 7 is provided in order to connect the tip end portion of the output shaft 12 of the electric motor 6 and the base end portion of the worm 7 to enable torque transmission. The hole 13 and the spline shaft portion 14 provided at the tip of the output shaft 12 are spline-engaged. If the spline shaft portion 14 and the spline hole 13 are spline-engaged with the circumferential gap set to zero, that is, in the absence of backlash.
No abnormal noise is generated at the spline engaging portion between the tip end portion of the output shaft 12 and the base end portion of the worm 7. However, in reality, there is backlash in the spline engaging portion. In particular, in a structure that suppresses backlash between the worm teeth 5 and the worm wheel 4, the backlash of the spline engaging portion cannot be completely eliminated because the worm 7 needs to be oscillated and displaced. Therefore, when the rotation direction of the output shaft 12 of the electric motor 6 is reversed, an abnormal noise may be generated based on the presence of the backlash.

特開２０１２−１３１２４９号公報には、電動モータの出力軸とウォームとを、金属製で円柱状の動力伝達部材を介して結合することにより、ウォームの揺動変位を円滑に行わせることができる構造が記載されている。ただし、この構造でも、ウォームを揺動変位させるために、動力伝達部材の両端部に設けられたスプライン軸部と、ウォームおよび電動モータの出力軸のそれぞれの端部に設けられたスプライン孔とのスプライン係合部には、それぞれバックラッシュが存在している。このため、このようなバックラッシュの存在に基づいて異音が発生する可能性がある。 According to Japanese Patent Application Laid-Open No. 2012-131249, the swing displacement of the worm can be smoothly performed by connecting the output shaft of the electric motor and the worm via a metal columnar power transmission member. The structure is described. However, even in this structure, in order to swing and displace the worm, the spline shafts provided at both ends of the power transmission member and the spline holes provided at the respective ends of the worm and the output shaft of the electric motor Backlash is present in each spline engaging portion. Therefore, abnormal noise may occur based on the presence of such backlash.

特開２００４−３０６８９８号公報Japanese Unexamined Patent Publication No. 2004-306988 特開２０１２−１３１２４９号公報Japanese Unexamined Patent Publication No. 2012-131249

本発明の目的は、駆動軸の回転方向を反転させる際における、異音の発生を抑えることができる構造のトルク伝達用継手、および、該トルク伝達用継手が組み込まれた電動式パワーステアリング装置を提供することにある。 An object of the present invention is to provide a torque transmission joint having a structure capable of suppressing the generation of abnormal noise when reversing the rotation direction of the drive shaft, and an electric power steering device incorporating the torque transmission joint. To provide.

本発明のトルク伝達用継手は、中間伝達部材と、１対の端部伝達部材と、１対の弾性部材とを備える。 The torque transmission joint of the present invention includes an intermediate transmission member, a pair of end transmission members, and a pair of elastic members.

前記中間伝達部材は、周方向複数箇所に配置された複数の中間伝達歯を有する。 The intermediate transmission member has a plurality of intermediate transmission teeth arranged at a plurality of locations in the circumferential direction.

前記１対の端部伝達部材は、前記中間伝達部材の軸方向両側に配置され、該１対の端部伝達部材のそれぞれは、周方向複数箇所に配置された複数の端部伝達歯を有する。 The pair of end transmission members are arranged on both sides in the axial direction of the intermediate transmission member, and each of the pair of end transmission members has a plurality of end transmission teeth arranged at a plurality of positions in the circumferential direction. ..

前記弾性部材は、前記中間伝達部材の軸方向両側部に組み付けられ、周方向複数箇所に配置された前記端部伝達歯が軸方向に挿通する挿通孔を有する。 The elastic member is assembled on both sides in the axial direction of the intermediate transmission member, and has insertion holes through which the end transmission teeth arranged at a plurality of positions in the circumferential direction are inserted in the axial direction.

前記挿通孔を軸方向に挿通した前記端部伝達歯と前記中間伝達歯とは、周方向に関して交互にかつ第１の周方向隙間を介して配置される。前記挿通孔の周方向両側縁同士の周方向間隔は、前記複数の中間伝達歯のうちの隣り合う中間伝達歯同士の周方向間隔よりも小さい。 The end transmission tooth and the intermediate transmission tooth through which the insertion hole is inserted in the axial direction are arranged alternately in the circumferential direction and through the first circumferential gap. The circumferential distance between the circumferential edges of the insertion hole is smaller than the circumferential distance between adjacent intermediate transmission teeth among the plurality of intermediate transmission teeth.

前記複数の端部伝達歯のうちの少なくとも１つの端部伝達歯は、その軸方向内端部に、軸方向内側に向かうほど周方向幅寸法が小さくなったテーパ部を備えた、案内用伝達歯により構成されている。
前記複数の端部伝達歯のうちの一部の端部伝達歯のみが、前記案内用伝達歯により構成されており、該案内用伝達歯の前記テーパ部が備えられた前記軸方向内端部は、前記複数の端部伝達歯のうちの残りの端部伝達歯の軸方向内端縁よりも軸方向内側に張り出している。 It said plurality of at least one end transmission teeth of the ends transmission teeth axially inner end of its, with a tapered portion as the circumferential width toward the axially inner side becomes small, guiding It is composed of transmission teeth.
Only a part of the end transmission teeth among the plurality of end transmission teeth is composed of the guide transmission tooth, and the axial inner end portion provided with the tapered portion of the guide transmission tooth. Overhangs axially inward from the axial inner edge of the remaining end transmission teeth of the plurality of end transmission teeth.

前記案内用伝達歯は、その軸方向外端部および中間部に、前記テーパ部に軸方向に連続して形成され、軸方向に関して周方向幅寸法が変化しないストレート部を備えることができる。The guide transmission tooth may be provided with a straight portion formed on the tapered portion in the tapered portion in the axial direction and whose circumferential width dimension does not change in the axial direction at its axial outer end portion and intermediate portion.

好ましくは、前記テーパ部の軸方向内端縁の周方向幅寸法は、前記挿通孔の周方向両側縁同士の周方向間隔よりも小さい。 Preferably, the circumferential width dimension of the axial inner edge of the tapered portion is smaller than the circumferential distance between the circumferential inner edges of the insertion hole.

本発明の技術的範囲からは外れるが、前記複数の端部伝達歯のうちのすべての端部伝達歯を、前記案内用伝達歯により構成し、前記すべての端部伝達歯の軸方向内側縁を同じ軸方向位置に存在させることもできる。 Although outside the technical scope of the present invention, all of the end transmission teeth, constituted by the guiding transmission teeth, said axially inner edges of all end transmission teeth of said plurality of end transmission teeth the can also benzalkonium be present in the same axial position.

本発明のトルク伝達用継手では、前記１対の端部伝達部材のうちの一方の端部伝達部材の前記案内用伝達歯の前記テーパ部と、前記１対の端部伝達部材のうちの他方の端部伝達部材の前記案内用伝達歯の前記テーパ部とを、第１の周方向隙間よりも大きい第２の周方向隙間を介在させた状態で、周方向に重畳して配置することができる。 In the torque transmission joint of the present invention, the tapered portion of the guide transmission tooth of one end transmission member of the pair of end transmission members and the other of the pair of end transmission members. The tapered portion of the guide transmission tooth of the end transmission member may be arranged so as to overlap in the circumferential direction with a second circumferential gap larger than the first circumferential gap interposed therebetween. can.

本発明のトルク伝達用継手では、前記１対の端部伝達部材のそれぞれは、前記複数の端部伝達歯の径方向片端部が結合された周面を有する端部連結部をさらに備えるとともに、前記案内用伝達歯の前記テーパ部と、前記端部連結部の軸方向内端部のうちで該テーパ部が結合された周方向部分である補強部とが、前記端部連結部の軸方向内端部のうちの他の周方向部分よりも軸方向内側に張り出している構成を採用することができる。 In the torque transmission joint of the present invention, each of the pair of end transmission members further includes an end connecting portion having a peripheral surface to which one radial end portion of the plurality of end transmission teeth is connected. The tapered portion of the guide transmission tooth and the reinforcing portion, which is the circumferential inner end portion of the end connecting portion to which the tapered portion is connected, are in the axial direction of the end connecting portion. It is possible to adopt a configuration in which the inner end portion projects inward in the axial direction with respect to the other circumferential portion.

この場合、前記１対の端部伝達部材のうちの一方の端部伝達部材の前記案内用伝達歯の前記補強部と、前記１対の端部伝達部材のうちの他方の端部伝達部材の前記案内用伝達歯の前記補強部とを、第１の周方向隙間よりも大きい第２の周方向隙間を介在させた状態で周方向に重畳して配置することができる。 In this case, the reinforcing portion of the guide transmission tooth of one end transmission member of the pair of end transmission members and the other end transmission member of the pair of end transmission members. The reinforcing portion of the guide transmission tooth can be arranged so as to be superimposed in the circumferential direction with a second circumferential gap larger than the first circumferential gap interposed therebetween.

前記補強部の周方向両側面を、該補強部に結合された前記テーパ部の周方向両側面よりも周方向両側に張り出させることができる。 Both sides in the circumferential direction of the reinforcing portion can be projected on both sides in the circumferential direction from both sides in the circumferential direction of the tapered portion coupled to the reinforcing portion.

前記弾性部材は、前記挿通孔のそれぞれの周方向両側縁の少なくとも一方の側縁の径方向一部に、周方向中央側に向けて突出する弾性突起を備えることができる。好ましくは、該弾性突起は、前記挿通孔のそれぞれの周方向両側縁の径方向外寄り部に備えられる。 The elastic member may be provided with elastic protrusions projecting toward the central side in the circumferential direction at least one of the side edges of the insertion holes in the circumferential direction in the radial direction. Preferably, the elastic projections are provided on the radial outer edges of the respective circumferential edges of the insertion hole.

本発明の電動式パワーステアリング装置は、ハウジングと、ウォームホイールと、ウォームと、電動モータとを備える。 The electric power steering device of the present invention includes a housing, a worm wheel, a worm, and an electric motor.

前記ウォームホイールは、前記ハウジングに対し回転自在に支持されている。 The worm wheel is rotatably supported with respect to the housing.

前記ウォームは、前記ウォームホイールに噛合した状態で、前記ハウジングに対し回転自在に支持されている。 The worm is rotatably supported by the housing in a state of being meshed with the worm wheel.

前記電動モータは、前記ウォームを回転駆動するための出力軸を有する。 The electric motor has an output shaft for rotationally driving the worm.

特に、本発明の電動式パワーステアリング装置は、前記電動モータの出力軸と前記ウォームとの間に、前記電動モータの出力軸と前記ウォームとをトルク伝達を可能に接続する、トルク伝達用継手を備える。 In particular, the electric power steering device of the present invention has a torque transmission joint that enables torque transmission between the output shaft of the electric motor and the worm. Be prepared.

該トルク伝達用継手は、本発明のトルク伝達用継手により構成される。前記１対の端部伝達部材のうちの一方の端部伝達部材は、前記電動モータの出力軸の先端部に固定または一体に形成されている。前記１対の端部伝達部材のうちの他方の端部伝達部材は、前記ウォームの基端部に固定または一体に形成されている。 The torque transmission joint is composed of the torque transmission joint of the present invention. One end transmission member of the pair of end transmission members is fixedly or integrally formed at the tip end of the output shaft of the electric motor. The other end transmission member of the pair of end transmission members is fixedly or integrally formed at the base end portion of the worm.

本発明の電動式パワーステアリング装置では、前記ウォームが前記電動モータの出力軸に対して揺動可能であり、かつ、前記ウォームの先端部と前記ハウジングとの間に、前記ウォームを前記ウォームホイールに向けて付勢する付勢機構を備えることができる。 In the electric power steering device of the present invention, the worm can swing with respect to the output shaft of the electric motor, and the worm is placed on the worm wheel between the tip of the worm and the housing. It can be provided with an urging mechanism for urging toward.

本発明のトルク伝達用継手および電動式パワーステアリング装置によれば、駆動軸の回転方向を反転させる際に、異音の発生を抑えることができる。 According to the torque transmission joint and the electric power steering device of the present invention, it is possible to suppress the generation of abnormal noise when the rotation direction of the drive shaft is reversed.

図１は、参考例の１例の電動式パワーステアリング装置を示す部分切断側面図である。FIG. 1 is a partially cut side view showing an electric power steering device of an example of a reference example. 図２は、一部を省略して示す、図１のＡ部拡大図である。FIG. 2 is an enlarged view of part A of FIG. 1, which is shown with a part omitted. 図３は、参考例の１例のトルク伝達用継手の斜視図である。FIG. 3 is a perspective view of a torque transmission joint of one example of the reference example. 図４は、参考例の１例のトルク伝達用継手を、径方向外側から見た図である。FIG. 4 is a view of the torque transmission joint of one example of the reference example from the outside in the radial direction. 図５は、図４の軸方向側方から見た図である。FIG. 5 is a view seen from the side in the axial direction of FIG. 図６は、図５のＢ−Ｂ断面図である。FIG. 6 is a cross-sectional view taken along the line BB of FIG. 図７は、図５のＣ−Ｏ−Ｃ断面図である。FIG. 7 is a cross-sectional view taken along the line COC of FIG. 図８は、図６のＤ−Ｄ断面図である。FIG. 8 is a cross-sectional view taken along the line DD of FIG. 図９は、図６のＥ−Ｅ断面図である。FIG. 9 is a cross-sectional view taken along the line EE of FIG. 図１０は、中間伝達部材と弾性部材との結合体を取り出して示す、図５のＢ−Ｂ断面図に相当する断面図である。FIG. 10 is a cross-sectional view corresponding to the cross-sectional view taken along the line BB of FIG. 5, showing a combined body of the intermediate transmission member and the elastic member taken out. 図１１（ａ）〜図１１（ｃ）は、参考例の１例のトルク伝達用継手を構成する中間伝達部材を示す図であり、図１１（ａ）は、一方の側面図であり、図１１（ｂ）は、図１１（ａ）のＦ−Ｆ断面図であり、図１１（ｃ）は、他方の側面図である。11 (a) to 11 (c) are views showing an intermediate transmission member constituting the torque transmission joint of one example of the reference example, and FIG. 11 (a) is a side view of one of them. 11 (b) is a cross-sectional view taken along the line FF of FIG. 11 (a), and FIG. 11 (c) is a side view of the other. 図１２（ａ）〜図１２（ｃ）は、参考例の１例のトルク伝達用継手を構成する弾性部材を示す図であり、図１２（ａ）は、一方の側面図であり、図１２（ｂ）は、図１２（ａ）のＧ−Ｇ断面図であり、図１２（ｃ）は、他方の側面図である。12 (a) to 12 (c) are views showing an elastic member constituting the torque transmission joint of one example of the reference example, and FIG. 12 (a) is a side view of one of the reference examples, FIG. (B) is a cross-sectional view taken along the line GG of FIG. 12 (a), and FIG. 12 (c) is a side view of the other. 図１３は、参考例の１例のトルク伝達用継手を構成する端部伝達部材の斜視図である。FIG. 13 is a perspective view of an end transmission member constituting the torque transmission joint of one example of the reference example. 図１４（ａ）および図１４（ｂ）は、参考例の１例のトルク伝達用継手を構成する端部伝達部材を示す図であり、図１４（ａ）は、端面図であり、図１４（ｂ）は、図１４（ａ）のＨ−Ｈ断面図である。14 (a) and 14 (b) are views showing an end transmission member constituting the torque transmission joint of one example of the reference example, and FIG. 14 (a) is an end view and FIG. 14 (B) is a cross-sectional view taken along the line HH of FIG. 14 (a). 図１５は、図１４（ｂ）の拡大Ｉ−Ｉ断面図である。FIG. 15 is an enlarged I-I cross-sectional view of FIG. 14 (b). 図１６は、参考例の１例に関して、中間伝達部材と弾性部材との結合体の挿通孔に、端部伝達部材の端部伝達歯を挿入する前の状態を示す斜視図である。FIG. 16 is a perspective view showing a state before inserting the end transmission tooth of the end transmission member into the insertion hole of the coupling body of the intermediate transmission member and the elastic member with respect to one example of the reference example. 図１７は、参考例の１例に関して、中間伝達部材と弾性部材との結合体の挿通孔に、端部伝達部材の端部伝達歯の軸方向内端部（テーパ部）を挿入した状態を示す斜視図である。FIG. 17 shows a state in which the axial inner end portion (tapered portion) of the end transmission tooth of the end transmission member is inserted into the insertion hole of the joint between the intermediate transmission member and the elastic member with respect to one example of the reference example. It is a perspective view which shows. 図１８は、実施の形態の１例のトルク伝達用継手の一部を分解して示す斜視図である。FIG. 18 is a perspective view showing a part of the torque transmission joint of one example of the embodiment in an exploded manner. 図１９は、実施の形態の１例に関する、図６に相当する図である。19, for one example of the embodiment and is a view corresponding to FIG. 図２０は、実施の形態の１例のトルク伝達用継手を構成する端部伝達部材の斜視図である。FIG. 20 is a perspective view of an end transmission member constituting the torque transmission joint of one example of the embodiment. 図２１は、実施の形態の１例のトルク伝達用継手を構成する端部伝達部材の第１の変形例の斜視図である。FIG. 21 is a perspective view of a first modification of the end transmission member constituting the torque transmission joint of one example of the embodiment. 図２２は、実施の形態の１例のトルク伝達用継手を構成する端部伝達部材の第２の変形例の斜視図である。FIG. 22 is a perspective view of a second modification of the end transmission member constituting the torque transmission joint of one example of the embodiment. 図２３は、電動式パワーステアリング装置の従来構造の１例を示す部分切断側面図である。FIG. 23 is a partially cut side view showing an example of the conventional structure of the electric power steering device. 図２４は、図２３の拡大Ｊ−Ｊ断面図である。FIG. 24 is an enlarged JJ cross-sectional view of FIG. 23.

［参考例の１例］
参考例の１例について、図１〜図１７を用いて説明する。本参考例の電動式パワーステアリング装置は、ハウジング３と、ハウジング３に対し回転自在に支持されているウォームホイール４と、ウォームホイール４と噛合した状態で、ハウジング３に対し回転自在に支持されているウォーム７ａと、ウォーム７ａを回転駆動するための出力軸１２ａを有する電動モータ６とを備える。ハウジング３は、後端部にステアリングホイール１が取り付けられたステアリングシャフト２の前端部（図２３および図２４参照）を、回転可能に支持する。ウォームホイール４は、ステアリングシャフト２により回転駆動される部分に固定される。より具体的には、ウォーム７ａは、ウォームホイール４と噛合するウォーム歯５を軸方向中間部に有し、ウォーム７ａの軸方向両端部は、深溝玉軸受などの１対の転がり軸受８、９により、ハウジング３内に回転可能に支持されている。 [ One example of reference example ]
One example of the reference example will be described with reference to FIGS. 1 to 17. The electric power steering device of this reference example is rotatably supported by the housing 3 in a state of being meshed with the housing 3, the worm wheel 4 rotatably supported by the housing 3, and the worm wheel 4. The worm 7a is provided with an electric motor 6 having an output shaft 12a for rotationally driving the worm 7a. The housing 3 rotatably supports the front end portion (see FIGS. 23 and 24) of the steering shaft 2 to which the steering wheel 1 is attached to the rear end portion. The worm wheel 4 is fixed to a portion that is rotationally driven by the steering shaft 2. More specifically, the worm 7a has worm teeth 5 that mesh with the worm wheel 4 in the axial intermediate portion, and both ends in the axial direction of the worm 7a are a pair of rolling bearings 8 and 9 such as deep groove ball bearings. Is rotatably supported in the housing 3.

ウォーム７ａの先端部に外嵌された転がり軸受８と、ハウジング３との間には、コイルばね、板ばねなどの弾性体を含む付勢機構１５が備えられている。付勢機構１５の弾性体の弾力に基づいて、ウォーム７ａのウォーム歯５は、ウォームホイール４に向けて、押圧あるいは付勢されている。このような構成により、ウォーム歯５とウォームホイール４との間のバックラッシュに起因する歯打ち音の発生が抑えられている。 An urging mechanism 15 including an elastic body such as a coil spring or a leaf spring is provided between the rolling bearing 8 fitted to the tip of the worm 7a and the housing 3. Based on the elasticity of the elastic body of the urging mechanism 15, the worm teeth 5 of the worm 7a are pressed or urged toward the worm wheel 4. With such a configuration, the generation of rattling noise due to backlash between the worm teeth 5 and the worm wheel 4 is suppressed.

本発明の電動式パワーステアリング装置は、駆動軸となる電動モータ６の出力軸１２ａと被駆動軸となるウォーム７ａとをトルク伝達を可能に接続するトルク伝達用継手１６を備える。本参考例では、軸方向に関して互いに直列に配置された、電動モータ６の出力軸１２ａの先端部と、ウォーム７ａの基端部とが、トルク伝達用継手１６を介して結合されている。 The electric power steering device of the present invention includes a torque transmission joint 16 that enables torque transmission between the output shaft 12a of the electric motor 6 serving as the driving shaft and the worm 7a serving as the driven shaft. In this reference example , the tip end portion of the output shaft 12a of the electric motor 6 and the base end portion of the worm 7a, which are arranged in series with each other in the axial direction, are connected via a torque transmission joint 16.

トルク伝達用継手１６は、中間伝達部材１７と、１対の端部伝達部材１８と、弾性部材１９とを備える。中間伝達部材１７は、周方向複数箇所に配置された複数の中間伝達歯２１を有する。１対の端部伝達部材１８は、周方向複数箇所に配置された複数の端部伝達歯３７を有する。１対の端部伝達部材１８を構成する一方（図２、図４、図６、図７における右方）の端部伝達部材１８は、出力軸１２ａに取り付けられる。他方（図２、図４、図６、図７における左方）の端部伝達部材１８は、ウォーム７ａの基端部に取り付けられる。１対の端部伝達部材１８は、トルク伝達用継手１６の軸方向外側から、中間伝達部材１７の軸方向両側に、複数の端部伝達歯３７と複数の中間伝達歯２１とが、周方向に関して交互にかつ周方向隙間を介して配置されるように、組み付けられる。中間伝達部材１７は、一方の端部伝達部材１８と他方の端部伝達部材１８の間でトルクを伝達する機能を有する。弾性部材１９は、ゴムおよびその他のエラストマーを含む弾性材料からなり、周方向複数箇所に配置され、複数の端部伝達歯３７が軸方向に挿通する複数の挿通孔３０を有する。弾性部材１９は、一方の端部伝達部材１８と中間伝達部材１７の間、および、他方の端部伝達部材１８と中間伝達部材１７の間で、緩衝機能を発揮する。 The torque transmission joint 16 includes an intermediate transmission member 17, a pair of end transmission members 18, and an elastic member 19. The intermediate transmission member 17 has a plurality of intermediate transmission teeth 21 arranged at a plurality of positions in the circumferential direction. The pair of end transmission members 18 has a plurality of end transmission teeth 37 arranged at a plurality of positions in the circumferential direction. One end transmission member 18 (on the right side in FIGS. 2, 4, 6 and 7) constituting a pair of end transmission members 18 is attached to the output shaft 12a. The other end transmission member 18 (left in FIGS. 2, 4, 6 and 7) is attached to the base end of the worm 7a. The pair of end transmission members 18 has a plurality of end transmission teeth 37 and a plurality of intermediate transmission teeth 21 in the circumferential direction from the axially outer side of the torque transmission joint 16 on both sides of the intermediate transmission member 17 in the axial direction. It is assembled so that it is arranged alternately with respect to and through a circumferential gap. The intermediate transmission member 17 has a function of transmitting torque between one end transmission member 18 and the other end transmission member 18. The elastic member 19 is made of an elastic material containing rubber and other elastomers, is arranged at a plurality of positions in the circumferential direction, and has a plurality of insertion holes 30 through which the plurality of end transmission teeth 37 are inserted in the axial direction. The elastic member 19 exerts a buffering function between one end transmission member 18 and the intermediate transmission member 17 and between the other end transmission member 18 and the intermediate transmission member 17.

以下の説明において、トルク伝達用継手１６を構成するそれぞれの部材に関する軸方向の内外は、トルク伝達用継手１６を組み立てた状態での、トルク伝達用継手１６の軸方向中央部を基準とする。すなわち、トルク伝達用継手１６の軸方向中央側が軸方向内側に相当し、トルク伝達用継手１６の軸方向両側が軸方向外側に相当する。たとえば、１対の端部伝達部材１８は、互いに軸方向内端部同士を対向させた状態で、トルク伝達用継手１６の軸方向両外側から、１対の端部伝達部材１８の軸方向内端部同士が近づき合う方向に中間伝達部材１７に組み付けられて、中間伝達部材１７の軸方向両外側に配置される。 In the following description, the inside and outside of each member constituting the torque transmission joint 16 in the axial direction is based on the central portion in the axial direction of the torque transmission joint 16 in the assembled state of the torque transmission joint 16. That is, the central side of the torque transmission joint 16 in the axial direction corresponds to the inner side in the axial direction, and both sides of the torque transmission joint 16 in the axial direction correspond to the outer side in the axial direction. For example, the pair of end transmission members 18 are in a state where the inner ends in the axial direction face each other, and the inner ends in the axial direction of the pair of end transmission members 18 are in the axial direction from both outer sides of the torque transmission joint 16 in the axial direction. It is assembled to the intermediate transmission member 17 in the direction in which the ends approach each other, and is arranged on both outer sides of the intermediate transmission member 17 in the axial direction.

中間伝達部材１７は、弾性部材１９を構成する弾性材料に比べて弾性変形しにくい（剛性が高い）材料により、全体として円環状に構成されている。中間伝達部材１７を構成する材料としては、布でゴムを強化したベルト材料、必要に応じて強化繊維を混入したＰＰＳ、ＰＥＥＫ、ポリアミドなどの合成樹脂、炭素鋼などの鉄合金、アルミニウム合金などの金属が挙げられる。中間伝達部材１７は、これらの材料に、射出成形、鋳造、鍛造、焼結、切削などの加工を施すことにより形成される。 The intermediate transmission member 17 is made of a material that is less likely to be elastically deformed (higher rigidity) than the elastic material constituting the elastic member 19, and is formed in an annular shape as a whole. Materials constituting the intermediate transmission member 17 include belt materials reinforced with cloth, synthetic resins such as PPS, PEEK, and polyamide mixed with reinforcing fibers as necessary, iron alloys such as carbon steel, and aluminum alloys. Metal is mentioned. The intermediate transmission member 17 is formed by subjecting these materials to processing such as injection molding, casting, forging, sintering, and cutting.

本参考例では、図１１（ａ）〜図１１（Ｃ）に示すように、中間伝達部材１７は、円筒状の中間筒部２０と、複数の中間伝達歯２１とを有する。中間筒部２０は、軸方向両側部の径方向中間部に、軸方向両側面に開口する周方向凹部２２を有する。周方向凹部２２は、中間伝達部材１７の周方向、かつ、中間伝達部材１７の全周にわたって伸長する。周方向凹部２２の内面を構成する内径側周面２３と外径側周面２４とは、中間伝達部材１７の中心軸を中心とする円筒面である。中間筒部２０は、軸方向両側部の径方向外端部に、軸方向両側に突出した円筒状の覆い部２５を有する。覆い部２５の内周面は、周方向凹部２２の外径側周面２４とともに単一円筒面を構成する。 In this reference example , as shown in FIGS. 11A to 11C, the intermediate transmission member 17 has a cylindrical intermediate tubular portion 20 and a plurality of intermediate transmission teeth 21. The intermediate tubular portion 20 has a circumferential recess 22 that opens on both axially side surfaces in the radial intermediate portion on both axially oriented portions. The circumferential recess 22 extends in the circumferential direction of the intermediate transmission member 17 and extends over the entire circumference of the intermediate transmission member 17. The inner diameter side peripheral surface 23 and the outer diameter side peripheral surface 24 constituting the inner surface of the circumferential recess 22 are cylindrical surfaces centered on the central axis of the intermediate transmission member 17. The intermediate tubular portion 20 has a cylindrical covering portion 25 projecting on both axially sides at the radial outer ends of both axially oriented portions. The inner peripheral surface of the covering portion 25 constitutes a single cylindrical surface together with the outer diameter side peripheral surface 24 of the circumferential recess 22.

本参考例では、中間伝達歯２１は、中間筒部２０の径方向内側の周方向等間隔となる複数箇所に放射状に配置され、中間伝達歯２１のそれぞれの径方向外端部は、中間筒部２０の内周面に結合されている。図示の例では、周方向に隣り合う１対の中間伝達歯２１の互いに対向する周方向側面は、互いに平行な平面からなる。周方向に隣り合う１対の中間伝達歯２１の間部分には、端部伝達部材１８の端部伝達歯３７が軸方向両側から挿入されて、中間伝達歯２１と端部伝達歯３７とが、周方向に関して交互に配置される。 In this reference example , the intermediate transmission teeth 21 are radially arranged at a plurality of locations at equal intervals in the circumferential direction inside the intermediate tubular portion 20 in the radial direction, and the radial outer ends of the intermediate transmission teeth 21 are the intermediate cylinders. It is connected to the inner peripheral surface of the portion 20. In the illustrated example, the circumferential side surfaces of the pair of intermediate transmission teeth 21 adjacent to each other in the circumferential direction are formed of planes parallel to each other. The end transmission teeth 37 of the end transmission member 18 are inserted from both sides in the axial direction into the intermediate portion between the pair of intermediate transmission teeth 21 adjacent to each other in the circumferential direction, and the intermediate transmission teeth 21 and the end transmission teeth 37 are inserted. , Arranged alternately in the circumferential direction.

中間伝達歯２１のそれぞれの軸方向外側面の周方向中央部には、軸方向に突出する係合凸部２６が備えられている。係合凸部２６は、軸方向から見た形状が、中間伝達部材１７の放射方向に伸長する略矩形状である。係合凸部２６の先端面である軸方向外側面のうちの径方向外側部は、傾斜側面部２７により構成されている。傾斜側面部２７は、径方向外側に向かうほど軸方向内側に向かう方向に傾斜している。係合凸部２６のうちの周方向に関して１つ置きに配置された係合凸部２６の径方向内側面の軸方向外半部には、径方向内方に張り出した爪部２８が備えられている。なお、図示の例では、爪部２８を備えている係合凸部２６の円周方向位置が、中間伝達部材１７の軸方向両側で互いに異なっている。 An engaging convex portion 26 projecting in the axial direction is provided at the central portion in the circumferential direction of the outer surface in the axial direction of each of the intermediate transmission teeth 21. The engaging convex portion 26 has a substantially rectangular shape when viewed from the axial direction and extends in the radial direction of the intermediate transmission member 17. The radial outer portion of the axial outer surface which is the tip surface of the engaging convex portion 26 is composed of the inclined side surface portion 27. The inclined side surface portion 27 is inclined in the direction toward the inner side in the axial direction toward the outer side in the radial direction. A claw portion 28 protruding inward in the radial direction is provided on the axial outer half portion of the radial inner side surface of the engaging convex portion 26 arranged every other in the circumferential direction of the engaging convex portions 26. ing. In the illustrated example, the circumferential positions of the engaging convex portions 26 including the claw portions 28 are different from each other on both sides of the intermediate transmission member 17 in the axial direction.

本参考例の弾性部材１９は、１対の弾性部材１９により構成される。１対の弾性部材１９のそれぞれは、弾性材料により全体として円輪状に構成されている。弾性部材１９を構成する弾性材料として、具体的には、ＮＢＲ、ＨＮＢＲなどのゴム、ポリウレタン、シリコンなどのエラストマーが挙げられる。本参考例では、１対の弾性部材１９のそれぞれは、互いに同形および同大である。１対の弾性部材１９は、中間伝達部材１７の軸方向両側部に、対称に組み付けられている。 The elastic member 19 of this reference example is composed of a pair of elastic members 19. Each of the pair of elastic members 19 is formed of an elastic material in an annular shape as a whole. Specific examples of the elastic material constituting the elastic member 19 include rubbers such as NBR and HNBR, and elastomers such as polyurethane and silicon. In this reference example , each of the pair of elastic members 19 has the same shape and the same size as each other. A pair of elastic members 19 are symmetrically assembled on both sides of the intermediate transmission member 17 in the axial direction.

図１２（ａ）〜図１２（ｃ）に示すように、１対の弾性部材１９のそれぞれは、中間伝達歯２１と同位相となる周方向複数箇所に、貫通孔である係合凹部２９を有する。また、弾性部材１９は、隣り合う１対の中間伝達歯２１の間部分（歯間部）と同位相となる周方向複数箇所に、スリット状の挿通孔３０を有する。本参考例の弾性部材１９では、係合凹部２９と挿通孔３０とが、周方向に交互に配置される。 As shown in FIGS. 12 (a) to 12 (c), each of the pair of elastic members 19 has engaging recesses 29, which are through holes, at a plurality of positions in the circumferential direction in the same phase as the intermediate transmission teeth 21. Have. Further, the elastic member 19 has slit-shaped insertion holes 30 at a plurality of positions in the circumferential direction in the same phase as the intermediate portion (interdental portion) of the pair of adjacent intermediate transmission teeth 21. In the elastic member 19 of this reference example , the engaging recesses 29 and the insertion holes 30 are alternately arranged in the circumferential direction.

係合凹部２９は、軸方向から見た形状が弾性部材１９の放射方向に伸長する略矩形状である。係合凹部２９は、中間伝達歯２１の軸方向外側面に備えられた係合凸部２６と係合して、弾性部材１９が中間伝達部材１７に対し相対回転することを阻止する。 The engaging recess 29 has a substantially rectangular shape when viewed from the axial direction and extends in the radial direction of the elastic member 19. The engaging recess 29 engages with the engaging protrusion 26 provided on the axially outer surface of the intermediate transmission tooth 21 to prevent the elastic member 19 from rotating relative to the intermediate transmission member 17.

弾性部材１９のうち、係合凹部２９の径方向内側部のうちの軸方向外側部には、係合凹部２９を径方向内側に延長したような形状を有する除肉部が備えられている。係合凹部２９の径方向内側部のうちの軸方向内側部には、周方向に伸長した係合梁３１が備えられている。 Among the elastic members 19, the axially outer portion of the radially inner portion of the engaging recess 29 is provided with a thinning portion having a shape such that the engaging recess 29 is extended radially inward. An axially inner portion of the radial inner portion of the engaging recess 29 is provided with an engaging beam 31 extending in the circumferential direction.

挿通孔３０は、弾性部材１９の放射方向に伸長し、かつ、弾性部材１９の内周縁に開口する。挿通孔３０には、端部伝達部材１８の端部伝達歯３７が軸方向外側から挿通する。図８および図９に示すように、挿通孔３０の周方向両側縁同士の周方向間隔ｔ30は、隣り合う中間伝達歯２１同士の周方向間隔Ｔ21よりも小さくなっている（ｔ30＜Ｔ21）。 The insertion hole 30 extends in the radial direction of the elastic member 19 and opens at the inner peripheral edge of the elastic member 19. The end transmission teeth 37 of the end transmission member 18 are inserted into the insertion hole 30 from the outside in the axial direction. As shown in FIGS. 8 and 9, the circumferential distance t 30 between the circumferential edges of the insertion hole 30 is smaller than the circumferential distance T 21 between the adjacent intermediate transmission teeth 21 (t 30 <. T 21 ).

弾性部材１９は、挿通孔３０のそれぞれの周方向両側縁の少なくとも一方の側縁の径方向一部に、周方向中央側に向けて突出する弾性突起３２を備えることができる。本参考例では、挿通孔３０の周方向両側縁の径方向外寄り部には、周方向中央側に向けて突出する弾性突起３２が備えられている。この場合、周方向に対向する弾性突起３２の先端面同士の周方向間隔が、挿通孔３０の周方向両側縁同士の周方向間隔ｔ30に相当する。本参考例では、弾性突起３２から径方向に外れた部分同士の間の周方向間隔に関しても、隣り合う中間伝達歯２１同士の周方向間隔Ｔ21よりも小さくなっている。弾性突起３２の軸方向から見た形状は、凸円弧形である。挿通孔３０の周方向両側縁のうち、弾性突起３２から径方向に外れた部分は、互いに平行な平坦部となっている。 The elastic member 19 may be provided with an elastic protrusion 32 projecting toward the central side in the circumferential direction at least one side edge of the insertion hole 30 in the circumferential direction. In this reference example , elastic protrusions 32 projecting toward the center side in the circumferential direction are provided at the radial outer portions of both peripheral edges of the insertion hole 30. In this case, the circumferential distance between the tip surfaces of the elastic protrusions 32 facing in the circumferential direction corresponds to the circumferential distance t 30 between the circumferential distances of the insertion holes 30. In this reference example , the circumferential distance between the portions radially deviated from the elastic protrusion 32 is also smaller than the circumferential distance T 21 between the adjacent intermediate transmission teeth 21. The shape of the elastic protrusion 32 seen from the axial direction is a convex arc shape. Of the circumferential edges of the insertion hole 30, the portions radially deviated from the elastic protrusions 32 are flat portions parallel to each other.

本発明を実施する場合、弾性突起３２の形状や形成位置は、図示の構造に限られない。たとえば、弾性突起３２の軸方向から見た形状として、三角形や台形などの他の形状を採用することもできる。弾性突起は、挿通孔の周方向両側縁の径方向外寄り部に配置されることが好ましいが、たとえば挿通孔の周方向両側縁の径方向中央部に配置することもできる。弾性突起の数も、１個に限られず、複数個とすることもできる。弾性突起３２を省略して、挿通孔の周方向両側縁のうちの一方または両方の全体を平坦部により構成することもできる。 When the present invention is carried out, the shape and formation position of the elastic protrusion 32 are not limited to the structure shown in the figure. For example, other shapes such as a triangle and a trapezoid can be adopted as the shape of the elastic protrusion 32 when viewed from the axial direction. The elastic protrusions are preferably arranged at the radial outer portions of the circumferential edges of the insertion hole, but can also be arranged at the radial center of the circumferential edges of the insertion hole, for example. The number of elastic protrusions is not limited to one, and may be a plurality. The elastic protrusion 32 may be omitted, and one or both of the peripheral edges of the insertion hole may be formed of a flat portion.

弾性部材１９は、係合凹部２９および挿通孔３０よりも径方向外側に位置する径方向外端部に、軸方向内側に突出した周方向凸部３３を有する。周方向凸部３３は、弾性部材１９の周方向に、かつ、弾性部材１９の全周にわたって伸長する。 The elastic member 19 has a circumferential convex portion 33 protruding inward in the axial direction at a radial outer end portion located radially outside the engaging recess 29 and the insertion hole 30. The circumferential convex portion 33 extends in the circumferential direction of the elastic member 19 and over the entire circumference of the elastic member 19.

弾性部材１９の軸方向外側面の径方向中間部は、傾斜側面部３４により構成されている。傾斜側面部３４は、径方向外側に向かうほど軸方向内側に向かう方向に傾斜している。 The radial intermediate portion of the axial outer surface of the elastic member 19 is composed of an inclined side surface portion 34. The inclined side surface portion 34 is inclined in the direction toward the inner side in the axial direction toward the outer side in the radial direction.

１対の弾性部材１９は、中間伝達部材１７の軸方向両側部に対称に組み付けられて、中間伝達部材１７と１対の弾性部材１９との結合体３５が構成される。結合体３５が構成された状態では、１対の弾性部材１９により、中間伝達部材１７の両側の軸方向外側面は覆われる。 The pair of elastic members 19 are symmetrically assembled on both sides of the intermediate transmission member 17 in the axial direction to form a coupling body 35 of the intermediate transmission member 17 and the pair of elastic members 19. In the state where the coupling body 35 is formed, the pair of elastic members 19 covers the axial outer surfaces on both sides of the intermediate transmission member 17.

結合体３５が構成された状態において、中間伝達部材１７の周方向凹部２２の内側に、弾性部材１９の周方向凸部３３が圧入され、周方向凹部２２の内径側周面２３と周方向凸部３３の内周面、および、周方向凹部２２の外径側周面２４と周方向凸部３３の外周面が、いずれも弾性的に接触して強く摩擦係合する。また、中間伝達部材１７の覆い部２５に弾性部材１９が締り嵌めで内嵌され、覆い部２５の内周面と弾性部材１９の外周面とが、弾性的に接触して強く摩擦係合する。これらの摩擦係合によって、中間伝達部材１７に対する弾性部材１９の軸方向外側への変位、並びに、中間伝達部材１７と弾性部材１９との分離の防止が図られている。さらに、弾性部材１９の外周面が覆い部２５により覆われるため、搬送中に、弾性部材１９の外周面に他の物品がぶつかったり、引っ掛かったりすることに起因する、中間伝達部材１７と弾性部材１９との分離の防止が図られている。 In the state where the combined body 35 is configured, the circumferential convex portion 33 of the elastic member 19 is press-fitted into the circumferential concave portion 22 of the intermediate transmission member 17, and the circumferential convex portion 23 and the circumferential convex portion of the circumferential concave 22 are convex. The inner peripheral surface of the portion 33, the outer diameter side peripheral surface 24 of the circumferential concave portion 22, and the outer peripheral surface of the circumferential convex portion 33 are both elastically contacted and strongly frictionally engaged. Further, the elastic member 19 is tightly fitted to the covering portion 25 of the intermediate transmission member 17, and the inner peripheral surface of the covering portion 25 and the outer peripheral surface of the elastic member 19 are elastically contacted and strongly frictionally engaged. .. By these frictional engagements, the displacement of the elastic member 19 with respect to the intermediate transmission member 17 in the axial direction and the separation of the intermediate transmission member 17 and the elastic member 19 are prevented. Further, since the outer peripheral surface of the elastic member 19 is covered by the covering portion 25, the intermediate transmission member 17 and the elastic member are caused by other articles colliding with or being caught by the outer peripheral surface of the elastic member 19 during transportation. The separation from 19 is planned.

本発明を実施する場合には、たとえば、内径側周面２３と周方向凸部３３の内周面との間の周方向少なくとも１箇所に隙間が備えられた構造、外径側周面２４と周方向凸部３３の外周面との間の周方向少なくとも１箇所に隙間が備えられた構造、内径側周面２３と外径側周面２４とのうちの一方の周面にのみ、周方向凸部３３の周面を弾性的に接触させた構造、覆い部２５の内周面と弾性部材１９の外周面との間に隙間が備えられた構造、周方向凸部３３の周方向少なくとも１箇所に不連続部が備えられた構造なども、採用することもできる。 When the present invention is carried out, for example, a structure having at least one gap in the circumferential direction between the inner peripheral side peripheral surface 23 and the inner peripheral surface of the circumferential convex portion 33, the outer diameter side peripheral surface 24 A structure in which a gap is provided at at least one peripheral surface of the circumferential convex portion 33 in the circumferential direction, only on one peripheral surface of the inner diameter side peripheral surface 23 and the outer diameter side peripheral surface 24 in the circumferential direction. A structure in which the peripheral surfaces of the convex portion 33 are elastically contacted, a structure in which a gap is provided between the inner peripheral surface of the covering portion 25 and the outer peripheral surface of the elastic member 19, and at least one in the circumferential direction of the circumferential convex portion 33. A structure in which a discontinuity is provided at a location can also be adopted.

弾性部材１９の係合凹部２９の内側に、中間伝達部材１７の係合凸部２６が挿入され係合することで、中間伝達部材１７と弾性部材１９との相対回転が阻止される。また、係合凸部２６の径方向内側に備えられた爪部２８が係合梁３１の軸方向外側面に係合する。これにより、中間伝達部材１７に対して弾性部材１９が軸方向外側に変位することの防止、および、中間伝達部材１７と弾性部材１９との分離の防止が図られている。弾性部材１９を中間伝達部材１７に取り付けた状態で、スリット状の挿通孔３０が、隣り合う中間伝達歯２１の間部分と同位相となる位置に配置される。 By inserting and engaging the engaging convex portion 26 of the intermediate transmission member 17 inside the engaging recess 29 of the elastic member 19, the relative rotation between the intermediate transmission member 17 and the elastic member 19 is prevented. Further, the claw portion 28 provided on the inner side in the radial direction of the engaging convex portion 26 engages with the lateral outer surface of the engaging beam 31 in the axial direction. As a result, the elastic member 19 is prevented from being displaced outward in the axial direction with respect to the intermediate transmission member 17, and the intermediate transmission member 17 and the elastic member 19 are prevented from being separated from each other. With the elastic member 19 attached to the intermediate transmission member 17, the slit-shaped insertion hole 30 is arranged at a position in phase with the intermediate portion between the adjacent intermediate transmission teeth 21.

弾性部材１９の軸方向外側面は、中間伝達部材１７の両側の軸方向外側面のうち最も軸方向外側に位置する係合凸部２６の先端面よりも、軸方向外側に位置する。すなわち、弾性部材１９は、中間伝達部材１７の両側の軸方向外側面よりも軸方向外側に張り出している。また、弾性部材１９の内周面は、中間伝達部材１７の中間伝達歯２１の径方向内側面および爪部２８の径方向内端縁よりも、径方向内側に位置している。すなわち、弾性部材１９は、中間伝達部材１７よりも径方向内側に張り出している。 The axial outer surface of the elastic member 19 is located axially outer than the tip surface of the engaging convex portion 26, which is the most axially outer of the axial outer surfaces on both sides of the intermediate transmission member 17. That is, the elastic member 19 projects axially outward from the axially outer surfaces on both sides of the intermediate transmission member 17. Further, the inner peripheral surface of the elastic member 19 is located radially inside the radial inner surface of the intermediate transmission tooth 21 of the intermediate transmission member 17 and the radial inner edge of the claw portion 28. That is, the elastic member 19 projects radially inward from the intermediate transmission member 17.

本参考例では、中間伝達部材１７と１対の弾性部材１９との結合体３５の両側の軸方向外側面の径方向中間部に、径方向外側に向かうほど軸方向内側に向かう方向に傾斜した傾斜側面部２７、３４が配置される In this reference example , the intermediate transmission member 17 and the pair of elastic members 19 are inclined in the radial direction of the axially outer surfaces on both sides of the coupling 35 in the axially inward direction toward the radial outer side. The inclined side surface portions 27 and 34 are arranged.

１対の端部伝達部材１８のそれぞれは、全体として円環状に構成される。端部伝達部材１８を構成する材料としては、必要に応じて強化繊維を混入したＰＰＳ、ＰＥＥＫ、ポリアミドなどの合成樹脂や、鉄合金、銅合金、アルミニウム合金などの金属が挙げられる。端部伝達部材１８は、これらの材料に、射出成形、鋳造、鍛造、焼結、切削などの加工を施すことにより形成される。本参考例では、１対の端部伝達部材１８は、互いに同形および同大である。１対の端部伝達部材１８は、中間伝達部材１７と１対の弾性部材１９との結合体３５の軸方向両側部に係合する。 Each of the pair of end transmission members 18 is formed in an annular shape as a whole. Examples of the material constituting the end transmission member 18 include synthetic resins such as PPS, PEEK, and polyamide mixed with reinforcing fibers as needed, and metals such as iron alloys, copper alloys, and aluminum alloys. The end transmission member 18 is formed by subjecting these materials to processing such as injection molding, casting, forging, sintering, and cutting. In this reference example , the pair of end transmission members 18 have the same shape and the same size as each other. The pair of end transmission members 18 engages on both axial sides of the coupling 35 of the intermediate transmission member 17 and the pair of elastic members 19.

図１３、図１４（ａ）および図１４（Ｂ）に示すように、１対の端部伝達部材１８のそれぞれは、端部連結部である円筒状の端部筒部３６と、複数の端部伝達歯３７と、円輪状の鍔部３８とを有する。鍔部３８の径方向内端部は、端部筒部３６の軸方向外端部に結合されている。複数の端部伝達歯３７のそれぞれは、略矩形板状であり、端部筒部３６の径方向外側の周方向等間隔となる複数箇所に放射状に配置されている。端部伝達歯３７のそれぞれの径方向内端部は、端部筒部３６の外周面に結合され、かつ、端部伝達歯３７のそれぞれの軸方向外端部は、鍔部３８の軸方向内側面である端部側面部４３に結合されている。トルク伝達用継手１６を組み立てた状態で、１対の端部伝達部材１８のそれぞれおよびその構成部分の軸方向内端部は、それぞれの端部伝達部材１８のうち、トルク伝達用継手１６の軸方向中央側に位置する端部を意味し、その軸方向外端部は、トルク伝達用継手１６の軸方向両側に位置する端部を意味する。 As shown in FIGS. 13, 14 (a) and 14 (B), each of the pair of end transmission members 18 has a cylindrical end cylinder portion 36 which is an end connecting portion and a plurality of ends. It has a partial transmission tooth 37 and a ring-shaped collar portion 38. The radial inner end of the collar 38 is coupled to the axial outer end of the end tube 36. Each of the plurality of end transmission teeth 37 has a substantially rectangular plate shape, and is radially arranged at a plurality of locations at equal intervals in the circumferential direction on the outer side in the radial direction of the end tubular portion 36. Each radial inner end of the end transmission tooth 37 is coupled to the outer peripheral surface of the end cylinder 36, and each axial outer end of the end transmission tooth 37 is axial to the collar 38. It is connected to the end side surface portion 43 which is the inner surface surface. In the state where the torque transmission joint 16 is assembled, the axial inner ends of each of the pair of end transmission members 18 and their constituent parts are the shafts of the torque transmission joint 16 among the respective end transmission members 18. It means an end portion located on the central side in the direction, and the outer end portion in the axial direction means an end portion located on both sides in the axial direction of the torque transmission joint 16.

本参考例では、端部筒部３６の軸方向内端面と、すべての端部伝達歯３７の軸方向内端面とが、端部筒部３６の中心軸に直交する同一の仮想平面内に配置されている。すなわち、端部筒部３６の軸方向内端面と、すべての端部伝達歯３７の軸方向内端面とは、同じ軸方向位置に存在する。本参考例では、すべての端部伝達歯３７が、案内用伝達歯に相当する。端部伝達歯３７のそれぞれの軸方向外端部および中間部は、ストレート部３９により構成されており、端部伝達歯３７のそれぞれの軸方向内端部は、テーパ部４０により構成されている。ストレート部３９とテーパ部４０とは、軸方向に連続して形成されており、ストレート部３９の表面とテーパ部４０の表面との間には、軸方向を向いた段差は存在しない。 In this reference example , the axial inner end faces of the end tube 36 and the axial inner end faces of all the end transmission teeth 37 are arranged in the same virtual plane orthogonal to the central axis of the end tube 36. Has been done. That is, the axial inner end surface of the end tubular portion 36 and the axial inner end surface of all the end transmission teeth 37 exist at the same axial position. In this reference example , all end transmission teeth 37 correspond to guide transmission teeth. Each axial outer end and intermediate portion of the end transmission tooth 37 is composed of a straight portion 39, and each axial inner end portion of the end transmission tooth 37 is composed of a tapered portion 40. .. The straight portion 39 and the tapered portion 40 are formed continuously in the axial direction, and there is no step in the axial direction between the surface of the straight portion 39 and the surface of the tapered portion 40.

ストレート部３９は、軸方向に関して周方向幅寸法および径方向高さ寸法が変化しない平板状である。図示の例では、ストレート部３９の周方向両側面は、互いに平行な平面である。 The straight portion 39 has a flat plate shape in which the circumferential width dimension and the radial height dimension do not change with respect to the axial direction. In the illustrated example, both sides of the straight portion 39 in the circumferential direction are planes parallel to each other.

テーパ部４０は、端部伝達歯３７を弾性部材１９の挿通孔３０に軸方向外側から挿入する際に案内部として機能し、軸方向内側に向かって先細りとなる楔状に形成されている。具体的には、テーパ部４０は、軸方向内側に向かうほど、周方向幅寸法および径方向高さ寸法が小さくなるように構成されている。換言すれば、テーパ部４０は、周方向両側面が、軸方向内側に向かうほど互いに近づき合う方向に傾斜しており、径方向外端面が、軸方向内側に向かうほど径方向内側に向かう方向に傾斜している。なお、本発明を実施する場合、テーパ部の径方向高さ寸法は、軸方向に関して変化させずに一定とすることもできる。 The tapered portion 40 functions as a guide portion when the end transmission tooth 37 is inserted into the insertion hole 30 of the elastic member 19 from the outside in the axial direction, and is formed in a wedge shape that tapers inward in the axial direction. Specifically, the tapered portion 40 is configured such that the circumferential width dimension and the radial height dimension become smaller toward the inner side in the axial direction. In other words, the tapered portion 40 is inclined in a direction in which both side surfaces in the circumferential direction are closer to each other toward the inner side in the axial direction, and the outer end surfaces in the radial direction are inward in the radial direction toward the inner side in the axial direction. It is tilted. When the present invention is carried out, the radial height dimension of the tapered portion can be kept constant with respect to the axial direction.

図１４（ａ）、図１４（ｂ）、および図１５に示すように、ストレート部３９の周方向幅寸法Ｗ39（図１４（ａ）および図１５参照）は、弾性部材１９の挿通孔３０の周方向両側縁同士の周方向間隔ｔ30よりも大きい（Ｗ39＞ｔ30）。本参考例では、ストレート部３９の周方向幅寸法Ｗ39は、挿通孔３０の周方向両側縁のうち、周方向に対向する弾性突起３２の先端面同士の周方向間隔ｔ30だけでなく、弾性突起３２から径方向に外れた部分同士の間の周方向間隔よりも大きい。ストレート部３９の周方向幅寸法Ｗ39は、隣り合う中間伝達歯２１同士の周方向間隔Ｔ21よりも小さい（Ｗ39＜Ｔ21）。 As shown in FIGS. 14 (a), 14 (b), and 15, the circumferential width dimension W 39 (see FIGS. 14 (a) and 15) of the straight portion 39 is the insertion hole 30 of the elastic member 19. It is larger than the circumferential distance t 30 between both edges in the circumferential direction (W 39 > t 30 ). In this reference example , the circumferential width dimension W 39 of the straight portion 39 is not only the circumferential distance t 30 between the tip surfaces of the elastic protrusions 32 facing in the circumferential direction among the circumferential width side edges of the insertion hole 30. It is larger than the circumferential distance between the portions radially deviated from the elastic protrusion 32. The circumferential width dimension W 39 of the straight portion 39 is smaller than the circumferential distance T 21 between adjacent intermediate transmission teeth 21 (W 39 <T 21 ).

テーパ部４０の軸方向外端縁の周方向幅寸法は、ストレート部３９の周方向幅寸法Ｗ39に等しい。テーパ部４０の軸方向内端縁の周方向幅寸法Ｗ40は、弾性部材１９の挿通孔３０の周方向両側縁同士の周方向間隔ｔ30よりも小さい（Ｗ40＜ｔ30）。本参考例では、図１５に示すように、端部伝達歯３７の径方向に直交する仮想平面に関する、テーパ部４０の周方向側面の断面形状は、直線形状である。 The circumferential width dimension of the axial outer edge of the tapered portion 40 is equal to the circumferential width dimension W 39 of the straight portion 39. Axially inner end circumferential width dimension W 40 of the edge of the tapered portion 40 is smaller than the circumferential both side edges circumferentially spacing t 30 between the insertion hole 30 of the elastic member 19 (W 40 <t 30) . In this reference example , as shown in FIG. 15, the cross-sectional shape of the circumferential side surface of the tapered portion 40 with respect to the virtual plane orthogonal to the radial direction of the end transmission tooth 37 is a linear shape.

本発明を実施する場合に、ストレート部３９の周方向側面に対するテーパ部４０の周方向側面の傾斜角度θの大きさは特に問われない。傾斜角度θを、約１０度〜５０度の範囲における任意の角度に設定することができる。テーパ部４０を案内部として、端部伝達歯３７を弾性部材１９の挿通孔３０に軸方向外側から押し込む際に、この押し込みに要する力を小さく抑える観点からは、傾斜角度θはより小さい方が好ましく、傾斜角度θは、４５度以下であることが好ましく、３０度以下であることがより好ましく、１５度以下であることがさらに好ましい。なお、テーパ部４０の周方向側面の断面形状は、図１５に二点鎖線で示すように、凸曲線形状とすることもできる。 When carrying out the present invention, the magnitude of the inclination angle θ of the circumferential side surface of the tapered portion 40 with respect to the circumferential side surface of the straight portion 39 is not particularly limited. The tilt angle θ can be set to any angle in the range of about 10 degrees to 50 degrees. When the end transmission tooth 37 is pushed into the insertion hole 30 of the elastic member 19 from the outside in the axial direction by using the tapered portion 40 as a guide portion, the smaller the inclination angle θ is, from the viewpoint of suppressing the force required for this pushing to be small. Preferably, the inclination angle θ is preferably 45 degrees or less, more preferably 30 degrees or less, and further preferably 15 degrees or less. The cross-sectional shape of the circumferential side surface of the tapered portion 40 may be a convex curve shape as shown by the alternate long and short dash line in FIG.

１対の端部伝達部材１８の軸方向内端部から中間部までが、結合体３５の軸方向両側部の径方向内側に、軸方向外側から挿入される。本参考例では、端部伝達歯３７のそれぞれのテーパ部４０を、端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する際の案内部として機能させる。具体的には、図１６および図１７に示すように、端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する際には、まず、端部伝達歯３７のそれぞれのテーパ部４０の軸方向内側部分を、弾性部材１９の挿通孔３０に差し込む。この差し込み作業は、テーパ部４０の軸方向内端縁の周方向幅寸法Ｗ40が、挿通孔３０の周方向両側縁同士の周方向間隔ｔ30よりも小さいため、容易に行うことができる。この差し込み作業により、端部伝達歯３７と挿通孔３０との周方向の位相を合わせる。本参考例では、テーパ部４０の径方向高さ寸法が、軸方向内側に向かうほど小さくなっているため、この差し込み作業を行う際に、端部伝達歯３７と挿通孔３０との径方向の位置合わせも容易に行うことができる。この状態から、端部伝達歯３７のそれぞれを、結合体３５の径方向内側に押し込む。これにより、端部伝達歯３７のそれぞれのストレート部３９を、弾性部材１９の挿通孔３０に、および、周方向に隣り合う中間伝達歯２１同士の間に、挿入する。 From the axial inner end to the middle of the pair of end transmission members 18, is inserted from the axial outer side into the radial inner side of both axial side portions of the coupling 35. In this reference example , each tapered portion 40 of the end transmission tooth 37 functions as a guide portion when the end transmission member 18 is inserted from the axial inner end portion to the intermediate portion in the radial direction of the coupling body 35. Let me. Specifically, as shown in FIGS. 16 and 17, when inserting the end transmission member 18 from the axially inner end to the middle portion in the radial direction of the coupling 35, first, the end transmission is performed. The axially inner portion of each tapered portion 40 of the tooth 37 is inserted into the insertion hole 30 of the elastic member 19. This insertion operation, the axially inner end circumferential width dimension W 40 of the edge of the tapered portion 40 is smaller than the circumferential spacing t 30 circumferential side edges to each other in the insertion hole 30 can be easily performed. By this insertion work, the phase of the end transmission tooth 37 and the insertion hole 30 in the circumferential direction is matched. In this reference example , the radial height dimension of the tapered portion 40 becomes smaller toward the inner side in the axial direction. Therefore, when performing this insertion work, the radial height dimension of the end transmission tooth 37 and the insertion hole 30 Alignment can also be easily performed. From this state, each of the end transmission teeth 37 is pushed inward in the radial direction of the coupling 35. As a result, each straight portion 39 of the end transmission tooth 37 is inserted into the insertion hole 30 of the elastic member 19 and between the intermediate transmission teeth 21 adjacent to each other in the circumferential direction.

１対の端部伝達部材１８のそれぞれの軸方向内端部から中間部までが、結合体３５の軸方向両側部の径方向内側に挿入された状態で、一方（図２、図４、図６、図７における右方）の端部伝達部材１８に備えられた端部伝達歯３７のストレート部３９は、一方の弾性部材１９の挿通孔３０に周方向のがたつきなく、好ましくは、周方向の締め代を有する状態で、係合する。また、他方（図２、図４、図６、図７における左方）の端部伝達部材１８に備えられた端部伝達歯３７のストレート部３９は、他方の弾性部材１９の挿通孔３０に周方向のがたつきなく、好ましくは、周方向の締め代を有する状態で、係合する。本参考例では、弾性部材１９は、挿通孔３０の周方向両側縁に弾性突起３２を備えていることから、弾性部材１９の弾性突起３２と端部伝達部材１８の端部伝達歯３７のストレート部３９とが弾性的に係合することができ、がたつき防止効果がより適切に実現される。 One of the pair of end transmission members 18 (FIGS. 2, FIG. 4, and FIGS. 6. The straight portion 39 of the end transmission tooth 37 provided on the end transmission member 18 (on the right side in FIG. 7) does not rattle in the insertion hole 30 of one elastic member 19 in the circumferential direction, and is preferably preferable. Engage with a circumferential tightening allowance. Further, the straight portion 39 of the end transmission tooth 37 provided on the other end transmission member 18 (left in FIGS. 2, 4, 6 and 7) is inserted into the insertion hole 30 of the other elastic member 19. Engage with no rattling in the circumferential direction, preferably with a tightening allowance in the circumferential direction. In this reference example , since the elastic member 19 is provided with elastic protrusions 32 on both peripheral edges of the insertion hole 30 in the circumferential direction, the elastic protrusions 32 of the elastic member 19 and the end transmission teeth 37 of the end transmission member 18 are straight. The portion 39 can be elastically engaged, and the rattling prevention effect is more appropriately realized.

一方の端部伝達部材１８のストレート部３９および他方の端部伝達部材１８のストレート部３９のいずれもが、隣り合う中間伝達歯２１同士の間に周方向隙間を介して係合する。すなわち、図９に示すように、端部伝達歯３７のストレート部３９と中間伝達歯２１との周方向側面同士の間に、第１の周方向隙間αが存在する。なお、本発明を実施する場合には、端部伝達歯３７を弾性部材１９の挿通孔３０に対し、周方向隙間を介在させた状態で係合させることもできる。ただし、この場合にも、この周方向隙間よりも、周方向隙間αを大きくする。 Both the straight portion 39 of one end transmission member 18 and the straight portion 39 of the other end transmission member 18 engage with each other of adjacent intermediate transmission teeth 21 via a circumferential gap. That is, as shown in FIG. 9, there is a first circumferential gap α between the circumferential side surfaces of the straight portion 39 of the end transmission tooth 37 and the intermediate transmission tooth 21. When carrying out the present invention, the end transmission tooth 37 may be engaged with the insertion hole 30 of the elastic member 19 with a circumferential gap interposed therebetween. However, also in this case, the circumferential gap α is made larger than this circumferential gap.

本参考例では、図９に示すように、端部伝達歯３７の先端面である径方向外端面と、挿通孔３０の底面（内面の径方向外端部）との間に、径方向隙間βが介在し、端部伝達歯３７の径方向外端面と、隣り合う中間伝達歯２１の間部分の底面（中間筒部２０の内周面）との間に、径方向隙間γが介在する。径方向隙間βは、径方向隙間γよりも小さい（β＜γ）。また、隣り合う端部伝達歯３７の間部分の底面（端部筒部３６の外周面）と、弾性部材１９の内周面との間に、径方向隙間εが介在し、隣り合う端部伝達歯３７の間部分の底面と、中間伝達歯２１の先端面である径方向内端面との間に、径方向隙間ηが介在する。径方向隙間εは、径方向隙間ηよりも小さい（ε＜η）。 In this reference example , as shown in FIG. 9, a radial gap is provided between the radial outer end surface, which is the tip surface of the end transmission tooth 37, and the bottom surface (the radial outer end portion of the inner surface) of the insertion hole 30. β is interposed, and a radial gap γ is interposed between the radial outer end surface of the end transmission tooth 37 and the bottom surface (inner peripheral surface of the intermediate cylinder portion 20) between the adjacent intermediate transmission teeth 21. .. The radial gap β is smaller than the radial gap γ (β <γ). Further, a radial gap ε is interposed between the bottom surface of the portion between the adjacent end transmission teeth 37 (the outer peripheral surface of the end cylinder portion 36) and the inner peripheral surface of the elastic member 19, and the adjacent end portions. A radial gap η is interposed between the bottom surface of the intermediate portion between the transmission teeth 37 and the radial inner end surface which is the tip surface of the intermediate transmission tooth 21. The radial gap ε is smaller than the radial gap η (ε <η).

本参考例では、この状態で、図７に示すように、結合体３５の軸方向外側面である、１対の弾性部材１９の軸方向外側面および複数の係合凸部２６の軸方向外側面と、１対の端部伝達部材１８の鍔部３８の軸方向内側面とが軸方向に対向する。 In this reference example , in this state, as shown in FIG. 7, the axial outer surface of the pair of elastic members 19 and the axial outer surfaces of the plurality of engaging convex portions 26, which are the axial outer surfaces of the coupling 35. The side surfaces and the axially inner side surfaces of the flanges 38 of the pair of end transmission members 18 face each other in the axial direction.

本参考例のトルク伝達用継手１６を電動式パワーステアリング装置に組み付けた状態で、一方の端部伝達部材１８の端部筒部３６は、出力軸１２ａ（図１および図２参照）の先端部に対し、締め代を有する円筒面嵌合、締め代を有するスプライン嵌合、かしめなどのトルク伝達可能な構造により、外嵌固定されている。また、他方の端部伝達部材１８の端部筒部３６は、一方の端部伝達部材１８と同様に、ウォーム７ａ（図１および図２参照）の基端部に外嵌固定されている。ただし、端部伝達部材１８は、出力軸１２ａの先端部やウォーム７ａの基端部に一体に形成することもできる。 With the torque transmission joint 16 of this reference example assembled to the electric power steering device, the end cylinder portion 36 of one end transmission member 18 is the tip end portion of the output shaft 12a (see FIGS. 1 and 2). On the other hand, the outer fitting is fixed by a structure capable of transmitting torque such as a cylindrical surface fitting having a tightening allowance, a spline fitting having a tightening allowance, and caulking. Further, the end tubular portion 36 of the other end transmission member 18 is externally fitted and fixed to the base end portion of the worm 7a (see FIGS. 1 and 2) in the same manner as the one end transmission member 18. However, the end transmission member 18 can also be integrally formed with the tip of the output shaft 12a or the base end of the worm 7a.

この状態で、１対の端部伝達部材１８のそれぞれの鍔部３８の軸方向内側面同士の間の
軸方向距離Ｌ38は、結合体３５の軸方向幅寸法Ｗ35よりも大きい（Ｌ38＞Ｗ35）。本参考例では、１対の端部伝達部材１８のそれぞれの鍔部３８の軸方向内側面によって、結合体３５の軸方向位置が規制される。すなわち、結合体３５は、１対の端部伝達部材１８のそれぞれの鍔部３８の軸方向内側面同士の間でのみ、軸方向に変位することが可能である。さらに、この状態で、１対の端部伝達部材１８の軸方向内端面同士の間に軸方向の隙間が存在する。 In this state, the axial distance L 38 between the axial inner surfaces of the respective flanges 38 of the pair of end transmission members 18 is larger than the axial width dimension W 35 of the coupling 35 (L 38). > W 35 ). In this reference example , the axial position of the coupling 35 is regulated by the axial inner surface of each of the flanges 38 of the pair of end transmission members 18. That is, the coupling body 35 can be displaced in the axial direction only between the axial inner side surfaces of the respective flange portions 38 of the pair of end transmission members 18. Further, in this state, there is an axial gap between the axial inner end faces of the pair of end transmission members 18.

本参考例の電動式パワーステアリング装置を組み立てる際に、電動モータ６の出力軸１２ａに一方の端部伝達部材１８を固定する作業と、ウォーム７ａの基端部に他方の端部伝達部材１８を固定する作業と、一方の端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する作業と、他方の端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する作業とは、適宜の順番で行うことができる。特に、本参考例では、ハウジング３の内側で、端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する作業を行う場合のように、作業者が目視で、端部伝達歯３７と挿通孔３０との周方向の位相合わせを行えない場合でも、端部伝達歯３７のそれぞれのテーパ部４０を案内部として機能させることによって、当該位相合わせを容易に行うことができる。 When assembling the electric power steering device of this reference example , the work of fixing one end transmission member 18 to the output shaft 12a of the electric motor 6 and the other end transmission member 18 to the base end of the worm 7a. The work of fixing, the work of inserting the axial inner end to the intermediate portion of one end transmission member 18 into the radial inside of the coupling 35, and the work of inserting the other end transmission member 18 in the axial direction. The work of inserting the intermediate portion up to the inside of the coupling 35 in the radial direction can be performed in an appropriate order. In particular, in this reference example , the operator performs the work of inserting the end transmission member 18 from the axially inner end to the intermediate portion inside the housing 3 in the radial direction of the coupling 35. Even if it is not possible to visually align the phase of the end transmission tooth 37 and the insertion hole 30 in the circumferential direction, the phase alignment can be easily performed by making each tapered portion 40 of the end transmission tooth 37 function as a guide portion. Can be done.

本参考例の電動式パワーステアリング装置では、電動モータ６の出力軸１２ａとウォーム７ａとの間で伝達されるトルクが比較的小さい場合には、出力軸１２ａの回転トルクは、一方の端部伝達部材１８、一方の弾性部材１９、中間伝達部材１７、他方の弾性部材１９、他方の端部伝達部材１８、およびウォーム７ａの順に伝達される。具体的には、出力軸１２ａの回転トルクは、一方の端部伝達部材１８から一方の弾性部材１９に、端部伝達歯３７と挿通孔３０との係合部を通じて伝達される。一方の弾性部材１９に伝達されたトルクは、中間伝達部材１７に、一方の弾性部材１９の係合凹部２９と中間伝達部材１７の係合凸部２６との係合部を通じて伝達される。中間伝達部材１７に伝達されたトルクは、他方の弾性部材１９に、中間伝達部材１７の係合凸部２６と他方の弾性部材１９の係合凹部２９との係合部を通じて伝達される。他方の弾性部材１９に伝達されたトルクは、他方の端部伝達部材１８およびウォーム７ａに、挿通孔３０と端部伝達歯３７との係合部を通じて伝達される。 In the electric power steering device of this reference example , when the torque transmitted between the output shaft 12a and the worm 7a of the electric motor 6 is relatively small, the rotational torque of the output shaft 12a is transmitted to one end. The members 18, one elastic member 19, the intermediate transmission member 17, the other elastic member 19, the other end transmission member 18, and the worm 7a are transmitted in this order. Specifically, the rotational torque of the output shaft 12a is transmitted from one end transmission member 18 to one elastic member 19 through an engaging portion between the end transmission tooth 37 and the insertion hole 30. The torque transmitted to one elastic member 19 is transmitted to the intermediate transmission member 17 through the engaging portion between the engaging concave portion 29 of the one elastic member 19 and the engaging convex portion 26 of the intermediate transmission member 17. The torque transmitted to the intermediate transmission member 17 is transmitted to the other elastic member 19 through the engaging portion between the engaging convex portion 26 of the intermediate transmitting member 17 and the engaging concave portion 29 of the other elastic member 19. The torque transmitted to the other elastic member 19 is transmitted to the other end transmission member 18 and the worm 7a through the engaging portion between the insertion hole 30 and the end transmission tooth 37.

これに対して、出力軸１２ａとウォーム７ａとの間で伝達されるトルクが大きくなると、一方の弾性部材１９の一部が、一方の端部伝達部材１８の端部伝達歯３７によって、周方向に弾性的に押し潰され、かつ、他方の弾性部材１９の一部が、他方の端部伝達部材１８の端部伝達歯３７によって、周方向に弾性的に押し潰される。そして、一方の端部伝達部材１８の端部伝達歯３７および他方の端部伝達部材１８の端部伝達歯３７と、中間伝達部材１７の中間伝達歯２１との、それぞれの周方向側面同士が直接当接する。これらの当接の勢いは、一方の弾性部材１９および他方の弾性部材１９の弾性変形により弱められているため、当接に伴う異音の発生は抑えられる。この状態では、出力軸１２ａの回転トルクの大部分は、一方の端部伝達部材１８から中間伝達部材１７に直接伝達され、中間伝達部材１７に伝達されたトルクの大部分は、中間伝達歯２１から他方の端部伝達部材１８に直接伝達される。また、残りのトルクは、上述したトルクが小さい場合と同様にして、出力軸１２ａからウォーム７ａに伝達される。 On the other hand, when the torque transmitted between the output shaft 12a and the worm 7a becomes large, a part of one elastic member 19 is subjected to the circumferential direction by the end transmission tooth 37 of the one end transmission member 18. And a part of the other elastic member 19 is elastically crushed in the circumferential direction by the end transmission teeth 37 of the other end transmission member 18. Then, the peripheral side surfaces of the end transmission tooth 37 of one end transmission member 18, the end transmission tooth 37 of the other end transmission member 18, and the intermediate transmission tooth 21 of the intermediate transmission member 17 are respectively. Direct contact. Since the momentum of these contacts is weakened by the elastic deformation of one elastic member 19 and the other elastic member 19, the generation of abnormal noise due to the contact is suppressed. In this state, most of the rotational torque of the output shaft 12a is directly transmitted from one end transmission member 18 to the intermediate transmission member 17, and most of the torque transmitted to the intermediate transmission member 17 is the intermediate transmission tooth 21. Is directly transmitted to the other end transmission member 18. Further, the remaining torque is transmitted from the output shaft 12a to the worm 7a in the same manner as in the case where the torque is small as described above.

本参考例では、電動モータ６の出力軸１２ａの回転方向を反転させる際にも、一方の端部伝達部材１８の端部伝達歯３７および他方の端部伝達部材１８の端部伝達歯３７と、中間伝達部材１７の中間伝達歯２１との、それぞれの周方向側面同士の当接の勢いを、一方の弾性部材１９および他方の弾性部材１９の弾性変形により弱められるため、当接に伴う異音の発生が抑えられる。 In this reference example , even when the rotation direction of the output shaft 12a of the electric motor 6 is reversed, the end transmission teeth 37 of one end transmission member 18 and the end transmission teeth 37 of the other end transmission member 18 , The momentum of contact between the peripheral side surfaces of the intermediate transmission member 17 with the intermediate transmission tooth 21 is weakened by the elastic deformation of one elastic member 19 and the other elastic member 19, so that the contact is different. The generation of sound is suppressed.

本参考例では、隣り合う１対の中間伝達歯２１の互いに対向する周方向側面は、互いに平行な平面になっており、かつ、端部伝達歯３７の周方向両側面も、互いに平行な平面になっている。ただし、本発明を実施する場合には、トルク伝達時に中間伝達歯２１と端部伝達歯３７との周方向側面同士が面で当接（面接触）しやすくなるように、周方向に隣り合う１対の中間伝達歯２１の互いに対向する周方向側面同士を互いに傾斜させる構成と、端部伝達歯３７の周方向両側面同士を互いに傾斜させる構成とのうちの、少なくとも一方の構成を採用することもできる。 In this reference example , the circumferential side surfaces of the pair of adjacent intermediate transmission teeth 21 facing each other are parallel planes, and the circumferential side surfaces of the end transmission teeth 37 are also parallel planes. It has become. However, when the present invention is carried out, the side surfaces in the circumferential direction of the intermediate transmission tooth 21 and the end transmission tooth 37 are adjacent to each other in the circumferential direction so as to be easily in contact with each other (surface contact) during torque transmission. At least one of a configuration in which the circumferential side surfaces of the pair of intermediate transmission teeth 21 facing each other are inclined to each other and a configuration in which both side surfaces in the circumferential direction of the end transmission teeth 37 are inclined to each other is adopted. You can also do it.

以上のように、本参考例の電動式パワーステアリング装置は、トルク伝達用継手１６の捩り剛性が、伝達するトルクが小さい場合には小さくなり、伝達するトルクが大きい場合には大きくなるといった、２段階特性を有する。ただし、本発明を実施する場合には、たとえば、１対の端部伝達部材１８同士で周方向隙間αの大きさを互いに異ならせたりすることによって、トルク伝達用継手１６の捩り剛性を２段階よりも多くすることもできる。 As described above, in the electric power steering device of this reference example , the torsional rigidity of the torque transmission joint 16 decreases when the torque to be transmitted is small, and increases when the torque to be transmitted is large. Has step characteristics. However, when the present invention is carried out, for example, the torsional rigidity of the torque transmission joint 16 is increased in two stages by making the size of the circumferential gap α different between the pair of end transmission members 18. Can be more than.

１対の端部伝達部材１８のそれぞれに関して、端部伝達歯３７と弾性部材１９との係合部、および、端部伝達歯３７と中間伝達歯２１との係合部に、それぞれ径方向隙間β、γ、ε、ηが介在する。また、１対の端部伝達部材１８のそれぞれの鍔部３８の軸方向内側面（端部側面部４３）同士の間の軸方向距離Ｌ38が、結合体３５の軸方向幅寸法Ｗ35よりも大きくなっている（Ｌ38＞Ｗ35）。さらに、１対の端部伝達部材１８のそれぞれの鍔部３８の軸方向内側面（端部側面部４３）と軸方向に対向する、結合体３５の両側の軸方向外側面の径方向中間部が、径方向外側に向かうほど軸方向内側に向かう方向に傾斜した傾斜側面部２７、３４になっている。このため、結合体３５と１対の端部伝達部材１８との中心軸同士の傾きを無理なく許容することができる。 For each of the pair of end transmission members 18, there is a radial gap between the engagement portion between the end transmission tooth 37 and the elastic member 19 and the engagement portion between the end transmission tooth 37 and the intermediate transmission tooth 21. Β, γ, ε, η intervene. Further, the axial distance L 38 between the axial inner side surfaces (end side surface portions 43) of the respective flange portions 38 of the pair of end transmission members 18 is from the axial width dimension W 35 of the coupling 35. Is also getting bigger (L 38 > W 35 ). Further, radial intermediate portions of the axially outer surfaces on both sides of the coupling 35 facing the axial inner side surface (end side surface portion 43) of each of the flange portions 38 of the pair of end transmission members 18 in the axial direction. However, the inclined side surface portions 27 and 34 are inclined in the direction toward the inward in the axial direction toward the outer side in the radial direction. Therefore, the inclination of the central axes of the coupling body 35 and the pair of end transmission members 18 can be reasonably allowed.

本参考例では、径方向隙間β、γ、ε、ηに関して、β＜γ、および、ε＜ηの関係が成立する。このため、１対の端部伝達部材１８同士の間で、大きな偏心や傾きなどが生じた場合でも、弾性部材１９の存在に基づいて、隣り合う１対の端部伝達歯３７の間部分の底面が、中間伝達歯２１の先端面に当接したり、端部伝達歯３７の先端面が、隣り合う１対の中間伝達歯２１の間部分の底面に当接したりすることが防止される。仮にこれらの面同士が当接した場合でも、当接の勢いは、弾性部材１９の弾性変形により弱められるため、当接に伴う異音の発生は抑えられる。 In this reference example , the relations of β <γ and ε <η are established with respect to the radial gaps β, γ, ε, and η. Therefore, even if a large eccentricity or inclination occurs between the pair of end transmission members 18, based on the presence of the elastic member 19, the portion between the pair of adjacent end transmission teeth 37 It is prevented that the bottom surface abuts on the tip surface of the intermediate transmission tooth 21 and that the tip surface of the end transmission tooth 37 abuts on the bottom surface of the intermediate portion between the adjacent pair of intermediate transmission teeth 21. Even if these surfaces come into contact with each other, the momentum of the contact is weakened by the elastic deformation of the elastic member 19, so that the generation of abnormal noise due to the contact is suppressed.

本参考例では、少なくとも中間伝達部材１７と端部伝達部材１８の端部側面部４３とが軸方向に対向する径方向範囲において、弾性部材１９の軸方向外側面が係合凸部２６の軸方向外側面よりも軸方向外側に位置している。このため、１対の端部伝達部材１８のそれぞれの端部側面部４３同士の間で中間伝達部材１７が軸方向に変位したり、１対の端部伝達部材１８同士の間で大きな偏心や傾きなどが生じたりした場合でも、弾性部材１９の存在に基づいて、端部側面部４３が係合凸部２６の軸方向外側面に当接することが防止される。仮に弾性部材１９が弾性的に押し潰されて、端部側面部４３が係合凸部２６の軸方向外側面に当接する場合でも、これらの当接の勢いは、弾性部材１９の弾性変形により弱められるため、当接に伴う異音の発生は抑えられる。 In this reference example , at least in the radial range in which the intermediate transmission member 17 and the end side surface portion 43 of the end transmission member 18 face each other in the axial direction, the axial outer surface of the elastic member 19 is the axis of the engaging convex portion 26. It is located on the outer side in the axial direction from the outer surface in the direction. Therefore, the intermediate transmission member 17 is displaced in the axial direction between the end side surface portions 43 of the pair of end transmission members 18, or a large eccentricity is generated between the pair of end transmission members 18. Even when tilting or the like occurs, it is possible to prevent the end side surface portion 43 from coming into contact with the axially outer surface of the engaging convex portion 26 based on the presence of the elastic member 19. Even if the elastic member 19 is elastically crushed and the end side surface portion 43 abuts on the axially outer surface of the engaging convex portion 26, the momentum of these abutments is due to the elastic deformation of the elastic member 19. Since it is weakened, the generation of abnormal noise due to contact is suppressed.

本参考例では、中間伝達歯が、中間伝達部材の径方向内側部に備えられており、端部伝達歯が、１対の端部伝達部材の径方向外側部に備えられている。ただし、本発明を実施する場合には、中間伝達歯が、中間伝達部材の径方向外側部に備えられ、端部伝達歯が、端部伝達部材の径方向内側部に備えられている構成を採用することもできる。 In this reference example , the intermediate transmission teeth are provided on the radial inner side of the intermediate transmission member, and the end transmission teeth are provided on the radial outer portion of the pair of end transmission members. However, when the present invention is carried out, an intermediate transmission tooth is provided on the radial outer portion of the intermediate transmission member, and an end transmission tooth is provided on the radial inner portion of the end transmission member. It can also be adopted.

本参考例では、弾性部材は、一方の端部伝達部材に係合する弾性部材と、他方の端部伝達部材に係合する弾性部材とからなる１対の弾性部材により構成されている。ただし、本発明を実施する場合には、弾性部材は、一方の端部伝達部材に係合する部分と他方の端部伝達部材に係合する部分とを含む１個の弾性部材により構成することもできる。この場合、弾性部材の有する弾性を利用して、弾性部材を中間伝達部材に組み付けることが可能である。 In this reference example , the elastic member is composed of a pair of elastic members including an elastic member that engages with one end transmission member and an elastic member that engages with the other end transmission member. However, in the case of carrying out the present invention, the elastic member shall be composed of one elastic member including a portion engaging with one end transmission member and a portion engaging with the other end transmission member. You can also. In this case, the elastic member can be assembled to the intermediate transmission member by utilizing the elasticity of the elastic member.

本発明を実施する場合には、中間伝達部材と弾性部材との相対回転を阻止することができれば、中間伝達部材の係合凸部の数および円周方向位置、並びに、弾性部材の係合凹部の数および円周方向位置についても、特に問われない。 In the case of carrying out the present invention, if the relative rotation between the intermediate transmission member and the elastic member can be prevented, the number and circumferential positions of the engaging protrusions of the intermediate transmission member, and the engaging concave portions of the elastic member. The number of and the position in the circumferential direction are not particularly limited.

［実施の形態の１例］
実施の形態の１例について、図１８〜図２０を用いて説明する。本例では、端部伝達部材１８ａのそれぞれは、複数（図示の例では８個）の端部伝達歯３７ａ、３７ｂのうち、周方向に関して１つ置きに配置された一部（図示の例では４個）の端部伝達歯３７ａの軸方向内端面が、残りの端部伝達歯３７ｂの軸方向内端面よりも、軸方向内側に位置する。すなわち、本例では、一部の端部伝達歯３７ａが、案内用伝達歯に相当し、端部伝達歯３７ａのうちのテーパ部４０を備えた軸方向内端部は、残りの端部伝達歯３７ｂの軸方向内端縁よりも軸方向内側に張り出している。 [1 Example Embodiment
For one example of the embodiment will be described with reference to FIGS. 18 to 20. In this example, each of the end transmission members 18a is a part of a plurality of (8 in the illustrated example) end transmission teeth 37a and 37b arranged every other in the circumferential direction (in the illustrated example). The axial inner end faces of the four) end transmission teeth 37a are located axially inward with respect to the axial inner end faces of the remaining end transmission teeth 37b. That is, in this example, a part of the end transmission teeth 37a corresponds to a guide transmission tooth, and the axial inner end portion of the end transmission teeth 37a provided with the tapered portion 40 is the remaining end transmission. The tooth 37b projects inward in the axial direction from the inner edge in the axial direction.

端部伝達歯３７ａのそれぞれの軸方向外端部および中間部は、ストレート部３９により構成されており、その軸方向内端部が、テーパ部４０により構成されている。端部伝達歯３７ａのテーパ部４０と、端部筒部３６ａの軸方向内端部のうちで外周面にテーパ部４０が結合された周方向部分である補強部４１とが、端部筒部３６ａの軸方向内端部のうちの他の周方向部分（補強部４１から周方向に外れた部分）よりも軸方向内側に張り出している。補強部４１の軸方向内側から見た形状は、端部伝達部材１８ａの中心軸を中心とする扇形であり、補強部４１の周方向両側面は、テーパ部４０の周方向両側面よりも周方向両側に張り出している。補強部４１の軸方向内端面と、端部伝達歯３７ａの軸方向内端面とは、端部筒部３６ａの中心軸に直交する同一の仮想平面内に配置されており、同じ軸方向位置に存在する。 The axial outer end and the intermediate portion of each of the end transmission teeth 37a are formed by a straight portion 39, and the axial inner end thereof is formed by a tapered portion 40. The tapered portion 40 of the end transmission tooth 37a and the reinforcing portion 41 which is a circumferential portion in which the tapered portion 40 is coupled to the outer peripheral surface of the axial inner end portion of the end tubular portion 36a are the end tubular portions. It projects inward in the axial direction from the other circumferential portion (the portion deviated in the circumferential direction from the reinforcing portion 41) of the inner end portion in the axial direction of 36a. The shape of the reinforcing portion 41 seen from the inside in the axial direction is a fan shape centered on the central axis of the end transmission member 18a, and the circumferential side surfaces of the reinforcing portion 41 are more circumferential than the circumferential side surfaces of the tapered portion 40. Overhanging on both sides of the direction. The axial inner end surface of the reinforcing portion 41 and the axial inner end surface of the end transmission tooth 37a are arranged in the same virtual plane orthogonal to the central axis of the end tubular portion 36a, and are located at the same axial position. exist.

端部伝達歯３７ｂは、その軸方向内端縁部の周縁部に備えられた面取り部４２を除いて、ストレート部３９により構成されている。面取り部４２の軸方向寸法は、テーパ部４０の軸方向寸法よりも十分に小さく、図示の例では、テーパ部４０の軸方向寸法の１／８程度である。また、端部伝達歯３７ｂの面取り部４２が備えられた部分の軸方向内端縁の周方向幅寸法は、弾性部材１９の挿通孔３０の周方向両側縁同士の周方向間隔ｔ30（図８参照）よりも大きい。また、端部伝達歯３７ｂのそれぞれの軸方向内端面と、端部筒部３６ａの軸方向内端面のうちで補強部４１から周方向に外れた部分とは、端部筒部３６ａの中心軸に直交する同一の仮想平面内に配置されており、同じ軸方向位置に存在する。なお、本発明を実施する場合には、テーパ部４０の軸方向内端縁部の周縁部に面取り部を備えることもできる。 The end transmission tooth 37b is composed of a straight portion 39 except for a chamfered portion 42 provided on a peripheral edge portion of an axially inner end edge portion thereof. The axial dimension of the chamfered portion 42 is sufficiently smaller than the axial dimension of the tapered portion 40, and in the illustrated example, it is about 1/8 of the axial dimension of the tapered portion 40. Further, the circumferential width dimension of the axial inner end edge of the portion of the end transmission tooth 37b provided with the chamfered portion 42 is the circumferential distance t 30 between the circumferential side edges of the insertion hole 30 of the elastic member 19 (FIG. 8) is larger. Further, the axial inner end surface of each of the end transmission teeth 37b and the portion of the axial inner end surface of the end tubular portion 36a that deviates from the reinforcing portion 41 in the circumferential direction are the central axes of the end tubular portion 36a. They are arranged in the same virtual plane orthogonal to, and exist in the same axial position. When the present invention is carried out, a chamfered portion may be provided on the peripheral edge of the axially inner edge portion of the tapered portion 40.

本例では、１対の端部伝達部材１８ａを構成する一方の端部伝達部材と他方の端部伝達部材との間で、案内用伝達歯である端部伝達歯３７ａの周方向に関する配置の位相を、互いに半ピッチずらしている。そして、一方の端部伝達部材１８ａのテーパ部４０および補強部４１と、他方の端部伝達部材１８ａのテーパ部４０および補強部４１とは、周方向に関して交互に、かつ、端部伝達部材１８ａの中心軸を中心とする角度幅が第１の周方向隙間α（図９参照）よりも大きい第２の周方向隙間λを介在させた状態で、周方向に重畳して配置される。この状態で、一方の端部伝達部材１８ａのテーパ部４０および補強部４１の軸方向内端面と、他方の端部伝達部材１８ａの軸方向内端面のうちのテーパ部４０および補強部４１から周方向に外れた部分との間、並びに、他方の端部伝達部材１８ａのテーパ部４０および補強部４１の軸方向内端面と、一方の端部伝達部材１８ａの軸方向内端面のうちのテーパ部４０および補強部４１から周方向に外れた部分との間に、それぞれ軸方向隙間が存在する。 In this example, the arrangement of the end transmission tooth 37a, which is a guide transmission tooth, in the circumferential direction is arranged between one end transmission member and the other end transmission member constituting the pair of end transmission members 18a. The phases are shifted by half a pitch from each other. The tapered portion 40 and the reinforcing portion 41 of one end transmitting member 18a and the tapered portion 40 and the reinforcing portion 41 of the other end transmitting member 18a are alternately arranged in the circumferential direction and the end transmitting member 18a. The angle width about the central axis of the above is larger than that of the first circumferential gap α (see FIG. 9). In this state, the circumference from the tapered portion 40 and the reinforcing portion 41 of the tapered portion 40 and the reinforcing portion 41 of one end transmitting member 18a and the axial inner end surface of the other end transmitting member 18a. The tapered portion between the portion deviated in the direction, the tapered portion 40 of the other end transmitting member 18a, the axial inner end surface of the reinforcing portion 41, and the axial inner end surface of one end transmitting member 18a. There is an axial gap between the 40 and the portion deviated from the reinforcing portion 41 in the circumferential direction.

本例では、このような構成を採用することにより、一方の端部伝達部材１８ａのテーパ部４０および補強部４１と、他方の端部伝達部材１８ａのテーパ部４０および補強部４１とを、軸方向に対向させた構成に比べて、結合体３５の径方向内側への１対の端部伝達部材１８ａの軸方向挿入量を大きくできる。その分、端部伝達歯３７ａ、３７ｂのそれぞれのストレート部３９と中間伝達歯２１との、軸方向の係合長さを大きくして、より大きなトルクの伝達を可能としている。 In this example, by adopting such a configuration, the tapered portion 40 and the reinforcing portion 41 of one end transmission member 18a and the tapered portion 40 and the reinforcing portion 41 of the other end transmitting member 18a are pivoted. The amount of axial insertion of the pair of end transmission members 18a inward in the radial direction of the coupling 35 can be increased as compared with the configuration in which they face each other in the direction. By that amount, the engagement length between the straight portion 39 of the end transmission teeth 37a and 37b and the intermediate transmission tooth 21 in the axial direction is increased to enable transmission of a larger torque.

本例の場合も、端部伝達部材１８の軸方向内端部から中間部までを結合体３５の径方向内側に挿入する作業を行う際には、テーパ部４０を案内部として機能させることにより、端部伝達歯３７ａ、３７ｂと挿通孔３０との周方向の位相合わせと、端部伝達歯３７ａ、３７ｂと挿通孔３０との径方向の位置合わせを容易に行うことが可能である。 Also in the case of this example, when the work of inserting the end transmission member 18 from the inner end portion in the axial direction to the intermediate portion in the radial direction of the coupling body 35 is performed, the tapered portion 40 is made to function as a guide portion. , It is possible to easily perform the phase alignment of the end transmission teeth 37a and 37b and the insertion hole 30 in the circumferential direction and the radial alignment of the end transmission teeth 37a and 37b and the insertion hole 30.

本例では、一部の端部伝達歯３７ａは、残部の端部伝達歯３７ｂよりも軸方向内側に張り出した部分がテーパ部４０により構成され、残りの部分がストレート部３９により構成される。端部伝達歯３７ｂは、軸方向内端縁部に備えられた面取り部４２を除いた残りの部分がストレート部３９により構成される。このため、本例では、端部伝達歯３７ｂの軸方向寸法が、参考例の１例の端部伝達歯３７の軸方向寸法と同じ大きさである場合には、すべての端部伝達歯３７ａ、３７ｂのストレート部３９の軸方向寸法を、参考例の１例の端部伝達歯３７のストレート部３９の軸方向寸法よりも大きくすることができる。その分、すべての端部伝達歯３７ａ、３７ｂのストレート部３９と中間伝達歯２１との、軸方向の係合長さを大きくして、より大きなトルクを伝達することが可能となる。 In this example, a part of the end transmission tooth 37a is formed of a tapered portion 40 at a portion protruding inward in the axial direction from the remaining end transmission tooth 37b, and the remaining portion is composed of a straight portion 39. The end transmission tooth 37b is composed of a straight portion 39 except for the chamfered portion 42 provided on the inner edge portion in the axial direction. Therefore, in this example, when the axial dimension of the end transmission tooth 37b is the same as the axial dimension of the end transmission tooth 37 of one example of the reference example, all the end transmission teeth 37a , 37b, the axial dimension of the straight portion 39 can be made larger than the axial dimension of the straight portion 39 of the end transmission tooth 37 of one example of the reference example. By that amount, it is possible to increase the axial engagement length between the straight portion 39 of all the end transmission teeth 37a and 37b and the intermediate transmission tooth 21 to transmit a larger torque.

本例では、補強部４１によりテーパ部４０が補強されているため、組み立て作業の際や、電動式パワーステアリング装置の運転時において、万一、テーパ部４０が他の物体と衝突した場合でも、テーパ部４０は破損しにくい。また、一方の端部伝達部材１８ａのテーパ部４０および補強部４１と、他方の端部伝達部材１８ａのテーパ部４０および補強部４１とが、周方向に関して交互に、かつ、第１の周方向隙間α（図９参照）よりも大きい第２の周方向隙間λを介在させた状態で配置されているため、万一、中間伝達部材１７が破損した場合でも、一方の端部伝達部材１８ａの補強部４１と、他方の端部伝達部材１８ａの補強部４１との周方向側面同士が当接することによって、トルク伝達を継続して行うことが可能となる。この際のトルク伝達を効率よく行えるようにするために、補強部４１の周方向側面は、少なくともトルク伝達時に相手側の補強部４１の周方向側面と面接触する平面、たとえば、周方向に直交する平面により構成されていることが好ましい。 In this example, since the tapered portion 40 is reinforced by the reinforcing portion 41, even if the tapered portion 40 collides with another object during assembly work or during operation of the electric power steering device, even if the tapered portion 40 collides with another object, The tapered portion 40 is not easily damaged. Further, the tapered portion 40 and the reinforcing portion 41 of one end transmitting member 18a and the tapered portion 40 and the reinforcing portion 41 of the other end transmitting member 18a are alternately arranged in the circumferential direction and in the first circumferential direction. Since it is arranged with the second circumferential gap λ larger than the gap α (see FIG. 9) interposed therebetween, even if the intermediate transmission member 17 is damaged, one end transmission member 18a When the reinforcing portion 41 and the circumferential side surfaces of the reinforcing portion 41 of the other end transmission member 18a come into contact with each other, torque transmission can be continuously performed. In order to efficiently transmit torque at this time, the circumferential side surface of the reinforcing portion 41 is at least a plane that makes surface contact with the circumferential side surface of the mating reinforcing portion 41 during torque transmission, for example, orthogonal to the circumferential direction. It is preferable that it is composed of planes.

実施の形態の１例のその他の構成および作用は、参考例の１例と同様である。 Other structure and operation of one example of this embodiment is similar to the example of embodiment.

実施の形態の１例の変形例として、図２１に示す、端部伝達歯３７ａ（テーパ部４０および補強部４１）が、周方向に関して等間隔となる２箇所に配置される構成の端部伝達部材１８ｂ、あるいは、図２２に示す、端部伝達歯３７ａ（テーパ部４０および補強部４１）が、周方向の１箇所にのみ配置される構成の端部伝達部材１８ｃを採用することができる。 As a modification of one example of the embodiment, the end transmission teeth 37a (tapered portion 40 and reinforcing portion 41) shown in FIG. 21 are arranged at two locations at equal intervals in the circumferential direction. An end transmission member 18c having a structure in which the end transmission teeth 37a (tapered portion 40 and reinforcing portion 41) shown in FIG. 22 or the member 18b is arranged only at one position in the circumferential direction can be adopted.

参考例の１例と実施の形態の１例の構造は、相互に矛盾しない限り、それぞれの構成を選択的あるいは追加的に採用されうる。 The structures of one example of the reference example and one example of the embodiment may selectively or additionally adopt their respective configurations as long as they do not contradict each other.

１ ステアリングホイール
２ ステアリングシャフト
３ ハウジング
４ ウォームホイール
５ ウォーム歯
６ 電動モータ
７、７ａ ウォーム
８ 転がり軸受
９ 転がり軸受
１０ 押圧駒
１１ コイルばね
１２、１２ａ 出力軸
１３ スプライン孔
１４ スプライン軸部
１５ 付勢機構
１６ トルク伝達用継手
１７ 中間伝達部材
１８、１８ａ、１８ｂ、１８ｃ 端部伝達部材
１９ 弾性部材
２０ 中間筒部
２１ 中間伝達歯
２２ 周方向凹部
２３ 内径側周面
２４ 外径側周面
２５ 覆い部
２６ 係合凸部
２７ 傾斜側面部
２８ 爪部
２９ 係合凹部
３０ 挿通孔
３１ 係合梁
３２ 弾性突起
３３ 周方向凸部
３４ 傾斜側面部
３５ 結合体
３６、３６ａ 端部筒部
３７、３７ａ、３７ｂ 端部伝達歯
３８ 鍔部
３９ ストレート部
４０ テーパ部
４１ 補強部
４２ 面取り部
４３ 端部側面部 1 Steering wheel 2 Steering shaft 3 Housing 4 Warm wheel 5 Warm tooth 6 Electric motor 7, 7a Warm 8 Rolling bearing 9 Rolling bearing 10 Pressing piece 11 Coil spring 12, 12a Output shaft 13 Spline hole 14 Spline shaft 15 Basis mechanism 16 Torque transmission joint 17 Intermediate transmission member 18, 18a, 18b, 18c End transmission member 19 Elastic member 20 Intermediate cylinder 21 Intermediate transmission tooth 22 Circumferential recess 23 Inner diameter side peripheral surface 24 Outer diameter side peripheral surface 25 Covering part 26 Convex part 27 Inclined side part 28 Claw part 29 Engagement recess 30 Insertion hole 31 Engagement beam 32 Elastic protrusion 33 Circumferential convex part 34 Inclined side part 35 Coupling 36, 36a End part Cylinder part 37, 37a, 37b End part Transmission tooth 38 Bearing 39 Straight part 40 Tapered part 41 Reinforcing part 42 Chamfered part 43 End side side part

Claims (9)

周方向複数箇所に配置された複数の中間伝達歯を有する中間伝達部材と、
前記中間伝達部材の軸方向両側に配置され、それぞれが周方向複数箇所に配置された複数の端部伝達歯を有する１対の端部伝達部材と、
前記中間伝達部材の軸方向両側部に組み付けられ、周方向複数箇所に配置された前記端部伝達歯が軸方向に挿通する挿通孔を有する弾性部材と、
を備え、
前記端部伝達歯が前記挿通孔を軸方向に挿通した状態で、前記端部伝達歯と前記中間伝達歯とが、周方向に関して交互にかつ第１の周方向隙間を介して配置され、
前記挿通孔の周方向両側縁同士の周方向間隔は、前記中間伝達歯のうちの隣り合う中間伝達歯同士の周方向間隔よりも小さく、および、
前記複数の端部伝達歯のうちの少なくとも１つの端部伝達歯は、その軸方向内端部に、軸方向内側に向かうほど周方向幅寸法が小さくなったテーパ部を備えた、案内用伝達歯により構成されており、
前記複数の端部伝達歯のうちの一部の端部伝達歯のみが、前記案内用伝達歯により構成され、該案内用伝達歯の前記テーパ部が備えられた前記軸方向内端部は、前記複数の端部伝達歯のうちの残りの端部伝達歯の軸方向内端縁よりも軸方向内側に張り出している、
トルク伝達用継手。 An intermediate transmission member having a plurality of intermediate transmission teeth arranged at a plurality of locations in the circumferential direction,
A pair of end transmission members having a plurality of end transmission teeth arranged on both sides in the axial direction of the intermediate transmission member and each arranged at a plurality of positions in the circumferential direction.
An elastic member assembled on both sides of the intermediate transmission member in the axial direction and having insertion holes through which the end transmission teeth arranged at a plurality of locations in the circumferential direction are inserted in the axial direction.
With
In a state where the end transmission tooth inserts the insertion hole in the axial direction, the end transmission tooth and the intermediate transmission tooth are arranged alternately in the circumferential direction and through the first circumferential gap.
The circumferential distance between the circumferential edges of the insertion hole is smaller than the circumferential distance between adjacent intermediate transmission teeth among the intermediate transmission teeth, and
It said plurality of at least one end transmission teeth of the ends transmission teeth axially inner end of its, with a tapered portion as the circumferential width toward the axially inner side becomes small, guiding is constituted by the transmission teeth,
Only a part of the end transmission teeth among the plurality of end transmission teeth is composed of the guide transmission teeth, and the axial inner end portion provided with the tapered portion of the guide transmission teeth is The remaining end transmission teeth of the plurality of end transmission teeth project axially inward from the axial inner edge.
Torque transmission fitting. 前記案内用伝達歯は、その軸方向外端部および中間部に、前記テーパ部に軸方向に連続して形成され、軸方向に関して周方向幅寸法が変化しないストレート部を備える、請求項１に記載のトルク伝達用継手。According to claim 1, the guide transmission tooth is provided with a straight portion formed on the tapered portion continuously in the axial direction at the outer end portion and the intermediate portion in the axial direction and the circumferential width dimension does not change with respect to the axial direction. The described torque transmission fitting. 前記テーパ部の軸方向内端縁の周方向幅寸法は、前記挿通孔の周方向両側縁同士の周方向間隔よりも小さい、請求項１または２に記載のトルク伝達用継手。 The torque transmission joint according to claim 1 or 2 , wherein the circumferential width dimension of the axial inner edge of the tapered portion is smaller than the circumferential distance between the circumferential inner edges of the insertion hole. 前記１対の端部伝達部材のうちの一方の端部伝達部材の前記案内用伝達歯の前記テーパ部と、前記１対の端部伝達部材のうちの他方の端部伝達部材の前記案内用伝達歯の前記テーパ部とが、第１の周方向隙間よりも大きい第２の周方向隙間を介在させた状態で、周方向に重畳して配置される、請求項１〜３のいずれかに記載のトルク伝達用継手。 The taper portion of the guide transmission tooth of one end transmission member of the pair of end transmission members and the guide of the other end transmission member of the pair of end transmission members. One of claims 1 to 3 in which the tapered portion of the transmission tooth is arranged so as to overlap in the circumferential direction with a second circumferential gap larger than the first circumferential gap interposed therebetween. The described torque transmission fitting. 前記１対の端部伝達部材のそれぞれは、前記複数の端部伝達歯の径方向片端部が結合された周面を有する端部連結部をさらに備え、前記案内用伝達歯の前記テーパ部と、前記端部連結部の軸方向内端部のうちで該テーパ部が結合された周方向部分である補強部とが、前記端部連結部の軸方向内端部のうちの他の周方向部分よりも軸方向内側に張り出している、請求項１〜４のいずれかに記載のトルク伝達用継手。 Each of the pair of end transmission members further includes an end connecting portion having a peripheral surface to which one radial end portion of the plurality of end transmission teeth is connected, and the tapered portion of the guide transmission tooth. The reinforcing portion, which is the circumferential portion to which the tapered portion is connected, is the axial inner end portion of the end connecting portion, and the other circumferential direction of the axial inner end portion of the end connecting portion. The torque transmission joint according to any one of claims 1 to 4, which projects inward in the axial direction from the portion. 前記１対の端部伝達部材のうちの一方の端部伝達部材の案内用伝達歯の前記補強部と、前記１対の端部伝達部材のうちの他方の端部伝達部材の案内用伝達歯の前記補強部とが、第１の周方向隙間よりも大きい第２の周方向隙間を介在させた状態で周方向に重畳して配置される、請求項５に記載のトルク伝達用継手。 The reinforcing portion of the guide transmission tooth of one end transmission member of the pair of end transmission members and the guidance transmission tooth of the other end transmission member of the pair of end transmission members. The torque transmission joint according to claim 5 , wherein the reinforcing portion is arranged so as to overlap in the circumferential direction with a second circumferential gap larger than the first circumferential gap interposed therebetween. 前記補強部の周方向両側面が、該補強部に結合された前記テーパ部の周方向両側面よりも周方向両側に張り出している、請求項５または６に記載のトルク伝達用継手。 The torque transmission joint according to claim 5 or 6 , wherein both sides in the circumferential direction of the reinforcing portion project on both sides in the circumferential direction from both sides in the circumferential direction of the tapered portion coupled to the reinforcing portion. 前記弾性部材は、前記挿通孔のそれぞれの周方向両側縁の少なくとも一方の側縁の径方
向一部に、周方向中央側に向けて突出する弾性突起を備える、請求項１〜７のいずれかに記載のトルク伝達用継手。 Any one of claims 1 to 7 , wherein the elastic member includes an elastic protrusion projecting toward the center side in the circumferential direction at least one side edge of the insertion hole in the circumferential direction at least in the radial direction. Torque transmission fittings described in. ハウジングと、
前記ハウジングに対し回転可能に支持されたウォームホイールと、
前記ウォームホイールと噛合した状態で、前記ハウジングに対し回転可能に支持されたウォームと、
前記ウォームを回転駆動するための出力軸を有する電動モータと、
を備えた、電動式パワーステアリング装置であって、
前記電動モータの出力軸と前記ウォームとの間に、前記電動モータの出力軸と前記ウォームとをトルク伝達を可能に接続する、トルク伝達用継手が備えられており、該トルク伝達用継手が、請求項１〜８のうちのいずれか１項に記載のトルク伝達用継手により構成され、前記１対の端部伝達部材のうちの一方の端部伝達部材は、前記電動モータの出力軸の先端部に固定または一体に形成されており、前記１対の端部伝達部材のうちの他方の端部伝達部材は、前記ウォームの基端部に固定または一体に形成されている、
電動式パワーステアリング装置。 With the housing
A worm wheel that is rotatably supported against the housing,
A worm that is rotatably supported with respect to the housing while meshed with the worm wheel.
An electric motor having an output shaft for rotationally driving the worm, and
It is an electric power steering device equipped with
A torque transmission joint is provided between the output shaft of the electric motor and the worm to enable torque transmission between the output shaft of the electric motor and the worm. The torque transmission joint according to any one of claims 1 to 8 is formed, and one end transmission member of the pair of end transmission members is the tip of the output shaft of the electric motor. The other end transmission member of the pair of end transmission members is fixedly or integrally formed on the base end portion of the worm.
Electric power steering device.
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JP5929451B2 (en) * 2012-01-31 2016-06-08 日本精工株式会社 Torque transmission joint and electric power steering device
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