JP2019095020A - Wave gear device - Google Patents

Abstract

To provide a wave gear device capable of suppressing backlash in transmitting rotation without reducing a magnitude of transmission torque, and suppressing degradation of power transmission efficiency.SOLUTION: A wave gear device 1 has a rotated wave generator, a cylindrical external gear 3 elastically deformed into the elliptical shape by being fitted to the wave generator, and an internal gear engaged with the external gear 3 on a long axis of the external gear 3 elastically deformed into the elliptical shape. Engagement pieces 30 of the external gear 3 are engaged with engagement piece reception recessed portions 31 formed on a pair of radial ribs 26, 26 of which circumferential end portions 34 at both sides along a circumferential direction of the external gear 3 are adjacent to each other. The circumferential end portions 34 are slid and kept into contact with engagement piece contact walls 35 of the engagement piece reception recessed portions 31 when the external gear 3 is elastically deformed into the elliptical shape by the wave generator, to prevent relative rotation of the external gear 3 and a fixed member 5.SELECTED DRAWING: Figure 3

Description

この発明は、回転を減速するために使用される波動歯車装置に関するものである。   The present invention relates to a wave gear device used to reduce rotation.

従来から、波動歯車装置は、ヒューマノイドロボット、半導体製造装置、及び工作機械等に幅広く使用され、サーボモータ等の回転を大きく減速して伝達するようになっている。そして、この波動歯車装置は、高精度の回転伝達を実現するために回転伝達部分のバックラッシュの低減化が求められている。   Conventionally, a wave gear device has been widely used in humanoid robots, semiconductor manufacturing devices, machine tools and the like, and is configured to largely decelerate and transmit the rotation of a servomotor or the like. And in this wave gear device, in order to realize highly accurate rotation transmission, reduction of backlash of the rotation transmission part is required.

（第１従来例）
図１０及び図１１は、第１従来例に係る波動歯車装置１００を示すものである。これらの図に示す波動歯車装置１００は、楕円形状の波動発生器１０１と、この波動発生器１０１の外周面に嵌合される外歯車１０２と、この外歯車１０２と噛み合う内歯車１０３と、を有している。この波動歯車装置１００において、波動発生器１０１は、外周面が楕円形状のカム部材１０４と、このカム部材１０４の外周面に嵌合されることによってカム部材１０４の外周面に倣って楕円形状に変形するボールベアリング１０５と、を有している。また、外歯車１０２は、弾性変形可能な薄肉の円筒部材１０６の外周面に複数の歯が形成されており、波動発生器（ボールベアリング）の楕円形状の外周面に嵌合されると、波動発生器の楕円形状の外周面に倣って楕円形状に変形させられるようになっている。また、この外歯車１０２は、円板状の出力部材１０７の係合突起１０８と係合する係合凹所１１０が円筒部材１０６の一端側の周方向に沿って形成されている。内歯車１０３は、変形し難い剛構造体であり、内歯が楕円形状に変形させられた外歯車１０２の長軸上に位置する外歯と噛み合うようになっている。 (First Conventional Example)
10 and 11 show a wave gear drive 100 according to a first conventional example. The wave gear device 100 shown in these figures includes an elliptical wave generator 101, an external gear 102 fitted to the outer peripheral surface of the wave generator 101, and an internal gear 103 meshing with the external gear 102. Have. In the wave gear device 100, the wave generator 101 has a cam member 104 whose outer peripheral surface is an elliptical shape, and by being fitted to the outer peripheral surface of the cam member 104, the outer peripheral surface of the cam member 104 conforms to an elliptical shape. And a ball bearing 105 that deforms. Further, in the external gear 102, a plurality of teeth are formed on the outer peripheral surface of the elastically deformable thin cylindrical member 106, and when the outer gear 102 is fitted to the elliptical outer peripheral surface of the wave generator (ball bearing) It is designed to be deformed into an elliptical shape following the outer peripheral surface of the generator. Further, in the external gear 102, an engagement recess 110 that engages with the engagement protrusion 108 of the disk-shaped output member 107 is formed along the circumferential direction on one end side of the cylindrical member 106. The internal gear 103 is a rigid structure that is not easily deformed, and the internal gear is engaged with an external gear positioned on the major axis of the external gear 102 deformed into an elliptical shape.

この第１従来例に係る波動歯車装置１００は、内歯車１０３の歯数をＺｃとし、外歯車１０２の歯数をＺｆとし、内歯車１０３を固定した場合、波動発生器１０１のＮ回転に対し、外歯車１０２がＮ・（Ｚｃ−Ｚｆ）／Ｚｆ回転するようになっている。なお、第１従来例に係る波動歯車装置１００は、内歯車１０３の歯数（Ｚｃ）と外歯車１０２の歯数（Ｚｆ）との差が２になっている。   In the wave gear device 100 according to the first conventional example, when the number of teeth of the internal gear 103 is Zc, the number of teeth of the external gear 102 is Zf, and the internal gear 103 is fixed, N rotation of the wave generator 101 is performed. The external gear 102 rotates N · (Zc−Zf) / Zf. In the wave gear device 100 according to the first conventional example, the difference between the number of teeth (Zc) of the internal gear 103 and the number of teeth (Zf) of the external gear 102 is two.

図１２に示すように、第１従来例に係る波動歯車装置１００は、外歯車１０２が波動発生器１０１によって円滑に楕円変形させられるようにするため、出力部材１０７の係合突起１０８が外歯車１０２の係合凹所１１０内をスライド移動できるようになっている。しかしながら、このような波動歯車装置１００は、出力部材１０７の係合突起１０８と外歯車１０２の係合凹所１１０との係合部分（回転伝達部分）に隙間が形成されると、その隙間分だけ回転伝達時に回転方向のガタツキ（バックラッシュ）を生じる。   As shown in FIG. 12, in the wave gear device 100 according to the first prior art, the engagement protrusion 108 of the output member 107 is an external gear so that the external gear 102 can be smoothly elliptically deformed by the wave generator 101. It can slide in the engagement recess 110 of 102. However, in such a wave gear device 100, when a gap is formed in the engagement portion (rotational transmission portion) of the engagement protrusion 108 of the output member 107 and the engagement recess 110 of the external gear 102, the gap In the rotation transmission, backlash occurs in the rotational direction.

そこで、図１３及び図１４に示すように、第１従来例に係る波動歯車装置１００は、出力部材１０７の係合突起１０８の幅方向両側にばね作用部１１１を設け、そのばね作用部１１１を弾性変形させた状態で円筒部材１０６の係合凹所１１０の両側の壁面１１２に当接させ、回転伝達時の回転方向へのガタツキ（バックラッシュ）を抑えるようになっている。   Therefore, as shown in FIGS. 13 and 14, the wave gear device 100 according to the first prior art is provided with the spring action parts 111 on both sides in the width direction of the engagement protrusion 108 of the output member 107. The elastic member is abutted against the wall surfaces 112 on both sides of the engagement recess 110 of the cylindrical member 106 in an elastically deformed state, so that backlash in the rotational direction at the time of rotational transmission is suppressed.

（第２従来例）
図１５乃至図１７は、第２従来例に係る波動歯車装置２００を示すものである。これらの図に示す第２従来例に係る波動歯車装置２００は、波動発生器２０１、外歯車２０２、、内歯車２０３、及び出力部材２０４からなっている。外歯車２０２は、弾性変形可能な薄肉状の円筒部材２０５の外周面に複数の歯（外歯）が形成されており、波動発生器２０１によって楕円形状に弾性変形させられ、長軸上の２箇所で内歯車２０３と噛み合っている。 (Second prior art example)
FIGS. 15 to 17 show a wave gear device 200 according to a second conventional example. The wave gear device 200 according to the second conventional example shown in these figures comprises a wave generator 201, an external gear 202, an internal gear 203, and an output member 204. The external gear 202 has a plurality of teeth (external teeth) formed on the outer peripheral surface of the elastically deformable thin-walled cylindrical member 205, and is elastically deformed into an elliptical shape by the wave generator 201. It meshes with the internal gear 203 at the point.

そして、この第２従来例に係る波動歯車装置２００の外歯車２０２は、円筒部材２０５の一側面側に棒状突起２０６を突出形成し、その棒状突起２０６の移動軌跡に沿う内面形状の係合穴２０７を出力部材２０４の円板状部２０８に形成し、棒状突起２０６とこの棒状突起２０６に係合する係合穴２０７とで回転伝達部分を構成して、外歯車２０２の楕円変形を許容しつつ、回転伝達時のバックラッシュを抑え、波動発生器２０１の回転を減速して出力部材２０４の出力軸２１０から出力するようになっている。   Then, the external gear 202 of the wave gear device 200 according to the second prior art has the rod-like protrusion 206 formed on one side of the cylindrical member 205 so as to protrude, and the engagement hole of the inner surface shape along the movement locus of the rod-like protrusion 206 207 is formed on the disc-like portion 208 of the output member 204, and a rod portion 206 and an engagement hole 207 engaged with the rod portion 206 constitute a rotation transmitting portion to allow the oval gear 202 to elliptically deform. At the same time, the backlash at the time of rotation transmission is suppressed, the rotation of the wave generator 201 is decelerated, and output from the output shaft 210 of the output member 204 is performed.

特開２０１１−１９６４２３号公報JP, 2011-196423, A 特開２０１５−１６９２５６号公報JP, 2015-169256, A

しかしながら、第１従来例に係る波動歯車装置１００は、外歯車１０２が波動発生器１０１によって楕円変形させられる際に、出力部材１０７の係合突起１０８のばね作用部１１１，１１１と円筒部材１０６の係合凹所１１０の壁面１１２，１１２とが常時摺接し、係合突起１０８のばね作用部１１１，１１１と円筒部材１０６の係合凹所１１０の壁面１１２，１１２との摺接部に摩擦抵抗（外歯車１０２の楕円変形を妨げる抵抗）が生じて、動力伝達効率の低下を生じる虞がある。   However, in the wave gear device 100 according to the first conventional example, when the external gear 102 is elliptically deformed by the wave generator 101, the spring action parts 111 and 111 of the engagement protrusion 108 of the output member 107 and the cylindrical member 106 The wall surfaces 112 and 112 of the engagement recess 110 are always in sliding contact with each other, and frictional resistance is generated between the spring action portions 111 and 111 of the engagement protrusion 108 and the wall surfaces 112 and 112 of the engagement recess 110 of the cylindrical member 106. (A resistance that prevents the elliptical deformation of the external gear 102) may occur, resulting in a reduction in power transmission efficiency.

また、第２従来例に係る波動歯車装置２００は、棒状突起２０６が弾性変形可能な薄肉状の円筒部材２０５の一側面側に突出形成される構成であるため、棒状突起２０６が細く、第１従来例の波動歯車装置１００のような大きさのトルク伝達が困難であった。   In addition, since the wave gear device 200 according to the second conventional example has a configuration in which the rod-like protrusion 206 is formed to protrude on one side of the thin cylindrical member 205 which can be elastically deformed, the rod-like protrusion 206 is thin. It is difficult to transmit a torque as large as the wave gear device 100 of the conventional example.

そこで、本発明は、伝達トルクの大きさを小さくすることなく、回転伝達時におけるバックラッシュを抑えることができると共に、動力伝達効率の低下を抑えることができる波動歯車装置の提供を目的とする。   Therefore, an object of the present invention is to provide a wave gear device capable of suppressing a backlash at the time of rotation transmission and reducing a reduction in power transmission efficiency without reducing the magnitude of the transmission torque.

本発明は、回転させられる波動発生器２と、この波動発生器２に嵌合されることによって楕円形状に弾性変形させられる円筒状の外歯車３と、この楕円形状に弾性変形させられた外歯車３の長軸上で前記外歯車３と噛み合う内歯車４と、を有する波動歯車装置１に関するものである。本発明において、前記外歯車３の歯幅方向に沿った一端面側には、固定部材５が対向するように配置されている。また、前記固定部材５は、前記外歯車３に対向する面側に、前記波動発生器２の回転中心２３ａに対して放射状に延びる複数の径方向リブ２６が形成されている。また、前記外歯車３は、前記歯幅方向に沿った一端面側に、前記固定部材５へ向かって突出する舌片状の係合片３０が周方向に沿って複数形成されている。また、前記係合片３０は、前記外歯車３の周方向に沿った両側の周方向端部３４が隣り合う一対の径方向リブ２６，２６にそれぞれ形成された係合片収容凹所３１，３１に係合され、前記外歯車３が前記波動発生器２によって楕円形状に弾性変形させられると、前記周方向端部３４が前記係合片収容凹所３１の係合片当接壁３５に摺接して、前記外歯車３と前記固定部材５との相対回動を阻止する。また、前記係合片収容凹所３１の係合片当接壁３５は、前記外歯車３が前記波動発生器２によって楕円形状に弾性変形された際の前記係合片３の前記周方向端部３４の移動軌跡に沿った曲面に形成されている。また、前記内歯車４は、前記波動発生器２の回転に伴って前記外歯車３及び前記固定部材５に対して回動させられる。   The present invention comprises a wave generator 2 which is rotated, a cylindrical external gear 3 which is elastically deformed into an elliptical shape by being fitted to the wave generator 2, and an outer member which is elastically deformed into the oval shape. The present invention relates to a wave gear device 1 having an internal gear 4 meshing with the external gear 3 on the major axis of the gear 3. In the present invention, the fixing member 5 is disposed to face the one end face side along the tooth width direction of the external gear 3. Further, on the surface side of the fixing member 5 facing the external gear 3, a plurality of radial ribs 26 radially extending with respect to the rotation center 23 a of the wave generator 2 are formed. Further, a plurality of tongue-like engagement pieces 30 protruding toward the fixing member 5 are formed along the circumferential direction on one end surface side along the tooth width direction of the external gear 3. Further, the engagement piece 30 is an engagement piece receiving recess 31 formed in each of a pair of radial ribs 26 adjacent to each other in the circumferential direction 34 on both sides along the circumferential direction of the external gear 3, 31 and when the external gear 3 is elastically deformed into an elliptical shape by the wave generator 2, the circumferential end 34 is in contact with the engagement piece abutment wall 35 of the engagement piece accommodation recess 31. The sliding contact prevents the relative rotation between the external gear 3 and the fixing member 5. The engagement piece abutting wall 35 of the engagement piece accommodation recess 31 is the circumferential end of the engagement piece 3 when the external gear 3 is elastically deformed into an elliptical shape by the wave generator 2. It is formed in the curved surface along the movement locus of section 34. Further, the internal gear 4 is rotated with respect to the external gear 3 and the fixing member 5 in accordance with the rotation of the wave generator 2.

本発明に係る波動歯車装置は、伝達トルクの大きさを小さくすることなく、回転伝達時におけるバックラッシュを抑えることができることはもちろんのこと、動力伝達効率の低下を抑えることができる。   The wave gear device according to the present invention can suppress a reduction in power transmission efficiency as well as being able to suppress a backlash at the time of rotation transmission without reducing the magnitude of the transmission torque.

本発明の第１実施形態に係る波動歯車装置を示す図であり、図１（ａ）は波動歯車装置の正面図、図１（ｂ）は波動歯車装置の側面図、図１（ｃ）は図１（ａ）のＡ１−Ａ１線に沿って切断して示す波動歯車装置１の断面図である。1 (a) is a front view of a wave gear device, FIG. 1 (b) is a side view of the wave gear device, and FIG. 1 (c) is a diagram showing a wave gear device according to a first embodiment of the present invention. It is sectional drawing of the wave gear apparatus 1 cut | disconnected and shown along the A1-A1 line of Fig.1 (a). 図２（ａ）は図１（ｃ）のＡ２−Ａ２線に沿って切断して示す波動歯車装置の断面図、図２（ｂ）は図２（ａ）のＢ１部の拡大図、図２（ｃ）は図２（ａ）のＢ２部の拡大図である。2 (a) is a cross-sectional view of the wave gear device taken along line A2-A2 of FIG. 1 (c), FIG. 2 (b) is an enlarged view of part B1 of FIG. 2 (a), FIG. (C) is an enlarged view of B2 part of FIG. 2 (a). 図３（ａ）は図１（ｃ）のＡ３−Ａ３線に沿って切断して示す波動歯車装置の断面図であり、図３（ｂ）は第１係合片と一対の係合片収容凹所との関係を示す第１状態の図、図３（ｃ）は第１係合片と一対の係合片収容凹所との関係を示す第２状態の図、図３（ｄ）は第１係合片と一対の係合片収容凹所との関係を示す第３状態の図、図３（ｅ）は第１係合片と一対の係合片収容凹所との関係を示す第４状態の図である。3 (a) is a cross-sectional view of the wave gear device taken along line A3-A3 of FIG. 1 (c), and FIG. 3 (b) is a diagram showing the first engagement piece and a pair of engagement pieces received. Figure 3 (c) shows the relationship between the first engagement piece and the pair of engagement piece storage recesses; Figure 3 (d) shows the relationship between the first engagement piece and the pair of engagement piece storage recesses; The figure of the 3rd state which shows the relation between the 1st engagement piece and a pair of engagement piece accommodation concaves, and Drawing 3 (e) shows the relation between the 1st engagement piece and a pair of engagement piece accommodation concaves It is a figure of a 4th state. 本発明の第１実施形態に係る波動歯車装置の波動発生器を示す図であり、図４（ａ）は波動発生器の正面図、図４（ｂ）は波動発生器の側面図、図４（ｃ）は図４（ａ）のＡ４−Ａ４線に沿って切断して示す波動発生器の断面図、図４（ｄ）は波動発生器の背面図である。It is a figure which shows the wave generator of the wave gear apparatus concerning 1st Embodiment of this invention, FIG. 4 (a) is a front view of a wave generator, FIG.4 (b) is a side view of a wave generator, FIG. (C) is a cross-sectional view of the wave generator shown by cutting along line A4-A4 in FIG. 4 (a), and FIG. 4 (d) is a rear view of the wave generator. 本発明の第１実施形態に係る波動歯車装置の固定部材を示す図であり、図５（ａ）は固定部材の正面図、図５（ｂ）は固定部材の側面図、図５（ｃ）は図５（ａ）のＡ５−Ａ５線に沿って切断して示す固定部材の断面図、図５（ｄ）は図５（ａ）のＡ６−Ａ６線に沿って切断して示す固定部材の断面図、図５（ｅ）は固定部材の背面図である。It is a figure which shows the fixing member of the wave gear apparatus concerning 1st Embodiment of this invention, FIG. 5 (a) is a front view of a fixing member, FIG.5 (b) is a side view of a fixing member, FIG.5 (c) 5 (a) is a cross-sectional view of the fixing member taken along line A5-A5 of FIG. 5 (a), and FIG. 5 (d) is a cutting member shown along line A6-A6 of FIG. 5 (a). FIG. 5E is a rear view of the fixing member. 図６（ａ）は固定部材の係合片収容凹所を部分的に拡大して示す図であり、図６（ｂ）は図６（ａ）に示した係合片収容凹所の変形例を示す図である。FIG. 6 (a) is a partially enlarged view of the engagement piece receiving recess of the fixing member, and FIG. 6 (b) is a modification of the engagement piece receiving recess shown in FIG. 6 (a). FIG. 本発明の第１実施形態に係る波動歯車装置の外歯車を示す図であり、図７（ａ）は外歯車の正面図、図７（ｂ）は外歯車の側面図、図７（ｃ）は図７（ａ）のＡ７−Ａ７線に沿って切断して示す外歯車の断面図、図７（ｄ）は外歯車の背面図、図７（ｅ）は図７（ｄ）に示した外歯車の係合片を拡大して示す図である。FIG. 7A is a front view of the external gear, FIG. 7B is a side view of the external gear, and FIG. 7C is a view showing the external gear of the wave gear device according to the first embodiment of the present invention. 7 (a) is a cross-sectional view of the external gear taken along line A7-A7, FIG. 7 (d) is a rear view of the external gear, and FIG. 7 (e) is shown in FIG. 7 (d). It is a figure which expands and shows the engagement piece of an external gear. 本発明の第１実施形態に係る波動歯車装置の内歯車を示す図であり、図８（ａ）は内歯車の正面図、図８（ｂ）は内歯車の側面図、図８（ｃ）は図８（ａ）のＡ８−Ａ８線に沿って切断して示す内歯車の断面図、図８（ｄ）は内歯車の背面図である。It is a figure which shows the internal gear of the wave gear apparatus concerning 1st Embodiment of this invention, FIG. 8 (a) is a front view of an internal gear, FIG.8 (b) is a side view of an internal gear, FIG.8 (c) 8 is a cross-sectional view of an internal gear taken along line A8-A8 in FIG. 8 (a), and FIG. 8 (d) is a rear view of the internal gear. 本発明の第１実施形態に係る波動歯車装置のカバーを示す図であり、図９（ａ）はカバーの正面図、図９（ｂ）はカバーの側面図、図９（ｃ）は図９（ａ）のＡ９−Ａ９線に沿って切断して示すカバーの断面図、図９（ｄ）はカバーの背面図である。9 is a view showing a cover of the wave gear device according to the first embodiment of the present invention, FIG. 9 (a) is a front view of the cover, FIG. 9 (b) is a side view of the cover, and FIG. FIG. 9D is a rear view of the cover, showing a cross section taken along line A9-A9 of FIG. 第１従来例に係る波動歯車装置を示す正面図である。It is a front view showing a wave gear device concerning the 1st conventional example. 第１従来例に係る波動歯車装置を示す図であり、図１０（ａ）のＡ１０−Ａ１０線に沿って切断して示す波動歯車装置の断面図である。It is a figure which shows the wave gear apparatus which concerns on a 1st prior art example, and is sectional drawing of the wave gear apparatus shown cutting along the A10-A10 line of Fig.10 (a). 第１従来例に係る波動歯車装置の出力部材と外歯車との関係を示す図である。It is a figure which shows the relationship of the output member and external gear of the wave gear apparatus which concern on a 1st prior art example. 第１従来例に係る波動歯車装置の出力部材の変形例を示す図である。It is a figure which shows the modification of the output member of the wave gear apparatus which concerns on a 1st prior art example. 図１３に示した出力部材と外歯車との係合部を示す図である。It is a figure which shows the engagement part of the output member and external gear shown in FIG. 第２従来例に係る波動歯車装置の縦断面図である。It is a longitudinal cross-sectional view of the wave gear apparatus concerning a 2nd prior art example. 第２従来例に係る波動歯車装置の外歯車を示す図であり、図１６（ａ）は外歯車の縦断面図（図１６（ｂ）のＡ１１−Ａ１１線に沿って切断して示す断面図）、図１６（ｂ）は外歯車の正面図である。FIG. 16 is a view showing an external gear of a wave gear device according to a second prior art, and FIG. 16 (a) is a longitudinal sectional view of the external gear (a sectional view taken along line A11-A11 in FIG. 16 (b)) Fig. 16 (b) is a front view of the external gear. 第２従来例に係る波動歯車装置における外歯車の棒状突起と出力部材の係合穴との係合状態を示す図である。It is a figure which shows the engagement state of the rod-shaped protrusion of the external gear in the wave gear apparatus concerning a 2nd prior art example, and the engagement hole of an output member.

以下、本発明の実施形態を図面に基づき詳述する。   Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

図１及び図２は、本発明の第１実施形態に係る波動歯車装置１を示す図である。なお、図１（ａ）は波動歯車装置１の正面図であり、図１（ｂ）は波動歯車装置１の側面図であり、図１（ｃ）は図１（ａ）のＡ１−Ａ１線に沿って切断して示す波動歯車装置１の断面図である。また、図２（ａ）は図１（ｃ）のＡ２−Ａ２線に沿って切断して示す波動歯車装置１の断面図であり、図２（ｂ）は図２（ａ）のＢ１部の拡大図であり、図２（ｃ）は図２（ａ）のＢ２部の拡大図である。   1 and 2 are views showing a wave gear device 1 according to a first embodiment of the present invention. 1 (a) is a front view of the wave gear device 1, FIG. 1 (b) is a side view of the wave gear device 1, and FIG. 1 (c) is an A1-A1 line of FIG. 1 (a). FIG. 2 is a cross-sectional view of the wave gear device 1 shown by cutting along FIG. 2 (a) is a cross-sectional view of the wave gear device 1 taken along line A2-A2 of FIG. 1 (c), and FIG. 2 (b) is a cross-sectional view of part B1 of FIG. 2 (a). It is an enlarged view, and FIG.2 (c) is an enlarged view of B2 part of Fig.2 (a).

（波動歯車装置の概略構成）
図１及び図２に示すように、本実施形態に係る波動歯車装置１は、図外のサーボモータ等の駆動手段によって回転させられる波動発生器２と、この波動発生器２に嵌合されることによって楕円形状に弾性変形させられる円筒状の外歯車３と、この楕円形状に変形させられた外歯車３の長軸上で外歯車３と噛み合う内歯車４と、図外のロボットアーム等の取付対象物に固定される固定部材（ハウジング）５と、固定部材５に固定されるカバー６と、を有している。そして、本実施形態に係る波動歯車装置１は、波動発生器２、外歯車３、内歯車４、固定部材５、及びカバー６がプラスチック（例えば、ポリアセタール（ＰＯＭ）、ポリアミド（ＰＡ）等）で形成されている。 (Schematic configuration of wave gear device)
As shown in FIGS. 1 and 2, the wave gear device 1 according to the present embodiment is fitted to a wave generator 2 which is rotated by a driving means such as a servomotor (not shown) and the wave generator 2. A cylindrical external gear 3 elastically deformed into an elliptical shape, an internal gear 4 meshing with the external gear 3 on the major axis of the elliptically deformed external gear 3, a robot arm (not shown), etc. It has a fixing member (housing) 5 fixed to the mounting object and a cover 6 fixed to the fixing member 5. In the wave gear device 1 according to the present embodiment, the wave generator 2, the external gear 3, the internal gear 4, the fixing member 5, and the cover 6 are made of plastic (for example, polyacetal (POM), polyamide (PA), etc.) It is formed.

（波動発生器）
図１、図２、及び図４に示すように、波動発生器２は、入力軸７と、この入力軸７の先端側に一体に形成された楕円状カム８と、楕円状カム８の正面の回転中心部から突出する（入力軸７の突出方向とは逆の方向に突出する）支持軸１０と、を有している。 (Wave generator)
As shown in FIGS. 1, 2 and 4, the wave generator 2 includes an input shaft 7, an elliptical cam 8 integrally formed on the tip end side of the input shaft 7, and a front face of the elliptical cam 8. And a support shaft 10 (projecting in a direction opposite to the direction in which the input shaft 7 protrudes) from the rotation center of

入力軸７は、固定部材５の軸穴１１で回動できるように支持され、図外の駆動手段に接続される。   The input shaft 7 is rotatably supported by the shaft hole 11 of the fixing member 5 and is connected to drive means (not shown).

楕円状カム８は、長軸側カム部１２と短軸側カム部１３とによって構成されており、正面側から見た形状が略十字状になっている。そして、長軸側カム部１２の外周面１４及び短軸側カム部１３の外周面１５は、外歯車３に接触する楕円状周面１６，１８と、この楕円状周面１６，１８の周方向両端側に滑らかに接続された円弧状周面１７，２０と、を有している。円弧状周面１７，２０は、曲率半径が楕円状周面１６，１８の周方向両端の曲率半径と同一になっており、楕円状周面１６，１８との接続部から周方向端部に向かうに従って、楕円状周面１６，１８に支持された外歯車３との間の隙間が楔状に漸増するように形成されている。そして、円弧状周面１７，２０は、楕円状周面１６，１８が外歯車３の内周面３ａと摺接する際に、潤滑剤を楔効果によって楕円状周面１６．１８と外歯車の内周面３ａとの間に導き入れるように機能する。また、楕円状カム１６，１８は、長軸側カム部１２と短軸側カム部１３との間が略Ｖ字形状の凹所２１になっており、長軸側カム部１２の楕円状周面１６と短軸側カム部１３の楕円状周面１８のみが外歯車３の内周面３ａに摺接するようになっているため、全周が外歯車３の内周面３ａと摺接する場合と比較して、外歯車３との摺接抵抗が小さく抑えられる。   The elliptical cam 8 is constituted by the major axis side cam portion 12 and the minor axis side cam portion 13, and the shape viewed from the front side is substantially in a cross shape. The outer peripheral surface 14 of the major axis side cam portion 12 and the outer peripheral surface 15 of the minor axis side cam portion 13 have elliptical peripheral surfaces 16 and 18 in contact with the external gear 3 and the peripheries of the elliptical peripheral surfaces 16 and 18. It has circular arc-shaped surrounding surfaces 17 and 20 smoothly connected to the direction both end side. The arc-shaped circumferential surfaces 17 and 20 have the same radius of curvature as that of both ends of the elliptical peripheral surfaces 16 and 18 in the circumferential direction, and from the connection with the elliptical peripheral surfaces 16 and 18 to the circumferential end The clearance between the external gear 3 supported by the elliptical peripheral surfaces 16 and 18 is formed so as to gradually increase in a bowl-like shape along the direction. Then, when the elliptical peripheral surfaces 16 and 18 are in sliding contact with the inner peripheral surface 3 a of the external gear 3, the arc-shaped peripheral surfaces 17 and 20 have an elliptical peripheral surface 16.18 and an external gear It functions to lead in between the inner circumferential surface 3a. The oval cams 16 and 18 have a substantially V-shaped recess 21 between the major axis side cam portion 12 and the minor axis side cam portion 13, and the elliptical periphery of the major axis side cam portion 12 When only the surface 16 and the elliptical peripheral surface 18 of the short shaft side cam portion 13 are in sliding contact with the inner peripheral surface 3 a of the external gear 3, the entire circumference is in sliding contact with the internal peripheral surface 3 a of the external gear 3 As compared with the above, the sliding contact resistance with the external gear 3 is suppressed small.

支持軸１０は、内歯車４の軸受け穴２２に嵌合されている。そして、支持軸１０の回転中心２３ｃは、入力軸７（波動発生器２）の回転中心２３ａ及び軸２４の回転中心２３ｂと同軸上に位置している。   The support shaft 10 is fitted in the bearing hole 22 of the internal gear 4. The rotation center 23c of the support shaft 10 is located coaxially with the rotation center 23a of the input shaft 7 (wave generator 2) and the rotation center 23b of the shaft 24.

（固定部材）
図１乃至図３、及び図５に示すように、固定部材（ハウジング）５は、外歯車３の一側面２５（歯幅方向に沿った一端面であって、図１（ｃ）の右側端面）に対向するように配置され、中心部に形成された軸穴１１で波動発生器２の入力軸７を回転できるように支持している。 (Fixing member)
As shown in FIG. 1 to FIG. 3 and FIG. 5, the fixing member (housing) 5 is one side face 25 of the external gear 3 (one end face along the tooth width direction, and the right end face of FIG. And the shaft hole 11 formed in the center supports the input shaft 7 of the wave generator 2 so as to be able to rotate.

また、図５に示すように、固定部材５は、外歯車３の一側面２５に対向する面側に、入力軸７（波動発生器２）の回転中心２３ａに対して放射状に延びる複数の径方向リブ２６が形成されている。この径方向リブ２６は、リブ幅が一定の部分（径方向内方側リブ部分２７）とリブ幅が変化する部分（径方向外方側リブ部分２８）とがある。すなわち、径方向リブ２６は、径方向内方端から径方向外方端側へ向けて一定のリブ幅で形成された径方向内方側リブ部分２７と、径方向内方側リブ部分２７の径方向外方端から径方向外方へ向かうに従ってリブ幅を漸増するように形成された径方向外方側リブ部分２８とがある。そして、径方向リブ２６には、外歯車３の舌片状の係合片３０を係合するための係合片収容凹所３１，３１が一対形成されている（図３参照）。この一対の係合片収容凹所３１，３１は、同一円周上に位置し、且つ、径方向リブ２６の幅方向の中心線３２（固定部材５の中心Ｃ１を通り、径方向へ延びる直線）に対して線対称の形状になっている。係合片収容凹所３１は、外歯車３の舌片状の係合片３０を固定部材５の正面側から係合させることができるように、径方向リブ２６の外歯車３に対向する面側に形成されており、正面側に向けて開口する周方向溝（固定部材５の周方向に沿った溝）である（図６（ａ）参照）。また、この係合片収容凹所３１は、一端側が隣り合う径方向リブ２６，２６間に形成される径方向溝３３に開口し、他端側が係合片３０の周方向端部３４と接触する係合片当接壁３５によって閉じられている（図６（ａ）参照）。係合片当接壁３５は、係合片３０の円弧形状に形成された周方向端部の移動軌跡に沿うような曲面になっている（図３（ｂ）〜（ｅ）、図６（ａ）、及び図７（ｅ）参照）。また、固定部材５の係合片収容凹所３１の溝幅ｗは、楕円状に変形させられる外歯車３の係合片３０の動きを許容する寸法になっている（図３（ｂ）〜（ｅ）参照）。   Further, as shown in FIG. 5, the fixing member 5 has a plurality of diameters extending radially with respect to the rotation center 23 a of the input shaft 7 (wave generator 2) on the side facing the one side surface 25 of the external gear 3. Directional ribs 26 are formed. The radial rib 26 has a portion with a constant rib width (radially inner side rib portion 27) and a portion with a variable rib width (radially outer side rib portion 28). That is, the radially inward rib portion 27 includes a radially inward rib portion 27 and a radially inward rib portion 27 which are formed with a constant rib width from the radially inward end toward the radially outward end. There is a radially outer rib portion 28 formed so as to gradually increase the rib width as going radially outward from the radially outer end. The radial direction rib 26 is provided with a pair of engagement piece receiving recesses 31 and 31 for engaging the tongue-like engagement pieces 30 of the external gear 3 (see FIG. 3). The pair of engagement piece receiving recesses 31 are located on the same circumference, and a center line 32 in the width direction of the radial rib 26 (a straight line extending in the radial direction through the center C1 of the fixing member 5) It has a line-symmetrical shape. The engagement piece receiving recess 31 has a surface facing the outer gear 3 of the radial rib 26 so that the tongue-shaped engagement piece 30 of the outer gear 3 can be engaged from the front side of the fixed member 5. It is a circumferential groove (a groove along the circumferential direction of the fixing member 5) formed on the side and opening toward the front side (see FIG. 6A). Further, the engagement piece receiving recess 31 opens at one end side in a radial groove 33 formed between the adjacent radial ribs 26, and the other end side contacts the circumferential end 34 of the engagement piece 30. It is closed by the engagement piece contact wall 35 (refer FIG. 6 (a)). The engagement piece abutting wall 35 has a curved surface along the movement trajectory of the circumferential end formed in the arc shape of the engagement piece 30 (FIGS. 3 (b) to (e), FIG. 6 ( a) and FIG. 7 (e)). Further, the groove width w of the engagement piece receiving recess 31 of the fixing member 5 is dimensioned to allow the movement of the engagement piece 30 of the external gear 3 to be deformed into an elliptical shape (FIG. 3 (b) ~ See (e)).

図３は、外歯車３の係合片３０と固定部材５の係合片収容凹所３１との関係を示す図である。なお、図３（ａ）は、図１（ｃ）のＡ３−Ａ３線に沿って切断して示す波動歯車装置１の断面図であり、Ｘ軸とＹ軸の交点が固定部材５の中心Ｃ１と一致し、波動発生器２の長軸の一端３６ａが＋Ｙ軸上に位置し、係合片３０の一つ（説明の便宜上、第１係合片３０と称する）が波動発生器２の長軸の一端３６ａ上に位置している状態を示す図である。そして、図３（ｂ）は、第１係合片３０が波動発生器２の長軸の一端３６ａ上にある場合の第１係合片３０と一対の係合片収容凹所３１，３１との関係を示す第１状態の図である。また、図３（ｃ）は、波動発生器２の長軸の一端３６ａが第１状態の位置から時計回り方向（矢印Ｒで示す方向）に４５°回動した場合の第１係合片３０と一対の係合片収容凹所３１，３１との関係を示す第２状態の図である。また、図３（ｄ）は、波動発生器２の長軸の一端３６ａが第１状態の位置から時計回り方向に９０°回動し、第１係合片３０が波動発生器２の短軸の一端３７ａ上に位置する場合の第１係合片３０と一対の係合片収容凹所３１，３１との関係を示す第３状態の図である。また、図３（ｅ）は、波動発生器２の長軸の一端３６ａが第１状態の位置から時計回り方向（矢印Ｒで示す方向）に１３５°回動した場合の第１係合片３０と一対の係合片収容凹所３１，３１との関係を示す第４状態の図である。また、波動発生器２の長軸の一端３６ａが第１状態の位置から時計回り方向（矢印Ｒで示す方向）に１８０°回動すると、第１係合片３０が波動発生器２の長軸の他端３６ｂ上に位置することになり、図３（ｂ）で示す第１状態に戻る。このように、第１係合片３０と一対の係合片収容凹所３１，３１との関係は、波動発生器２が半回転すると、第１〜第４状態を経て第１状態に戻るようになっている。したがって、第１係合片３０と一対の係合片収容凹所３１，３１との関係は、波動発生器が１回転すると、第１〜第４状態を経て第１状態に戻るサイクルが２回繰り返されることになる。   FIG. 3 is a view showing the relationship between the engagement piece 30 of the external gear 3 and the engagement piece receiving recess 31 of the fixed member 5. 3 (a) is a cross-sectional view of the wave gear device 1 taken along line A3-A3 of FIG. 1 (c), and the intersection point of the X axis and the Y axis is the center C1 of the fixing member 5. , One end 36a of the long axis of the wave generator 2 is located on the + Y axis, and one of the engagement pieces 30 (referred to as the first engagement piece 30 for convenience of description) is the length of the wave generator 2 It is a figure which shows the state located on the end 36a of an axis | shaft. 3B shows the first engagement piece 30 and the pair of engagement piece receiving recesses 31, 31 when the first engagement piece 30 is on one end 36a of the long axis of the wave generator 2. Is a diagram of a first state showing the relationship of 3C shows the first engagement piece 30 when one end 36a of the major axis of the wave generator 2 is rotated 45 ° clockwise from the position in the first state (the direction indicated by the arrow R). It is a figure of the 2nd state which shows the relationship between and a pair of engagement piece storage concave parts 31 and 31. FIG. Further, in FIG. 3D, one end 36a of the long axis of the wave generator 2 is rotated 90 ° clockwise from the position in the first state, and the first engagement piece 30 is the short axis of the wave generator 2. It is a figure of the 3rd state which shows the relation between the 1st engagement piece 30 and a pair of engagement piece storage concave parts 31 and 31 at the time of being located on one end 37a of a. 3 (e) shows the first engagement piece 30 when one end 36a of the major axis of the wave generator 2 is rotated 135 ° clockwise from the position in the first state (the direction indicated by the arrow R). It is a figure of the 4th state which shows the relationship between and a pair of engagement piece storage concave parts 31 and 31. FIG. In addition, when one end 36a of the major axis of the wave generator 2 is rotated 180 ° clockwise from the position in the first state (the direction indicated by the arrow R), the first engagement piece 30 is the major axis of the wave generator 2. 3b, and returns to the first state shown in FIG. 3 (b). Thus, the relationship between the first engagement piece 30 and the pair of engagement piece storage recesses 31 and 31 is such that when the wave generator 2 makes a half rotation, it returns to the first state through the first to fourth states. It has become. Therefore, the relationship between the first engagement piece 30 and the pair of engagement piece accommodation recesses 31 and 31 is such that, when the wave generator makes one rotation, the cycle of returning to the first state through the first to fourth states is twice. It will be repeated.

図３（ｂ）及び図３（ｄ）に示すように、第１係合片３０は、波動発生器２の長軸（一端３６ａ、他端３６ｂ）上及び短軸（一端３７ａ、他端３７ｂ上に位置する場合、両周方向端部３４，３４が一対の係合片収容凹所３１，３１の係合片当接壁３５，３５に接触する。これにより、外歯車３は、固定部材５に対して回り止めされる。   As shown in FIGS. 3 (b) and 3 (d), the first engagement piece 30 is on the major axis (one end 36a, the other end 36b) of the wave generator 2 and the short axis (one end 37a, the other end 37b). When positioned on the upper side, both circumferential end portions 34, 34 contact the engaging piece abutting walls 35, 35 of the pair of engaging piece accommodating recesses 31, 31. Thereby, the external gear 3 is a fixing member It is locked against 5

また、第１係合片３０は、波動発生器２の長軸の一端３６ａが第１状態から第１象限を時計回り方向に回動すると、一対の周方向端部３４，３４のうちの一方（図中右側）の周方向端部３４が一対の係合片収容凹所３１，３１のうちの一方（図中右側）の係合片収容凹所３１の係合片当接壁３５に当接する。また、第１係合片３０は、波動発生器２の長軸の一端３６ａが第３状態から第４象限を時計回り方向に回動すると、他方（図中左側）の周方向端部３４が他方（図中左側）の係合片収容凹所３１の係合片当接壁３５に当接する。   Further, when one end 36a of the major axis of the wave generator 2 pivots the first quadrant clockwise from the first state in the first engagement piece 30, one of the pair of circumferential end portions 34, 34 The circumferential end 34 (right side in the figure) abuts against the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 in one (right side in the figure) of the pair of engagement piece accommodation recesses 31, 31. Contact. Further, when the first engagement piece 30 is rotated clockwise in the fourth quadrant from the third state by one end 36a of the long axis of the wave generator 2, the circumferential end 34 of the other (left side in the figure) It abuts on the engagement piece abutment wall 35 of the other (left side in the drawing) engagement piece accommodation recess 31.

すなわち、外歯車３は、波動発生器２の長軸がＹ軸上に位置し、波動発生器２の短軸がＸ軸上に位置すると仮定すると、第１象限の係合片３０の一対の周方向端部３４，３４の一方（波動発生器２の回動方向側の周方向端部３４）が波動発生器２の回動方向（Ｒ方向）側の係合片収容凹所３１の係合片当接壁３５に摺接し、第４象限の係合片３０の一対の周方向端部３４，３４の他方（波動発生器２の回動方向と逆側の周方向端部３４）が波動発生器２の回動方向（Ｒ方向）と逆側の係合片収容凹所３１の係合片当接壁３５に摺接する結果、固定部材５に対する相対回動が阻止される。   That is, assuming that the major axis of the wave generator 2 is located on the Y axis and the short axis of the wave generator 2 is located on the X axis, the external gear 3 has a pair of engagement pieces 30 of the first quadrant. One of the circumferential ends 34, 34 (circumferential end 34 on the rotational direction side of the wave generator 2) is engaged with the engagement piece accommodating recess 31 on the rotational direction (R direction) of the wave generator 2 The other of the pair of circumferential ends 34, 34 of the pair of engagement pieces 30 of the fourth quadrant (the circumferential end 34 on the opposite side of the rotational direction of the wave generator 2) As a result of sliding contact with the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 opposite to the rotational direction (R direction) of the wave generator 2, relative rotation with respect to the fixing member 5 is blocked.

また、外歯車３は、波動発生器２の長軸がＹ軸上に位置し、波動発生器２の短軸がＸ軸上に位置すると仮定すると、第３象限の係合片３０の一対の周方向端部３４，３４の一方（波動発生器２の回動方向側の周方向端部３４）が波動発生器２の回動方向（Ｒ方向）側の係合片収容凹所３１の係合片当接壁３５に摺接し、第２象限の係合片３０の一対の周方向端部３４，３４の他方（波動発生器２の回動方向と逆側の周方向端部３４）が波動発生器２の回動方向（Ｒ方向）と逆側の係合片収容凹所３１の係合片当接壁３５に摺接する結果、固定部材５に対する相対回動が阻止される。   Also, assuming that the major axis of the wave generator 2 is located on the Y axis and the short axis of the wave generator 2 is located on the X axis, the external gear 3 has a pair of engagement pieces 30 of the third quadrant. One of the circumferential ends 34, 34 (circumferential end 34 on the rotational direction side of the wave generator 2) is engaged with the engagement piece accommodating recess 31 on the rotational direction (R direction) of the wave generator 2 The other of the pair of circumferential ends 34, 34 of the pair of engagement pieces 30 of the second quadrant (the circumferential end 34 on the opposite side of the rotation direction of the wave generator 2) As a result of sliding contact with the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 opposite to the rotational direction (R direction) of the wave generator 2, relative rotation with respect to the fixing member 5 is blocked.

このように、第１係合片３０は、波動発生器２が１回転し、第１乃至第４状態を経て第１状態に戻るサイクルが２回行われる間に、係合片収容凹所３１の係合片当接壁３５に常時摺接（滑り接触）することになる。その結果、外歯車３と固定部材５は、外歯車３に回動トルクが作用しても、外歯車３が固定部材５に対してガタツキ（回動方向のずれ動き）を生じることがない。   Thus, while the wave generator 2 makes one rotation, and the cycle of returning to the first state is performed twice through the first to fourth states, the first engagement piece 30 has the engagement piece storage recess 31. Is always in sliding contact (sliding contact) with the engagement piece abutting wall 35 of the second embodiment. As a result, in the external gear 3 and the fixing member 5, even if a rotational torque acts on the external gear 3, the external gear 3 does not rattle (displacement movement in the rotational direction) with respect to the fixing member 5.

図１及び図５に示すように、固定部材５のボス３８は、固定部材５の中央部に位置し、軸穴１１が貫通しており、先端面４０が波動発生器２の楕円状カム８の位置決め面４１に当接して、波動発生器２の回転中心２３ａに沿った方向の位置決めを行うようになっている。そして、固定部材５は、波動発生器２との接触を少なくするための環状の逃げ溝４２がボス３８の周囲に形成されている。   As shown in FIGS. 1 and 5, the boss 38 of the fixing member 5 is located at the central portion of the fixing member 5, the shaft hole 11 passes through, and the tip surface 40 is an elliptical cam 8 of the wave generator 2. The positioning of the direction along the rotation center 23 a of the wave generator 2 is performed in contact with the positioning surface 41 of the second embodiment. Further, in the fixing member 5, an annular relief groove 42 for reducing the contact with the wave generator 2 is formed around the boss 38.

また、図１及び図５に示すように、固定部材５は、内歯車４の外周面４３に嵌合して、内歯車４（軸２４）の回転中心２３ｂが波動発生器２（入力軸７）の回転中心２３ａと同軸上に位置するように、内歯車４を径方向に位置決めする内歯車位置決め内周面４４が形成されている。また、固定部材５は、内歯車４の一端面４５に当接して、内歯車４の回転中心２３ｂに沿った方向に、内歯車４を位置決めする内歯車位置決め端面４６が形成されている。   Further, as shown in FIG. 1 and FIG. 5, the fixing member 5 is fitted to the outer peripheral surface 43 of the internal gear 4, and the rotation center 23 b of the internal gear 4 (shaft 24) is the wave generator 2 (input shaft 7). An inner gear positioning inner circumferential surface 44 for positioning the inner gear 4 in the radial direction is formed coaxially with the rotation center 23a of. Further, the fixing member 5 is in contact with one end surface 45 of the internal gear 4, and an internal gear positioning end surface 46 for positioning the internal gear 4 in the direction along the rotation center 23 b of the internal gear 4 is formed.

また、図１及び図５に示すように、固定部材５は、カバー６の円筒部４７の内周面４８に嵌合され、且つ、カバー６の内側面５０に突き当てられる円筒状のカバー係合突起５１が内歯車位置決め内周面４４よりも径方向外方側の位置に形成されている。なお、固定部材５とカバー６とは、ボルト等の締結手段、溶着、又はクリップ等で固定される。   Further, as shown in FIGS. 1 and 5, the fixing member 5 is fitted on the inner peripheral surface 48 of the cylindrical portion 47 of the cover 6 and is in contact with the inner surface 50 of the cover 6. The mating projection 51 is formed at a position radially outward of the inner gear positioning inner circumferential surface 44. The fixing member 5 and the cover 6 are fixed by fastening means such as a bolt, welding, or a clip.

なお、図６（ｂ）は、固定部材５の係合片収容凹所３１の変形例を示す図であり、図６（ａ）に対応する図である。この図６（ｂ）に示すように、本変形例に係る係合片収容凹所３１は、一対の溝側壁５２，５２が周方向に沿って平行に（一定の溝幅ｗで）延びる図６（ａ）の係合片収容凹所３１と異なり、溝幅を係合片当接壁３５との接続部から径方向溝３３に向けて漸増するように（ｗａ＞ｗとなるように）一対の溝側壁５２，５２が傾斜している。すなわち、本変形例に係る係合片収容凹所３１は、係合片当接壁３５及び溝側壁５２で形成されている。このような係合片収容凹所３１に、溝側壁５２が設けられることで、溝側壁５２が係合片３０を導くガイドのような役割を果たし、係合片３０がスムーズに当接壁３５に接触するようになる。このような本変形例に係る係合片収容凹所３１は、係合片３０の周方向端部３４のみと確実に摺接し、係合片３０の周方向端部３４以外の部分との接触を回避し、係合片３０との摺接時の抵抗を低減することが可能になる。   FIG. 6B is a view showing a modification of the engagement piece receiving recess 31 of the fixing member 5 and corresponds to FIG. 6A. As shown in FIG. 6B, in the engagement piece receiving recess 31 according to the present modification, a pair of groove side walls 52, 52 extend in parallel along the circumferential direction (with a constant groove width w) Unlike the engagement piece storage recess 31 of 6 (a), the groove width is gradually increased from the connecting portion with the engagement piece contact wall 35 toward the radial groove 33 (so that wa> w) The pair of groove side walls 52, 52 are inclined. That is, the engagement piece receiving recess 31 according to the present modification is formed by the engagement piece abutting wall 35 and the groove side wall 52. The groove side wall 52 is provided in such an engagement piece receiving recess 31 so that the groove side wall 52 acts as a guide for guiding the engagement piece 30, and the engagement piece 30 smoothly contacts the contact wall 35. Will come into contact with The engagement piece accommodation recess 31 according to the present modification reliably contacts only the circumferential end 34 of the engagement piece 30 and contacts with parts other than the circumferential end 34 of the engagement piece 30. As a result, it is possible to reduce the resistance at the time of sliding contact with the engagement piece 30.

（外歯車）
図１乃至図３、及び図７に示すように、外歯車３は、薄肉の円筒状部材５３の外周面５４に複数の歯（外歯）５５が形成され、内周面３ａに波動発生器２の楕円状カム８が嵌合されることにより、波動発生器２の楕円状カム８によって弾性変形させられ、楕円状カム８の楕円状周面１６，１８に倣って楕円形状に変形させられる。 (External gear)
As shown in FIG. 1 to FIG. 3 and FIG. 7, the external gear 3 has a plurality of teeth (outer teeth) 55 formed on the outer peripheral surface 54 of the thin cylindrical member 53, and a wave generator on the inner peripheral surface 3a. When the elliptical cams 8 of 2 are fitted, they are elastically deformed by the elliptical cams 8 of the wave generator 2, and are deformed into an elliptical shape following the elliptical peripheral surfaces 16 and 18 of the elliptical cams 8 .

この外歯車３は、固定部材５の径方向リブ２６に対向する側（一側面２５側）に、隣り合う径方向リブ２６，２６の係合片収容凹所３１，３１に係合される舌片状の係合片３０が固定部材５の径方向溝３３と同数形成されている。この外歯車３の係合片３０は、固定部材５の径方向リブ２６を係合するための径方向リブ収容凹所５６が外歯車３の一側面２５側を切り欠くように径方向リブ２６と同数形成されることにより、隣り合う径方向リブ収容凹所４７，４７間に形成されている。そして、この外歯車３の係合片３０は、外歯車３の径方向（板厚方向）に撓み変形するものの、板厚（ｔ）に対する周方向長さ（Ｌ）が数倍大きく、周方向に対する強度が大きくて、周方向に弾性変形し難くなっているため、周方向端部３４が係合片収容凹所３１の係合片当接壁３５に当接することにより、外歯車３を固定部材５に対して確実に回り止めすることができる。また、係合片３０の周方向両側の周方向端部３４，３４は、円弧状に形成され、固定部材５の係合片収容凹所３１の係合片当接壁３５に滑らかに摺接できるようになっている。   The external gear 3 is a tongue engaged with the engagement piece accommodating recess 31, 31 of the adjacent radial ribs 26, 26 on the side (one side 25 side) opposite to the radial rib 26 of the fixing member 5. The piece-like engagement pieces 30 are formed in the same number as the radial grooves 33 of the fixing member 5. The engagement piece 30 of the external gear 3 has the radial rib 26 so that the radial rib housing recess 56 for engaging the radial rib 26 of the fixing member 5 cuts out the one side 25 side of the external gear 3. By being formed in the same number, it is formed between adjacent radial rib receiving recesses 47, 47. And although the engagement piece 30 of this external gear 3 is bent and deformed in the radial direction (plate thickness direction) of the external gear 3, the circumferential length (L) with respect to the plate thickness (t) is several times larger, the circumferential direction The external gear 3 is fixed by the circumferential end 34 coming into contact with the engagement piece abutting wall 35 of the engagement piece housing recess 31 because the strength against the rubber is large and elastic deformation in the circumferential direction is difficult. The member 5 can be securely locked against rotation. Further, the circumferential end portions 34, 34 on both sides in the circumferential direction of the engagement piece 30 are formed in an arc shape, and slidably contact the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 of the fixing member 5. It can be done.

このような外歯車３は、波動発生器２の楕円状カム８が１回転すると、図３（ｂ）〜（ｅ）に示した第１乃至第４状態を経て第１状態に戻るサイクルが２回行われ、係合片３０の周方向端部３４が係合片収容凹所３１の係合片当接壁３５に常時摺接（滑り接触）する。   When the elliptical cam 8 of the wave generator 2 makes one rotation, the external gear 3 returns to the first state through the first to fourth states shown in FIGS. 3 (b) to 3 (e). The circumferential end 34 of the engagement piece 30 is always in sliding contact (sliding contact) with the engagement piece abutting wall 35 of the engagement piece accommodation recess 31.

（内歯車）
図１、図２、及び図８に示すように、内歯車４は、歯（内歯）５７が内周面側に形成された円筒状部５８と、円筒状部５８の端部から径方向内方へ延びる円板状部６０と、円板状部６０の外側面６０ａの中心部分に一体に形成された軸２４と、を有している。また、円板状部６０の内側面６０ｂの中心部には、波動発生器２の支持軸１０を相対回動可能に収容する軸受け穴２２が形成されている。また、円板状部６０の外側面６０ａの中心部には、カバー６と当接する位置決め突起６１が形成されている。また、軸２４は、カバー６の軸穴６２に嵌合される大径軸部２４ａが円板状部６０の位置決め突起６１に隣接して形成されている。 (Internal gear)
As shown in FIGS. 1, 2 and 8, in the internal gear 4, a cylindrical portion 58 having teeth (inner teeth) 57 formed on the inner peripheral surface side and a radial direction from an end of the cylindrical portion 58 An inwardly extending disc-like portion 60 and a shaft 24 integrally formed at the central portion of the outer side surface 60 a of the disc-like portion 60 are provided. Further, at the central portion of the inner side surface 60b of the disk-like portion 60, a bearing hole 22 for accommodating the support shaft 10 of the wave generator 2 so as to be capable of relative rotation is formed. Further, at a central portion of the outer side surface 60 a of the disk-like portion 60, a positioning protrusion 61 that contacts the cover 6 is formed. In the shaft 24, a large diameter shaft portion 24 a fitted in the shaft hole 62 of the cover 6 is formed adjacent to the positioning projection 61 of the disc-like portion 60.

また、この内歯車４は、円筒状部５８の外周面４３が固定部材５の内歯車位置決め内周面４４に嵌合され、円筒状部５８の一端面４５が固定部材５の内歯車位置決め端面４６に当接させられ（カバー６の径方向内方端側で押されて内歯車位置決め端面４６に当接させられ）、固定部材５に対して相対回動できるようになっている。   Further, in the internal gear 4, the outer peripheral surface 43 of the cylindrical portion 58 is fitted to the internal gear positioning inner peripheral surface 44 of the fixing member 5, and one end surface 45 of the cylindrical portion 58 is the internal gear positioning end surface of the fixing member 5. It is brought into contact with the fixed member 46 (pushed on the radially inward end side of the cover 6 and brought into contact with the internal gear positioning end face 46), and can be rotated relative to the fixing member 5.

このような内歯車４は、波動発生器２の楕円状カム８によって楕円形状に変形させられた外歯車３の長軸上の２箇所で外歯車３と噛み合い、波動発生器２の楕円状カム８によって楕円形状に変形させられた外歯車３の短軸上で外歯車３と最も大きく離間するようになっている。   Such an internal gear 4 meshes with the external gear 3 at two points on the major axis of the external gear 3 deformed into an elliptical shape by the elliptical cam 8 of the wave generator 2, and the elliptical cam of the wave generator 2 The external gear 3 is most widely separated from the external gear 3 on the short axis of the external gear 3 deformed into an elliptical shape by 8.

（カバー）
図１、図２、及び図９に示すように、カバー６は、円板状部６３の径方向外方端に円筒部４７が一体に形成され、円筒部４７が固定部材５のカバー係合突起５１に嵌合され、円板状部６３の内側面５０の径方向外方端に位置する第１リング状突起６４が固定部材５のカバー係合突起５１の先端面５１ａに突き当てられ、円板状部６３の内側面５０の径方向内方端に位置する第２リング状突起６５が内歯車４の円板状部６０の位置決め突起６１に当接させられるようになっている。なお、カバー６は、円板状部６３の第１リング状突起６４と第２リング状突起６５との間の内側面が内歯車４との接触を避けるための接触回避凹所６６になっており、相対回動する内歯車４との摺接抵抗を削減するようになっている。 (cover)
As shown in FIGS. 1, 2 and 9, in the cover 6, the cylindrical portion 47 is integrally formed at the radially outer end of the disc-like portion 63, and the cylindrical portion 47 engages with the cover of the fixing member 5. The first ring-shaped projection 64 fitted to the projection 51 and positioned at the radially outer end of the inner side surface 50 of the disc-like portion 63 abuts against the tip surface 51 a of the cover engaging projection 51 of the fixing member 5, The second ring-shaped projection 65 located at the radially inward end of the inner side surface 50 of the disc-shaped portion 63 is brought into contact with the positioning projection 61 of the disc-shaped portion 60 of the internal gear 4. In the cover 6, the inner side surface between the first ring-shaped projection 64 and the second ring-shaped projection 65 of the disc-shaped portion 63 is a contact avoidance recess 66 for avoiding contact with the internal gear 4. The sliding contact resistance with the internally rotating internal gear 4 is reduced.

（第１実施形態に係る波動歯車装置の作動状態）
以上のように構成された本実施形態に係る波動歯車装置１は、波動発生器２が駆動手段（例えば、サーボモータ）によって回転させられると、楕円形状に弾性変形させられた外歯車３の長軸位置が波動発生器２の楕円状カム８の回動に伴って波動発生器２の回転中心２３ａの回りを移動（回動）する。そして、外歯車３と内歯車４の噛み合い位置は、外歯車３の長軸上の２箇所であるため、波動発生器２の回動位置に応じて移動する。ここで、波動歯車装置１は、外歯車３及び固定部材５が固定され、内歯車４が回転可能に構成されている場合であって、例えば、内歯車４の歯数をＺｃとし、外歯車３の歯数をＺｆ（Ｚｆ＝Ｚｃ−２）とすると（内歯車４よりも歯数を２だけ少なくすると）、波動発生器２の１回転に対し、内歯車４が波動発生器２の回転方向と同一方向に２歯分だけ回動する。すなわち、本実施形態に係る波動歯車装置１は、外歯車３及び固定部材５が固定された場合、駆動手段の回転を２／Ｚｃに減速して内歯車４の軸２４から被回転体に伝達することができる。 (Operating state of the wave gear device according to the first embodiment)
The wave gear device 1 according to the present embodiment configured as described above has the length of the external gear 3 elastically deformed into an elliptical shape when the wave generator 2 is rotated by the drive means (for example, a servomotor). The axial position moves (rotates) around the rotation center 23 a of the wave generator 2 as the elliptical cam 8 of the wave generator 2 rotates. And since the meshing position of the external gear 3 and the internal gear 4 is two places on the long axis of the external gear 3, it moves according to the rotation position of the wave generator 2. Here, in the wave gear device 1, the external gear 3 and the fixing member 5 are fixed, and the internal gear 4 is configured to be rotatable. For example, assuming that the number of teeth of the internal gear 4 is Zc, the external gear Assuming that the number of teeth of 3 is Zf (Zf = Zc-2) (when the number of teeth is smaller than that of the internal gear 4 by 2), the internal gear 4 rotates the wave generator 2 for one rotation of the wave generator 2. Rotate by two teeth in the same direction as the direction. That is, in the wave gear device 1 according to the present embodiment, when the external gear 3 and the fixing member 5 are fixed, the rotation of the driving means is reduced to 2 / Zc and transmitted from the shaft 24 of the internal gear 4 to the rotating object can do.

（本実施形態に係る波動歯車装置の効果）
本実施形態に係る波動歯車装置１は、外歯車３が波動発生器２によって楕円形状に弾性変形させられると、外歯車３の係合片３０の周方向端部３４が固定部材５の径方向リブ２６に形成された係合片収容凹所３１の係合片当接壁３５に常時摺接するため、外歯車３と固定部材５の相対回動が阻止され、外歯車３と固定部材５のガタツキ（回動方向のずれ動きであるバックラッシ）を抑えることができる。その結果、本実施形態に係る波動歯車装置１は、内歯車４の回転ムラを抑えることができ、高精度の回転伝達が可能になる。 (Effect of the wave gear device according to the present embodiment)
In the wave gear device 1 according to the present embodiment, when the external gear 3 is elastically deformed into an elliptical shape by the wave generator 2, the circumferential end 34 of the engagement piece 30 of the external gear 3 is in the radial direction of the fixing member 5 Since the external gear 3 and the fixing member 5 are prevented from rotating relative to each other, the external gear 3 and the fixing member 5 are prevented from rotating relative to each other because the engaging piece abutting wall 35 of the engaging piece housing recess 31 formed in the rib 26 is always in sliding contact with it. It is possible to suppress rattling (backlash which is a shift movement in the rotation direction). As a result, in the wave gear device 1 according to the present embodiment, the rotation unevenness of the internal gear 4 can be suppressed, and rotation transmission with high accuracy becomes possible.

また、本実施形態に係る波動歯車装置１は、外歯車３が固定部材５に固定され、内歯車４が外歯車３によって回動させられ、内歯車４から回動トルクが出力されるようになっている。その結果、本実施形態に係る波動歯車装置１は、回動トルクを外部に出力するための出力部材を設置する必要がなく、部品点数を削減でき、全体構造をコンパクト化することが可能になる。   Further, in the wave gear device 1 according to the present embodiment, the external gear 3 is fixed to the fixing member 5, the internal gear 4 is rotated by the external gear 3, and a rotational torque is output from the internal gear 4. It has become. As a result, in the wave gear device 1 according to the present embodiment, it is not necessary to provide an output member for outputting the rotational torque to the outside, and the number of parts can be reduced, and the overall structure can be made compact. .

また、本実施形態に係る波動歯車装置１は、外歯車３の係合片３０の周方向端部３４が摺接する固定部材５の係合片収容凹所３１の係合片当接壁３５を係合片３０の周方向端部３４の移動軌跡に沿った形状に形成してあるため、外歯車３が楕円形状に変形させられる際に、係合片３０の周方向端部３４が係合片収容凹所３１の係合片当接壁３５に円滑に案内され、外歯車３の楕円変形を妨げる摩擦抵抗が生じにくい。その結果、本実施形態に係る波動歯車装置１は、第１従来例に係る波動歯車装置１００と比較した場合、動力伝達効率の低下を抑えることができる。   Further, in the wave gear device 1 according to the present embodiment, the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 of the fixing member 5 in sliding contact with the circumferential end 34 of the engagement piece 30 of the external gear 3 Since the shape is formed along the movement trajectory of the circumferential end 34 of the engagement piece 30, the circumferential end 34 of the engagement piece 30 is engaged when the external gear 3 is deformed into an elliptical shape. It is smoothly guided by the engagement piece abutting wall 35 of the piece accommodation recess 31, and it is difficult to generate a frictional resistance that prevents the elliptical deformation of the external gear 3. As a result, when compared with the wave gear drive 100 according to the first conventional example, the wave gear drive 1 according to the present embodiment can suppress the reduction in power transmission efficiency.

また、本実施形態に係る波動歯車装置１は、外歯車３の係合片３０が舌片状に形成され、板厚（ｔ）に対する周方向長さ（Ｌ）が数倍大きく、周方向に対する強度が大きくて、周方向に弾性変形し難くなっているため、周方向端部３４が係合片収容凹所３１の係合片当接壁３５に当接することにより、外歯車３を固定部材５に対して確実に回り止めすることができる。その結果、本実施形態に係る波動歯車装置１は、第２従来例に係る波動歯車装置２００と比較した場合、大きな回動トルクの伝達が可能になる。   Further, in the wave gear device 1 according to the present embodiment, the engagement piece 30 of the external gear 3 is formed in a tongue shape, and the circumferential length (L) with respect to the plate thickness (t) is several times larger The external gear 3 is fixed by allowing the circumferential end 34 to abut on the engagement piece abutting wall 35 of the engagement piece accommodation recess 31 because the strength is large and it is difficult to elastically deform in the circumferential direction. It can be securely locked against 5. As a result, the wave gear device 1 according to the present embodiment can transmit a large rotational torque as compared with the wave gear device 200 according to the second conventional example.

本実施形態に係る波動歯車装置１は、全体をプラスチックで形成するようになっているため、全体を金属で形成する場合と比較し、軽量化、低コスト化を図ることができる。   Since the wave gear device 1 according to the present embodiment is formed entirely of plastic, weight reduction and cost reduction can be achieved as compared to the case where the whole is formed of metal.

なお、本実施形態に係る波動歯車装置１は、全体をプラスチックで形成する場合を例示したが、これに限定されず、一部又は全体を金属で形成してもよい。   In addition, although the wave gear apparatus 1 which concerns on this embodiment illustrated the case where the whole was formed with a plastic, it is not limited to this, You may form a part or whole with a metal.

１……波動歯車装置、２……波動発生器、３……外歯車、４……内歯車、５……固定部材、２３ａ……回転中心、２６……径方向リブ、３０……係合片、３１……係合片収容凹所、３４……周方向端部、３５……係合片当接壁   DESCRIPTION OF SYMBOLS 1 ...... Wave gear gear apparatus 2 ... Wave generator, 3 ...... Outer gear, 4 ...... Inner gear, 5 ...... Fixing member, 23a ...... Rotation center, 26 ...... Radial rib, 30 ...... Engage 31, 31 ... engaging piece receiving recess, 34 ... circumferential end, 35 ... engaging piece abutting wall

Claims (5)

回転させられる波動発生器と、この波動発生器に嵌合されることによって楕円形状に弾性変形させられる円筒状の外歯車と、この楕円形状に弾性変形させられた外歯車の長軸上で前記外歯車と噛み合う内歯車と、を有する波動歯車装置において、
前記外歯車の歯幅方向に沿った一端面側には、固定部材が対向するように配置され、
前記固定部材は、前記外歯車に対向する面側に、前記波動発生器の回転中心に対して放射状に延びる複数の径方向リブが形成され、
前記外歯車は、前記歯幅方向に沿った一端面側に、前記固定部材へ向かって突出する舌片状の係合片が周方向に沿って複数形成され、
前記係合片は、前記外歯車の周方向に沿った両側の周方向端部が隣り合う一対の径方向リブにそれぞれ形成された係合片収容凹所に係合され、前記外歯車が前記波動発生器によって楕円形状に弾性変形させられると、前記周方向端部が前記係合片収容凹所の係合片当接壁に摺接して、前記外歯車と前記固定部材との相対回動を阻止し、
前記係合片収容凹所の係合片当接壁は、前記外歯車が前記波動発生器によって楕円形状に弾性変形された際の前記係合片の前記周方向端部の移動軌跡に沿った曲面に形成され、
前記内歯車は、前記波動発生器の回転に伴って前記外歯車及び前記固定部材に対して回動させられる、
ことを特徴とする波動歯車装置。 The wave generator to be rotated, the cylindrical external gear that is elastically deformed into an elliptical shape by being fitted to the wave generator, and the long axis of the external gear that is elastically deformed into the elliptical shape. In a wave gear device having an internal gear meshing with an external gear,
Fixing members are disposed to face each other on one end surface side along the tooth width direction of the external gear,
The fixing member is formed with a plurality of radial ribs extending radially with respect to the rotation center of the wave generator on the side facing the external gear.
A plurality of tongue-like engagement pieces projecting toward the fixing member are formed along the circumferential direction on one end surface side along the tooth width direction of the external gear.
The engagement piece is engaged with an engagement piece receiving recess formed in each of a pair of radial ribs adjacent to each other in the circumferential direction on both sides along the circumferential direction of the external gear, the external gear being When it is elastically deformed into an elliptical shape by a wave generator, the circumferential end is in sliding contact with the engagement piece abutting wall of the engagement piece accommodation recess, and relative rotation between the external gear and the fixing member To stop
The engagement piece abutting wall of the engagement piece accommodation recess is along the movement locus of the circumferential end of the engagement piece when the external gear is elastically deformed into an elliptical shape by the wave generator. Formed on a curved surface,
The internal gear is rotated relative to the external gear and the fixing member as the wave generator rotates.
Wave gear device characterized by 前記外歯車が前記波動発生器によって楕円形状に弾性変形させられ、前記係合片が前記外歯車の長軸上及び短軸上に位置した場合に、前記両側の周方向端部が一対の前記係合片収容凹所の係合片当接壁にそれぞれ当接し、
前記外歯車が前記波動発生器によって楕円形状に弾性変形させられ、前記係合片が前記外歯車の長軸上及び短軸上に位置しない場合に、前記両側の周方向端部の一方が一対の前記係合片収容凹所の一方の前記係合片当接壁に摺接するか、又は前記両側の周方向端部の他方が一対の前記係合片収容凹所の他方の前記係合片当接壁に摺接する、
ことを特徴とする請求項１に記載の波動歯車装置。 When the external gear is elastically deformed into an elliptical shape by the wave generator, and the engagement piece is positioned on the major axis and the minor axis of the external gear, the circumferential end portions on both sides are a pair of the above Contact each engagement piece abutment wall of the engagement piece accommodation recess,
When the external gear is elastically deformed into an elliptical shape by the wave generator and the engagement piece is not positioned on the major axis and the minor axis of the external gear, one of the circumferential end portions on both sides is a pair Sliding contact with one of the engagement piece abutment walls of the engagement piece accommodation recess, or the other of the other of the two circumferential end portions is the other of the pair of engagement piece accommodation recesses Sliding contact with the contact wall,
A wave gear device according to claim 1, characterized in that. 前記係合片収容凹所は、前記径方向リブの前記外歯車に対向する面側に形成された周方向溝であり、前記周方向溝の一端が隣り合う径方向リブ間の径方向溝に開口し、前記周方向溝の他端が前記係合片当接壁によって閉じられた、
ことを特徴とする請求項１又は２に記載の波動歯車装置。 The engagement piece receiving recess is a circumferential groove formed on the side of the radial rib facing the external gear, and one end of the circumferential groove is adjacent to the radial groove between the radial ribs. Open, the other end of the circumferential groove is closed by the engagement piece abutment wall,
The wave gear device according to claim 1 or 2 characterized by things. 前記係合片収容凹所は、前記係合片当接壁から前記径方向溝に向けて溝幅を漸増させるように形成された、
ことを特徴とする請求項３に記載の波動歯車装置。 The engagement piece receiving recess is formed to gradually increase the groove width from the engagement piece contact wall toward the radial groove.
A wave gear device according to claim 3, characterized in that. 前記係合片は、周方向長さＬが板厚ｔと比較して大きい、
ことを特徴とする請求項１乃至４のいずれかに記載の波動歯車装置。 The engagement piece has a circumferential length L greater than a thickness t.
The wave gear device according to any one of claims 1 to 4, characterized in that:

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