JP7342055B2

JP7342055B2 - joint unit

Info

Publication number: JP7342055B2
Application number: JP2021056072A
Authority: JP
Inventors: 勝嗣深町; 圭司外川; 洋大澤
Original assignee: Sony Interactive Entertainment Inc
Current assignee: Sony Interactive Entertainment Inc
Priority date: 2021-03-29
Filing date: 2021-03-29
Publication date: 2023-09-11
Anticipated expiration: 2041-03-29
Also published as: JP2022153045A

Description

本発明は関節ユニットに関する。 The present invention relates to an articulation unit.

下記特許文献１には、ロボット等のアームを動かすことができる関節ユニットが開示されている。関節ユニットには、互いに向き合う２つの傘歯ギア（以下では、対向ギアと称する）が設けられ、これらの間に１つの傘歯ギア（以下では、中間ギアと称する）が位置している。中間ギアはアームと接続し、中間ギアには２つの対向ギアの双方が噛み合っている。２つの対向ギアは互いに異なるモータの動力を受け、互いに独立して回転可能である。２つの対向ギアの間から見て２つの対向ギア同じ方向に回転する場合（例えば、双方が時計回りに回転する場合）、中間ギアは、中間ギアの軸線を中心に回転する。また、２つの対向ギアの間から見て２つの対向ギアが互いに異なる方向に回転する場合（例えば、一方が時計回りに回転し、他方が反時計回りに回転する場合）、中間ギアは、対向ギアの軸線を中心に回転移動する。この２種類の中間ギアの動きにより、中間ギアに接続されるアームを２方向（例えば、前後方向及び左右方向）において動作させることが可能である。 Patent Document 1 listed below discloses a joint unit that can move an arm of a robot or the like. The joint unit is provided with two bevel gears facing each other (hereinafter referred to as opposing gears), and one bevel gear (hereinafter referred to as intermediate gear) located between these gears. The intermediate gear is connected to the arm, and both of the two opposing gears mesh with the intermediate gear. The two opposing gears receive power from different motors and are rotatable independently of each other. When the two opposing gears rotate in the same direction when viewed from between the two opposing gears (for example, when both rotate clockwise), the intermediate gear rotates about the axis of the intermediate gear. Also, when the two opposing gears rotate in different directions when viewed from between the two opposing gears (for example, when one rotates clockwise and the other counterclockwise), the intermediate gear Rotates around the axis of the gear. The movement of these two types of intermediate gears allows the arms connected to the intermediate gears to be operated in two directions (for example, forward and backward directions and left and right directions).

国際公開第２０１７／２１７４１５号International Publication No. 2017/217415

対向ギアと中間ギアとで歯と歯の間の隙間（バックラッシュ）が大きい場合、対向ギアが回転を開始した際に、対向ギアの歯と中間ギアとの歯との衝突が生じる。このことが、騒音や振動が発生する原因になる。バックラッシュは歯の摩耗によっても大きくなるため、対向ギアと中間ギアとの少なくとも一方には、バックラッシュを低減するための機構が設けられることが好ましい。 If the gap (backlash) between the teeth of the opposing gear and the intermediate gear is large, when the opposing gear starts rotating, the teeth of the opposing gear will collide with the teeth of the intermediate gear. This causes noise and vibration to occur. Backlash also increases due to tooth wear, so it is preferable that at least one of the opposing gear and the intermediate gear is provided with a mechanism for reducing backlash.

本発明の目的は、対向ギアと中間ギアとのバックラッシュを低減できる関節ユニットを提供することにある。 An object of the present invention is to provide a joint unit that can reduce backlash between an opposing gear and an intermediate gear.

本発明に係る関節ユニットは、対向する２つの傘歯ギア部をそれぞれ含む２つの対向ギアと、前記２つの傘歯ギア部の双方に噛み合う傘歯ギア部を含む中間ギアと、を含む。前記２つの対向ギアと前記中間ギアとのうちの一方のギアの傘歯ギア部は、前記一方のギアの回転方向に沿って並ぶ複数の歯を有し、前記複数の歯のそれぞれの幅は、前記一方のギアの傘歯ギア部の外周に向かうにつれて徐々に大きくなっている。前記一方のギアは、前記一方のギアの回転中心線に沿った方向で、前記一方のギアの前記傘歯ギア部の少なくとも一部分を他方のギアに付勢する弾性部材を含む、本発明によれば、対向ギアと中間ギアとのバックラッシュを低減できる。 The joint unit according to the present invention includes two opposing gears each including two opposing bevel gear parts, and an intermediate gear including a bevel gear part that meshes with both of the two bevel gear parts. The bevel gear portion of one of the two opposing gears and the intermediate gear has a plurality of teeth arranged along the rotational direction of the one gear, and each of the plurality of teeth has a width of , gradually increases in size toward the outer periphery of the bevel gear portion of the one gear. According to the present invention, the one gear includes an elastic member that biases at least a portion of the bevel gear portion of the one gear toward the other gear in a direction along a rotation center line of the one gear. For example, backlash between the opposing gear and the intermediate gear can be reduced.

本発明の実施形態の一例に係る関節ユニットを示す斜視図である。FIG. 1 is a perspective view showing a joint unit according to an example of an embodiment of the present invention. 関節ユニットを示す正面図である。It is a front view showing a joint unit. 関節ユニットの一部分を示す正面図である。FIG. 3 is a front view showing a portion of the joint unit. 関節ユニットの一部分を示す正面図である。FIG. 3 is a front view showing a portion of the joint unit. 図１ＢのＩＩＩ‐ＩＩＩ切断線における断面を示す断面図である。FIG. 1B is a cross-sectional view taken along the line III-III in FIG. 1B. 対向ギアを示す斜視図である。FIG. 3 is a perspective view showing opposing gears. 対向ギアの分解斜視図である。It is an exploded perspective view of an opposing gear. 対向ギアの第１部材を示す斜視図である。It is a perspective view showing the 1st member of an opposing gear. 対向ギアの規制部を示す図である。It is a figure which shows the restriction part of an opposing gear. 対向ギアの傘歯を示す拡大図である。FIG. 3 is an enlarged view showing bevel teeth of an opposing gear. 本発明の他の実施形態の一例に係る対向ギアの分解斜視図である。FIG. 7 is an exploded perspective view of an opposing gear according to an example of another embodiment of the present invention. 本発明の他の実施形態の一例に係る関節ユニットの一部分を示す正面図である。It is a front view which shows a part of joint unit based on an example of other embodiment of this invention. 本発明の変形例に係る弾性部材及び第２部材を示す斜視図である。FIG. 7 is a perspective view showing an elastic member and a second member according to a modification of the present invention. 本発明の変形例に係る弾性部材及び第２部材を示す斜視図である。FIG. 7 is a perspective view showing an elastic member and a second member according to a modification of the present invention. 本発明の変形例に係る弾性部材及び第２部材を示す斜視図である。FIG. 7 is a perspective view showing an elastic member and a second member according to a modification of the present invention.

［第１の実施形態］
最初に、本開示の実施形態の一例（第１の実施形態）について図面を参照しながら説明する。図１Ａは、本発明の実施形態の一例に係る関節ユニット１を示す斜視図である。図１Ｂは、関節ユニット１の正面図である。図２Ａ及び図２Ｂは、図１Ｂの拡大図であり、関節ユニット１に設けられる２つの対向ギア２（２Ａ，２Ｂ）と、中間ギア３とを示している。図３は、図１ＢのＩＩＩ‐ＩＩＩ切断線における断面を示す断面図である。これらの図面においては、各図に示すＸ１及びＸ２をそれぞれ左方向及び右方向と称し、Ｙ１及びＹ２をそれぞれ前方及び後方と称し、Ｚ１及びＺ２をそれぞれ上方及び下方と称する。 [First embodiment]
First, an example of an embodiment (first embodiment) of the present disclosure will be described with reference to the drawings. FIG. 1A is a perspective view showing a joint unit 1 according to an example of an embodiment of the present invention. FIG. 1B is a front view of the joint unit 1. 2A and 2B are enlarged views of FIG. 1B, showing two opposing gears 2 (2A, 2B) and an intermediate gear 3 provided in the joint unit 1. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1B. In these drawings, X1 and X2 shown in each figure are referred to as leftward and rightward, respectively, Y1 and Y2 are referred to as forward and backward, respectively, and Z1 and Z2 are referred to as upper and lower, respectively.

［関節ユニットの概要］
関節ユニット１は、ロボット等のアームを動かすためにロボット等に取り付けられる。関節ユニット１は、例えば、人又は動物を模したロボットに取り付けられ、ロボットの首、腕、足、腰等を動かす関節として機能する。 [Overview of joint unit]
The joint unit 1 is attached to a robot or the like to move the arm of the robot or the like. The joint unit 1 is attached to, for example, a robot imitating a human or an animal, and functions as a joint that moves the robot's neck, arms, legs, waist, etc.

図１Ａ及び図１Ｂに示すように、関節ユニット１は、互いに対向する２つの対向ギア２（２Ａ及び２Ｂ）と、これら２つの対向ギア２のそれぞれによって相対的に駆動される中間ギア３とを有している。２つの対向ギア２は、互いに対向する２つの傘歯ギア部２７をそれぞれ含む。中間ギア３は傘歯ギア部３７を含み、この傘歯ギア部３７が、２つの対向ギア２のそれぞれに設けられる２つの傘歯ギア部２７の双方に噛み合っている。図１Ａ及び図１Ｂに示した例では、中間ギア３の左右方向において、２つの対向ギア２の傘歯ギア部２７が対向している。より具体的には、対向ギア２Ａが中間ギア３の左に位置し、対向ギア２Ｂが中間ギア３の右に位置している。これに限らず、２つの対向ギア２は、中間ギア３を挟んで他の方向（例えば、上下方向や左右且つ上下の斜め方向）で対向していてもよい。 As shown in FIGS. 1A and 1B, the joint unit 1 includes two opposing gears 2 (2A and 2B) that face each other, and an intermediate gear 3 that is relatively driven by each of these two opposing gears 2. have. The two opposing gears 2 each include two bevel gear portions 27 facing each other. The intermediate gear 3 includes a bevel gear portion 37, and the bevel gear portion 37 meshes with both of the two bevel gear portions 27 provided on each of the two opposing gears 2. In the example shown in FIGS. 1A and 1B, the bevel gear portions 27 of the two opposing gears 2 face each other in the left-right direction of the intermediate gear 3. More specifically, the opposing gear 2A is located on the left of the intermediate gear 3, and the opposing gear 2B is located on the right of the intermediate gear 3. However, the present invention is not limited thereto, and the two opposing gears 2 may be opposed to each other in other directions (for example, in the vertical direction or in the diagonal directions from left to right and up and down) with the intermediate gear 3 interposed therebetween.

また、図２Ａ及び図２Ｂに示すように、２つの対向ギア２のそれぞれの傘歯ギア部２７ギアは、対向ギア２の回転方向に沿って並ぶ複数の歯２７１を有し、中間ギア３の傘歯ギア部３７も、中間ギア３の回転方向に沿って並ぶ複数の歯３７１を有する。対向ギア２に設けられる複数の歯２７１のそれぞれの幅は、対向ギア２の外周に向かうにつれて徐々に大きくなっている。中間ギア３に設けられる複数の歯３７１のそれぞれの幅も、中間ギア３の外周に向かうにつれて徐々に大きくなっている。なお、対向ギア２に設けられる歯２７１は、後述するギア内周部分２７ａの歯２７１ａと、後述するギア外周部分２７ｂの歯２７１ｂとを含んで構成される。 Further, as shown in FIGS. 2A and 2B, each bevel gear portion 27 gear of the two opposing gears 2 has a plurality of teeth 271 arranged along the rotation direction of the opposing gear 2, and the intermediate gear 3 The bevel gear portion 37 also has a plurality of teeth 371 arranged along the rotation direction of the intermediate gear 3. The width of each of the plurality of teeth 271 provided on the opposing gear 2 gradually increases toward the outer periphery of the opposing gear 2. The width of each of the plurality of teeth 371 provided on the intermediate gear 3 also gradually increases toward the outer periphery of the intermediate gear 3. The teeth 271 provided on the opposing gear 2 include teeth 271a on an inner gear portion 27a, which will be described later, and teeth 271b on an outer gear portion 27b, which will be described later.

関節ユニット１は、図１Ａに示す第１軸線Ａｘ１を中心とした中間ギア３の対向ギア２に対する相対的な回転と、第２軸線Ａｘ２を中心とした中間ギア３の対向ギア２に対する相対的な回転とを許容するよう構成されている。中間ギア３には、傘歯ギア部３７の反対側に基部３８が固定されている。この基部３８に、例えば図示しないアームが固定され、中間ギア３が第１軸線Ａｘ１と第２軸線Ａｘ２とのそれぞれで回転することによって、第１軸線Ａｘ１を中心としたアームの動きと、第２軸線Ａｘ２を中心としたアームの動きを実現できる。また、関節ユニット１は、アームの端部に設けられてもよく、この場合、中間ギア３の基部３８に対して関節ユニット１（より具体的には、２つの対向ギア２）が相対的に動くことによって、第１軸線Ａｘ１を中心としたアームの動きと、第２軸線Ａｘ２を中心としたアームの動きを実現できる。 The joint unit 1 rotates the intermediate gear 3 relative to the opposing gear 2 around the first axis Ax1 shown in FIG. 1A, and the intermediate gear 3 relative to the opposing gear 2 around the second axis Ax2. It is configured to allow rotation. A base portion 38 is fixed to the intermediate gear 3 on the opposite side of the bevel gear portion 37. For example, an arm (not shown) is fixed to the base 38, and the intermediate gear 3 rotates about the first axis Ax1 and the second axis Ax2, so that the movement of the arm about the first axis Ax1 and the second axis Movement of the arm around axis Ax2 can be realized. Further, the joint unit 1 may be provided at the end of the arm, and in this case, the joint unit 1 (more specifically, the two opposing gears 2) is relatively By moving, it is possible to realize arm movement around the first axis Ax1 and arm movement around the second axis Ax2.

図１Ａに示すように、関節ユニット１は、２つのモータ４（４Ａ及び４Ｂ）を含む。モータ４Ａは対向ギア２Ａを駆動させ、モータ４Ｂは対向ギア２Ｂを駆動させる。より具体的には、関節ユニット１は２つの対向ギア２にそれぞれ固定される２つの駆動ギア２８を含み、２つの駆動ギア２８が２つのモータ４にそれぞれ接続している。これにより、２つの対向ギア２は、異なるモータ４の動力を受けて、第１軸線Ａｘ１を中心に互いに独立して回転できる。２つの対向ギア２は、これら２つの対向ギア２の間から見て、同じ方向に回転したり、反対方向に回転したりすることができる。また、２つの対向ギア２は、同じ方向に回転しながら回転の速度が互いに異なるように回転することもできる。また、２つの対向ギア２のうち一方は停止している状態で、他方だけが回転することも可能である。 As shown in FIG. 1A, the joint unit 1 includes two motors 4 (4A and 4B). The motor 4A drives the opposing gear 2A, and the motor 4B drives the opposing gear 2B. More specifically, the articulation unit 1 includes two drive gears 28 each fixed to two opposing gears 2, and the two drive gears 28 are connected to two motors 4, respectively. Thereby, the two opposing gears 2 can receive power from different motors 4 and rotate independently of each other about the first axis Ax1. The two opposing gears 2 can rotate in the same direction or in opposite directions when viewed from between these two opposing gears 2. Further, the two opposing gears 2 can also rotate in the same direction but at different rotational speeds. Further, it is also possible that one of the two opposing gears 2 is stopped and only the other rotates.

なお、関節ユニット１の内側では、２つのモータ４が前後方向に並び、前後方向において重なるように配置されている。このように２つのモータ４を配置することで、関節ユニット１の内側のスペースを有効に活用することができる。また、関節ユニット１では、２つのモータ４をそれぞれ制御する２つの制御基板５も、前後方向において重なっている。 Note that, inside the joint unit 1, two motors 4 are arranged in a line in the front-rear direction and overlapped in the front-rear direction. By arranging the two motors 4 in this manner, the space inside the joint unit 1 can be effectively utilized. Furthermore, in the joint unit 1, the two control boards 5 that respectively control the two motors 4 also overlap in the front-rear direction.

本実施形態において、２つの対向ギア２が、これら２つの対向ギア２の間から見て、同じ方向に回転するとは、２つの対向ギア２の双方が、図１ＡにおいてＲ１で示した方向に回転するか、または、２つの対向ギア２の双方が、図１ＡにおいてＲ２で示した方向に回転することである。また、本実施形態において、２つの対向ギア２が、これら２つの対向ギア２の間から見て、互いに反対の方向に回転するとは、２つの対向ギア２のうち一方のギアが図１ＡにおいてＲ１で示した方向に回転し、他方のギアが図１ＡにおいてＲ２で示した方向に回転することである。 In this embodiment, the two opposing gears 2 rotate in the same direction when viewed from between these two opposing gears 2. This means that both of the two opposing gears 2 rotate in the direction indicated by R1 in FIG. 1A. Alternatively, both of the two opposing gears 2 rotate in the direction indicated by R2 in FIG. 1A. In addition, in this embodiment, the two opposing gears 2 rotate in opposite directions when viewed from between these two opposing gears 2, which means that one of the two opposing gears 2 is R1 in FIG. 1A. The other gear rotates in the direction shown by R2 in FIG. 1A.

２つの対向ギア２が互いに反対方向に回転する場合（２つの対向ギア２のうち一方のギアが図１ＡのＲ１で示した方向に回転し、他方のギアが図１ＡのＲ２で示した方向に回転する場合）、中間ギア３は第２軸線Ａｘ２を中心に相対的に回転する。このような中間ギア３の第２軸線Ａｘ２を中心とした相対的な動きを、以下ではロール動作とも称する。また、２つの対向ギア２が同じ方向に回転する場合（２つの対向ギア２の双方が、図１ＡのＲ１又はＲ２で示した方向に回転する場合）、中間ギア３は、第１軸線Ａｘ１を中心として相対的に回転（移動）する。このような中間ギア３の第１軸線Ａｘ１を中心とした相対的な動きを、以下ではピッチ動作とも称する。中間ギア３は、ピッチ動作と、ロール動作と、ピッチ動作及びロール動作を複合した動作とを行うことができる。 When the two opposing gears 2 rotate in opposite directions (one gear of the two opposing gears 2 rotates in the direction indicated by R1 in FIG. 1A, and the other gear rotates in the direction indicated by R2 in FIG. 1A) (when rotating), the intermediate gear 3 rotates relatively around the second axis Ax2. Such a relative movement of the intermediate gear 3 about the second axis Ax2 will also be referred to as a roll movement hereinafter. Further, when the two opposing gears 2 rotate in the same direction (when both of the two opposing gears 2 rotate in the direction indicated by R1 or R2 in FIG. 1A), the intermediate gear 3 rotates along the first axis Ax1. Rotate (move) relative to the center. Such a relative movement of the intermediate gear 3 about the first axis Ax1 will also be referred to as a pitch movement hereinafter. The intermediate gear 3 can perform a pitch operation, a roll operation, and a combined operation of the pitch and roll operations.

［対向ギアの構成］
図４は、対向ギア２を示す斜視図である。図５は、対向ギアの分解斜視図である。本実施形態では、２つの対向ギア２が同一の構造を有しており、２つの対向ギア２が互いに異なる構造を有している場合に比べて対向ギア２の各部材の製造を簡便にできる。図４及び図５に示すように、対向ギア２は、第１部材２１及び第２部材２２により構成される。第１部材２１は対向ギア２の傘歯ギア部２７の内周部分２７ａ（以下では、ギア内周部分２７ａと称する）を含み、第２部材２２は対向ギア２の傘歯ギア部２７の外周部分２７ｂ（以下では、ギア外周部分２７ｂと称する）を含んでいる。第１部材２１と第２部材２２とを組み合わせることにより、ギア内周部分２７ａはギア外周部分２７ｂの内側かつ先端側に配置されて、１つの傘歯ギア部２７が構成される。傘歯ギア部２７はギア内周部分２７ａとギア外周部分２７ｂとに分割可能である。ギア内周部分２７ａは対向ギア２の回転方向に沿って並ぶ複数の歯２７１ａを有し、ギア外周部分２７ｂも対向ギア２の回転方向に沿って並ぶ複数の歯２７１ｂを有している。図４に示すように、ギア内周部分２７ａの歯２７１ａとギア外周部分２７ｂの歯２７１ｂとが傘歯ギア部２７の径方向に並ぶことで、傘歯ギア部２７の歯２７１が構成される。 [Composition of opposing gear]
FIG. 4 is a perspective view showing the opposing gear 2. FIG. 5 is an exploded perspective view of the opposing gear. In this embodiment, the two opposing gears 2 have the same structure, and each member of the opposing gears 2 can be manufactured more easily than when the two opposing gears 2 have different structures. . As shown in FIGS. 4 and 5, the opposing gear 2 includes a first member 21 and a second member 22. As shown in FIGS. The first member 21 includes an inner peripheral portion 27a (hereinafter referred to as gear inner peripheral portion 27a) of the bevel gear portion 27 of the opposing gear 2, and the second member 22 includes an outer peripheral portion of the bevel gear portion 27 of the opposing gear 2. It includes a portion 27b (hereinafter referred to as gear outer peripheral portion 27b). By combining the first member 21 and the second member 22, the gear inner circumferential portion 27a is disposed inside and on the distal end side of the gear outer circumferential portion 27b, and one bevel gear portion 27 is configured. The bevel gear portion 27 can be divided into an inner gear portion 27a and an outer gear portion 27b. The gear inner peripheral portion 27a has a plurality of teeth 271a arranged along the rotational direction of the opposing gear 2, and the gear outer peripheral portion 27b also has a plurality of teeth 271b arranged along the rotational direction of the opposing gear 2. As shown in FIG. 4, the teeth 271 of the bevel gear portion 27 are configured by the teeth 271a of the gear inner peripheral portion 27a and the teeth 271b of the gear outer peripheral portion 27b being lined up in the radial direction of the bevel gear portion 27. .

また、図５に示すように、第２部材２２には第１筒部２３が形成されている。第１筒部２３は、対向ギア２のギア外周部分２７ｂから対向ギア２の回転中心線（第１軸線Ａｘ１）に沿って延びている。この第１筒部２３に、第１部材２１が嵌まる。第１筒部２３は円筒形であり、第１筒部２３の内側に環状のスペースＣが形成されている。第１部材２１には、対向ギア２のギア内周部分２７ａから対向ギア２の回転中心線（第１軸線Ａｘ１）に沿って延びている円筒形の第３筒部２５が形成されており、この第３筒部２５が、第１筒部２３に形成された環状のスペースＣの内側に嵌まる。 Further, as shown in FIG. 5, a first cylindrical portion 23 is formed in the second member 22. As shown in FIG. The first cylindrical portion 23 extends from the gear outer peripheral portion 27b of the opposing gear 2 along the rotation center line (first axis Ax1) of the opposing gear 2. The first member 21 is fitted into the first cylindrical portion 23 . The first cylindrical portion 23 has a cylindrical shape, and an annular space C is formed inside the first cylindrical portion 23 . A cylindrical third tube portion 25 is formed in the first member 21 and extends from the gear inner peripheral portion 27a of the opposing gear 2 along the rotation center line (first axis Ax1) of the opposing gear 2. This third cylindrical portion 25 fits inside the annular space C formed in the first cylindrical portion 23.

図５に示すように、第１筒部２３の内側には、第１筒部２３よりも径が小さい円筒形の第２筒部２４が設けられている。環状のスペースＣは、第１筒部２３の内周面と第２筒部２４の外周面とにより規定される。第２筒部２４が構成する円の内側には、円形の軸穴Ｈ２が形成されている。また、第１部材２１において、ギア内周部分２７ａは環状であり、その中心位置に、円形の軸穴Ｈ１が形成されている。図３に示すように、第１部材２１の軸穴Ｈ１、及び第２部材２２の軸穴Ｈ２には、対向ギア２を支持する第１支持軸６１（軸部材）が挿通される。 As shown in FIG. 5 , a cylindrical second cylindrical portion 24 having a smaller diameter than the first cylindrical portion 23 is provided inside the first cylindrical portion 23 . The annular space C is defined by the inner circumferential surface of the first cylindrical portion 23 and the outer circumferential surface of the second cylindrical portion 24 . A circular shaft hole H2 is formed inside the circle formed by the second cylindrical portion 24. Further, in the first member 21, the gear inner peripheral portion 27a is annular, and a circular shaft hole H1 is formed at the center thereof. As shown in FIG. 3, a first support shaft 61 (shaft member) that supports the opposing gear 2 is inserted into the shaft hole H1 of the first member 21 and the shaft hole H2 of the second member 22.

図５に示すように、第２部材２２は駆動ギア２８に固定される。より具体的には、駆動ギア２８は第１筒部２３に固定され、第１筒部２３を挟んで傘歯ギア部２７の外周部分２７ｂの反対側に設けられる。駆動ギア２８は、対向ギア２と一体的に形成されてもよい。駆動ギア２８はモータ４に接続し、モータ４からの動力を受ける。このため、駆動ギア２８に固定される第２部材２２に設けられるギア外周部分２７ｂには、駆動ギア２８の力が直接的に働く。また、第１部材２１は弾性部材２９Ａを介して第２部材２２に固定されるため、第１部材２１に形成されるギア内周部分２７ａには、駆動ギア２８の力が関節的に働く。 As shown in FIG. 5, the second member 22 is fixed to the drive gear 28. More specifically, the drive gear 28 is fixed to the first cylindrical portion 23 and is provided on the opposite side of the outer peripheral portion 27b of the bevel gear portion 27 with the first cylindrical portion 23 in between. The drive gear 28 may be formed integrally with the opposing gear 2. The drive gear 28 is connected to the motor 4 and receives power from the motor 4. Therefore, the force of the drive gear 28 acts directly on the gear outer peripheral portion 27b provided on the second member 22 that is fixed to the drive gear 28. Further, since the first member 21 is fixed to the second member 22 via the elastic member 29A, the force of the drive gear 28 acts on the gear inner peripheral portion 27a formed in the first member 21 in an articulated manner.

また、図５に示すように、対向ギア２は弾性部材２９Ａを有している。弾性部材２９Ａは、第２部材２２の第１筒部２３の内側（より具体的には、スペースＣの内側）に収容される。このように弾性部材２９Ａを対向ギア２の内部に収容することで、関節ユニット１の組み立てを簡便にできる。 Moreover, as shown in FIG. 5, the opposing gear 2 has an elastic member 29A. The elastic member 29A is housed inside the first cylindrical portion 23 of the second member 22 (more specifically, inside the space C). By accommodating the elastic member 29A inside the opposing gear 2 in this manner, the joint unit 1 can be assembled easily.

［関節ユニットにおける配置位置の詳細］
図３に示すように、関節ユニット１は、第１軸線Ａｘ１に沿って棒状に延びる第１支持軸６１と、第２軸線Ａｘ２に沿って棒状に延びる第２支持軸６２とを有している。第２支持軸６２は、螺子６３等によって第１支持軸６１に固定されている。２つの対向ギア２は、第１支持軸６１に支持されている。第１支持軸６１は、対向ギア２の第１部材２１及び第２部材２２を貫通している。 [Details of placement position in joint unit]
As shown in FIG. 3, the joint unit 1 has a first support shaft 61 extending in a rod shape along a first axis Ax1, and a second support shaft 62 extending in a rod shape along a second axis Ax2. . The second support shaft 62 is fixed to the first support shaft 61 with a screw 63 or the like. The two opposing gears 2 are supported by a first support shaft 61. The first support shaft 61 passes through the first member 21 and the second member 22 of the opposing gear 2 .

第１支持軸６１には、リング状の軸受け部材７１が取り付けられている。軸受け部材７１は、対向ギア２の第２部材２２（より具体的には、第２筒部２４）と、第１支持軸６１との間に配置される。軸受け部材７１は対向ギア２と第１支持軸６１とに接しており、これにより、対向ギア２は、第１支持軸６１の周方向（すなわち、第１軸線Ａｘ１を中心とした周方向）に回転可能である。先述したように、対向ギア２において、円筒形の第１筒部２３の内側には円筒形の第２筒部２４が形成されており、弾性部材２９Ａは、第１筒部２３の内周面と第２筒部２４の外周面とにより規定される環状のスペースＣに収容される。そして、本実施形態では、図５に示すように、弾性部材２９Ａはリング状であるため、図３に示すように、軸受け部材７１は、第２部材２２の第２筒部２４と第１支持軸６１との間において、リング状の弾性部材２９Ａの内側に配置される。このような配置にすることで、関節ユニット１の内部のスペースを有効活用できる。また、第２支持軸６２にも、リング状の軸受け部材７２けられている。軸受け部材７２は中間ギア３と第２支持軸６２とに接しており、これにより、中間ギア３は、第２支持軸６２の周方向（すなわち、第２軸線Ａｘ２を中心とした周方向）に回転可能である。なお、軸受け部材７１，７２は、アンギュラ軸受としてよい。 A ring-shaped bearing member 71 is attached to the first support shaft 61 . The bearing member 71 is arranged between the second member 22 (more specifically, the second cylindrical portion 24) of the opposing gear 2 and the first support shaft 61. The bearing member 71 is in contact with the opposing gear 2 and the first support shaft 61, so that the opposing gear 2 is rotated in the circumferential direction of the first supporting shaft 61 (that is, in the circumferential direction around the first axis Ax1). It is rotatable. As mentioned above, in the opposing gear 2, the cylindrical second cylindrical part 24 is formed inside the cylindrical first cylindrical part 23, and the elastic member 29A is attached to the inner peripheral surface of the first cylindrical part 23. and the outer peripheral surface of the second cylindrical portion 24. In the present embodiment, as shown in FIG. 5, the elastic member 29A is ring-shaped, so as shown in FIG. It is arranged between the ring-shaped elastic member 29A and the shaft 61. With this arrangement, the space inside the joint unit 1 can be effectively utilized. A ring-shaped bearing member 72 is also mounted on the second support shaft 62 . The bearing member 72 is in contact with the intermediate gear 3 and the second support shaft 62, so that the intermediate gear 3 is rotated in the circumferential direction of the second support shaft 62 (that is, in the circumferential direction around the second axis Ax2). It is rotatable. Note that the bearing members 71 and 72 may be angular bearings.

本実施形態では、弾性部材２９Ａは第２部材２２（より具体的には、第１筒部２３の内側）に取り付けられ、第１部材２１を対向ギア２の回転方向に沿った方向で付勢する。なお、弾性部材２９Ａが第２部材２２に取り付けられるとは、弾性部材２９Ａの端部が第２部材２２に固定されていることであってもよいし、単に弾性部材２９Ａの端部が第２部材２２に当たっていることであってもよい。対向ギア２は、第１軸線Ａｘ１を中心とした周方向で回転可能であり、弾性部材２９Ａは、対向ギア２の回転方向に沿った方向で第１部材２１を付勢する。対向ギア２の回転方向に沿った方向とは、第１軸線Ａｘ１を中心とした周方向であり、対向ギア２の回転方向（図１ＡのＲ１，Ｒ２で示した方向）そのものであってもよいし、その逆方向であってもよい。図５に示した例では、弾性部材２９Ａはトーションバネによって実現され、トーションバネの一端が第１部材２１に固定され、トーションバネの他端が第２部材２２に固定される。これに限らず、弾性部材２９Ａとして他の種類のバネを用いてもよい。 In this embodiment, the elastic member 29A is attached to the second member 22 (more specifically, inside the first cylindrical part 23), and urges the first member 21 in a direction along the rotational direction of the opposing gear 2. do. Note that the elastic member 29A being attached to the second member 22 may mean that the end of the elastic member 29A is fixed to the second member 22, or simply that the end of the elastic member 29A is attached to the second member 22. It may be in contact with the member 22. The opposing gear 2 is rotatable in the circumferential direction about the first axis Ax1, and the elastic member 29A urges the first member 21 in a direction along the rotation direction of the opposing gear 2. The direction along the rotational direction of the opposing gear 2 is a circumferential direction centered on the first axis Ax1, and may be the rotational direction of the opposing gear 2 itself (the direction indicated by R1 and R2 in FIG. 1A). However, it may be in the opposite direction. In the example shown in FIG. 5, the elastic member 29A is realized by a torsion spring, one end of the torsion spring is fixed to the first member 21, and the other end of the torsion spring is fixed to the second member 22. The present invention is not limited to this, and other types of springs may be used as the elastic member 29A.

このように、弾性部材２９Ａの弾性力で、対向ギア２の回転方向に沿った方向で第１部材２１を付勢することにより、中間ギア３の傘歯ギア部３７の歯３７１を、第１部材２１のギア内周部分２７ａの歯２７１ａと、第２部材２２のギア外周部分２７ｂの歯２７１ｂとで挟み込む機構（シザーズ機構）が構成される。これにより、対向ギア２の歯２７１と中間ギア３の歯３７１との隙間であるバックラッシュを低減でき、対向ギア２と中間ギア３とのバックラッシュに起因する騒音や振動の発生を抑制することができる。 In this way, by urging the first member 21 in the direction along the rotational direction of the opposing gear 2 with the elastic force of the elastic member 29A, the teeth 371 of the bevel gear portion 37 of the intermediate gear 3 are A sandwiching mechanism (scissor mechanism) is formed between the teeth 271a of the gear inner peripheral portion 27a of the member 21 and the teeth 271b of the gear outer peripheral portion 27b of the second member 22. As a result, backlash, which is the gap between the teeth 271 of the opposing gear 2 and the teeth 371 of the intermediate gear 3, can be reduced, and the generation of noise and vibration caused by the backlash between the opposing gear 2 and the intermediate gear 3 can be suppressed. I can do it.

本実施形態では、第１部材２１、第２部材２２、及び弾性部材２９Ａは２つの対向ギア２のそれぞれに含まれている。ここで、図２Ａに示したように、２つの対向ギア２にそれぞれ含まれる２つの第１部材２１は、弾性部材２９Ａにより、２つの対向ギア２の間の位置から見て同じ方向に付勢されてよい。図２Ａに示した例では、２つの第１部材２１の双方が、図１Ａ及び図２ＡにおいてＲ１で示した方向に付勢される。これに限らず、２つの第１部材２１の双方が、図１ＡにおいてＲ２で示した方向に付勢されてもよい。 In this embodiment, the first member 21, the second member 22, and the elastic member 29A are included in each of the two opposing gears 2. Here, as shown in FIG. 2A, the two first members 21 included in the two opposing gears 2 are urged in the same direction by the elastic member 29A when viewed from the position between the two opposing gears 2. It's okay to be. In the example shown in FIG. 2A, both of the two first members 21 are biased in the direction indicated by R1 in FIGS. 1A and 2A. The present invention is not limited to this, and both of the two first members 21 may be biased in the direction indicated by R2 in FIG. 1A.

このように、２つの対向ギア２にそれぞれ含まれる２つの第１部材２１が、２つの対向ギア２の間の位置から見て同じ方向に付勢させることにより、２つの対向ギア２が配置される位置で、バランスよく中間ギア３の位置制御が可能になる。このため、第１軸線Ａｘ１を中心として２つの対向ギア２を同じ方向に回転させて、第２軸線Ａｘ２を中心に中間ギア３を回転させる場合（中間ギア３にロール動作を行わせる場合）に好適である。 In this way, the two first members 21 included in the two opposing gears 2 are biased in the same direction when viewed from the position between the two opposing gears 2, so that the two opposing gears 2 are arranged. In this position, the position of the intermediate gear 3 can be controlled in a well-balanced manner. Therefore, when rotating the two opposing gears 2 in the same direction around the first axis Ax1 and rotating the intermediate gear 3 around the second axis Ax2 (when causing the intermediate gear 3 to perform a roll operation), suitable.

この他にも、図２Ｂに示したように、２つの対向ギア２にそれぞれ含まれる２つの第１部材２１は、弾性部材２９Ａにより、２つの対向ギア２の間の位置から見て互いに反対の方向に付勢されてもよい。図２Ｂに示した例では、一方の対向ギア２Ａの第１部材２１が、図１Ａ及び図２ＡにおいてＲ１で示した方向に付勢され、他方の対向ギア２Ｂの第１部材２１がＲ２で示した方向に付勢される。これに限らず、一方の対向ギア２Ａの第１部材２１が、図１ＡにおいてＲ２で示した方向に付勢され、他方の対向ギア２Ｂの第１部材２１が、図１ＡにおいてＲ１で示した方向に付勢されてもよい。 In addition, as shown in FIG. 2B, the two first members 21 included in the two opposing gears 2 are arranged opposite to each other when viewed from the position between the two opposing gears 2 by the elastic member 29A. It may be biased in the direction. In the example shown in FIG. 2B, the first member 21 of one opposing gear 2A is biased in the direction indicated by R1 in FIGS. 1A and 2A, and the first member 21 of the other opposing gear 2B is urged in the direction indicated by R2. is biased in the opposite direction. However, the first member 21 of one opposing gear 2A is biased in the direction indicated by R2 in FIG. 1A, and the first member 21 of the other opposing gear 2B is urged in the direction indicated by R1 in FIG. 1A. may be energized.

このように、２つの対向ギア２にそれぞれ含まれる２つの第１部材２１が、２つの対向ギア２の間の位置から見て互いに反対の方向に付勢させることにより、第１部材２１のギア内周部分２７ａの歯２７１ａを一方向に押し当てた状態での中間ギア３の位置制御が可能になる。このため、第１軸線Ａｘ１を中心として２つの対向ギア２を互いに反対の方向に動かして、第１軸線Ａｘ１を中心に中間ギア３を回転移動させる場合（中間ギア３にピッチ動作を行わせる場合）に好適である。 In this way, the two first members 21 included in the two opposing gears 2 are biased in opposite directions when viewed from the position between the two opposing gears 2, so that the gear of the first member 21 The position of the intermediate gear 3 can be controlled while the teeth 271a of the inner peripheral portion 27a are pressed in one direction. Therefore, when the two opposing gears 2 are moved in opposite directions about the first axis Ax1 and the intermediate gear 3 is rotated about the first axis Ax1 (when the intermediate gear 3 is caused to perform a pitch operation) ) is suitable for

［規制部］
対向ギア２の第２部材２２は、対向ギア２の回転方向に沿った方向での第１部材２１の動きを規制する規制部を含む。図５に示すように、第２部材２２の内側には第２筒部２４が形成されており、この第２筒部２４の頂部に凹部２４ａが形成されている。第１部材２１の動きを規制する規制部は、凹部２４ａを含む。凹部２４ａは、第２筒部２４において円形の軸穴Ｈ２から僅かにずれた位置に形成されている。凹部２４ａは、第２筒部２４の端部に形成されている。 [Regulatory Department]
The second member 22 of the opposing gear 2 includes a restriction portion that restricts the movement of the first member 21 in a direction along the rotational direction of the opposing gear 2. As shown in FIG. 5, a second cylindrical portion 24 is formed inside the second member 22, and a recess 24a is formed at the top of the second cylindrical portion 24. As shown in FIG. The restriction portion that restricts the movement of the first member 21 includes a recess 24a. The recessed portion 24a is formed in the second cylindrical portion 24 at a position slightly shifted from the circular shaft hole H2. The recessed portion 24a is formed at the end of the second cylindrical portion 24.

図６は、対向ギア２の第１部材２１を示す斜視図である。図６に示すように、第１部材２１の円筒形の第３筒部２５の内側に、凸部２５ａが形成されている。第１部材２１と第２部材２２とを組み合わせた際、第１部材２１に形成される凸部２５ａが第２部材２２に形成されている凹部２４ａの内側に嵌まる。これにより、対向ギア２の回転方向に沿った方向での第１部材２１の動きが規制される。 FIG. 6 is a perspective view showing the first member 21 of the opposing gear 2. As shown in FIG. As shown in FIG. 6, a convex portion 25a is formed inside the cylindrical third tube portion 25 of the first member 21. As shown in FIG. When the first member 21 and the second member 22 are combined, the protrusion 25a formed on the first member 21 fits inside the recess 24a formed on the second member 22. Thereby, movement of the first member 21 in the direction along the rotational direction of the opposing gear 2 is restricted.

図７は、対向ギア２の規制部を示す図であり、第１部材２１に形成される凸部２５ａが第２部材２２に形成されている凹部２４ａの内側に嵌まった状態を示す。図７に示すように、第２部材２２に第１部材２１を組み合わせることにより、第１部材２１の凸部２５ａが第２部材２２の凹部２４ａの内側に嵌まる。ここで、対向ギア２の回転方向に沿った方向における一方側（図７における左側）では、凸部２５ａ縁が弾性部材２９Ａの付勢力により凹部２４ａの縁に当接し、対向ギア２の回転方向に沿った方向における他方側（図７における右側）では、凸部２５ａ縁と凹部２４ａの縁との間に隙間ΔＤ１が形成される。 FIG. 7 is a diagram showing the regulating portion of the opposing gear 2, and shows a state in which a convex portion 25a formed on the first member 21 is fitted inside a recess portion 24a formed on the second member 22. As shown in FIG. 7, by combining the first member 21 with the second member 22, the convex portion 25a of the first member 21 fits inside the concave portion 24a of the second member 22. Here, on one side (the left side in FIG. 7) in the direction along the rotational direction of the opposing gear 2, the edge of the convex portion 25a abuts the edge of the recessed portion 24a due to the biasing force of the elastic member 29A, and On the other side in the direction along (the right side in FIG. 7), a gap ΔD1 is formed between the edge of the convex portion 25a and the edge of the recessed portion 24a.

第１部材２１は、第２部材２２の規制部（凹部２４ａ）において許容される範囲で動くことができる。図７に示した例では、第１部材２１は、凸部２５ａ縁と凹部２４ａの縁との間の隙間ΔＤ１の範囲で動くことができる。仮に、この許容される範囲（図７では、隙間ΔＤ１）を超えて第１部材２１が回転すると、第１部材２１に対する弾性部材２９Ａの弾性力が得られなくなる。そこで、規制部（凹部２４ａ）を設けることで、許容される範囲を超えて第１部材２１が回転するのを防ぐことができ、第１部材２１に対する弾性部材２９Ａの弾性力を担保できる。また、規制部（凹部２４ａ）を設けることで、対向ギア２の回転方向における第１部材２１と第２部材２２との位置決めを行うことができ、弾性部材２９Ａから得られる弾性力として予め設計された力を担保できる。すなわち、中間ギア３の歯に噛み合う力を設計的に担保することができる。 The first member 21 can move within a permissible range in the regulating portion (recess 24a) of the second member 22. In the example shown in FIG. 7, the first member 21 can move within the range of the gap ΔD1 between the edge of the convex portion 25a and the edge of the concave portion 24a. If the first member 21 rotates beyond this allowable range (in FIG. 7, the gap ΔD1), the elastic force of the elastic member 29A against the first member 21 will not be obtained. Therefore, by providing the restricting portion (recess 24a), it is possible to prevent the first member 21 from rotating beyond the permissible range, and the elastic force of the elastic member 29A with respect to the first member 21 can be ensured. Further, by providing the regulating portion (recessed portion 24a), the first member 21 and the second member 22 can be positioned in the rotational direction of the opposing gear 2, and the elastic force obtained from the elastic member 29A is designed in advance. It is possible to guarantee the strength of That is, the force of meshing with the teeth of the intermediate gear 3 can be ensured in terms of design.

図８は、対向ギア２のギア内周部分２７ａの一部分とギア外周部分２７ｂの一部分とを示す拡大図であり、対向ギア２が中間ギア３と噛み合っていない状態を示す。図８に示すように、対向ギア２の規制部（凹部２４ａ）において第１部材２１の動きが許容される範囲（隙間ΔＤ１）の角度θ１は、対向ギア２の傘歯ギア部２７において隣り合う２つの歯２７１のなす角度θ２の１／２以下に設定される。なお、図８では、ギア外周部分２７ｂにおいて隣り合う２つの歯２７１ｂのなす角度をθ２としているが、ギア内周部分２７ａにおいて隣り合う２つの歯２７１ａのなす角度もこれと同一である。このようにすることで、対向ギア２のギア内周部分２７ａの歯２７１ａの間と、ギア外周部分２７ｂの歯２７１ｂの間とに、中間ギア３の歯３７１を通すことができ、対向ギア２と中間ギア３との組み合わせを容易にすることができる。規制部（凹部２４ａ）において第１部材２１の動きが許容される範囲（隙間ΔＤ１）の角度θ１は、対向ギア２の傘歯ギア部２７において隣り合う２つの歯２７１のなす角度θ２の１／３以下に設定されてもよい。 FIG. 8 is an enlarged view showing a portion of the gear inner peripheral portion 27a and a portion of the gear outer peripheral portion 27b of the opposing gear 2, and shows a state where the opposing gear 2 is not engaged with the intermediate gear 3. As shown in FIG. 8, the angle θ1 of the range (gap ΔD1) in which the movement of the first member 21 is allowed in the restriction portion (recessed portion 24a) of the opposing gear 2 is the same as that of the adjacent bevel gear portion 27 of the opposing gear 2. The angle θ2 formed by the two teeth 271 is set to 1/2 or less. In FIG. 8, the angle formed by two adjacent teeth 271b in the gear outer peripheral portion 27b is set to θ2, but the angle formed by two adjacent teeth 271a in the gear inner peripheral portion 27a is also the same. By doing so, the teeth 371 of the intermediate gear 3 can be passed between the teeth 271a of the gear inner circumferential portion 27a of the opposing gear 2 and the teeth 271b of the gear outer circumferential portion 27b, and the opposing gear 2 and the intermediate gear 3 can be easily combined. The angle θ1 of the range (gap ΔD1) in which movement of the first member 21 is allowed in the regulating portion (recessed portion 24a) is 1/1 of the angle θ2 formed by two adjacent teeth 271 in the bevel gear portion 27 of the opposing gear 2. It may be set to 3 or less.

以上説明したように、本実施形態に係る関節ユニット１の対向ギア２は、ギア内周部分２７ａを含む第１部材２１と、ギア外周部分２７ｂを含む第２部材２２と、弾性部材２９Ａとを含み、弾性部材２９Ａは、対向ギア２の回転方向に沿った方向（第１軸線Ａｘ１を中心とした周方向）で、第１部材２１を付勢する。このようにすることで、中間ギア３の傘歯ギア部３７の歯３７１を、第１部材２１のギア内周部分２７ａの歯２７１ａと、第２部材２２のギア外周部分２７ｂの歯２７１ｂとで挟み込み、対向ギア２と中間ギア３とのバックラッシュを低減できる。 As explained above, the opposing gear 2 of the joint unit 1 according to the present embodiment includes the first member 21 including the gear inner peripheral portion 27a, the second member 22 including the gear outer peripheral portion 27b, and the elastic member 29A. The elastic member 29A urges the first member 21 in a direction along the rotational direction of the opposing gear 2 (circumferential direction centered on the first axis Ax1). By doing so, the teeth 371 of the bevel gear portion 37 of the intermediate gear 3 are formed by the teeth 271a of the gear inner peripheral portion 27a of the first member 21 and the teeth 271b of the gear outer peripheral portion 27b of the second member 22. It is possible to reduce pinching and backlash between the opposing gear 2 and the intermediate gear 3.

［第２の実施形態］
次に、本開示の実施形態の他の一例（第２の実施形態）について説明する。本実施形態に係る関節ユニット１は、第１の実施形態と同様に、互いに対向する２つの対向ギア２と、これら２つの対向ギア２の双方に噛み合う中間ギア３とを有している。以下では、本実施形態と第１の実施形態との相違点について、図面を参照しながら説明する。 [Second embodiment]
Next, another example (second embodiment) of the embodiment of the present disclosure will be described. Like the first embodiment, the joint unit 1 according to this embodiment includes two opposed gears 2 that face each other, and an intermediate gear 3 that meshes with both of these two opposed gears 2. Below, differences between this embodiment and the first embodiment will be explained with reference to the drawings.

図９は、本実施形態に係る対向ギア２の分解斜視図である。図９に示すように、本実施形態に係る対向ギア２は、第１の実施形態で説明した弾性部材２９Ａとは形状が異なる弾性部材２９Ｂを有している。図９に示した例では、弾性部材２９Ｂはコイルバネによって実現されるが、これに限らず、弾性部材２９Ｂとして他の種類のバネを用いてもよい。 FIG. 9 is an exploded perspective view of the opposing gear 2 according to this embodiment. As shown in FIG. 9, the opposing gear 2 according to this embodiment includes an elastic member 29B having a different shape from the elastic member 29A described in the first embodiment. In the example shown in FIG. 9, the elastic member 29B is realized by a coil spring, but the present invention is not limited to this, and other types of springs may be used as the elastic member 29B.

図１０は、本実施形態に係る関節ユニット１の一部分を示した正面図であり、関節ユニット１に設けられる２つの対向ギア２（２Ａ，２Ｂ）と、中間ギア３とを示している。図１０に示すように、本実施形態に係る弾性部材２９Ｂは、対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で、対向ギア２の傘歯ギア部２７の少なくとも一部分を中間ギア３に付勢する。 FIG. 10 is a front view showing a part of the joint unit 1 according to the present embodiment, and shows two opposing gears 2 (2A, 2B) and an intermediate gear 3 provided in the joint unit 1. As shown in FIG. 10, the elastic member 29B according to the present embodiment connects at least a portion of the bevel gear portion 27 of the opposing gear 2 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2. energizes gear 3.

対向ギア２の傘歯ギア部２７に設けられる複数の歯２７１のそれぞれの幅は、傘歯ギア部２７の外周に向かうにつれて徐々に大きくなっている。ここで、弾性部材２９Ｂが対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で傘歯ギア部２７の少なくとも一部分を付勢することにより、中間ギア３の傘歯ギア部３７において隣り合う２つの歯３７１の間の隙間を埋めるように、傘歯ギア部２７の歯２７１が押し込まれる。このため、弾性部材２９Ｂが対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で傘歯ギア部２７の少なくとも一部分を付勢することでも、対向ギア２の歯２７１と中間ギア３の歯３７１との隙間であるバックラッシュを低減でき、バックラッシュに起因する騒音や振動の発生を抑制することができる。 The width of each of the plurality of teeth 271 provided on the bevel gear portion 27 of the opposing gear 2 gradually increases toward the outer periphery of the bevel gear portion 27. Here, the elastic member 29B biases at least a portion of the bevel gear portion 27 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2, so that the bevel gear portion 37 of the intermediate gear 3 The teeth 271 of the bevel gear portion 27 are pushed in so as to fill the gap between two adjacent teeth 371. Therefore, the elastic member 29B biases at least a portion of the bevel gear portion 27 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2, so that the teeth 271 of the opposing gear 2 and the intermediate gear 3 Backlash, which is the gap between the teeth 371, can be reduced, and the generation of noise and vibration caused by backlash can be suppressed.

本実施形態では、関節ユニット１に設けられる２つの対向ギア２の双方が、弾性部材２９Ｂを含む。２つの対向ギア２にそれぞれで、弾性部材２９Ｂが傘歯ギア部２７の少なくとも一部分を付勢し、中間ギア３が両側から押されることで、対向ギア２と中間ギア３とのバックラッシュを低減でき、また、対向ギア２の回転中心線（第１軸線Ａｘ１）上における中間ギア３の位置を適正に調整（調心）できる。 In this embodiment, both of the two opposing gears 2 provided in the joint unit 1 include the elastic member 29B. The elastic member 29B biases at least a portion of the bevel gear portion 27 on each of the two opposing gears 2, and the intermediate gear 3 is pushed from both sides, thereby reducing backlash between the opposing gear 2 and the intermediate gear 3. In addition, the position of the intermediate gear 3 on the rotation center line (first axis Ax1) of the opposing gear 2 can be appropriately adjusted (aligned).

図９に示すように、本実施形態に係る対向ギア２は、第１の実施形態と同様の第１部材２１と第２部材２２とを含む。このため、弾性部材２９Ｂは、対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で、第１部材２１を中間ギア３に付勢する。本実施形態では、関節ユニット１に設けられる２つの対向ギア２双方で、第１部材２１が付勢される。 As shown in FIG. 9, the opposing gear 2 according to this embodiment includes a first member 21 and a second member 22 similar to those in the first embodiment. Therefore, the elastic member 29B urges the first member 21 against the intermediate gear 3 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2. In this embodiment, the first member 21 is biased by both of the two opposing gears 2 provided in the joint unit 1 .

また、弾性部材２９Ｂは、第１の実施形態で説明した弾性部材２９Ａと同様に、対向ギア２の内部に設けられる。より具体的には、図９に示すように、第２部材２２は、第１部材２１のギア外周部分２７ｂから対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向に延びている第１筒部２３を含んでおり、弾性部材２９Ｂは、この第２部材２２の第１筒部２３の内側に設けられる。これにより、関節ユニット１の組み立てを簡便にできる。円筒形の第１筒部２３の内側には、円筒形の第２筒部２４が形成されており、弾性部材２９Ｂは、第１筒部２３の内周面と第２筒部２４の外周面とにより規定される環状のスペースＣに収容される。 Further, the elastic member 29B is provided inside the opposing gear 2, similar to the elastic member 29A described in the first embodiment. More specifically, as shown in FIG. 9, the second member 22 extends from the gear outer peripheral portion 27b of the first member 21 in a direction along the rotation center line (first axis Ax1) of the opposing gear 2. The second member 22 includes a first cylindrical portion 23, and the elastic member 29B is provided inside the first cylindrical portion 23 of the second member 22. Thereby, the joint unit 1 can be assembled easily. A cylindrical second cylindrical portion 24 is formed inside the cylindrical first cylindrical portion 23, and the elastic member 29B is connected to the inner circumferential surface of the first cylindrical portion 23 and the outer circumferential surface of the second cylindrical portion 24. It is accommodated in an annular space C defined by.

また、本実施形態に係る関節ユニット１は、図３で示した関節ユニット１と同様の構成を有しており、弾性部材２９Ｂは、図３における弾性部材２９Ａの配置位置と同じ位置に配置される。本実施形態でも、関節ユニット１は、対向ギア２の第１部材２１及び第２部材２２を貫通する第１支持軸６１（軸部材）と、第２部材２２（より具体的には、第２筒部）と第１支持軸６１との間に配置される軸受け部材７１とを含んでいる。図９に示したように、本実施形態でも弾性部材２９Ｂはコイル型であり、軸受け部材７１は、第２部材２２の第２筒部２４と第１支持軸６１との間において、弾性部材２９Ｂの内側に位置に配置される。このような配置にすることで、関節ユニット１の内部のスペースを有効活用できる。 Further, the joint unit 1 according to the present embodiment has the same configuration as the joint unit 1 shown in FIG. 3, and the elastic member 29B is arranged at the same position as the elastic member 29A in FIG. Ru. Also in this embodiment, the joint unit 1 includes a first support shaft 61 (shaft member) that passes through the first member 21 and second member 22 of the opposing gear 2, and a second member 22 (more specifically, a second cylindrical portion) and a bearing member 71 disposed between the first support shaft 61. As shown in FIG. 9, the elastic member 29B is of a coil type in this embodiment as well, and the bearing member 71 is connected to the elastic member 29B between the second cylindrical portion 24 of the second member 22 and the first support shaft 61. is placed inside the position. With this arrangement, the space inside the joint unit 1 can be effectively utilized.

以上説明したように、本実施形態に係る関節ユニット１では、弾性部材２９Ｂは、対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で、対向ギア２の傘歯ギア部２７の少なくとも一部分を中間ギア３に付勢する。このようにすることで、対向ギア２の歯２７１と中間ギア３の歯３７１との隙間であるバックラッシュを低減できる。 As described above, in the joint unit 1 according to the present embodiment, the elastic member 29B is attached to the bevel gear portion 27 of the opposing gear 2 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2. At least a portion of the intermediate gear 3 is biased. By doing so, backlash, which is a gap between the teeth 271 of the opposing gear 2 and the teeth 371 of the intermediate gear 3, can be reduced.

［変形例］
本発明は以上説明した関節ユニット１に限られず、種々の変更がなされてよい。例えば、第１の実施形態では、２つの対向ギア２が、ギア内周部分２７ａを含む第１部材２１と、ギア外周部分２７ｂを含む第２部材２２とに分割可能であり、対向ギア２の第１部材２１を弾性部材２９Ａによって付勢する形態について説明したが、これに限らず、中間ギア３が、傘歯ギア部３７の内周部分と傘歯ギア部３７の外周部分とに分割可能であり、この傘歯ギア部３７の内周部分を、中間ギア３の内側に設けられた弾性部材によって、中間ギア３の回転方向に沿った方向（第２軸線Ａｘ２を中心とした周方向）で付勢してもよい。このようにすることでも、中間ギア３の傘歯ギア部３７の内周部分の歯と外周部分の歯とで対向ギア２の傘歯ギア部２７の歯２７１を挟み込み、対向ギア２と中間ギア３とのバックラッシュを低減できる。 [Modified example]
The present invention is not limited to the joint unit 1 described above, and various modifications may be made. For example, in the first embodiment, the two opposing gears 2 can be divided into a first member 21 including a gear inner circumferential portion 27a and a second member 22 including a gear outer circumferential portion 27b. Although the embodiment in which the first member 21 is biased by the elastic member 29A has been described, the present invention is not limited to this, and the intermediate gear 3 can be divided into an inner circumferential portion of the bevel gear portion 37 and an outer circumferential portion of the bevel gear portion 37. The inner peripheral portion of the bevel gear portion 37 is rotated in a direction along the rotational direction of the intermediate gear 3 (circumferential direction centered on the second axis Ax2) by an elastic member provided inside the intermediate gear 3. It may be energized by By doing so, the teeth 271 of the bevel gear portion 27 of the opposing gear 2 are sandwiched between the teeth on the inner circumferential portion and the teeth on the outer circumferential portion of the bevel gear portion 37 of the intermediate gear 3, and the teeth 271 of the bevel gear portion 27 of the opposing gear 2 are connected to the intermediate gear. Backlash with 3 can be reduced.

また、第１の実施形態では、対向ギア２において、弾性部材２９Ａがギア外周部分２７ｂを含む第２部材２２に取り付けられ、対向ギア２の回転方向に沿った方向でギア内周部分２７ａを含む第１部材２１を付勢する場合について説明したが、これに限らず、弾性部材２９Ａは、ギア内周部分２７ａを含む第１部材２１に取り付けられてよく、対向ギア２の回転方向に沿った方向（第１軸線Ａｘ１を中心とした周方向）で、ギア外周部分２７ｂを含む第２部材２２を付勢してもよい。このようにすることでも、中間ギア３の傘歯ギア部３７の歯３７１をギア内周部分２７ａの歯２７１ａとギア外周部分２７ｂの歯２７１ｂとで挟み込み、対向ギア２と中間ギア３とのバックラッシュを低減できる。 Further, in the first embodiment, in the opposing gear 2, the elastic member 29A is attached to the second member 22 including the gear outer peripheral portion 27b, and includes the gear inner peripheral portion 27a in the direction along the rotation direction of the opposing gear 2. Although the case where the first member 21 is biased has been described, the elastic member 29A may be attached to the first member 21 including the gear inner peripheral portion 27a, and the elastic member 29A may be attached to the first member 21 including the gear inner peripheral portion 27a, and The second member 22 including the gear outer peripheral portion 27b may be biased in the direction (circumferential direction centered on the first axis Ax1). By doing so, the teeth 371 of the bevel gear portion 37 of the intermediate gear 3 are sandwiched between the teeth 271a of the gear inner peripheral portion 27a and the teeth 271b of the gear outer peripheral portion 27b, and the back of the opposing gear 2 and the intermediate gear 3 is Rush can be reduced.

また、第２の実施形態では、対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で、弾性部材２９Ｂが傘歯ギア部２７の少なくとも一部分を中間ギア３に付勢する形態について説明したが、これに限らず、中間ギア３の回転中心線（第２軸線Ａｘ２）に沿った方向で、中間ギア３に設けられる弾性部材が、中間ギア３の傘歯ギア部３７の少なくとも一部分を対向ギア２に付勢してもよい。この場合、中間ギア３が、傘歯ギア部３７の内周部分と傘歯ギア部３７の外周部分とに分割可能であり、これらの内周部分と外周部分との一方が、中間ギア３の弾性部材によって付勢されてもよい。このようにすることでも、対向ギア２において隣り合う歯２７１の間の隙間を埋めるように中間ギア３の歯３７１が押し込まれ、対向ギア２の歯２７１と中間ギア３の歯３７１との間の隙間であるバックラッシュを低減できる。 Further, in the second embodiment, the elastic member 29B biases at least a portion of the bevel gear portion 27 against the intermediate gear 3 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2. Although described above, the present invention is not limited to this, and the elastic member provided on the intermediate gear 3 may be attached to at least a portion of the bevel gear portion 37 of the intermediate gear 3 in the direction along the rotation center line (second axis Ax2) of the intermediate gear 3. may be applied to the opposing gear 2. In this case, the intermediate gear 3 can be divided into an inner peripheral part of the bevel gear part 37 and an outer peripheral part of the bevel gear part 37, and one of the inner peripheral part and the outer peripheral part of the intermediate gear 3 It may be biased by an elastic member. By doing so, the teeth 371 of the intermediate gear 3 are pushed in so as to fill the gaps between the adjacent teeth 271 in the opposing gear 2, and the teeth 371 of the opposing gear 2 and the teeth 371 of the intermediate gear 3 are Backlash, which is a gap, can be reduced.

また、第１の実施形態では、弾性部材２９Ａがトーションバネによって実現される形態について説明したが、これに限らず、弾性部材２９Ａは種々のバネによって実現されてよい。 Further, in the first embodiment, the elastic member 29A is realized by a torsion spring, but the elastic member 29A is not limited to this, and the elastic member 29A may be realized by various springs.

図１１は、本発明の変形例に係る弾性部材２９Ｃ、及び第２部材２２を示す斜視図である。図１１に示すように、弾性部材２９Ｃは板バネで構成される。弾性部材２９Ｃは、板バネ部２９１Ｃと、第２部材２２に固定される固定部２９２Ｃとを含む。固定部２９２Ｃは、環状のスペースＣと対応する形状を有した板状であり、スペースＣの外周（第１筒部２３の内周面）から内周（第２筒部２４の外周面）にかけての幅を有し、スペースＣの円弧状に延びている。固定部２９２Ｃは、第１筒部２３の内周面と第２筒部２４の外周面との間に形成される壁面２６に固定される。板バネ部２９１Ｃは固定部２９２Ｃと一体的に形成される板状であり、固定部２９２Ｃと同じ幅で、固定部２９２Ｃに対して垂直に延びている。弾性部材２９Ｃは、板バネ部２９１Ｃが固定部２９２Ｃに対して弾性的に撓むことにより、第１の実施形態と同様に、第１軸線Ａｘ１の周方向で、第１部材２１を付勢することができる。なお、図１１では、１つの対向ギア２に含まれる弾性部材２９Ｃの数を３つとしているが、１つの対向ギア２に含まれる弾性部材２９Ｃの数は、１つであってもよいし、３以外の複数であってもよい。 FIG. 11 is a perspective view showing an elastic member 29C and a second member 22 according to a modification of the present invention. As shown in FIG. 11, the elastic member 29C is composed of a plate spring. The elastic member 29C includes a leaf spring portion 291C and a fixing portion 292C fixed to the second member 22. The fixing part 292C is a plate having a shape corresponding to the annular space C, and extends from the outer circumference of the space C (the inner circumferential surface of the first cylindrical part 23) to the inner periphery (the outer circumferential surface of the second cylindrical part 24). It has a width of , and extends in an arc shape of space C. The fixing portion 292C is fixed to the wall surface 26 formed between the inner circumferential surface of the first cylindrical portion 23 and the outer circumferential surface of the second cylindrical portion 24. The plate spring portion 291C is plate-shaped and integrally formed with the fixing portion 292C, has the same width as the fixing portion 292C, and extends perpendicularly to the fixing portion 292C. The elastic member 29C biases the first member 21 in the circumferential direction of the first axis Ax1, as in the first embodiment, by the plate spring portion 291C elastically bending with respect to the fixed portion 292C. be able to. In addition, in FIG. 11, the number of elastic members 29C included in one opposing gear 2 is three, but the number of elastic members 29C included in one opposing gear 2 may be one, It may be a plural number other than 3.

図１２は、本発明の他の変形例に係る弾性部材２９Ｄ、及び第２部材２２を示す斜視図である。図１２に示すように、弾性部材２９Ｄは、弾性部材２９Ｃと同様に板バネで構成され、板バネ部２９１Ｄと、第２部材２２に固定される固定部２９２Ｄとを含む。固定部２９２Ｄは、第２筒部２４の外周面に形成された溝部２４ｃの内側に固定される。弾性部材２９Ｄにおいても板バネ部２９１Ｄが固定部２９２Ｄに対して弾性的に撓むことにより、第１軸線Ａｘ１の周方向で第１部材２１を付勢することができる。なお、図１２では、１つの対向ギア２に含まれる弾性部材２９Ｄの数を３つとしているが、１つの対向ギア２に含まれる弾性部材２９Ｄの数も、１つであってもよいし、３以外の複数であってもよい。 FIG. 12 is a perspective view showing an elastic member 29D and a second member 22 according to another modification of the present invention. As shown in FIG. 12, the elastic member 29D is made of a plate spring like the elastic member 29C, and includes a plate spring portion 291D and a fixing portion 292D fixed to the second member 22. The fixing portion 292D is fixed inside a groove portion 24c formed on the outer peripheral surface of the second cylindrical portion 24. Also in the elastic member 29D, the leaf spring portion 291D elastically bends with respect to the fixing portion 292D, so that the first member 21 can be biased in the circumferential direction of the first axis Ax1. In addition, in FIG. 12, the number of elastic members 29D included in one opposing gear 2 is three, but the number of elastic members 29D included in one opposing gear 2 may also be one, It may be a plural number other than 3.

図１１に示した弾性部材２９Ｃでは、板バネ部２９１Ｃと固定部２９２Ｃとの接続部分である接続部２９３Ｃが第１軸線Ａｘ１に対して垂直な方向に延びているのに対し、図１２に示した弾性部材２９Ｄでは、板バネ部２９１Ｄと固定部２９２Ｄとの接続部分である接続部２９３Ｄが第１軸線Ａｘ１に対して平行に延びており、接続部２９３Ｄは接続部２９３Ｃよりも長くなっている。このようにすることで、板バネ部２９１Ｄのバネの硬さを板バネ部２９１Ｃよりも強くすることができ、より強い力で第１部材２１を付勢することができる。 In the elastic member 29C shown in FIG. 11, the connection part 293C, which is the connection part between the leaf spring part 291C and the fixing part 292C, extends in a direction perpendicular to the first axis Ax1. In the elastic member 29D, a connecting portion 293D, which is a connecting portion between the leaf spring portion 291D and the fixed portion 292D, extends parallel to the first axis Ax1, and the connecting portion 293D is longer than the connecting portion 293C. . By doing so, the spring hardness of the leaf spring portion 291D can be made stronger than that of the leaf spring portion 291C, and the first member 21 can be biased with a stronger force.

図１３は、本発明の他の変形例に係る弾性部材２９Ｅ、及び第２部材２２を示す斜視図である。図１３に示すように、弾性部材２９Ｅはコイルバネであり、弾性部材２９Ｅの外径は、第２部材２２のスペースＣの内周（第２筒部２４の外周面）から外周（第１筒部２３の内周面）かけての幅以下に設計され、スペースＣの内側に横たわる様に設けられる。このようにすることでも、第１軸線Ａｘ１の周方向で、弾性部材２９Ｅによって第１部材２１を付勢することができる。なお、図１３では、１つの対向ギア２に含まれる弾性部材２９Ｅの数を３つとしているが、１つの対向ギア２に含まれる弾性部材２９Ｅの数も、１つであってもよいし、３以外の複数であってもよい。 FIG. 13 is a perspective view showing an elastic member 29E and a second member 22 according to another modification of the present invention. As shown in FIG. 13, the elastic member 29E is a coil spring, and the outer diameter of the elastic member 29E varies from the inner circumference (outer circumferential surface of the second cylindrical part 24) of the space C of the second member 22 to the outer periphery (the outer circumferential surface of the first cylindrical part 24). It is designed to have a width equal to or less than the width of the inner peripheral surface of 23, and is provided so as to lie inside the space C. By doing so, the first member 21 can also be biased by the elastic member 29E in the circumferential direction of the first axis Ax1. In addition, in FIG. 13, the number of elastic members 29E included in one opposing gear 2 is three, but the number of elastic members 29E included in one opposing gear 2 may also be one. It may be a plural number other than 3.

図１３は、本発明の他の変形例に係る弾性部材２９Ｅ、及び第２部材２２を示す斜視図である。図１３に示すように、弾性部材２９Ｅはコイルバネであり、弾性部材２９Ｅの外径は、第２部材２２のスペースＣの内周（第２筒部２４の外周面）から外周（第１筒部２３の内周面）かけての幅以下に設計され、スペースＣの内側に横たわる様に設けられる。このようにすることでも、第１軸線Ａｘ１の周方向で、弾性部材２９Ｅによって第１部材２１を付勢することができる。 FIG. 13 is a perspective view showing an elastic member 29E and a second member 22 according to another modification of the present invention. As shown in FIG. 13, the elastic member 29E is a coil spring, and the outer diameter of the elastic member 29E varies from the inner circumference (outer circumferential surface of the second cylindrical part 24) of the space C of the second member 22 to the outer periphery (the outer circumferential surface of the first cylindrical part 24). It is designed to have a width equal to or less than the width of the inner peripheral surface of 23, and is provided so as to lie inside the space C. By doing so, the first member 21 can also be biased by the elastic member 29E in the circumferential direction of the first axis Ax1.

なお、図１３に示した弾性部材２９Ｅは、スペースＣの内側に立つ様に設けられてもよい。このようにすることで、対向ギア２の回転中心線（第１軸線Ａｘ１）に沿った方向で、第１部材２１を中間ギア３に付勢することができ、対向ギア２と中間ギア３との間の隙間であるバックラッシュを低減することができる。 Note that the elastic member 29E shown in FIG. 13 may be provided so as to stand inside the space C. By doing so, the first member 21 can be biased against the intermediate gear 3 in the direction along the rotation center line (first axis Ax1) of the opposing gear 2, and the opposing gear 2 and the intermediate gear 3 can be biased. Backlash, which is the gap between the two, can be reduced.

１関節ユニット、２，２Ａ，２Ｂ対向ギア、３中間ギア、４，４Ａ，４Ｂモータ、５制御基板、２１第１部材、２２第２部材、２３第１筒部、２４第２筒部、２５第３筒部、２４ａ凹部、２５ａ凸部、２７傘歯ギア部、２７ａギア内周部分、２７ｂギア外周部分、２７１，２７１ａ，２７１ｂ歯、２８駆動ギア、２９Ａ，２９Ｂ，２９Ｃ，２９Ｄ，２９Ｅ弾性部材、２９１Ｃ，２９１Ｄ板バネ部、２９２Ｃ，２９２Ｄ固定部、２９３Ｃ，２９３Ｄ接続部、３７傘歯ギア部、３７１歯、３８基部、６１第１支持軸、６２第２支持軸、６３螺子、７１，７２軸受け部材、Ａｘ１第１軸線、Ａｘ２第２軸線、Ｃスペース、Ｈ１，Ｈ２軸穴、ΔＤ１隙間、θ１，θ２角度。

1 Joint unit, 2, 2A, 2B Opposing gear, 3 Intermediate gear, 4, 4A, 4B Motor, 5 Control board, 21 First member, 22 Second member, 23 First cylinder part, 24 Second cylinder part, 25 Third cylindrical portion, 24a concave portion, 25a convex portion, 27 bevel gear portion, 27a gear inner peripheral portion, 27b gear outer peripheral portion, 271, 271a, 271b teeth, 28 drive gear, 29A, 29B, 29C, 29D, 29E elasticity Member, 291C, 291D Leaf spring portion, 292C, 292D Fixed portion, 293C, 293D Connection portion, 37 Bevel gear portion, 371 Teeth, 38 Base, 61 First support shaft, 62 Second support shaft, 63 Screw, 71, 72 Bearing member, Ax1 1st axis, Ax2 2nd axis, C space, H1, H2 shaft hole, ΔD1 gap, θ1, θ2 angle.

Claims

A joint unit including two opposing gears each including two opposing bevel gear parts, an intermediate gear including a bevel gear part meshing with both of the two bevel gear parts, a shaft member, and a bearing member. And,
The bevel gear portion of one of the two opposing gears and the intermediate gear has a plurality of teeth arranged along the rotational direction of the one gear, and each of the plurality of teeth has a width of , gradually becoming larger toward the outer periphery of the bevel gear portion of the one gear,
The one gear includes a first member including an inner circumferential portion of the bevel gear portion of the one gear, a second member including an outer circumferential portion of the bevel gear portion of the one gear, and a second member including an outer circumferential portion of the bevel gear portion of the one gear. an elastic member that biases the first member against the other gear in a direction along the rotation center line ;
The second member includes a first cylindrical portion extending from an outer peripheral portion of the bevel gear portion of the one gear along the rotation center line of the one gear, and a first cylindrical portion extending from the outer peripheral portion of the bevel gear portion of the one gear along the rotation center line of the one gear; a second cylindrical portion extending along the rotation center line of the gear;
The shaft member passes through the first member and the second member,
The bearing member is arranged between the second member and the shaft member,
The first member fits into the first cylindrical portion of the second member,
The elastic member is housed in a space defined between the first cylindrical part and the second cylindrical part of the second member,
The bearing member is disposed inside the elastic member between the second cylindrical portion of the second member and the shaft member.
joint unit.

both of the two opposing gears include the elastic member;
An articulation unit according to claim 1.

further including a driving gear;
the second member is fixed to the drive gear;
An articulation unit according to claim 1 .

further including a motor;
the drive gear is connected to the motor;
The joint unit according to claim 3 .