JP5052072B2

JP5052072B2 - Two-way clutch and joint structure

Info

Publication number: JP5052072B2
Application number: JP2006232141A
Authority: JP
Inventors: 研吾小林; 昌憲高田
Original assignee: IHI Corp; IHI Aerospace Co Ltd
Current assignee: IHI Corp; IHI Aerospace Co Ltd
Priority date: 2006-08-29
Filing date: 2006-08-29
Publication date: 2012-10-17
Anticipated expiration: 2026-08-29
Also published as: JP2008057566A

Description

本発明は、内方部材と外輪との間で両回転方向に駆動と空転を切り替えることが可能なツーウェイクラッチ及びこのようなツーウェイクラッチを備えた関節部構造に関する。 The present invention relates to a two-way clutch capable of switching between driving and idling in both directions of rotation between an inner member and an outer ring, and a joint part structure including such a two-way clutch.

近年、４足歩行可能な犬型などの移動ロボットが提案されている（例えば下記特許文献１参照）。この種の移動ロボットは、胴体部に２本以上の脚部が回動可能に取り付けられている。この脚部は関節部を有し、脚部の動体部に対する回動と脚部自体の屈伸によって歩行を行なうようになっている。 In recent years, a dog-type mobile robot capable of walking on four legs has been proposed (see, for example, Patent Document 1 below). In this type of mobile robot, two or more legs are rotatably attached to the body. This leg part has a joint part, and walks by the rotation of the leg part with respect to the moving body part and the bending and extension of the leg part itself.

また、図５に示す別の移動ロボットは、胴体部６１を、関節を有する脚体６２で支持し、各脚体６２が足部、関節部、股部に車輪６３を有している。各脚体６２は、関節部で回動可能に連結された上脚６２ａと下脚６２ｂからなり、それぞれ脚駆動モータ６４で揺動駆動される。また、各車輪６３には、インホイールモータ６５が内蔵され、各車輪６３を回転駆動するようになっている。
なおこの図で、６６は軸受であり脚駆動モータ６４の出力軸（上脚６２ａと下脚６２ｂにそれぞれ固定されている）を回転可能に支持する。また６７は、インホイールモータ６５の固定軸であり、下脚６２ｂに回転しないように固定されている。
この構成により、脚駆動モータ６４で上脚６２ａと下脚６２ｂを揺動駆動することにより、歩行移動が可能であり、インホイールモータ６５で各車輪６３を回転駆動することにより高速移動が可能である。 Further, another mobile robot shown in FIG. 5 supports the body portion 61 with a leg body 62 having a joint, and each leg body 62 has wheels 63 at the foot portion, the joint portion, and the crotch portion. Each leg 62 is composed of an upper leg 62a and a lower leg 62b that are rotatably connected to each other at a joint portion, and each leg 62 is driven to swing by a leg drive motor 64. Each wheel 63 has an in-wheel motor 65 built therein so as to rotate each wheel 63.
In this figure, reference numeral 66 denotes a bearing which rotatably supports the output shaft of the leg drive motor 64 (fixed to the upper leg 62a and the lower leg 62b, respectively). Reference numeral 67 denotes a fixed shaft of the in-wheel motor 65, which is fixed to the lower leg 62b so as not to rotate.
With this configuration, the upper leg 62a and the lower leg 62b are driven to swing by the leg drive motor 64, so that the walking movement is possible, and each wheel 63 is rotationally driven by the in-wheel motor 65, so that the high-speed movement is possible. .

上記の移動ロボット、その他ロボットアームなどでは、その関節部にクラッチ（回転伝達装置）を装備することにより、クラッチを連結したときは関節部を固定して高トルクを発生し、クラッチを切ったときは関節部をフリーにして脚部やアームなどを屈伸運動させる。
従来、このようなクラッチとして、電磁クラッチやツーウェイクラッチを使用していた。電磁クラッチは、電磁石の磁気的な作用を利用して動力の伝達（クラッチオン）と遮断（クラッチオフ）を行なうものである（例えば、下記特許文献２、３参照） The above mobile robots and other robot arms are equipped with a clutch (rotation transmission device) at their joints, so that when the clutch is connected, the joint is fixed and high torque is generated, and the clutch is disconnected. Makes the joints free and exercises the legs and arms.
Conventionally, an electromagnetic clutch or a two-way clutch has been used as such a clutch. The electromagnetic clutch performs power transmission (clutch on) and disengagement (clutch off) using the magnetic action of an electromagnet (see, for example, Patent Documents 2 and 3 below).

また、ツーウェイクラッチは、図６に示す構造をしている。このツーウェイクラッチ３０は、内方部材３１と外輪３３を内外に配置し同一軸心周りに相対的に回転可能な構成としている。このツーウェイクラッチ３０では、内方部材３１が回転軸であり、外輪３３が固定側である。内方部材３１の外周には円筒面３２が設けられ、外輪３３の内周には円筒面３２との間に楔形空間３５を形成する複数のカム面３４が設けられている。この楔形空間３５に周方向に等間隔に係合子としてのローラ３６，３６・・・が配置されている。ローラ３６は楔形空間に設けられた保持器３７により、互いに等間隔を置くように保持されている。保持器３７には切り替えレバー３８が連結されている。切り替レバー３８を操作することにより、外輪３３に対する保持器３７の位相をＡ方向（反時計方向）又はＢ方向（時計方向）に変化させることができる。 Further, the two-way clutch has a structure shown in FIG. The two-way clutch 30 has an inner member 31 and an outer ring 33 arranged inside and outside, and is relatively rotatable around the same axis. In the two-way clutch 30, the inner member 31 is a rotating shaft and the outer ring 33 is a fixed side. A cylindrical surface 32 is provided on the outer periphery of the inner member 31, and a plurality of cam surfaces 34 that form wedge-shaped spaces 35 are provided on the inner periphery of the outer ring 33. In this wedge-shaped space 35, rollers 36, 36,... Serving as engagement elements are arranged at equal intervals in the circumferential direction. The rollers 36 are held at regular intervals by a holder 37 provided in the wedge-shaped space. A switching lever 38 is connected to the holder 37. By operating the switching lever 38, the phase of the cage 37 with respect to the outer ring 33 can be changed in the A direction (counterclockwise) or the B direction (clockwise).

図７（Ａ）〜（Ｃ）は図６に示したツーウェイクラッチ３０の拡大図である。上記のように構成されたツーウェイクラッチ３０では、以下の４つの制御状態を切り替えることができる。 7A to 7C are enlarged views of the two-way clutch 30 shown in FIG. In the two-way clutch 30 configured as described above, the following four control states can be switched.

（状態１）
図７（Ａ）に示すように、ローラ３６が円筒面３２とカム面３４に係合しない中立位置となるように保持器３７の位置を固定したときは、内方部材３１は両方向に自由に回転する。 (State 1)
As shown in FIG. 7A, when the position of the retainer 37 is fixed so that the roller 36 is in a neutral position where it does not engage the cylindrical surface 32 and the cam surface 34, the inner member 31 can freely move in both directions. Rotate.

（状態２）
図７（Ｂ）に示すように、切り替えレバー３８を図６のＡ方向に操作し、上記の中立位置よりも反時計方向においてローラ３６が円筒面３２とカム面３４に係合する位置に保持器３７の位置を固定したときは、内方部材３１は反時計方向にはロックするが、時計方向には空転する。 (State 2)
As shown in FIG. 7 (B), the switching lever 38 is operated in the direction A in FIG. 6, and the roller 36 is held at the position where it engages with the cylindrical surface 32 and the cam surface 34 in the counterclockwise direction from the neutral position. When the position of the container 37 is fixed, the inner member 31 locks in the counterclockwise direction but idles in the clockwise direction.

（状態３）
図７（Ｃ）に示すように、切り替えレバー３８を図６のＢ方向に操作し、上記の中立位置よりも時計方向においてローラ３６が円筒面３２とカム面３４に係合する位置に保持器３７の位置を固定したときは、内方部材３１は時計方向にはロックするが、反時計方向には空転する。 (State 3)
As shown in FIG. 7C, the switching lever 38 is operated in the direction B in FIG. 6 so that the roller 36 is engaged with the cylindrical surface 32 and the cam surface 34 in the clockwise direction from the neutral position. When the position 37 is fixed, the inward member 31 locks in the clockwise direction, but idles in the counterclockwise direction.

（状態４）
保持器３７を固定せずフリーの状態とすれば、保持器３７は内方部材３１の回転方向に連れ回るため、内方部材３１を反時計回りに回転させると図７（Ｂ）と同様のロック状態となり、内方部材３１を時計回りに回転させると図７（Ｃ）と同様のロック状態となる。 (State 4)
If the retainer 37 is not fixed and is in a free state, the retainer 37 is rotated in the direction of rotation of the inner member 31. Therefore, when the inner member 31 is rotated counterclockwise, the same as FIG. When the inner member 31 is rotated clockwise, the locked state similar to that shown in FIG. 7C is obtained.

したがって、移動ロボットの脚部やロボットアームにおける関節部にツーウェイクラッチを用いる場合、状態４の機能を使うことにより、関節部を固定することができる。 Therefore, when the two-way clutch is used for the leg portion of the mobile robot or the joint portion of the robot arm, the joint portion can be fixed by using the function of the state 4.

特開２００５−１３１７５６号公報JP 2005-131756 A 特開平１１−１５９５４４号公報JP 11-159544 A 特開２００６−１５３０３０公報JP 2006-153030 A

上述した電磁クラッチは電磁コイルなどの構成部品が重いため、軽量化が要求される移動ロボットなどでは採用が困難であった。
また、ツーウェイクラッチはバックラッシュ（がたつき）がある。すなわち、図７（Ｂ）において、反時計方向にロックした状態から時計方向に負荷が掛かると、ローラ３６が時計方向に移動し、図７の時計方向のロック状態となる。この移動の際に一瞬、図７（Ａ）のフリー状態となるため、バックラッシュが発生していた。このため、移動ロボットやロボットアームの関節部などの負荷方向か切り替わる機構に適用すると、位置精度が低下するという問題があった。 The electromagnetic clutch described above is difficult to employ in mobile robots and the like that are required to be lightweight because of the heavy components such as the electromagnetic coil.
The two-way clutch also has backlash. That is, in FIG. 7B, when a load is applied in the clockwise direction from the counterclockwise locked state, the roller 36 moves in the clockwise direction, and the clockwise locked state in FIG. 7 is obtained. During this movement, the free state shown in FIG. 7A was instantaneously generated, so that backlash occurred. For this reason, when applied to a mechanism that switches the load direction, such as a joint part of a mobile robot or a robot arm, there is a problem that the position accuracy is lowered.

本発明は、上述した問題に鑑みてなされたものであり、軽量で、バックラッシュの無いツーウェイクラッチ及びこのようなツーウェイクラッチを備えた関節部構造を提供することを目的とする。 The present invention has been made in view of the above-described problems, and an object thereof is to provide a two-way clutch that is lightweight and has no backlash, and a joint structure including such a two-way clutch.

上記の課題を解決するため、本発明のツーウェイクラッチ及び関節部構造は、以下の手段を採用する。
すなわち、本発明にかかるツーウェイクラッチは、内方部材と該内方部材を同心状に囲む外輪を互いに相対回転可能に構成し、前記内方部材の外周と前記外輪の内周の一方に円筒面を設け、他方に前記円筒面との間に楔形空間を形成するように複数のカム面を設け、該楔形空間に係合子を組み込み、該係合子が軸方向に互いに重複しない位置に配置された第１の係合子と第２の係合子とからなり、前記第１の係合子を第１の保持器により保持し、前記第２の係合子を第２の保持器により保持した構成とし、
前記第１の保持器及び第２の保持器にそれぞれ連結された第１レバー部材及び第２レバー部材と、
第１レバー部材と第２レバー部材の周方向間隔を拡げるように付勢する付勢手段と、
付勢手段の付勢に抗して第１の保持器と第２の保持器の周方向間隔を短縮させる駆動装置とを備え、
駆動装置により第１の保持器と第２の保持器の周方向間隔を短縮させることにより、前記第１の係合子と前記第２の係合子が共に前記円筒面と前記カム面に係合しない状態とすることにより前記内方部材と前記外輪とが両方向に相対回転可能となり、
駆動装置を解除し、付勢手段の付勢により、前記第１の係合子が前記円筒面と前記カム面に係合して前記内方部材と前記外輪の一方向の相対回転を阻止するとともに前記第２の係合子が前記円筒面と前記カム面に係合して内方部材と外輪の他方向の相対回転を阻止する状態とすることにより前記内方部材と前記外輪の両方向の相対回転をバックラッシュなしで阻止する、ことを特徴とする。 In order to solve the above problems, the two-way clutch and the joint structure of the present invention employ the following means.
That is, the two-way clutch according to the present invention is configured such that an inner member and an outer ring that concentrically surrounds the inner member can be rotated relative to each other, and a cylindrical surface is provided on one of the outer periphery of the inner member and the inner periphery of the outer ring. A plurality of cam surfaces are formed on the other side so as to form a wedge-shaped space between the cylindrical surfaces, and an engagement element is incorporated in the wedge-shaped space, and the engagement elements are arranged at positions that do not overlap each other in the axial direction. It is composed of a first engagement element and a second engagement element, the first engagement element is held by a first holder, and the second engagement element is held by a second holder,
A first lever member and a second lever member respectively connected to the first cage and the second cage;
Biasing means for biasing the first lever member and the second lever member so as to widen the circumferential interval;
A driving device that shortens the circumferential interval between the first cage and the second cage against the bias of the biasing means;
By reducing the circumferential distance between the first cage and the second cage by the driving device, the first engagement element and the second engagement element are not engaged with the cylindrical surface and the cam surface. By making the state, the inner member and the outer ring can be relatively rotated in both directions,
The drive device is released, and the first engaging element is engaged with the cylindrical surface and the cam surface by the urging force of the urging means to prevent relative rotation in one direction of the inner member and the outer ring. The second engaging element engages with the cylindrical surface and the cam surface to prevent relative rotation in the other direction of the inner member and the outer ring, thereby causing relative rotation in both directions of the inner member and the outer ring. It is characterized by blocking without backlash .

また、上記本発明にかかるツーウェイクラッチにおいて、前記第１の保持器は、前記第１の係合子が前記円筒面と前記カム面に係合し前記内方部材と前記外輪の一方向の相対回転を阻止する第１阻止位置と、前記第１の係合子が前記円筒面及び前記カム面と係合しない中立位置との間を移動可能であり、前記第２の保持器は、前記第２の係合子が前記円筒面と前記カム面に係合し前記内方部材と前記外輪の他方向の相対回転を阻止する第２阻止位置と、前記第２の係合子が前記円筒面及び前記カム面と係合しない中立位置との間を移動可能であり、前記第１及び第２の保持器を中立位置にしたときに前記内方部材と前記外輪とが両方向に相対回転可能となり、前記第１の保持器を前記第１阻止位置とし前記第２の保持器を前記第２阻止位置としたときに前記内方部材と前記外輪の両方向の相対回転を阻止する、ことを特徴とする。Further, in the two-way clutch according to the present invention, the first retainer is configured such that the first engagement element engages the cylindrical surface and the cam surface, and the inner member and the outer ring rotate in one direction. The first retainer is movable between a first blocking position and a neutral position where the first engagement element does not engage with the cylindrical surface and the cam surface, and the second retainer is A second blocking position in which an engagement element engages with the cylindrical surface and the cam surface to prevent relative rotation in the other direction of the inner member and the outer ring; and the second engagement element includes the cylindrical surface and the cam surface. The inner member and the outer ring can be relatively rotated in both directions when the first and second cages are set to the neutral position. And the second retainer as the second blocking position. Preventing relative rotation of both of the the inner member and the outer ring when the, characterized in that.

上記のように構成された本発明にかかるツーウェイクラッチによれば、第１及び第２の保持器を中立位置にしたときに内方部材と外輪とが両方向に相対回転可能となり、第１の保持器を第１阻止位置とし第２の保持器を第２阻止位置としたときに内方部材と外輪の両方向の相対回転を阻止するように構成したので、負荷方向が切り替わっても、従来のツーウェイクラッチのようなバックラッシュが発生しない。また、本発明のツーウェイクラッチは、電磁コイルなどの重量部品が無いため、軽量である。
また、このような付勢手段により、第１の保持器を第１阻止位置とし第２の保持器を第２阻止位置とする方向に常時付勢するので、外力を加えないときは内方部材と外輪の両方向の相対回転が阻止される。また、クラッチ外部に駆動装置（例えばソレノイド）を設け、この駆動装置により付勢手段の付勢に抗して第１と第２の保持器を共に中立位置に移動させることにより両方向に相対回転可能に切り替えることができる。 According to the two-way clutch of the present invention configured as described above, the inner member and the outer ring can be relatively rotated in both directions when the first and second cages are set to the neutral position, and the first holding When the cage is set to the first blocking position and the second cage is set to the second blocking position, the relative rotation in both directions of the inner member and the outer ring is blocked. There is no backlash like a clutch. In addition, the two-way clutch of the present invention is lightweight because there are no heavy parts such as electromagnetic coils.
Further, by such an urging means, the first retainer is always urged in the direction to be the first blocking position and the second cage is to be the second blocking position, so that when the external force is not applied, the inner member And the relative rotation of the outer ring in both directions is prevented. In addition, a drive device (for example, a solenoid) is provided outside the clutch, and both the first and second cages are moved to the neutral position against the urging force of the urging means by this drive device, so that the relative rotation in both directions is possible. You can switch to

また、上記本発明にかかるツーウェイクラッチにおいて、前記外輪は、軸方向に直列に配置された第１の外輪と第２の外輪とからなり、前記内方部材と前記第１の外輪との間に前記第１の保持器が設けられ、前記内方部材と前記第２の外輪との間に前記第２の保持器が設けられている、ことを特徴とする。 In the two-way clutch according to the present invention, the outer ring includes a first outer ring and a second outer ring that are arranged in series in the axial direction, and is between the inner member and the first outer ring. The first retainer is provided, and the second retainer is provided between the inner member and the second outer ring.

このように、外輪は、第１の保持器と第２の保持器を共通に囲む一体のものに限られず、第１の外輪と第２の外輪とからなるものであってもよい。 Thus, the outer ring is not limited to an integral one that surrounds the first retainer and the second retainer in common, and may be composed of a first outer ring and a second outer ring.

本発明にかかる関節部構造は、上記のツーウェイクラッチを２つ備え、第１部材と第２部材を同一の回転軸を中心に回動可能に連結する関節部構造であって、
前記第１部材に設置され関節部を駆動するためのモータと、
該モータにより回転駆動される駆動軸と、
該駆動軸に連結され該駆動軸の回転を減速して伝達する減速機構と、を備え、
前記第２部材に前記２つのツーウェイクラッチが設置され、一方のツーウェイクラッチは前記駆動軸に連結されており、他方のツーウェイクラッチは前記減速機構を介して前記駆動軸に連結されており、
前記一方のツーウェイクラッチをＯＮとし、前記他方のツーウェイクラッチをＯＦＦとしたときに、前記駆動軸の両方向の回転が、前記２つのツーウェイクラッチのうち前記一方のツーウェイクラッチのみを介して前記第２部材に伝達され、
前記一方のツーウェイクラッチをＯＦＦとし、前記他方のツーウェイクラッチをＯＮとしたときに、前記駆動軸の両方向の回転が、前記減速機構によって減速され前記２つのツーウェイクラッチのうち前記他方のツーウェイクラッチのみを介して前記第２部材に伝達される、ことを特徴とする。 A joint part structure according to the present invention is a joint part structure provided with the two two-way clutches described above, wherein the first member and the second member are connected so as to be rotatable about the same rotation axis .
A motor installed on the first member for driving the joint;
A drive shaft that is rotationally driven by the motor;
A speed reduction mechanism connected to the drive shaft and transmitting the rotation of the drive shaft at a reduced speed,
The two two-way clutches are installed on the second member, one two-way clutch is connected to the drive shaft, and the other two-way clutch is connected to the drive shaft via the speed reduction mechanism,
When the one two-way clutch is turned on and the other two-way clutch is turned off, the rotation of the drive shaft in both directions is caused by the second member only through the one two-way clutch of the two two-way clutches. Communicated to
When the one two-way clutch is turned off and the other two-way clutch is turned on, the rotation of the drive shaft in both directions is decelerated by the reduction mechanism, and only the other two-way clutch of the two two-way clutches is turned on. Via the second member.

このように構成されているので、一方のクラッチをＯＮとし、他方のクラッチをＯＦＦとしたときは、駆動軸の回転が減速されずに第２部材に伝達されるので、第２部材を高速旋回させることができる。
一方、一方のクラッチをＯＦＦとし、他方のクラッチをＯＮとしたときは、駆動軸の回転が減速機構によって減速されて第２部材に伝達されるので、第２部材を高トルクで旋回させることができる。 With this configuration, when one clutch is turned on and the other clutch is turned off, the rotation of the drive shaft is transmitted to the second member without being decelerated. Can be made.
On the other hand, when one clutch is turned off and the other clutch is turned on, the rotation of the drive shaft is decelerated by the speed reduction mechanism and transmitted to the second member, so that the second member can be turned with high torque. it can.

本発明によれば、軽量で、バックラッシュを無くすことができるという優れた効果が得られる。 According to the present invention, an excellent effect of being lightweight and capable of eliminating backlash can be obtained.

以下、本発明の好ましい実施形態を添付図面に基づいて詳細に説明する。なお、各図において共通する部分には同一の符号を付し、重複した説明を省略する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted.

図１は、本発明の実施形態にかかるツーウェイクラッチ１の軸心方向の断面図である。図２（Ａ）及び（Ｂ）は、図１のＩ−Ｉ線断面図である。図１及び図２に示すように、このツーウェイクラッチ１は、内方部材２と外輪４とを有している。本実施形態では、内方部材２が回転軸であり、外輪４が固定側である。外輪４は、内方部材２を同心状に囲み、内方部材２に対して同一軸心を中心に相対回転可能に構成されている。内方部材２の外周には円筒面３が設けられ、外輪４の内周には円筒面３との間に楔形空間７を形成するように複数のカム面５が設けられている。この楔形空間７に周方向に等間隔に係合子（ローラ）８，９が配置されている。 FIG. 1 is a cross-sectional view in the axial direction of a two-way clutch 1 according to an embodiment of the present invention. 2A and 2B are cross-sectional views taken along the line II of FIG. As shown in FIGS. 1 and 2, the two-way clutch 1 has an inner member 2 and an outer ring 4. In this embodiment, the inner member 2 is a rotating shaft, and the outer ring 4 is a fixed side. The outer ring 4 surrounds the inner member 2 concentrically, and is configured to be rotatable relative to the inner member 2 around the same axis. A cylindrical surface 3 is provided on the outer periphery of the inner member 2, and a plurality of cam surfaces 5 are provided on the inner periphery of the outer ring 4 so as to form a wedge-shaped space 7 between the inner surface 2 and the cylindrical surface 3. Engaging elements (rollers) 8 and 9 are arranged in the wedge-shaped space 7 at equal intervals in the circumferential direction.

係合子８，９は、軸方向に互いに重複しない位置に配置された第１の係合子８と第２の係合子９とからなる。
第１の係合子８は、楔形空間７に設けられた第１の保持器１０により互いに等間隔を置いて静止するように保持されている。第２の係合子９は、楔形空間７に設けられた第２の保持器１１により互いに等間隔を置いて静止するように保持されている。ただし、図２（Ａ）では、第２の係合子９と第２の保持器１１は、第１の係合子８と第１の保持器１０で遮られた位置にあるため図には表れていない。図２（Ｂ）では、理解を容易にするため、第１の係合子８を実線で示し、第２の係合子９を破線で示している。 The engagement elements 8 and 9 include a first engagement element 8 and a second engagement element 9 that are arranged at positions that do not overlap each other in the axial direction.
The first engagement element 8 is held by a first holder 10 provided in the wedge-shaped space 7 so as to be stationary at equal intervals. The second engaging elements 9 are held by a second holder 11 provided in the wedge-shaped space 7 so as to be stationary at equal intervals. However, in FIG. 2A, the second engaging element 9 and the second retainer 11 are not shown in the figure because they are in a position blocked by the first engaging element 8 and the first retainer 10. Absent. In FIG. 2B, for easy understanding, the first engagement element 8 is indicated by a solid line, and the second engagement element 9 is indicated by a broken line.

第１の保持器１０は、第１の係合子８が円筒面３とカム面５に係合し内方部材２と外輪４の一方向の相対回転（図２で内方部材２の反時計方向の回転）を阻止する第１阻止位置と、第１の係合子８が円筒面３及びカム面５と係合しない中立位置との間を移動可能に構成されている。このように、カム面５を有する外輪４と第１の保持器１０の相対位置（外輪４と第１の係合子８の相対位置）を変えることにより、内方部材２と外輪４の一方向の相対回転を阻止する状態（図２（Ｂ）の状態）と、この阻止を解除する状態（図２（Ａ）の状態）とを切り替えることができる。 In the first cage 10, the first engaging element 8 is engaged with the cylindrical surface 3 and the cam surface 5, and the inner member 2 and the outer ring 4 are rotated relative to each other in one direction (the counterclockwise direction of the inner member 2 in FIG. The first engaging position where the first engaging element 8 is not engaged with the cylindrical surface 3 and the cam surface 5 is configured to be movable. In this way, by changing the relative position of the outer ring 4 having the cam surface 5 and the first retainer 10 (the relative position of the outer ring 4 and the first engagement element 8), the inner member 2 and the outer ring 4 are in one direction. It is possible to switch between a state where the relative rotation is blocked (the state shown in FIG. 2B) and a state where the blocking is released (the state shown in FIG. 2A).

第２の保持器１１は、第２の係合子９が円筒面３とカム面５に係合し内方部材２と外輪４の他方向の相対回転（図２で内方部材２の時計方向の回転）を阻止する第２阻止位置と、第２の係合子９が円筒面３及びカム面５と係合しない中立位置との間を移動可能に構成されている。このように、カム面５を有する外輪４と第２の保持器１１の相対位置（外輪４と第２の係合子９の相対位置）を変えることにより、内方部材２と外輪４の一方向の相対回転を阻止する状態（図２（Ｂ）の状態）と、この阻止を解除する状態（図２（Ａ）の状態）とを切り替えることができる。 In the second retainer 11, the second engaging element 9 engages with the cylindrical surface 3 and the cam surface 5, and the relative rotation in the other direction of the inner member 2 and the outer ring 4 (the clockwise direction of the inner member 2 in FIG. 2). The second engaging position is configured to be movable between a second blocking position where the second engaging element 9 is not engaged with the cylindrical surface 3 and the cam surface 5. In this way, by changing the relative position of the outer ring 4 having the cam surface 5 and the second retainer 11 (the relative position of the outer ring 4 and the second engagement element 9), the inner member 2 and the outer ring 4 are in one direction. It is possible to switch between a state where the relative rotation is blocked (the state shown in FIG. 2B) and a state where the blocking is released (the state shown in FIG. 2A).

上記のように構成されたツーウェイクラッチ１では、第１及び第２の保持器１０，１１を中立位置にすると、第１の係合子８と第２の係合子９が共に円筒面３とカム面５に係合しない状態（図２（Ａ）の状態）となるので、内方部材２と外輪４とが両方向に相対回転可能となる。すなわち、本実施形態では、内方部材２が左右いずれの方向にも自由回転可能となる。 In the two-way clutch 1 configured as described above, when the first and second cages 10 and 11 are set to the neutral position, the first engaging element 8 and the second engaging element 9 are both the cylindrical surface 3 and the cam surface. 5 (the state shown in FIG. 2A), the inner member 2 and the outer ring 4 can be relatively rotated in both directions. That is, in this embodiment, the inner member 2 can freely rotate in either the left or right direction.

一方、第１の保持器１０を第１阻止位置とし第２の保持器１１を第２阻止位置にすると、第１の係合子８が円筒面３とカム面５に係合して内方部材２と外輪４の一方向の相対回転を阻止するとともに第２の係合子９が円筒面３とカム面５に係合して内方部材２と外輪４の他方向の相対回転を阻止する状態（図２（Ｂ）の状態）となるので、内方部材２と外輪４の両方向の相対回転を阻止する。すなわち、本実施形態では、内方部材２が左右いずれの方向にも回転不可能となる。 On the other hand, when the first cage 10 is set to the first blocking position and the second cage 11 is set to the second blocking position, the first engagement element 8 is engaged with the cylindrical surface 3 and the cam surface 5 to form the inner member. 2 and a state where the second engagement element 9 is engaged with the cylindrical surface 3 and the cam surface 5 to prevent relative rotation in the other direction of the inner member 2 and the outer ring 4. Therefore, the relative rotation in both directions of the inner member 2 and the outer ring 4 is prevented. That is, in this embodiment, the inner member 2 cannot be rotated in either the left or right direction.

図７に示したように、従来のツーウェイクラッチ３０では、反時計方向にロックした状態（図７（Ｂ）参照）から時計方向に負荷が掛かると、ローラ３６が時計方向に移動し、時計方向のロック状態となるが（図７（Ｃ）参照）、このとき一瞬、フリー状態（図７（Ａ）参照）となるため、バックラッシュが発生していた。 As shown in FIG. 7, in the conventional two-way clutch 30, when a load is applied in the clockwise direction from the counterclockwise locked state (see FIG. 7B), the roller 36 moves in the clockwise direction, and the clockwise direction (See FIG. 7C), but at this time, since it is in a free state (see FIG. 7A), backlash has occurred.

これに対し、本発明のツーウェイクラッチ１によれば、第１及び第２の保持器１０，１１を中立位置にしたときに内方部材２と外輪４とが両方向に相対回転可能となり、第１の保持器１０を第１阻止位置とし第２の保持器１１を第２阻止位置としたときに内方部材２と外輪４の両方向の相対回転を阻止するように構成したので、負荷方向が切り替わっても、従来のツーウェイクラッチ１のようなバックラッシュが発生しない。また、本発明のツーウェイクラッチ１は、電磁コイルなどの重量部品が無いため、軽量である。 On the other hand, according to the two-way clutch 1 of the present invention, when the first and second cages 10 and 11 are set to the neutral position, the inner member 2 and the outer ring 4 can be relatively rotated in both directions. When the second cage 11 is set to the first blocking position and the second cage 11 is set to the second blocking position, the relative rotation in both directions of the inner member 2 and the outer ring 4 is blocked, so that the load direction is switched. However, the backlash unlike the conventional two-way clutch 1 does not occur. Further, the two-way clutch 1 of the present invention is lightweight because there are no heavy parts such as an electromagnetic coil.

図１及び図２に示すように、第１の保持器１０を第１阻止位置とし第２の保持器１１を第２の阻止位置とするように第１と第２の保持器１０，１１を付勢する付勢手段１３が設けられている。本実施形態において付勢手段１３は圧縮バネである。第１と第２の保持器１０，１１には、それぞれ第１レバー部材１４、第２レバー部材１５が連結されており、その間に圧縮バネが配置されている。この圧縮バネの弾発力により、第１と第２の保持器１０，１１が互いに反対方向に回転するように常時付勢されるようになっている。 As shown in FIGS. 1 and 2, the first and second cages 10 and 11 are arranged so that the first cage 10 is in the first blocking position and the second cage 11 is in the second blocking position. A biasing means 13 for biasing is provided. In the present embodiment, the biasing means 13 is a compression spring. A first lever member 14 and a second lever member 15 are connected to the first and second cages 10 and 11, respectively, and a compression spring is disposed therebetween. Due to the elastic force of the compression spring, the first and second cages 10 and 11 are always urged so as to rotate in opposite directions.

このような付勢手段１３により、第１の保持器１０を第１阻止位置とし第２の保持器１１を第２阻止位置とする方向に常時付勢するので、外力を加えないときには図２（Ｂ）の状態となり、内方部材２と外輪４の両方向の相対回転が阻止される。一方、付勢手段１３の付勢力に抗するように外力を加えたときは図２（Ａ）の状態となり、内方部材２と外輪４の両方向の相対回転が可能となる。したがって、本発明のツーウェイクラッチ１を移動ロボットやロボットアームの関節部に適用するときは、クラッチ外部に駆動装置（例えばソレノイド）を設け、この駆動装置により付勢手段１３の付勢に抗して第１と第２の保持器１０，１１を共に中立位置に移動させることにより両方向に相対回転可能に切り替えることができる。 Such a biasing means 13 constantly biases the first cage 10 in the direction of the first blocking position and the second cage 11 in the second blocking position, so that when no external force is applied, FIG. B), the relative rotation of the inner member 2 and the outer ring 4 in both directions is prevented. On the other hand, when an external force is applied so as to resist the urging force of the urging means 13, the state shown in FIG. 2 (A) is obtained, and the inner member 2 and the outer ring 4 can be rotated in both directions. Therefore, when the two-way clutch 1 of the present invention is applied to a joint part of a mobile robot or robot arm, a driving device (for example, a solenoid) is provided outside the clutch, and the driving device resists the biasing of the biasing means 13. By moving both the first and second cages 10 and 11 to the neutral position, they can be switched so as to be relatively rotatable in both directions.

なお、上述した実施形態では、内方部材２の外周に円筒面３を設け、外輪４の内周にカム面５を設けたが、これとは逆に、内方部材２の外周にカム面を設け、外輪４の内周に円筒面を設けるようにしてもよい。この場合、外輪が回転側となり内方部材が固定側となる。 In the above-described embodiment, the cylindrical surface 3 is provided on the outer periphery of the inner member 2, and the cam surface 5 is provided on the inner periphery of the outer ring 4. On the contrary, the cam surface is provided on the outer periphery of the inner member 2. And a cylindrical surface may be provided on the inner periphery of the outer ring 4. In this case, the outer ring is the rotating side and the inner member is the fixed side.

上述した実施形態では、外輪４は、第１の保持器１０と第２の保持器１１を共通に囲む一体のものであったが、第１の保持器１０を囲む部分と第２の保持器１１を囲む部分とを別部品で構成しこれらを連結してもよい。すなわち、外輪４が軸方向に直列に配置された第１の外輪と第２の外輪とからなり、内方部材２と第１の外輪との間に第１の保持器１０が設けられ、内方部材２と第２の外輪との間に第２の保持器１１が設けられている構成であってもよい。 In the above-described embodiment, the outer ring 4 is an integral one that surrounds the first cage 10 and the second cage 11 in common, but the portion surrounding the first cage 10 and the second cage The part surrounding 11 may be configured as a separate part and connected. That is, the outer ring 4 includes a first outer ring and a second outer ring arranged in series in the axial direction, and the first retainer 10 is provided between the inner member 2 and the first outer ring, The structure by which the 2nd holder | retainer 11 is provided between the direction member 2 and the 2nd outer ring | wheel may be sufficient.

上述した実施形態では、圧縮バネにより第１の保持器１０を第１阻止位置に付勢し、第２の保持器１１を第２阻止位置に付勢したが、ソレノイド等の駆動装置により第１と第２の保持器をそれぞれ駆動して、第１の保持器１０の中立位置と第１阻止位置の切り替えと、第２の保持器１１の中立位置と第２阻止位置の切り替えを行ってもよい。 In the embodiment described above, the first retainer 10 is biased to the first blocking position and the second retainer 11 is biased to the second blocking position by the compression spring, but the first retainer 10 is biased to the second blocking position. And the second cage are driven to switch between the neutral position and the first blocking position of the first cage 10 and to switch between the neutral position and the second blocking position of the second cage 11. Good.

次に、本発明の実施形態にかかる関節部構造について説明する。図３に、本発明のツーウェイクラッチ１をロボットアーム１の関節部２３に適用した例を示す。
このロボットアーム１は、基部２１に回動可能に連結された第１部材としての第１アーム２２と、第１アーム２２に関節部２３を介して回動可能に連結された第２部材としての第２アーム２４と、第２アーム２４に連結され物品２６を把持するハンド２５とを備える。 Next, the joint structure according to the embodiment of the present invention will be described. FIG. 3 shows an example in which the two-way clutch 1 of the present invention is applied to the joint portion 23 of the robot arm 1.
The robot arm 1 includes a first arm 22 as a first member that is rotatably connected to a base portion 21, and a second member that is rotatably connected to the first arm 22 via a joint portion 23. A second arm 24 and a hand 25 connected to the second arm 24 and holding the article 26 are provided.

図４に、図３に示したロボットアーム１の関節部２３の構造を示す。図４において、（Ｂ）は（Ａ）のＩＩ−ＩＩ線断面図である。
第１アーム２２には、関節部２３を駆動するためのモータ２７が固定されている。モータ２７には駆動軸２８が連結されている。駆動軸２８は第１アーム２２を貫通し、軸受３６ａを介して第１アーム２２に回転可能に支持されている。また駆動軸２８は、第２アーム２４を貫通し、軸受３６ｂを介して第２アーム２４に回転可能に支持されている。 FIG. 4 shows the structure of the joint portion 23 of the robot arm 1 shown in FIG. 4B is a cross-sectional view taken along line II-II in FIG.
A motor 27 for driving the joint portion 23 is fixed to the first arm 22. A drive shaft 28 is connected to the motor 27. The drive shaft 28 penetrates the first arm 22 and is rotatably supported by the first arm 22 via a bearing 36a. The drive shaft 28 penetrates through the second arm 24 and is rotatably supported by the second arm 24 via a bearing 36b.

第１アーム２２には環状突出部２２ａが形成されている。環状突出部２２ａの内周には外輪歯車３０が設けられている。環状突出部２２ａの内側において、駆動軸２８には太陽歯車３１が固定されている。この太陽歯車３１と外輪歯車３０の間に、複数（この例では２個）の遊星歯車３２が設けられている。遊星歯車３２は太陽歯車３１を中心として公転しながら自転するようになっている。 An annular protrusion 22 a is formed on the first arm 22. An outer ring gear 30 is provided on the inner periphery of the annular protrusion 22a. A sun gear 31 is fixed to the drive shaft 28 inside the annular protrusion 22a. A plurality (two in this example) of planetary gears 32 are provided between the sun gear 31 and the outer ring gear 30. The planetary gear 32 rotates around the sun gear 31 while revolving.

各遊星歯車３２は、遊星支持軸３３に回転可能に支持されている。遊星支持軸３３は、駆動軸２８に軸受３６ｃを介して回転可能に支持された中空円筒形のスリーブ部材３４に連結されている。したがって、外輪歯車３０、太陽歯車３１および遊星歯車３２により、減速機構としての遊星歯車機構２９が構成されており、駆動軸２８の回転が減速されてスリーブ部材３４に伝達されるようになっている。 Each planetary gear 32 is rotatably supported by the planetary support shaft 33. The planetary support shaft 33 is coupled to a hollow cylindrical sleeve member 34 that is rotatably supported by the drive shaft 28 via a bearing 36c. Therefore, the outer ring gear 30, the sun gear 31, and the planetary gear 32 constitute a planetary gear mechanism 29 as a speed reduction mechanism, and the rotation of the drive shaft 28 is decelerated and transmitted to the sleeve member 34. .

第２アーム２４には、第２アーム２４を基準に第１アーム２２とは反対側で、駆動軸２８を内側で支持するように第１クラッチ１Ａが固定されている。また第２アーム２４には、第２アーム２４を基準に第１アーム２２側で、スリーブ部材３４を内側で支持するように第２クラッチ１Ｂが固定されている。この第１及び第２のクラッチ１Ａ，１Ｂは、図４では詳細な構造は示していないが、上述した実施形態のツーウェイクラッチ１と同様の構成を有している。 The first clutch 1A is fixed to the second arm 24 so as to support the drive shaft 28 on the opposite side of the first arm 22 with respect to the second arm 24. The second clutch 1B is fixed to the second arm 24 so as to support the sleeve member 34 on the inner side on the first arm 22 side with respect to the second arm 24. Although the detailed structure is not shown in FIG. 4, the first and second clutches 1 </ b> A and 1 </ b> B have the same configuration as the two-way clutch 1 of the above-described embodiment.

第１クラッチ１Ａの外輪は、第２アーム２４とは相対回転不可能に固定されている。一方、第１クラッチ１Ａの内方部材は、駆動軸２８に相対回転不可能に嵌合している。
第２クラッチ１Ｂの外輪は、第２アーム２４とは相対回転不可能に固定されている。一方、第２クラッチ１Ｂの内方部材は、スリーブ部材に相対回転不可能に嵌合している。 The outer ring of the first clutch 1 </ b> A is fixed so as not to rotate relative to the second arm 24. On the other hand, the inner member of the first clutch 1A is fitted to the drive shaft 28 so as not to be relatively rotatable.
The outer ring of the second clutch 1B is fixed so as not to rotate relative to the second arm 24. On the other hand, the inner member of the second clutch 1B is fitted to the sleeve member so as not to be relatively rotatable.

上記のように構成された関節部構造において、第１クラッチ１ＡをＯＮ（外輪と内方部材とが両方向に相対回転不可能な状態）とし、第２クラッチ１ＢをＯＦＦ（外輪と内方部材とが両方向に相対回転可能な状態）としたときは、駆動軸２８の回転は２つのクラッチのうち第１クラッチ１Ａのみを介して第２アーム２４に伝達される。したがって、駆動軸２８の回転が減速されずに第２アーム２４に伝達されるので、第２アーム２４を高速旋回させることができる。 In the joint part structure configured as described above, the first clutch 1A is turned ON (the outer ring and the inner member are not relatively rotatable in both directions), and the second clutch 1B is turned OFF (the outer ring and the inner member are disconnected). ), The rotation of the drive shaft 28 is transmitted to the second arm 24 only through the first clutch 1A of the two clutches. Accordingly, since the rotation of the drive shaft 28 is transmitted to the second arm 24 without being decelerated, the second arm 24 can be turned at a high speed.

一方、第１クラッチ１ＡをＯＦＦとし、第２クラッチ１ＢをＯＮとしたときは、駆動軸２８の回転は、２つのクラッチのうち第２クラッチ１Ｂのみを介して第２アーム２４に伝達される。したがって、駆動軸２８の回転が遊星歯車機構２９によって減速されて第２アーム２４に伝達されるので、第２アーム２４を高トルクで旋回させることができる。 On the other hand, when the first clutch 1A is turned off and the second clutch 1B is turned on, the rotation of the drive shaft 28 is transmitted to the second arm 24 only through the second clutch 1B of the two clutches. Therefore, since the rotation of the drive shaft 28 is decelerated by the planetary gear mechanism 29 and transmitted to the second arm 24, the second arm 24 can be turned with high torque.

このように、本発明のツーウェイクラッチ１をロボットアームの関節部に適用すれば、重量物を搬送するときは高トルクを発生し、軽量物を搬送するときは高速にアームを動かしてタクトタイムを短縮できる。 As described above, when the two-way clutch 1 of the present invention is applied to the joint portion of the robot arm, a high torque is generated when transporting a heavy object, and a tact time is increased by moving the arm at a high speed when transporting a light object. Can be shortened.

なお、図４の実施形態では、本発明の関節部構造をロボットアームに適用した例を説明したが、第１部材と第２部材を回動可能に連結するものであれば、他の装置や構造体にも適用できる。
また、図４の実施形態では、減速機構として遊星歯車機構を用いたが、駆動軸２８の回転を減速して伝達できる限りで、他の形態の減速機構を採用してもよい。 In the embodiment of FIG. 4, an example in which the joint structure of the present invention is applied to a robot arm has been described. However, as long as the first member and the second member are rotatably connected, other devices or It can also be applied to structures.
In the embodiment of FIG. 4, the planetary gear mechanism is used as the speed reduction mechanism. However, as long as the rotation of the drive shaft 28 can be reduced and transmitted, another form of speed reduction mechanism may be employed.

なお、上記において、本発明の実施形態について説明を行ったが、上記に開示された本発明の実施の形態は、あくまで例示であって、本発明の範囲はこれら発明の実施の形態に限定されない。本発明の範囲は、特許請求の範囲の記載によって示され、さらに特許請求の範囲の記載と均等の意味および範囲内でのすべての変更を含むものである。 Although the embodiments of the present invention have been described above, the embodiments of the present invention disclosed above are merely examples, and the scope of the present invention is not limited to these embodiments. . The scope of the present invention is indicated by the description of the scope of claims, and further includes meanings equivalent to the description of the scope of claims and all modifications within the scope.

本発明にかかるツーウェイクラッチの軸心方向の断面図である。It is sectional drawing of the axial center direction of the two-way clutch concerning this invention. 図１のＩ−Ｉ線断面図である。It is the II sectional view taken on the line of FIG. 本発明にかかる関節部構造を適用したロボットアームの概略構成を示す図である。It is a figure which shows schematic structure of the robot arm to which the joint part structure concerning this invention is applied. 本発明にかかる関節部構造の構成を示す図である。It is a figure which shows the structure of the joint part structure concerning this invention. 従来の移動ロボットの一例を示す図である。It is a figure which shows an example of the conventional mobile robot. 従来のツーウェイクラッチの断面図である。It is sectional drawing of the conventional two-way clutch. 図６の拡大図である。FIG. 7 is an enlarged view of FIG. 6.

Explanation of symbols

１ツーウェイクラッチ
１Ａ第１クラッチ
１Ｂ第２クラッチ
２内方部材
３円筒面
４外輪
５カム面
７楔形空間
８第１の係合子
９第２の係合子
１０第１の保持器
１１第２の保持器
１３付勢手段
１４第１レバー部材
１５第２レバー部材
２０ロボットアーム
２２第１アーム（第１部材）
２３関節部
２４第２アーム（第２部材）
２７モータ
２８駆動軸
２９遊星歯車機構（減速機構）
３３遊星支持軸
３４スリーブ部材 DESCRIPTION OF SYMBOLS 1 Two-way clutch 1A 1st clutch 1B 2nd clutch 2 Inner member 3 Cylindrical surface 4 Outer ring 5 Cam surface 7 Wedge-shaped space 8 1st engagement element 9 2nd engagement element 10 1st retainer 11 2nd retainer 13 Biasing means 14 First lever member 15 Second lever member 20 Robot arm 22 First arm (first member)
23 joint 24 second arm (second member)
27 Motor 28 Drive shaft 29 Planetary gear mechanism (reduction mechanism)
33 Planetary support shaft 34 Sleeve member

Claims

An inner member and an outer ring that concentrically surrounds the inner member are configured to be rotatable relative to each other, and a cylindrical surface is provided on one of the outer periphery of the inner member and the inner periphery of the outer ring, and the cylindrical surface is provided on the other A plurality of cam surfaces are provided so as to form a wedge-shaped space therebetween, an engagement element is incorporated in the wedge-shaped space, and the first engagement element and the second engagement element are disposed at positions where the engagement elements do not overlap each other in the axial direction. The first engaging element is held by a first holder, and the second engaging element is held by a second holder.
A first lever member and a second lever member respectively connected to the first cage and the second cage;
Biasing means for biasing the first lever member and the second lever member so as to widen the circumferential interval;
A driving device that shortens the circumferential interval between the first cage and the second cage against the bias of the biasing means;
By reducing the circumferential distance between the first cage and the second cage by the driving device, the first engagement element and the second engagement element are not engaged with the cylindrical surface and the cam surface. By making the state, the inner member and the outer ring can be relatively rotated in both directions,
The drive device is released, and the first engaging element is engaged with the cylindrical surface and the cam surface by the urging force of the urging means to prevent relative rotation in one direction of the inner member and the outer ring. The second engaging element engages with the cylindrical surface and the cam surface to prevent relative rotation in the other direction of the inner member and the outer ring, thereby causing relative rotation in both directions of the inner member and the outer ring. The two-way clutch is characterized by blocking without backlash .

The first cage includes a first blocking position in which the first engaging element engages with the cylindrical surface and the cam surface and prevents relative rotation in one direction of the inner member and the outer ring, 1 is movable between a neutral position where the engagement element does not engage with the cylindrical surface and the cam surface;
The second cage includes a second blocking position in which the second engaging element engages with the cylindrical surface and the cam surface and prevents relative rotation in the other direction of the inner member and the outer ring, 2 is movable between the cylindrical surface and the neutral position where it does not engage with the cam surface;
When the first and second cages are in the neutral position, the inner member and the outer ring can be relatively rotated in both directions,
Relative rotation of the inner member and the outer ring in both directions is prevented when the first cage is in the first blocking position and the second cage is in the second blocking position. The two-way clutch according to claim 1.

The outer ring is composed of a first outer ring and a second outer ring arranged in series in the axial direction, and the first retainer is provided between the inner member and the first outer ring, The two-way clutch according to claim 1 or 2, wherein the second retainer is provided between an inner member and the second outer ring.

A joint structure comprising two two-way clutches according to any one of claims 1 to 3 , wherein the first member and the second member are rotatably connected around the same rotation axis ,
A motor installed on the first member for driving the joint;
A drive shaft that is rotationally driven by the motor;
A speed reduction mechanism connected to the drive shaft and transmitting the rotation of the drive shaft at a reduced speed,
The two two-way clutches are installed on the second member, one two-way clutch is connected to the drive shaft, and the other two-way clutch is connected to the drive shaft via the speed reduction mechanism,
When the one two-way clutch is turned on and the other two-way clutch is turned off, the rotation of the drive shaft in both directions is caused by the second member only through the one two-way clutch of the two two-way clutches. Communicated to
When the one two-way clutch is turned off and the other two-way clutch is turned on, the rotation of the drive shaft in both directions is decelerated by the reduction mechanism, and only the other two-way clutch of the two two-way clutches is turned on. The joint part structure is transmitted to the second member via the joint member.