【０００１】
【発明の属する技術分野】
本発明は、動力伝達機構に関するものである。
【０００２】
【従来の技術】
外部駆動源により回転駆動される環状の第１回転体と、第１回転体の中央開口内に在る第２回転体と、第１回転体と第２回転体との間に介挿され、両端が第１回転体に支持され且つ第２回転体へ向けて凸に湾曲して第２回転体の外周面に当接するバネ部材とを備え、第２回転体外周面のバネ部材との当接部が径方向内方へ凸の曲面であることを特徴とする動力伝達機構が特許文献１に開示されている。
特許文献１の動力伝達機構においては、バネ部材を介して第１回転体から第２回転体へトルクが伝達される。第１回転体から第２回転体へ伝達されるトルクが過大になると、第２回転体とバネ部材との間に周方向の滑りが生じ、第２回転体により径方向外方へ押圧されたバネ部材が反転して第１回転体へ向けて凸に湾曲し、バネ部材と第２回転体との当接状態が解除されて、第１回転体から第２回転体へのトルク伝達が遮断される。
【０００３】
【特許文献１】特開２０００−２４９１６０
【０００４】
【発明が解決しようとする課題】
特許文献１の動力伝達機構には、第２回転体外周面のバネ部材との当接部が、バネ部材と相補形状で湾曲しており、両者の接触面積が広いので両者の間に周方向の滑りが生じ難く、安定したトルク遮断性能を発揮し難いという問題がある。
本発明は上記問題に鑑みてなされたものであり、安定したトルク遮断性能を発揮できる動力伝達機構を提供することを目的とする。
【０００５】
【課題を解決するための手段】
上記課題を解決するために、本発明においては、外部駆動源により回転駆動される環状の第１回転体と、第１回転体の中央開口内に在る第２回転体と、第１回転体と第２回転体との間に介挿され、両端が第１回転体に固定又は支持され且つ第２回転体へ向けて凸に湾曲して第２回転体の外周面に当接するバネ部材とを備え、第２回転体外周面のバネ部材との当接部が平坦面又は径方向外方へ凸の曲面であることを特徴とする動力伝達機構を提供する。
また本発明においては、外部駆動源により回転駆動される環状の第１回転体と、第１回転体の中央開口内に在る第２回転体と、第１回転体と第２回転体との間に介挿され、両端が第２回転体に固定又は支持され且つ第１回転体へ向けて凸に湾曲して第１回転体の内周面に当接するバネ部材とを備え、第１回転体内周面のバネ部材との当接部が平坦面又は径方向内方へ凸の曲面であることを特徴とする動力伝達機構を提供する。
本発明に係る動力伝達機構においては、バネ部材を介して第１回転体から第２回転体へトルクが伝達される。第１回転体から第２回転体へ伝達されるトルクが過大になると、第２回転体とバネ部材との間に周方向の滑りが生じ、第２回転体により径方向外方へ押圧されたバネ部材が反転して第１回転体へ向けて凸に湾曲し、バネ部材と第２回転体との当接状態が解除されて、第１回転体から第２回転体へのトルク伝達が遮断され、或いは、第１回転体とバネ部材との間に周方向の滑りが生じ、第１回転体により径方向内方へ押圧されたバネ部材が反転して第２回転体へ向けて凸に湾曲し、バネ部材と第１回転体との当接状態が解除されて、第１回転体から第２回転体へのトルク伝達が遮断される。
本発明に係る動力伝達機構においては、第２回転体外周面のバネ部材との当接部が平坦面又は径方向外方へ凸の曲面であり、両者の接触面積が狭いので、両者の間に周方向の滑りが支障無く生じ、或いは第１回転体内周面のバネ部材との当接部が平坦面又は径方向内方へ凸の曲面であり、両者の接触面積が狭いので、両者の間に周方向の滑りが支障なく生ずる。この結果、バネ部材が支障なく反転して、第１回転体から第２回転体へのトルク伝達が支障なく遮断される。従って、本発明に係る動力伝達機構は安定したトルク遮断性能を発揮できる。
【０００６】
本発明の好ましい態様においては、周方向に互いに間隔を隔てて複数のバネ部材が配設されている。
周方向に互いに間隔を隔てて複数のバネ部材を配設することにより、バネ部材が小型化され、動力伝達機構が小型化される。
【０００７】
本発明の好ましい態様においては、バネ部材は帯板状又はワイヤー状である。
バネ部材は帯板状でも良くワイヤー状でも良い。
【０００８】
本発明の好ましい態様においては、第１回転体と第２回転体との間に介挿される前のバネ部材の形状が伸直形状又は湾曲形状である。
伸直形状のバネ部材を撓ませて第１回転体と第２回転体との間に介挿しても良く、或いは湾曲形状のバネ部材を第１回転体と第２回転体との間に介挿しても良い。
【０００９】
本発明の好ましい態様においては、第２回転体のバネ部材との当接部に回転体が取り付けられている。
本発明の好ましい態様においては、第１回転体のバネ部材との当接部に回転体が取り付けられている。
回転体を取り付けることにより、第２回転体とバネ部材との間の周方向の滑り又は第１回転体とバネ部材との間の周方向の滑りを、支障なく生じさせることができる。
【００１０】
本発明の好ましい態様においては、回転体が弾性を有する。
回転体に弾性を持たせることにより、第２回転体とバネ部材との間の周方向の滑り又は第１回転体とバネ部材との間の周方向の滑りを、更に支障なく生じさせることができる。
【００１１】
本発明の好ましい態様においては、バネ部材が制振機能を有する。
バネ部材が制振機能を有することにより、第１回転部材が接続される外部駆動源の短周期トルク変動や第２回転部材が接続される回転機器の短周期トルク変動に起因する回転機器主軸の捩じり振動が抑制され、ひいては動力伝達機構作動が安定する。
【００１２】
本発明の好ましい態様においては、バネ部材と第２回転部材との当接部が潤滑されている。
本発明の好ましい態様においては、バネ部材と第１回転部材との当接部が潤滑されている。
バネ部材と第２回転部材との当接部を潤滑し、或いはバネ部材と第１回転部材との当接部を潤滑することにより、第２回転体とバネ部材との間の周方向の滑り、或いは第１回転体とバネ部材との間の周方向の滑りを、支障なく生じさせることができる。
【００１３】
【発明の実施の形態】
本発明の実施例に係る動力伝達機構を説明する。
図１（ａ）に示すように、動力伝達機構１は、外周が円形で内周が六角形の環状のプーリー２を備えている。プーリー２は、ベアリング３を介して図示しない圧縮機のケーシングにより支持されている。プーリー２は図示しない無端ベルトを介して図示しない車両エンジンに接続されている。
動力伝達機構１は、プーリー２の中心開口内に在る外周が六角形のハブ４を備えている。ハブ４と同心に延在する図示しない圧縮機の主軸が、ハブ４に固定されている。
帯板から成る断面が略六角形の環状のバネ５が、プーリー２とハブ４との間に介挿されている。バネ５の六角形の各頂点はブロック６を介して、プーリー２内周の六角形の各辺に固定されている。バネ５の六角形の各辺は、ハブ４へ向けて凸に湾曲しており、前記各辺の中央部はハブ４外周の六角形の各辺に当接している。
【００１４】
動力伝達機構１の作動を説明する。
図示しない無端ベルトを介して図示しない車両エンジンからプーリー２にトルクが伝達される。バネ部材５を介してプーリー２からハブ４へトルクが伝達される。ハブ４から図示しない圧縮機の主軸へトルクが伝達され、図示しない圧縮機が稼動する。
プーリー２とハブ４との間の伝達トルクが所定値を超えると、ハブ４外周面の六角形の各辺とバネ部材５の略六角形の各辺の中央部との間に周方向の滑りが生じ、ハブ４外周面の六角形の各辺により径方向外方へ押圧されたバネ部材５の略六角形の各辺が反転して、図１（ｂ）に示すように、プーリー２へ向けて凸に湾曲する。反転したバネ部材５の略六角形の各辺は、プーリー２内周の六角形の各頂点近傍の空間に収容される。この結果、バネ部材５とハブ４外周面との当接状態が解除され、プーリー２からハブ４へのトルク伝達が遮断される。
【００１５】
動力伝達機構１においては、ハブ４外周面のバネ部材５との当接部が平坦面であり、両者の接触面積が狭いので、両者の間に周方向の滑りが支障無く生ずる。この結果、バネ部材５が支障なく反転して、プーリー２からハブ４へのトルク伝達が支障なく遮断される。従って、動力伝達機構１は安定したトルク遮断性能を発揮できる。
ハブ４外周面とバネ部材５との複数の当接部を介してプーリー２からハブ４へトルクを伝達することにより、バネ部材５のハブ４外周面との当接部の部材強度低減が可能となる。この結果、バネ部材５が小型化され、ひいては動力伝達機構１が小型化される。
【００１６】
バネ部材５を帯板ではなくワイヤーで形成しても良い。
断面が略六角形の環状のバネ部材５に代えて、ハブ４へ向けて凸に湾曲したバネ部材を、隣接するブロック６間に一個ずつ配設しても良い。各バネ部材両端のブロック６との取り合いは、固定でも良く支持でも良く或いは両者の中間でも良い。各バネ部材のブロック６への取付け前の形状は、伸直でも良く湾曲していても良い。
図２に示すように、ハブ４外周面の六角形の各辺の端部、すなわちハブ４外周面の六角形の各頂点に、回転体７を取り付けても良い。回転体７を取り付けることにより、ハブ４外周面とバネ部材５との間の周方向の滑りを、支障なく生じさせることができる。
回転体７を弾性体で形成し、或いは回転体７に弾性体を外嵌合させても良い。回転体７に弾性を持たせることにより、ハブ４外周面とバネ部材５との間の周方向の滑りを、より一層支障なく生じさせることができる。
バネ部材５を金属と粘弾性体とのクラッド材等の制振材で形成しても良い。バネ部材５が制振機能を有することにより、プーリー２が接続される車両エンジンの短周期トルク変動やハブ４が接続される圧縮機の短周期トルク変動に起因する圧縮機主軸の捩じり振動が抑制され、ひいては動力伝達機構１の作動が安定する。バネ部材５及び／又はハブ４外周面のバネ部材５との当接部に固体潤滑材等を塗布しても良い。バネ部材５とハブ４外周面との当接部を潤滑することにより、ハブ４外周面とバネ部材５との間の周方向の滑りを、支障なく生じさせることができる。
プーリー２の内周は六角形以外の多角形でも良く円形でも良く、他の任意形状でも良い。ハブ４の外周を六角形以外の多角形にしても良く、或いは楕円形にしても良い。図３に示すように、楕円形のハブ１４外周面のバネ部材１５との当接部は径方向外方へ凸に湾曲し、両者の接触面積は狭いので、ハブ１４外周面とバネ部材１５との間の周方向の滑りを、支障なく生じさせることができる。図３において、トルク伝達時のバネ部材１５を実線で示し、トルク遮断時のバネ部材１５を一点鎖線で示している。
図４に示すように、円環形状のプーリー２２の内周面に三角形の突起２２ａを形成し、プーリー２２へ向けて凸に湾曲したバネ部材２５の両端を略円形のハブ２４に固定し又は略円形のハブ２４で支持し、バネ部材２５を突起２２ａに当接可能としても良い。反転したバネ部材２５を収容する凹部２４ａをハブ２４に形成する。突起２２ａのバネ部材２５との当接部は平坦面であり、両者の接触面積は狭いので、突起２２ａとバネ部材２５との間の周方向の滑りを、支障なく生じさせることができる。図４において、トルク伝達時のバネ部材２５を実線で示し、トルク遮断時のバネ部材２５を一点鎖線で示している。突起２２ａの外形を径方向内方へ凸の曲面としても良い。突起２２ａの頂点に回転体を取り付けても良い。突起２２ａとバネ部材２５との当接部を潤滑しても良い。
【００１７】
【発明の効果】
以上説明したごとく、本発明に係る動力伝達機構においては、第２回転体外周面のバネ部材との当接部が平坦面又は径方向外方へ凸の曲面であり、両者の接触面積が狭いので、両者の間に周方向の滑りが支障無く生じ、或いは第１回転体内周面のバネ部材との当接部が平坦面又は径方向内方へ凸の曲面であり、両者の接触面積が狭いので、両者の間に周方向の滑りが支障なく生ずる。この結果、バネ部材が支障なく反転して、第１回転体から第２回転体へのトルク伝達が支障なく遮断される。従って、本発明に係る動力伝達機構は安定したトルク遮断性能を発揮できる。
【図面の簡単な説明】
【図１】本発明の実施例に係る動力伝達機構の斜視図である。（ａ）はトルク伝達時の形態を示し、（ｂ）はトルク遮断時の形態を示す。
【図２】本発明の他の実施例に係る動力伝達機構の斜視図である。
【図３】本発明の他の実施例に係る動力伝達機構の断面図である。
【図４】本発明の他の実施例に係る動力伝達機構の断面図である。
【符号の説明】
１ 動力伝達機構
２、１２、２２ プーリー
３ ベアリング
４、１４、２４ ハブ
５、１５、２５ バネ部材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power transmission mechanism.
[0002]
[Prior art]
An annular first rotator driven by an external drive source, a second rotator located in a central opening of the first rotator, and interposed between the first rotator and the second rotator; A spring member, both ends of which are supported by the first rotator and which are convexly curved toward the second rotator and contact the outer peripheral surface of the second rotator; Patent Document 1 discloses a power transmission mechanism in which a contact portion has a curved surface that is convex inward in the radial direction.
In the power transmission mechanism of Patent Document 1, torque is transmitted from the first rotating body to the second rotating body via a spring member. When the torque transmitted from the first rotator to the second rotator becomes excessive, a circumferential slip occurs between the second rotator and the spring member, and the second rotator is pressed radially outward. The spring member reverses and curves convexly toward the first rotator, the contact state between the spring member and the second rotator is released, and torque transmission from the first rotator to the second rotator is interrupted. Is done.
[0003]
[Patent Document 1] JP-A-2000-249160
[0004]
[Problems to be solved by the invention]
In the power transmission mechanism disclosed in Patent Document 1, the contact portion of the outer peripheral surface of the second rotating body with the spring member is curved in a complementary shape to the spring member, and the contact area between the two is large. This is problematic in that slippage does not easily occur and it is difficult to exhibit stable torque interruption performance.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a power transmission mechanism that can exhibit stable torque cutoff performance.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the present invention, an annular first rotator driven by an external drive source, a second rotator located in a central opening of the first rotator, and a first rotator are provided. A spring member interposed between the first rotating body and the first rotating body, both ends of which are fixed or supported, and which convexly curves toward the second rotating body and abuts on the outer peripheral surface of the second rotating body; And a contact portion of the outer peripheral surface of the second rotating body with the spring member is a flat surface or a curved surface that projects radially outward.
Further, in the present invention, an annular first rotator that is rotationally driven by an external drive source, a second rotator located in a central opening of the first rotator, and a first rotator and a second rotator are included. A spring member interposed therebetween, both ends of which are fixed or supported by the second rotating body, and which are convexly curved toward the first rotating body and abut against the inner peripheral surface of the first rotating body; A power transmission mechanism characterized in that a contact portion of a peripheral surface of a body with a spring member is a flat surface or a curved surface convex inward in a radial direction.
In the power transmission mechanism according to the present invention, torque is transmitted from the first rotating body to the second rotating body via the spring member. When the torque transmitted from the first rotator to the second rotator becomes excessive, a circumferential slip occurs between the second rotator and the spring member, and the second rotator is pressed radially outward. The spring member reverses and curves convexly toward the first rotator, the contact state between the spring member and the second rotator is released, and torque transmission from the first rotator to the second rotator is interrupted. Alternatively, a circumferential slip occurs between the first rotating body and the spring member, and the spring member pressed inward in the radial direction by the first rotating body is inverted to be convex toward the second rotating body. It is bent, and the contact state between the spring member and the first rotating body is released, and the transmission of torque from the first rotating body to the second rotating body is interrupted.
In the power transmission mechanism according to the present invention, the contact portion between the outer peripheral surface of the second rotating body and the spring member is a flat surface or a curved surface that is convex radially outward, and the contact area between the two is small. In this case, the sliding in the circumferential direction occurs without any trouble, or the contact portion of the peripheral surface of the first rotating body with the spring member is a flat surface or a curved surface that is convex inward in the radial direction, and the contact area between them is small. A circumferential slippage occurs without any trouble. As a result, the spring member is turned over without hindrance, and the transmission of torque from the first rotator to the second rotator is interrupted without hindrance. Therefore, the power transmission mechanism according to the present invention can exhibit stable torque interruption performance.
[0006]
In a preferred aspect of the present invention, a plurality of spring members are arranged at intervals in the circumferential direction.
By disposing a plurality of spring members at intervals in the circumferential direction, the size of the spring members is reduced, and the power transmission mechanism is reduced in size.
[0007]
In a preferred aspect of the present invention, the spring member is in the shape of a strip or a wire.
The spring member may have a strip shape or a wire shape.
[0008]
In a preferred aspect of the present invention, the shape of the spring member before being inserted between the first rotating body and the second rotating body is an elongated shape or a curved shape.
The straight spring member may be bent and inserted between the first rotating body and the second rotating body, or a curved spring member may be inserted between the first rotating body and the second rotating body. May be inserted.
[0009]
In a preferred aspect of the present invention, the rotating body is attached to a contact portion of the second rotating body with the spring member.
In a preferred aspect of the present invention, the rotating body is attached to a contact portion of the first rotating body with the spring member.
By attaching the rotating body, circumferential sliding between the second rotating body and the spring member or circumferential sliding between the first rotating body and the spring member can be generated without any trouble.
[0010]
In a preferred aspect of the present invention, the rotating body has elasticity.
By providing the rotating body with elasticity, circumferential sliding between the second rotating body and the spring member or circumferential sliding between the first rotating body and the spring member can be caused without any trouble. it can.
[0011]
In a preferred aspect of the present invention, the spring member has a vibration damping function.
Since the spring member has the vibration damping function, the short-period torque fluctuation of the external drive source to which the first rotating member is connected and the short-period torque fluctuation of the rotating device to which the second rotating member is connected are caused by the rotation device main shaft. The torsional vibration is suppressed, and the operation of the power transmission mechanism is stabilized.
[0012]
In a preferred aspect of the present invention, a contact portion between the spring member and the second rotating member is lubricated.
In a preferred aspect of the present invention, a contact portion between the spring member and the first rotating member is lubricated.
By lubricating the contact portion between the spring member and the second rotating member, or by lubricating the contact portion between the spring member and the first rotating member, circumferential sliding between the second rotating body and the spring member is performed. Alternatively, the circumferential sliding between the first rotating body and the spring member can be caused without any trouble.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
A power transmission mechanism according to an embodiment of the present invention will be described.
As shown in FIG. 1A, the power transmission mechanism 1 includes an annular pulley 2 having a circular outer periphery and a hexagonal inner periphery. The pulley 2 is supported by a compressor casing (not shown) via a bearing 3. The pulley 2 is connected to a vehicle engine (not shown) via an endless belt (not shown).
The power transmission mechanism 1 includes a hub 4 having a hexagonal outer periphery in the center opening of the pulley 2. A main shaft of a compressor (not shown) extending concentrically with the hub 4 is fixed to the hub 4.
An annular spring 5 having a substantially hexagonal cross section and made of a strip is inserted between the pulley 2 and the hub 4. Each vertex of the hexagon of the spring 5 is fixed to each side of the hexagon on the inner periphery of the pulley 2 via the block 6. Each hexagonal side of the spring 5 is convexly curved toward the hub 4, and the center of each side is in contact with each hexagonal side of the outer periphery of the hub 4.
[0014]
The operation of the power transmission mechanism 1 will be described.
Torque is transmitted to the pulley 2 from a vehicle engine (not shown) via an endless belt (not shown). Torque is transmitted from the pulley 2 to the hub 4 via the spring member 5. Torque is transmitted from the hub 4 to the main shaft of the compressor (not shown), and the compressor (not shown) operates.
When the transmission torque between the pulley 2 and the hub 4 exceeds a predetermined value, a circumferential slippage occurs between each hexagonal side of the outer peripheral surface of the hub 4 and the center portion of each substantially hexagonal side of the spring member 5. Occurs, and the substantially hexagonal sides of the spring member 5 pressed radially outward by the hexagonal sides of the outer peripheral surface of the hub 4 are inverted, and as shown in FIG. It curves convex toward it. Each hexagonal side of the inverted spring member 5 is accommodated in a space near each vertex of the hexagon on the inner periphery of the pulley 2. As a result, the contact state between the spring member 5 and the outer peripheral surface of the hub 4 is released, and the transmission of torque from the pulley 2 to the hub 4 is interrupted.
[0015]
In the power transmission mechanism 1, the contact portion between the outer peripheral surface of the hub 4 and the spring member 5 is a flat surface, and the contact area between the two is small, so that circumferential slippage occurs between the two without any trouble. As a result, the spring member 5 is inverted without any trouble, and the torque transmission from the pulley 2 to the hub 4 is interrupted without any trouble. Therefore, the power transmission mechanism 1 can exhibit stable torque interruption performance.
By transmitting torque from the pulley 2 to the hub 4 via a plurality of contact portions between the outer peripheral surface of the hub 4 and the spring member 5, the member strength of the contact portion of the spring member 5 with the outer peripheral surface of the hub 4 can be reduced. It becomes. As a result, the size of the spring member 5 is reduced, and the power transmission mechanism 1 is reduced in size.
[0016]
The spring member 5 may be formed of a wire instead of a strip.
Instead of the annular spring member 5 having a substantially hexagonal cross section, a spring member convexly curved toward the hub 4 may be provided between adjacent blocks 6 one by one. The engagement between the ends of each spring member and the block 6 may be fixed, supported, or intermediate between the two. The shape of each spring member before being attached to the block 6 may be straight or curved.
As shown in FIG. 2, the rotating body 7 may be attached to the end of each side of the hexagon on the outer peripheral surface of the hub 4, that is, to each vertex of the hexagon on the outer peripheral surface of the hub 4. By attaching the rotating body 7, circumferential sliding between the outer peripheral surface of the hub 4 and the spring member 5 can be generated without any trouble.
The rotating body 7 may be formed of an elastic body, or the elastic body may be externally fitted to the rotating body 7. By making the rotating body 7 elastic, the sliding in the circumferential direction between the outer peripheral surface of the hub 4 and the spring member 5 can be generated without any trouble.
The spring member 5 may be formed of a damping material such as a clad material of a metal and a viscoelastic body. Since the spring member 5 has the vibration damping function, the torsional vibration of the compressor main shaft caused by the short-period torque fluctuation of the vehicle engine to which the pulley 2 is connected and the short-period torque fluctuation of the compressor to which the hub 4 is connected. And the operation of the power transmission mechanism 1 is stabilized. A solid lubricant or the like may be applied to the spring member 5 and / or a contact portion of the outer peripheral surface of the hub 4 with the spring member 5. By lubricating the contact portion between the spring member 5 and the outer peripheral surface of the hub 4, circumferential sliding between the outer peripheral surface of the hub 4 and the spring member 5 can be caused without any trouble.
The inner circumference of the pulley 2 may be a polygon other than a hexagon, a circle, or any other shape. The outer periphery of the hub 4 may be a polygon other than a hexagon, or may be an ellipse. As shown in FIG. 3, the contact portion of the outer peripheral surface of the elliptical hub 14 with the spring member 15 is convexly curved radially outward, and the contact area between the two is small. In the circumferential direction can be caused without any trouble. In FIG. 3, the spring member 15 at the time of torque transmission is indicated by a solid line, and the spring member 15 at the time of torque interruption is indicated by a dashed line.
As shown in FIG. 4, a triangular protrusion 22 a is formed on the inner peripheral surface of the annular pulley 22, and both ends of a spring member 25 convexly curved toward the pulley 22 are fixed to a substantially circular hub 24. The support may be supported by a substantially circular hub 24 so that the spring member 25 can contact the projection 22a. A recess 24 a for receiving the inverted spring member 25 is formed in the hub 24. The contact portion of the projection 22a with the spring member 25 is a flat surface, and the contact area between them is small, so that circumferential sliding between the projection 22a and the spring member 25 can be caused without any trouble. In FIG. 4, the spring member 25 at the time of torque transmission is indicated by a solid line, and the spring member 25 at the time of torque interruption is indicated by a dashed line. The outer shape of the projection 22a may be a curved surface that is convex inward in the radial direction. A rotating body may be attached to the top of the projection 22a. The contact portion between the projection 22a and the spring member 25 may be lubricated.
[0017]
【The invention's effect】
As described above, in the power transmission mechanism according to the present invention, the contact portion between the outer peripheral surface of the second rotating body and the spring member is a flat surface or a curved surface that projects radially outward, and the contact area between the two is small. Therefore, circumferential slippage occurs between the two members without any trouble, or the contact portion of the peripheral surface of the first rotating body with the spring member is a flat surface or a curved surface that is convex inward in the radial direction. Due to the narrowness, circumferential slippage occurs between the two without any problem. As a result, the spring member is turned over without hindrance, and the transmission of torque from the first rotator to the second rotator is interrupted without hindrance. Therefore, the power transmission mechanism according to the present invention can exhibit stable torque interruption performance.
[Brief description of the drawings]
FIG. 1 is a perspective view of a power transmission mechanism according to an embodiment of the present invention. (A) shows the form at the time of torque transmission, and (b) shows the form at the time of torque interruption.
FIG. 2 is a perspective view of a power transmission mechanism according to another embodiment of the present invention.
FIG. 3 is a cross-sectional view of a power transmission mechanism according to another embodiment of the present invention.
FIG. 4 is a cross-sectional view of a power transmission mechanism according to another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Power transmission mechanism 2, 12, 22 Pulley 3 Bearing 4, 14, 24 Hub 5, 15, 25 Spring member
