To realize a structure which enables a bearing fitted on a tip part of a worm to be easily removed from the worm.SOLUTION: A worm reducer includes: an inner diameter side holder 25 which holds a bearing 18c fitted therein; an outer diameter side holder having a holder holding part which holds the inner diameter side holder fitted therein in a manner that the inner diameter side holder can relatively rotate and can be displaced in a direction perpendicular to a center axis of a worm wheel and a center axis of a worm, the outer diameter side holder fitted in and held by a holding recessed part of the housing; and a circumferential elastic biasing member which elastically biases the inner diameter side holder in a direction that the inner diameter side holder is rotated relative to the outer diameter side holder in a circumferential direction. An outer peripheral surface of the inner diameter side holder and an inner peripheral surface of the outer diameter side holder are formed so as to displace the bearing in the direction perpendicular to the center axis of the worm wheel and the center axis of the worm when the inner diameter side holder rotates relative to the outer diameter side holder in the circumferential direction. Notches 82 which open from an axial end surface of the inner diameter side holder and have an axial length longer than at least an axial length of the bearing are provided on an inner peripheral surface of a bearing holding part.SELECTED DRAWING: Figure 12
【課題】ウォームの先端部に外嵌された軸受をウォームから分離しやすい構造を実現する。【解決手段】ウォーム減速機は、軸受18cを内嵌保持する内径側ホルダ25と、内径側ホルダを相対的に回転移動可能、並びに、ウォームホイールの中心軸及びウォームの中心軸に直交する方向の変位を可能に内嵌保持するホルダ保持部を有し、ハウジングの保持凹部に内嵌保持された外径側ホルダと、内径側ホルダを外径側ホルダに対して周方向に回転させる方向に弾性的に付勢する周方向の弾性付勢部材とを備える。内径側ホルダの外周面と外径側ホルダの内周面とは、内径側ホルダが外径側ホルダに対して周方向に回転したときに、軸受をウォームホイール及びウォームの中心軸に直交する方向に変位させるように形成される。また、軸受保持部の内周面には、内径側ホルダの軸方向端面から開口し、少なくとも軸受の軸方向長さよりも長い軸方向長さを有する切り欠き82が設けられる。【選択図】図12
WORM REDUCER
ウォーム減速機
2019-04-11
Patent
Electronic Resource
Japanese