To attain a structure capable of making an energization direction of an energization member always consistent with an engagement direction between a worm wheel and a worm shaft.SOLUTION: A worm gear speed reducer is configured to cause a pressing member 41 constituting an energization member 20 to press an energization member body 40 in an axis direction, to press against an outer peripheral surface of a second bearing 20 a pressing surface 48 directly provided on the energization member body 40, to energize a one-side lateral part in the axis direction of a worm shaft 17 in a direction of approaching a worm wheel. The pressing surface 48 is arranged in parallel with a second virtual plane P2 containing a central axis Oof a worm wheel 18, of a virtual plane orthogonal to a first virtual plane P1 passing through each of an engagement part M between a worm gear 25 and a worm wheel gear part 27 and the central axis Oof the worm wheel 18.SELECTED DRAWING: Figure 4
【課題】付勢部材による付勢方向を、ウォームホイールとウォーム軸との噛み合い方向に常に一致させることができる構造を実現する。【解決手段】付勢部材20を構成する押圧部材41により、付勢部材本体40を軸方向に押圧することで、付勢部材本体40に直接設けられた押圧面48を第二軸受20の外周面に押し付け、ウォーム軸17の軸方向他方側部をウォームホイールに近づく方向に付勢する。押圧面48を、ウォーム歯部25とウォームホイール歯部27との噛合部M及びウォームホイール18の中心軸O18をそれぞれ通る第一仮想平面P1に直交する仮想平面のうち、ウォームホイール18の中心軸O18を含む第二仮想平面P2と平行に配置する。【選択図】図4
WORM GEAR SPEED REDUCER
ウォーム減速機
2018-12-06
Patent
Electronic Resource
Japanese