POWER UNIT FOR ELECTRIC VEHICLE

PROBLEM TO BE SOLVED: To provide a power unit for an electric vehicle which enables a motor case side first speed reduction ring gear to be stably and securely supported by a hub case while securing a high speed reduction ratio in a speed reduction mechanism part which transmits driving force of a motor to the hub case.SOLUTION: A speed reduction mechanism part R includes: a speed reduction sun gear 51 which is rotationally driven by a motor M; a speed reduction carrier 53 rotatably supporting a first gear 52a which engages with the speed reduction sun gear and a second gear 52b coaxially arranged with the first gear; a first speed reduction ring gear 54 which fits in an open end part 31a of a motor case H and engages with the first gear; and a second speed reduction ring gear 55 which is provided at one end wall part He of a hub case H and engages with the second gear. A bering B7 which enables the first speed reduction ring gear 54 to be rotationally supported by the hub case H is disposed between the first speed reduction ring gear 54 and the hub case H.SELECTED DRAWING: Figure 1 【課題】電動車両用動力ユニットにおいて、モータの駆動力をハブケースに伝達する減速機構部で高い減速比を確保しつつ、モータケース側の第１減速リングギヤをハブケースに安定よく強固に支持できるようにする。【解決手段】減速機構部Ｒは、モータＭにより回転駆動される減速サンギヤ５１と、前記減速サンギヤに噛合する第１ギヤ５２ａ、及び該第１ギヤに対し同軸に並ぶ第２ギヤ５２ｂを回転自在に支持する減速キャリア５３と、モータケースＨの開放端部３１ａに嵌着されて第１ギヤに噛合する第１減速リングギヤ５４と、ハブケースＨの一端壁部Ｈｅに設けられて第２ギヤに噛合する第２減速リングギヤ５５とを備え、第１減速リングギヤ５４とハブケースＨとの間には、第１減速リングギヤ５４をハブケースＨに回転自在に支持させる軸受Ｂ７が介装される。【選択図】 図１