Patent ID: 7658257

Claim:
An axle-driving system comprising: an axle case having an outer wall which supports a drive axle in a rotatable manner around its axis in a state that the drive axle is along a widthwise direction of a vehicle and an inner wall which is disposed apart from the outer wall inwardly in the widthwise direction of the vehicle so that the inner end portion of the drive axle in the widthwise direction of the vehicle is positioned between the inner wall and the outer wall; a motor unit forming a non-stepwise speed change device in cooperation with an actuator disposed apart therefrom, the motor unit including a motor ease which is connected to the inner wall of the axle case, a motor shaft which is supported by the motor case in a rotatable manner around its axis in a state that the motor shaft is along the widthwise direction of the vehicle so as to be parallel to the drive axle, and a motor body which is accommodated in the motor case while being supported on the motor shaft; and a reduction transmission unit accommodated in the axle case, wherein the motor shaft has an outer end portion and an inner end portion in the widthwise direction of the vehicle, the outer end portion protruding outwardly from the motor case so as to be positioned inside an accommodating space of the axle case, and the inner end portion protruding outwardly from the motor case, the inner end portion of the motor shaft is provided with a brake unit, the reduction transmission unit includes an intermediate shaft supported by the axle case so as to be parallel to the motor shaft and the drive axle, an output gear provided on the motor shaft at its outer end portion in the widthwise direction of the vehicle, a first intermediate gear provided on the intermediate shaft so as to mesh with the output gear, a second intermediate gear provided on the intermediate shaft, and a final gear provided on the drive axle so as to mesh with the second intermediate gear, and the drive axle is positioned on a side of the motor shaft and the intermediate shaft is positioned on an opposite side of the motor shaft.