MOTOR DRIVE FORCE TRANSMISSION DEVICE

A motor driving force transmission system with which generation of NV can be suppressed is provided. A motor driving force transmission system 1 includes an electric motor 4 that generates motor torque for actuating a differential mechanism portion and outputs the motor torque, and that has a motor shaft 42 with eccentric portions, and a bearing mechanism including a ball bearing 34 interposed between one-side axial end portion of a housing 2 and one-side axial end portion of a differential case 30, a ball bearing 35 interposed between the other-side axial end portion of the differential case 30 and one-side axial end portion of the motor shaft 42, and a ball bearing 46 interposed between the other-side axial end portion of the housing 2 and the other-side axial end portion of the motor shaft 42. An axial load is applied to the ball bearings 34, 35, 46 of the bearing mechanism by a spring 48.