Motor driving device and electric vehicle equipped with the same

A motor driving device includes a motor and a brake mechanism which brakes rotation of the motor. The motor and the brake mechanism are disposed in parallel to each other. A connection portion for connecting the motor and the brake mechanism is disposed between the motor and the brake mechanism. A size of the connection portion in the radial direction with respect to the axis of the motor is smaller than outer diameter of the motor as well as outer diameter of the brake mechanism.