BigPatents India

To provide a motor-assisted drive unit for a motor-assisted vehicle, which is made as small in size as possible. A first control board 136 on which control devices of a drive motor 21 are mounted is disposed in a casing 94. In this case, the first control board 136 extends in the direction nearly perpendicular to the motor shaft of a motor 21; and at least part of the first control board 136 extends, as seen along the axial direction a of the motor 21, to a position at which it is overlapped to the motor 21. The second control board 135 is overlapped to part of the first control board 136. as a result, it is possible to dispose a CPU 20 having a relatively large mounting area on a portion overlapped to the motor 21, of the first control board, 136, and hence to effectively use the inner space of the casing. Further, since the second control board 135 is configured as an aluminum board and is directly mounted on the inner wall of the casing 94, it is possible to effectively transfer the heat generated from a FET and the like mounted on the second control board 135. Drawing: 11 Sheets Total Pages: 52 Fig. 1