| 摘要 |
PROBLEM TO BE SOLVED: To solve such a problem that a fin vibrates and noise is generated in a motor drive device having a vibrating object therein.SOLUTION: A motor drive device is provided with: a semiconductor module 2 which switches; a smoothing capacitor 3 for smoothing a surge caused by the switching of the semiconductor module; a heat sink 4 for dissipating heat generated from the semiconductor module, and fixing the smoothing capacitor; and a cover 1 mounted on the heat sink. The smoothing capacitor 3 has an electrode vibrated by putting in/out of electric charges, and the heat sink 4 has a plurality of fins 41 and 42, the fins 41 of both ends out of the plurality of fins are controlled so as to have thicknesses thicker than the thicknesses of the fins 42 located so as to be inner than the fins 41, and the vibration is reduced. |
