Patent ID: 8854816

Claim:
A combination comprising: a unit case for an inverter unit, the unit case having a front case and a rear case, the front case containing a circuit section including a power semiconductor module, and the rear case having a wind channel containing a cooling fin assembly for the power semiconductor module and at least one cooling fan ventilating cooling air through the cooling fin assembly in the wind channel and discharging the cooling air from a top of the unit case; and a water-proof cover made of a molded resin and disposed over the unit case to surround the top of the unit case, said water-proof cover forming a ventilating path for the cooling air discharged from the unit case and exhausting paths downward along side surfaces of the unit case, wherein the water-proof cover includes: a top portion, rear side portions extending downwardly from two sides of the top portion to cover upper rear sides of the unit case, front side portions extending downwardly from the two sides of the top portion to cover upper front sides of the unit case, the front side portions expanding laterally outwardly from the unit case to form the exhausting paths with respect to the unit case for exhausting the cooling air downward through the exhausting paths, a ventilation guide formed at the top portion around an exhausting port of the at least one cooling fan, a front portion connecting the front side portions, and spaced from the unit case so that air from the exhausting port is guided by the ventilation guide and ejected downwardly between the front portion and the unit case, and a rear opening at a side opposite to the front portion, and said ventilation guide is spaced from the top portion, and includes two side panels inclining relative to the rear side portions, and a rear side panel inclining toward the front portion.