PURPOSE: To suppress the temperature rise of bearings by a method wherein an annular ventilation guide composed of an attaching part which is provided outside suction holes at the bottom and a guide part which is provided between the suction holes and windings is provided.

CONSTITUTION: The holding part 4a2 of bearings 5 whose center part supports the rotary shaft 7 of a rotor 6 which has fans 3 on both ends is formed on a stator 1 to which windings 2 are applied to constitute a motor which further has a bottom part 4a which has a plurality of suction holes 4a1 along its outer circumference and a bottomed cylindrical bracket 4 which is composed of a cylindrical part 4b on which a plurality of exhaust holes 4b1 are formed. An annular ventilation guide 8 which is composed of an attaching part 8a which is positioned outside the suction holes at the bottom and a guide part 8b which is provided between the suction holes and the windings and through which the bearings of the rotor are inserted is provided inside the bottom part of the bracket. Thus a ventilation path through which the air cooling the windings is made to flow by the fans is provided from the suction holes and the exhaust holes. As a result, the temperature rise of the bearings can be suppressed and the life and reliability of the motor can be improved.