Patent ID: 7629717

Claim:
A totally-enclosed fan-cooled motor comprising: a stator provided in the air-tightly closed motor; a rotor provided oppositely to the stator and mounted to a rotation shaft; a pair of bearings for holding a drive side and a side opposite to the drive side of the rotation shaft; an external fan provided on the side opposite to the drive side of the rotation shaft and outside the motor for sending wind to the stator; an internal fan provided inside the motor for circulating air in the motor to send wind to the rotor and the stator; a radiator mounted to the rotation shaft so as to be located on an outer side of the bearing holding the drive side of the rotation shaft, outside the motor and in the vicinity of the bearing for cooling the bearing holding the drive side of the rotation shaft, wherein the radiator includes: a plurality of through holes passing through both of a surface on the drive side and a surface on the side opposite to the drive side, and a plurality of grooves on a surface on the side opposite to the drive side, one end of the respective grooves being opened to an outer circumferential surface of the radiator, an area of the respective grooves being larger than an area of the respective through holes in view of a longitudinal direction of the rotation shaft, the plurality of grooves and plurality of through holes from a plurality of flow paths in which air flows from the drive side of the radiator to the side opposite to the drive side of the radiator and flows from the inner circumferential side to the outer circumferential side in the respective grooves.