Patent ID: 7612477

Claim:
An electromagnetic brake built-in type small-sized motor comprising: an electromagnetic brake device for locking rotation of a motor rotation shaft; wherein the electromagnetic brake device is assembled between a motor main section and a motor end plate, and a shaft end part of a rear end extension part of the motor rotation shaft is rotatably supported by the motor end plate via a bearing; the electromagnetic brake device comprises: a rotating disc fixed to the motor rotation shaft so as to rotate together with the motor rotation shaft; a sliding disc that is slidable along an axial line of the motor rotation shaft so as to come close to and move away from the rotating disc; a spring member that presses the sliding disc against the rotating disc; and an electromagnet that is able to pull the sliding disc in a direction for moving away from the rotating disc while being against a spring force of the spring member; wherein the electromagnet includes a yoke and an exciting coil; the yoke includes an outer cylindrical part and an inner cylindrical part, both of which are formed so as to be concentric each other, and a circular end plate part that blockades a rear end of a circular space formed between the outer cylindrical part and the inner cylindrical part; the exciting coil is installed in the circular space; a circular recess with a specified depth is formed in the circular end plate part of the yoke by having an inner circumference side of the circular end plate part bend forward in a step form in a sectional shape cut along the axial line; and the electromagnetic brake device is assembled to the rear end extension part of the motor rotation shaft in such a manner that a part of the bearing is housed in the circular recess of the electromagnetic brake device.