US 7,612,477 B2
Electromagnetic brake device for small-sized motor
Toshiyuki Abe, Minamiazumi-gun (Japan); and Kiyoto Kobayashi, Minamiazumi-gun (Japan)
Assigned to Harmonic Drive Systems Inc., Tokyo (Japan)
Appl. No. 11/910,267
PCT Filed Apr. 22, 2005, PCT No. PCT/JP2005/007681
§ 371(c)(1), (2), (4) Date Sep. 30, 2007,
PCT Pub. No. WO2006/114881, PCT Pub. Date Nov. 02, 2006.
Prior Publication US 2008/0191567 A1, Aug. 14, 2008
Int. Cl. H02K 7/10 (2006.01)
U.S. Cl. 310—90  [310/77] 2 Claims
OG exemplary drawing
 
1. 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.