Patent ID: 8869952

Claim:
An electromagnetic brake system comprising: a rotation shaft; a rotated body, which is attached to the rotation shaft directly or via another member, and is rotated concentrically with the axis of the rotation shaft; a ring shaped yoke having a first hole portion through which the rotation shaft penetrates; a concave groove, an inner cylinder portion and an outer cylinder portion, which are formed on the yoke, the concave groove being concentric with the first hole portion and having a ring shape, the inner cylinder portion being formed inward in the radial direction of the concave groove, and the outer cylinder portion being formed outward in the radial direction; a coil portion accommodated in the concave groove; a friction plate, which has a second hole portion in the center thereof, through which the rotation shaft penetrates, and which is connected to the rotated body in a state of being arranged between the rotated body and the yoke; and a fixing member, which fixes the yoke, wherein the inner cylinder portion has a protruded shaft portion which protrudes toward the friction plate and is rotatably inserted to the second hole portion, wherein the protruded shaft portion has an outer wall surface, which is concentric with the first hole portion, wherein the fixing member has a support portion, which rotatably supports the rotation shaft, and wherein the support portion has an inner wall surface, which is concentric with the first hole portion in a state of being fixed to the yoke, and the rotation shaft is supported by the inner wall surface.