PURPOSE: To extend design freedom and to save fabrication cost by making it possible to operate a reduction gear as a parking brake.
CONSTITUTION: A hollow movable frame 21 having nonmagnetic conical outer tubular section 24 is supported on a fixed frame 17 projecting into a brake drum 14 having conical inner circumferential face 13. A large number of ferromagnetic boards 26 are arranged, at same intervals, in the circumferential direction while being coupled with the outer tubular section 24 of the movable frame 21. A large number of permanent magnets 28 are coupled with a magnet supporting tube 27, supported in the hollow part of the movable frame 21, so that the polarity for each ferromagnetic board 26 alternates in the circumferential direction. When a vehicle is traveling, an actuator 31 drives the magnet supporting tube 27 in the axial direction to switch the magnet supporting tube 27 between a brake position where the ferromagnetic board 26 is superposed by the permanent magnet 28 and a non-brake position where the ferromagnetic board 26 is not superposed by the permanent magnet 28. At the time of parking, a parking brake operating mechanism 40 moves the movable frame 21 in the axial direction to push the outer circumferential face 24a of the movable face 21 against the inner circumferential face 13 of the brake drum 14.
KUWABARA TORU
KUBOMIYA TOMOYUKI
ISOYAMA HAYAO
