To enable cost and size reductions, and achievement of high torque transmission by using sintered ferrite permanent magnet materials as the hysteresis materials.
A first votary shaft 1 provided with disk-shaped Nd-Fe-B sintered permanent magnets 4 magnetized into 4-12 N/S poles, and a permanent magnet fixing yoke 3 of a magnetic substance to which the rears of these permanent magnets 4 are caused to adhere closely and fixed, and a second votary shaft 2 to which the disk-shaped sintered ferrite permanent magnet materials 7 are fixed, are inserted and fitted to each other in such a way as to be rotatable. Along with this, repective surfaces of the Nd-Fe-B sintered permanent magnets 4 and the sintered ferrite permanent magnet materials 7 are made to face mutually opposite, and through a hysteresis torque generated between both, so that rotation is transmitted between the first and second votary shafts 1, 2.
KUBO MORIO
SAITO SHIGEO
