An eddy current deceleration device comprises: a rotor mounted on a rotary shaft; a first magnet ring arranged facing this rotor and including permanent magnets that are arranged at prescribed intervals in the circumferential direction and such that the poles thereof facing each other in the circumferential direction are of a same polarity, and magnetic members interposed between these permanent magnets; and a second magnet ring arranged between this first magnet ring and the rotor and including permanent magnets and magnetic members which are similar to those of the first magnet ring; at least one of the first and second magnet rings being freely rotatable. The permanent magnets of the first and second magnet rings can be magnetized separately between the first and second magnet rings. This means that the permanent magnets of length half of the length of the permanent magnet pairs are magnetized, so even though the intervals between adjacent permanent magnets in the circumferential direction are made smaller, ample magnetization can still be achieved. Also, the braking force exhibited by the permanent magnets is that of the length of the sets of pairs of permanent magnets. Consequently, the braking force can be increased.
REFERENCE TO RELATED APPLICATION
This application is a Divisional Application of U.S. Ser. No. 10/445,529 entitled `Eddy Current Deceleration Device`, Tohru Kuwahara, filed on May 27, 2003, now U.S. Pat. No. 6,948,597, and claims the benefit of the filing date thereof under 35 U.S.C. .sctn.120. The present invention also claims priority from Japanese Patent Application 2002-154349 filed in Japan on 28 May 2002 and Japanese Patent Application No. 2002-187293 filed in Japan on 27 Jun. 2002. The content of these Japanese applications is hereby incorporated in the specification of the present application by reference.
Priority Data
May 28, 2002 [JP] 2002-154349 Jun 27, 2002 [JP] 2002-187293
A magnetic transmission having an input shaft and an output shaft with two or more gear assemblies, each gear assembly having an input sprocket affixed to the input shaft, an output armature with peripheral electromagnets affixed to the output shaft, a transfer drum concentric with the output armature and having electromagnets inset from the inside surface of the transfer drum and a drum sprocket on the periphery of the transfer drum, and a transfer chain engaging the input sprocket and the drum sprocket. A gear assembly actuator is used to select and energize a desired gear assembly. A hysteresis clutch can also be used in lieu of the output armature and the transfer drum.
