EDDY CURRENT SPEED REDUCER

摘要

The invention provides an eddy current braking apparatus that, though simple in construction, is superior in brake efficiency. Moreover an object is to provide an eddy current braking apparatus that has a small switching stoke and is capable of rapid switching. Thus, an eddy current braking apparatus according to the invention comprises: a brake disk (2) connected to a rotary shaft (1); a plurality of permanent magnets (7) arranged so that magnetic pole surfaces are opposed to the brake disk (2); and a drive mechanism for moving the permanent magnets (7) toward and away from the brake disk (2). Preferably, it further comprises a guide sleeve (3) supported by a nonrotatable structural section not connected to the rotary shaft (1), which receives a support ring (4) supporting the permanent magnets (7) and is arranged facing to the brake disk (2). Moreover, in the guide sleeve (3), there are provided ferromagnetic members (8) positioned opposite to the brake disk (2). Alternatively, the whole of said guide sleeve (3) including an end face opposed to said permanent magnets (7) is constructed of nonmagnetic material.