Eddy current retarder.

摘要

An eddy current retarder includes a rotor (3) fitted over a rotating shaft (1) at one end thereof and a support ring (7) around which a plurality of permanent magnets (10) are circumferentially provided in such a manner that the polarities of any adjacent magnets become opposite to each other. The support ring (7) is provided such that it is allowed to move back and forth in the axial direction of the rotating shaft (1) from a first position where the pole surfaces of the permanent magnets (10) fully confront the rotor (3) with a predetermined gap being secured therebetween to a second position where the former fully deviate from the latter. A boss portion (22) of the rotor (3) adapted to confront the permanent magnets (10) circumferentially provided around the support ring (7) and a cylindrical portion of the same are connected to each other by means of a support member (31), and this support member (31) comprises a fan (30) having axial blades (35) and radial blades (36) formed, respectively, radially inwardly and radially outwardly of the support member (31). Stator blades (37) are circumferentially provided close to the axial blades (35) on a bearing housing tube (4) fitted over the rotating shaft (1), and cooling fins (28) are radially provided on the external circumferential surface of the bearing housing tube (4) in such a manner as to protrude therefrom.