Improvements relating to dynamo-electric machines, electro-magnetic slip couplings, electro-magnetic brakes and the like

摘要

614,091. Eddy-current brakes. ENGLISH ELECTRIC CO., Ltd., and BALL, R. D. July 5, 1946, No. 20124. [Class 103 (i)] [Also in Group XXXV] A machine such as an alternator, synchronous motor, electromagnetic brake or slip coupling, has a set of imbricated polepieces carried by two rings, each of which is linked magnetically across a radial air-gap with one of a pair of spaced annular poles of opposite polarity, the polepieces co-operating with a further relatively moving member of the machine. As shown, the shaft 10 of an alternator or synchronous motor carries imbricated polepieces 12a and 13a magnetized by stationary pole rings 7a, 7b and the coil 8 and they co-operate with A.C. windings 2 on the-member 1 shown stationary. The latter could, however, be driven in the opposite direction to the imbricated polepieces to give double frequency in the case of an alternator, or both members may rotate in the same direction to serve as a slip coupling. In that case, the outer member may have a squirrel-cage winding or have an unlaminated core with or without teeth. There may be more than one exciting coil.