GB1266621A - - Google Patents

Abstract

1,266,621. Homopolar machines. GENERAL ELECTRIC CO. Ltd. 27 July, 1970 [1 Aug., 1969], No. 38623/69. Heading H2A. A homopolar machine comprises a stator magnetic circuit consisting of a yoke 55 formed with an annular cavity 3 in which are located annular stator members 4...8 defining a plurality of axial air gaps in each of which is located one of a plurality of annular, conducting rotor members 15 ... 19, each of the stator members comprising a polepiece 24 surrounded by conducting material 25 through which the rotor members are connected in series between terminals 26, 27. Preferably, the rotor members also comprise polepieces 24 surrounded by conducting material 25. The stator members are insulated from each other by spacers 11, and the rotor members, which are carried by a hub 13, are separated by insulating spacers 23. Connection between the members and between the stationary terminal 26 and hub 13 is effected by conducting liquid such as a sodium potassium alloy, at the points 30, 35 and 38, the liquid being circulated through the machine through ducts 28, 31, 33, 36, 39, 40, 41. Those surfaces of the stator and rotor members where connections are not required are covered by a thin layer of insulation. End plates 42 define an enclosure for the assembly of stator and rotor members which is filled with gas such as nitrogen. To alleviate magnetic pressure on the conducting liquid at the connection points, produced by the load current through the machine, a connection parallel to the tube 20 extending from terminal 26 to rotor member 15 is made through a tube (52), Fig. 3 (not shown), fixed to the stator adjacent the radially outer ends of the rotor members to provide an opposing magnetic pressure. Alternatively, one of the contact surfaces at each connection point may be slotted to increase the surface tension sufficiently to counteract the magnetic pressure. In other alternative arrangements the gaps at each connection point may have radial portions filled with liquid and of a length such that the centrifugal force acting on the liquid therein maintains liquid in axial portions of the gaps, Figs. 4-6 (not shown), or the connections may be of the type described in Specification 1,266,622, Fig. 7 (not shown). The conducting liquid provides a measure of cooling for the machine which may be supplemented by circulating water through channels in the stator members 4 ... 8.