GB936236A - Improvements in homopolar generator - Google Patents

Abstract

936,236. Homopolar generators; current collection. GENERAL ELECTRIC CO. Jan. 4, 1960 [Jan. 2, 1959], No. 208/60. Class 35. In a homopolar generator, the velocity imparted to the liquid metal used for current transfer by centrifugal and magnetic forces is converted into a liquid pressure to avoid the formation of voids in the current-transfer area. The generated rotor current is carried by copper sleeves 51, and passes via the collector 50, 86 and stator sleeves 74 to terminal rings 76, 77. Liquid metal is supplied under pressure via pipes 94 to the current transfer chamber 90. Centrifugal and magnetic forces tend to push the liquid axially toward opposite sides of the chamber where it is deflected back, according to the invention, by the curved surfaces of annular " pumping " rings 92 and rotor shoulder 62. The liquid is withdrawn through fine holes from the current transfer chamber, via pipes 108, for cooling (Fig. 6, not shown). In addition, leakage metal is drawn from annular channels 109 (Fig. 4, not shown). The rotor collector 50 is faced with stainless steel 56 while the stator collector 86 may be copper faced or made of copper-aluminium alloy or stainless steel. The liquid metal may be a sodiumpotassium alloy, gallium, mercury, tin, lead, or bismuth. Cooling.-The machine casing is filled with inert gas, e.g. nitrogen, helium or argon at 1/2 p.s.i. above atmospheric pressure, and is cooled by heat exchangers 34 within the machine casing. The stator field coils 44 have cooling fins 49. Cooling gas enters the collecting chamber at both sides of the current transfer chamber via the outer air-gaps and holes 110 in parallel, and passes through the labyrinths 64 at each side to the annular channels 109 from whence it is withdrawn together with leakage conducting metal. Terminals, Fig. 8.-Connection is made uniformly round the terminal rings 76, 77 by laminated copper plates 144 welded thereto. These connectors are bolted to rising conductors 146 resiliently supported by adjustable springs 168. Positive and negative risers, i.e. connected to rings 76, 77 respectively are separated by an insulating plate and bolted through (Fig. 10, not shown). These risers pass through seals 148 since the machine is gas-filled.