GB1344698A - Hermetically sealed electric motors - Google Patents

Abstract

1344698 Liquid cooled electric motors LOUIS ALLIS CO 14 May 1971 [18 May 1970 18 Jan 1971] 15404/71 Heading H2A [Also in Division F4] In a hermetically sealed electric motor 1, e.g. a refrigeration plant compressor motor, comprising a hermetically sealed casing 15 housing in an annular chamber 38 a stator assembly 30 and a rotor assembly 20 with a rotor/stator gap 60 therebetween; and an inlet conduit 46 for feeding liquid coolant, e.g. refrigerant to the casing and an outlet conduit 47 for withdrawing coolant after cooling the assemblies, coolant is caused to flow from a cavity 48 defined by a baffle 49 into one end of the rotor/stator gap. and then unidirectionally through the length of the gap by the coaction of the baffle and an impeller which is disposed in the cavity 48, at one end of and rotatable with the rotor assembly. The impeller may be formed by an end ring above the rotor squirrel cage winding or, as shown, by vanes 29 attached thereto. The stator assembly is supported onaxial bars 43 in the chamber 38 and is immersed in the liquid up to a level (59) Fig. 1, the gap liquid being fed from the chamber to the cavity 48 by a tube 50 and the stator assembly cooling liquid boiling off during heat transfer. At the-other end of the rotor are coolant distributing vanes 29a which it is stated have little pumping effect. Vaporized rotor assembly coolant exits either through pipes 55, 56, or passages 67, 68 to the chamber 38, to be recirculated.