GB290043A - Improvements in alternating current induction motors - Google Patents

Abstract

290,043. British Electric Plant Co., Ltd., Maudling, A. W., and Clarke, H. B. May 12,1927. Armatures and field magnets, cooling; motors, cooling; insulation.-An alternating current, induction motor has an enclosed stator and an open rotor provided with a fan for circulating cooling air through it, the stator windings being enclosed in air or solid insulating compound, ventilating air ducts being provided in the stator so disposed that the air passing therethrough cannot come in contact with stator windings. The rotor B is of the squirrel cage type and air is drawn through by a fan D mounted on the shaft. The stator is formed with axial passages E through which air is drawn by the fan. The end windings F are entirely enclosed by metal sheaths H fitting tightly in grooves in thickened end plates J of the stator core and drawn up tightly by bolts P, a hard setting adhesive being applied to the abutting surfaces. The slot portions of the windings Fare enclosed in waterproof insulating tubes K, the ends of the tubes are sealed with an insulating waterproof compound, and the slot openings and the ends of the slots are sealed with suitable cement. The chambers G may be filled with insulating compound or retained as air enclosures in which case a drain pipe M, M' and an opening M<2> are provided for the discharge of any water that may collect in the chambers. Specification 221,838 is referred to.