20/2-POLE-CHANGING WINDING Russian patent published in 2001 - IPC

FIELD: electrical engineering; dual- speed motors. SUBSTANCE: all winding coils are assembled in 36 groups wound at coil pitch y = 5 with coil leads brought out from starts of phases and from points of connection of phase halves. First half of first phase incorporates coils numbered 1, 5, 8, -21, -24, -28; second half of first phase includes coils numbered -26, -23, -19, 10, 6, 3; first half of second phase has coils numbered 13, 17, 20, -33, -36, -4; second half of second phase includes coils numbered -2, -35, -31, 22, 6, 3; coils numbered 25, 29, 32, -9, -12, -16 are incorporated in first half of third phase and those numbered -14, -11, -7, 34, 30, 27, in second half of third phase; coil numbers bearing sign minus indicate their opposing connection. Applying voltage to leads 37, 39, 41 gives 20-pole arrangement with phase leads connected in star. Two-pole circuit is obtained by applying voltage to leads 38, 40, 42 and connecting leads 37,39, 41 to common neutral. Star-star connection of phase leads is used here. EFFECT: improved characteristics of magnetomotive forces of winding; improved winding factor. 5 dwg