JPS6412846A - Armature winding - Google Patents

Abstract

PURPOSE:To switch the number of poles with the same windings by so disposing coils that a coil pitch of small number of poles becomes near the pole pitch of the small number of poles and a coil pitch of large number of poles become near the odd number of magnification of the pole pitch of large number of poles. CONSTITUTION:In case of 3-phase 4-poles, the ratio of a coil pitch to a pole pitch (36 slots/4 poles) becomes 0.889 near 1. Accordingly, a fractional pitch winding coefficient becomes 0.985, and 4-pole basic waves less decrease. The number of slots per one pole and one phase becomes 3. In case of 3-phase 32 poles, the connections of the coils are altered, and the ratio of the coil pitch to the pole pitch of 1.12 (36 slots/32 poles) becomes 7.11 near 7 of odd number. Accordingly, its fractional pitch winding coefficient becomes -0.985, and 32-pole basic waves less decrease. The number of slots per one pole and one phase becomes 3/8. Thus, the pole change of large pole number ratio can be performed by altering the connections of the coils.