| 摘要 |
PROBLEM TO BE SOLVED: To provide a fan motor having two-pole to for-pole switch function without increasing no-load current (exciting current) even if a two-pole operation is switched to a four-pole operation, and a method for switching a speed of the motor. SOLUTION: Three-phase star-connected armature coils of the fan motor are equivalently divided into two halves. Terminals A, X1, X2, B, Y1, Y2, C, Z1, Z2 are provided at coil ends except start-connecting part N of the respective coils, and the coils divided into two halves are engaged with slots for symmetrical two-pole formed at three-phase four-pole at respective phases A, B and C. Further, the method for switching speeds of the motor of the above structure comprises the steps of connecting each two exciting coils A1, A2, B1, B2, and C1, C2 of the respective phases A, B and C in series in the case of two-pole drive, or inverting connections of external coils A1, B1 and C1 of the exciting coils A1, A2, B1, B2 and C1, C2 divided into two halves in the case of four-pole drive, and switching connection of powers of two-phase exciting coils. |
