1 A rotor core diameter size is too small or the stator core diameter size is too large, and the stator, the rotor core axial offset the low magnetic properties of electrical steel sheet, will result in no-load current increases, the power factor is reduced.

    2 stator, the rotor core press-fit of poor quality, the net core length, caused by the no-load current and iron loss increases, power factor and efficiency.

    3 The chute of the rotor 3 is too large, The rotor cores stacked unevenness, the notch size is reduced, will result in the rotor slot leakage reactance increases, the reactance of the current increases, the power factor, the maximum torque and the starting torque is reduced.

    4 stator punching burr is too large, the stator lamination surface insulation of poor quality or press-fit pressure is too large, the unit of electrical steel sheet loss on the high side, it will cause the iron loss increases, the efficiency decreases, temperature increased.

    5 when the winding tension is too large, so that the diameter of the wire is thinner, the stator winding resistance increases, the rotor consumption of aluminum is increased, reduced efficiency, increased temperature.