Abstract: A single-phase permanent magnet synchronous motor and dust collector. The single-phase permanent magnet synchronous motor includes a plurality of stator teeth, the plurality of stator teeth include at least: a first-type and second-type stator tooth; the first-type and second-type stator teeth enclose an annular working cavity for accommodating a rotor part, where the size of a central angle corresponding to a first contour line of an end face of the first-type stator tooth facing the rotor part is different from the size of a central angle corresponding to a second contour line of an end face of the second-type stator tooth facing the rotor part The motor has a significantly reduced cogging torque, a greatly reduced torque ripple, and an obviously increased motor output torque. The single-phase permanent magnet synchronous motor is small in size, light in weight, simple in structure, convenient for large-scale manufacture and low in manufacturing cost.

Abstract: Disclosed are a rotor assembly and an alternating-pole motor. The rotor assembly includes a rotor core including permanent magnetic poles and alternating poles that are arranged alternately in a circumferential direction, each permanent magnetic pole includes a mounting groove, a permanent magnet is mounted in the mounting groove, polarities of the permanent magnets facing an outer periphery of the rotor core are the same, both ends of the mounting groove are respectively provided with a second air slot, the second air slot includes a slot body and a first extension part and a second extension part that are extended from the slot body to a center line of a magnetic pole, and the first extension part and the second extension part are sequentially disposed to form a stepped slot with a decreasing radial thickness.