Single phase brushless motor

A single phase brushless motor comprising:

• a stator, the stator comprising a stator core and stator windings wound around the stator core, the stator core comprising a yoke portion, and a first pole portion and a second pole portion extending inwardly from the yoke portion, an end surface of the first pole portion comprising a first arc surface, the first arc surface comprising a first groove, an end surface of the second pole portion comprising a second arc surface, the second arc surface comprising a second groove, the first arc surface and the second arc surface being opposed to each other and defining a receiving space therebetween;
• and
• a rotor, the rotor comprising a rotary shaft and permanent magnetic poles fixed to the rotary shaft, the permanent magnetic poles being received in the receiving space formed between the first arc surface and the second arc surface,
• wherein major parts of the first arc surface and the second arc surface are located at a circle which is concentric with the rotor;
• and
• wherein circumferential ends of the first pole portion and the second pole portion are connected by a magnetic bridge or separated by a slot, an angle formed between a center line of the first pole portion and a line connecting a center of the rotor and a center of the magnetic bridge or the slot being less than 90 degrees.