Patent ID: 8866359

Claim:
A brushless motor, comprising: a stator comprising a stator core and windings, the stator core comprising a plurality of salient poles each of which extends inwardly, the windings being wound about the salient poles; and a rotor comprising a shaft, a rotor core fixed onto the shaft, and magnets fixed in the rotor core to form four magnetic poles, the rotor being rotatably mounted to the stator, wherein each of the salient poles comprises a pole shoe extending along a circumferential direction of the rotor and having a pole face confronting the rotor core and being spaced from the rotor core by an air gap; wherein each of the magnetic poles is formed by a plurality of permanent magnets inserted in the rotor core and arranged at least in an inner layer and an outer layer, the inner layer is closer to the shaft than the outer layer, the permanent magnets in the inner layer are spaced from the permanent magnets in the outer layer; wherein for each of the magnetic poles, the permanent magnets in the outer layer consists of two permanent magnets forming a “V” open outwardly in a cross section of the rotor core, and the permanent magnets in the inner layer comprises three permanent magnets forming a truncated “V” open outwardly in a cross section of the rotor core; wherein each of the magnetic poles comprises a pair of first permanent magnets and a second permanent magnet in the inner layer, the first permanent magnets in the inner layer are respectively located at two circumferential sides of the magnetic pole in radial directions of the rotor core and is shared mutually by two adjacent magnetic poles, and the second permanent magnet extends between radially inner ends of the pair of first permanent magnets in the inner layer; wherein the second permanent magnets have a thickness equal to a thickness of each of the pair of first permanent magnets in the inner layer; and wherein the second permanent magnets of the four magnetic poles are respectively located at four sides of a square.