Patent ID: 7071592

Claim:
A rotor comprising a shaft and a magnetic body surrounding said shaft, said magnetic body comprising a plurality of protruding portions, a plurality of magnetic gaps respectively defined between each two adjacent protruding portions, and a plurality of magnets respectively fixedly covered on said protruding portions, wherein said protruding portions are alternately arranged in two rows around the periphery of said magnetic body, the magnetic gaps of one row being offset with respect to the magnetic gaps of the other row so that the protruding portions of one row block one end of each of the magnetic gaps in between each two adjacent protruding portions of the other row, each of said magnets having a semicircular cross-sectional contour, the magnets at the protruding portions of one row each having one end respectively abutted against the magnets at the protruding portions of the other row to form a magnetic line of force blocking structure between the two rows of the magnets at the two rows of the protruding portions.