Abstract: A permanent-magnet spindle motor includes a rotor in which a plurality of magnet units have a specific spatial configuration that results in a concentrated magnetic flux and consequently a high rotation speed. Each magnet unit has two first magnets and two magnetic barrier spaces, wherein the first magnets are provided in the tubular rotating shaft of the rotor mirror-symmetrically with respect to an axis of mirror symmetry defined by a diameter of the rotating shaft, and wherein each of the magnetic barrier spaces is formed as a hole, penetrates the rotating shaft along the axial direction thereof, is open at the two axial ends of the rotating shaft, is located between the outer periphery of the rotating shaft and one of the first magnets, and is adjacent to the distal end (with respect to the axis of mirror symmetry) of the one of the first magnets.

Abstract: A permanent-magnet spindle motor includes a rotor in which a plurality of magnet units have a specific spatial configuration that results in a concentrated magnetic flux and consequently a high rotation speed. Each magnet unit has two first magnets and two magnetic barrier spaces, wherein the first magnets are provided in the tubular rotating shaft of the rotor mirror-symmetrically with respect to an axis of mirror symmetry defined by a diameter of the rotating shaft, and wherein each of the magnetic barrier spaces is formed as a hole, penetrates the rotating shaft along the axial direction thereof, is open at the two axial ends of the rotating shaft, is located between the outer periphery of the rotating shaft and one of the first magnets, and is adjacent to the distal end (with respect to the axis of mirror symmetry) of the one of the first magnets.

Abstract: An angular position sensing device for detecting angular position of a rotor of a motor includes a first resolver that includes an annular rotor, an annular stator, a plurality of excitation coils and four induction coils. The annular stator has a stator annular body, and a plurality of stator magnetic poles. One of the annular rotor and the annular stator surrounds the other one of the annular rotor and the annular stator. The excitation coils are respectively wound on the stator magnetic poles of the annular stator. The induction coils are respectively wound on four of the stator magnetic poles.

Abstract: An interior permanent magnet electric machine including a stator, a rotor, a plurality of magnet units and a plurality of divisions is provided. The magnet units are contained within the slots of the rotor. Each magnet unit includes at least two magnets, and the divisions are configured between the neighboring magnets to separate the magnets such that the magnetic distribution is enlarged and the torque ripple is decreased.