Abstract: A method for testing a motor having a rotor and a winding is provided. The method includes steps of (a) providing a power to rotate the rotor to a predetermined speed, (b) removing the power, (c) measuring a terminal voltage of the winding while a current within the winding is zero, (d) obtaining a back electromotive force in the winding by compensating the terminal voltage with a performance of the rotor, (e) selecting a characteristic of the back electromotive force and (f) determining a magnetization of the motor by comparing the characteristic with a predetermined parameter.

Abstract: A rotary structure of a permanent magnet electric machine including a stator and a rotor is provided. The stator has K salient teeth peripherally spaced with equal intervals for forming K winding slots, wherein K is a natural number greater than 1. The rotor has an annular inner surface and has P pairs of permanent magnets peripherally spaced with equal intervals along the inner surface for rotating around the stator, wherein P is a natural number. Each permanent magnet having two sides along a peripheral direction of the rotor includes a pair of inclined surfaces on the two sides, the pair of inclined surfaces is symmetric with respect to a radial plane of the each permanent magnet, and an inclined angle ? between the inclined surface and the radial plane is selected from a range of 90(1?1/(4P))<?<90(1+1/(4P)).

Abstract: A rotary structure of a permanent magnet electric machine including a stator and a rotor is provided. The stator has K salient teeth peripherally spaced with equal intervals for forming K winding slots, wherein K is a natural number greater than 1. The rotor has an annular inner surface and has P pairs of permanent magnets peripherally spaced with equal intervals along the inner surface for rotating around the stator, wherein P is a natural number. Each permanent magnet having two sides along a peripheral direction of the rotor includes a pair of inclined surfaces on the two sides, the pair of inclined surfaces is symmetric with respect to a radial plane of the each permanent magnet, and an inclined angle ? between the inclined surface and the radial plane is selected from a range of 90(1?1/(4P))<?<90(1+1/(4P)).

Abstract: A method for testing a motor having a rotor and a winding is provided. The method includes steps of (a) providing a power to rotate the rotor to a predetermined speed, (b) removing the power, (c) measuring a terminal voltage of the winding while a current within the winding is zero, (d) obtaining a back electromotive force in the winding by compensating the terminal voltage with a performance of the rotor, (e) selecting a characteristic of the back electromotive force and (f) determining a magnetization of the motor by comparing the characteristic with a predetermined parameter.

Abstract: An rotor and stator structure of a motor is provided. The rotor structure includes a rotation axis and a magnet encircling the rotation axis. The magnet is magnetized radially or axially. The stator structure includes a sleeve, a first ring positioned on one opening of the sleeve, and a second ring positioned on the other opening of the sleeve. N pieces of first salients and N pieces of second salients are spacedly and coplanarly extended from the first ring and the second ring respectively, and the position of each piece of the first salients corresponds to that of each piece of the second salients.

Abstract: An rotor and stator structure of a motor is provided. The rotor structure includes a rotation axis and a magnet encircling the rotation axis. The magnet is magnetized radially or axially. The stator structure includes a sleeve, a first ring positioned on one opening of the sleeve, and a second ring positioned on the other opening of the sleeve. N pieces of first salients and N pieces of second salients are spacedly and coplanarly extended from the first ring and the second ring respectively, and the position of each piece of the first salients corresponds to that of each piece of the second salients.