Abstract: The invention relates to a method of manufacturing a rotor for performing a magnetizing process of magnetizing a plurality of magnet materials that are assembled in a rotor core. A magnetization device is used which has a coil group configured of a plurality of coils that are disposed side by side in a manner that winding directions of adjacent coils are opposite to each other, the coil group is configured of sub coils at both ends and two or more main coils between the sub coils, and all of the coils are connected in series. Further, in the magnetizing process, a partial magnetization of magnetizing the magnet material among the plurality of magnet materials to which magnetic flux interlinking with two adjacent main coils is applied is performed a plurality of times, so as to magnetize all the plurality of magnet materials.

Abstract: The present inventions provides a magnetizing apparatus 100 for magnetic particle testing of a wheel 7 that includes a hub 71, a plate 72, and a rim 73 in sequence from inward to outward in a radial direction of the wheel. The apparatus includes: a conductor 1 inserted through a bore 711 of the hub 71; and a pair of auxiliary conductors 2 connected to respective opposite end portions of the conductor 1, and so disposed as to face respective opposite side surfaces of the wheel 7, and to extend from the hub 71 to the rim 73 outwardly in a radial direction of the wheel 7, wherein the pair of auxiliary conductors 2 and the conductor 1 are energized with alternating current.

Abstract: The invention relates to a method of manufacturing a rotor for performing a magnetizing process of magnetizing a plurality of magnet materials that are assembled in a rotor core. A magnetization device is used which has a coil group configured of a plurality of coils that are disposed side by side in a manner that winding directions of adjacent coils are opposite to each other, the coil group is configured of sub coils at both ends and two or more main coils between the sub coils, and all of the coils are connected in series. Further, in the magnetizing process, a partial magnetization of magnetizing the magnet material among the plurality of magnet materials to which magnetic flux interlinking with two adjacent main coils is applied is performed a plurality of times, so as to magnetize all the plurality of magnet materials.

Abstract: The present inventions provides a magnetizing apparatus 100 for magnetic particle testing of a wheel 7 that includes a hub 71, a plate 72, and a rim 73 in sequence from inward to outward in a radial direction of the wheel. The apparatus includes: a conductor 1 inserted through a bore 711 of the hub 71; and a pair of auxiliary conductors 2 connected to respective opposite end portions of the conductor 1, and so disposed as to face respective opposite side surfaces of the wheel 7, and to extend from the hub 71 to the rim 73 outwardly in a radial direction of the wheel 7, wherein the pair of auxiliary conductors 2 and the conductor 1 are energized with alternating current.

Abstract: A motor speed control system takes one approach to establish dummy load models having characteristics equivalent to an electric motor to be controlled. One of the dummy load models is established for feedback controlling the electric motor on the basis of the speed of the dummy model. The dummy model is divided into first and second models. The first model is designed to have equivalent characteristics to output a first motor speed representative data. The current to supply to the first model is so adjusted as to reduce a difference between the motor speed representative data and a desired motor speed data to zero. A frequency signal is added to the current applied to the first model and supplied to the electric motor to drive the latter. The second model receives the frequency signal to output a frequency signal dependent second motor speed representative value.