To prevent thrust load from increasing in accordance with an increase in the number of rotations.
A winding type upper stator (50) and a non-winding type lower stator (60) are oppositely arranged on both sides in an axial direction of a rotor (70). Permanent magnet structures (80) are stored in a plurality of holder chambers (75) formed in a circumferential direction of the rotor (70). An inclination plate (91) having an inclination face (91a) which approaches the upper stator (50) as it goes to an external side in a radial direction is arranged in a lower part of the holder chamber (75). The permanent magnet structure (80) is constituted so that the inclination plate (91) can slide in the radial direction. An electromagnet (92) for attracting the permanent magnet structure (80) is arranged in a boss part (72) corresponding to each permanent magnet structure (80). When the number of rotations of the rotor (70) increases and centrifugal force exceeds the suction force of the electromagnet (92), the permanent magnet structure (80) slides and moves to the external side in the radial direction. The structure deforms upward with movement and approaches the upper stator (50).
Hiroshi Takeuchi
Takahisa Shimada
Yuji Takeuchi
Katsumi Imae
Kazunari Ninomiya
Tomoo Harada
Iseki Katsumori
Seki Kei
Yasuya Sugiura