| 摘要 |
PROBLEM TO BE SOLVED: To prevent unbalancing due to displacement to the axial center of a shaft of a rotor yoke even when the temperature of a revolution body is elevated by revoluton at high speed by forming a fitting hole having an inside diameter smaller than the outside diameter of the fitting section of the shaft and press-fitting and fixing the rotor yoke to the shaft. SOLUTION: This revolution body is constituted in such a manner that a fitting hole 21 having an inside diameter smaller than the outside diameter of the fitting section of a shaft is formed by three or more of projecting sections 20b arranged on the circumference of the fitting hole 21 of a rotor yoke 20 at equal intervals and the rotor yoke 20 is press-fitted and fixed to the shaft. Consequently, since the inner circumferential section of the fitting hole 21 is brought into contact uniformly and fixed onto the outer circumference of the fitting section of a fixed shaft, no clearance is formed between the fitting hole 21 of the rotor yoke 20 and the fitting section of the shaft. Accordingly, even when the temperature of the revolution body is elevated by rotation at high speed and the shaft and the rotor yoke 20 are thermally expanded in the radial direction, the rotor yoke 20 is displaced to the axial center of rotation, and the unbalancing of the revolution body is prevented. |
