| 摘要 |
PURPOSE:To increase the thermal resistance of the shaft of a rotor by increasing the diameter of the said shaft, which supports a target, from the target to the shoulder of the rotor. CONSTITUTION:The diameter of a shaft 2a of a rotor 2 becomes smaller from a shoulder 2b of the rotor 2 to a target 1. The shape of the above shaft 2a is not limited to one straight line, but may be a shape formed by connecting not less than two straight lines. In addition, the shaft 2a may be formed so that it has a hollow center. As a result, the mean sectional area of the shaft 2a of the rotor 2, which develops the maximal bending stress equal to that of the conventional structure, becomes about 70% that of the conventional structure. Conseqneutly, the thermal resistance of the shaft 2a can be increased. |
