| 摘要 |
PROBLEM TO BE SOLVED: To provide a rotor shaft for preventing occurrence of crack or breakage even if an excessive torque is applied.SOLUTION: The rotor shaft 3 used for a rotor 2 of a rotating electric machine 1 has an inner shaft 4 and an outer shaft 5 disposed on the outer circumference of the inner shaft 4. The outer shaft 5 has a cylindrical part 51 for inserting and fitting the inner shaft 4 and an iron core attaching part 53 for attaching an iron core 54 forming a magnetic circuit. The inner shaft 4 and the outer shaft 5 are fastened to each other by a frictional force in contact surfaces 61 of both. A static friction moment as a product of a statistic frictional force in the contact surfaces 61 and the inner circumferential radius of the cylindrical part 51 is larger than the maximum drive torque applied to the rotor shaft 3 in driving, and smaller than a breakdown strength torque applied to a weakest part 39 when the weakest part 39 having the weakest breakdown strength in the rotor shaft 3 is broken. |
