| 摘要 |
PURPOSE:To mitigate stress of a key part and prevent a crack due to stress corrosion by forming an axial gap between a key part and a wheel shrunk part and further forming a radial gap between the inner peripheral face of the fitting hole of a wheel except the key part and the outer peripheral face of a shaft. CONSTITUTION:A wheel 2 is shrunk on a shaft 3 through a shrunk part 8, while a projection 9, acting as a key part provided on an inner peripheral face adjacent to the exit of a fitting hole for the wheel 2, is inserted in the key groove 6 of the shaft 3. Then a gap 11 is interposed between an axial end face 9b of the projection 9 and the shrunk part 8, and the projection 9 axially isolated from the shrunk part 8 due to the gap 11. Further, on both sides in circumferential direction of the projection 9, radial gaps 13 are interposed between the inner peripheral face of the shaft 3. This prevents the stress generated due to shrinkage, that is, the pressure of the shrunk face, from operating on the projection 9 and concentration of the stress in the projection 9 is mitigated. |
