| 摘要 |
PURPOSE:To prevent stress corrosion cracks in a wheel in a device in which a plurality of wheels provided with a plurality of blades are fitted onto and arranged axially of a shaft, by forming, on the inner peripheral surface of each wheel, a key part having a convex section fitted in a key groove in a shaft. CONSTITUTION:A key part 5 having a convex section is integrally incorporated with the inner peripheral surface of a wheel 2 fitted onto a shaft 3. This key part 5 is formed in the substantially axial-middle part of the inner peripheral surface of the wheel 2, and the axial end faces 6 of the key part 5 are connected with the inner peripheral surface of the wheel 2 by means of arcs 7. Further, both radial side surfaces 8 of the key part 5 are also connected to the inner peripheral surface of the wheel 2 by means of arcs 9. The key part 2 is fitted into a key groove 10 formed in the outer peripheral surface of the shaft 3. That is, the shaft 3 is formed with a stepped part 11 having a difference W in level at a distance corresponding to the axial width of the wheel 2. A key groove 10 having a depth less than the difference W is formed from the side surface of the stepped part 11 in the axial direction. With this arrangment, the provision of key groove in the wheel 2 may be eliminated. |
