| 摘要 |
A steam turbine wheel has a male dovetail projecting about its peripheral margin and a gap in the margin. Buckets having bases with complementary female dovetails are disposed in the gap and register with the male dovetail of the wheel, enabling the buckets to slide about the wheel into positions stacking the bases of the buckets against one another. The final three buckets including a closure bucket are disposed about the wheel margin with two buckets straddling the closure bucket secured to the wheel margin by the dovetails. The closure bucket is secured to the straddling buckets by axially extending pins. The closure and straddling buckets, as well as the pins, are formed of materials having a higher creep rupture strength than the materials forming the remaining buckets, enhancing the capability of the closure bucket to withstand high temperature and stresses over time without creep.
|
