To solve the problems that an airfoil part or a bucket used in a steam turbine receives harmonic excitation from a multiple generation sources during operation of the steam turbine and there is a risk causing large scale resonance in the bucket at a harmonic excitation frequency matching with natural frequency of the bucket, and that there is a risk that the resonance causes high cycle fatigue in the bucket with the passage of time and that that becomes one of the reasons shortening effective use life of the bucket.
The turbine assembly comprises a rotor wheel 14 provided with at least one dove-tail slot formed therein, at least two buckets 16 comprising an axial direction insertion dove-tail 22, a tip 34 and the airfoil part 30 extending therebetween respectively, and a bucket cover 42. Each of at least two buckets is connected to a rotor wheel via the dove-tail slot. The bucket cover is connected to the tip of at least two buckets to substantially circumscribe wheel rotor.
EMETERIO ELOY VINCENT
DEALLENBACH ROBERT EDWARD
| JPS5214110A | 1977-02-02 |
| US3572968A | 1971-03-30 | |||
| US1129920A | 1915-03-02 | |||
| US3367629A | 1968-02-06 |
Hirokazu Ogura
Toshihisa Kurokawa
Arakawa Satoshi