Bucket assembly for replacing old bucket provided with turbine and method for replacing the same
AssigneeDoosan Heavy Industries Construction Co., Ltd
InventorSung Man Choi
Life of this patent
Estimating the term…
Abstract
A bucket assembly for replacing an old bucket is provided with a turbine and a method for replacing the same. The bucket to be replaced is removed and then the bucket assembly configured of a blade part, first and second dovetail members, and a coupling member is simply assembled in a male dovetail, without sequentially disassembling the already installed buckets though a notch opening upon replacing the damaged bucket among the already installed buckets in a tangential entry type dovetail, thereby shortening replacement time and replacement costs of the bucket assembly and preventing a secondary damage occurring to the rotor or the rotor wheel during the disassembling process.
Claims13
A bucket assembly for use in replacing an old bucket of a turbine among a plurality of installed bucket assemblies sequentially inserted in a tangential direction of a rotor through a notch opening formed in a male dovetail of the rotor, the bucket assembly comprising:
- a blade part having an inside end with respect to a radial direction of the rotor;
- a first dovetail member having an outside end with respect to the radial direction of the rotor and including
- a first coupling part formed at the outside end of the first dovetail member and configured to be coupled with the inside end of the blade part,
- an inner side surface in which a first female dovetail is formed in a shape corresponding to the male dovetail of the rotor,
- a first through hole penetrating the first dovetail member at a location between the first female dovetail and the first coupling part, and
- a stepped part formed at an outer end of the first through hole in an axial direction of the rotor, the stepped part having an inner circumference communicating with a concentric through hole that communicates with the outer end of the first through hole;
- a second dovetail member having an outside end in the radial direction of the rotor and including
- a second coupling part formed at the outside end of the second dovetail member and configured to be coupled with the inside end of the blade part in a state in which the second dovetail member faces the first dovetail member,
- an inner side surface in which a second female dovetail facing the first female dovetail is formed in a shape corresponding to the male dovetail of the rotor, and
- a second through hole penetrating the second dovetail member at a location between the second female dovetail and the second coupling part and aligning with the first through hole;
- and
- a coupling member configured to be inserted into the first through hole through the second through hole in order to fasten the first dovetail member with the second dovetail member, the coupling member including a tip portion configured to be inserted into the first through hole and to engage with the stepped part.
A method for replacing a bucket provided with a turbine, comprising:
- removing a damaged bucket from among a plurality of buckets provided in the turbine;
- first cutting a blade part of the damaged bucket in a horizontal direction following a horizontal line through the blade part of the damaged bucket adjacent to a dovetail groove of the blade part of the damaged bucket;
- second cutting the blade part of the damaged bucket in a vertical direction toward the dovetail groove, the second cutting beginning at a center of the horizontal line of the first cutting;
- disposing a blade part of a replacement bucket assembly between adjacent normal buckets;
- seating a first coupling part at one side of a fastening part protruding inwardly from an inside end in a radial direction of the blade part of the replacement bucket assembly and seating a first female dovetail at one side of a male dovetail to couple a first dovetail member thereto;
- seating a second coupling part at the other side of the fastening part and seating a second female dovetail at the other side of the male dovetail to couple a second dovetail member with the first dovetail member while facing the first dovetail member;
- and
- inserting a coupling member into a first through hole of the first dovetail member and a second through hole of the second dovetail member.
Dependencies are inferred from the claim text.