Seal ring for steam turbine

Abstract

Seal ring provided between rotating portion and fixed portion in rotating machine of steam turbine and the like is improved to carry out predetermined movement accurately so as not to cause deterioration of sealing performance. Seal ring is split into upper, lower, right side and left side seal ring pieces 1a, 1b, 1c, 1d, contacting slidably with each other via split planes 3a, 3b, 3c, 3d with spaces 9a, 9b, 9c, 9d being formed in the respective split planes. Springs 4a, 4b, 4c, 4d are interposed in the spaces 9a to 9d for activation in upward and downward directions. The upper and lower seal ring pieces 1a, 1b are engaged with seal ring guides 5a, 5b and 6a, 6b and the right side and left side seal ring pieces 1c, 1d are engaged with seal ring guides 7, 8 so that all of the seal ring pieces 1a to 1d are slidable in the upward and downward directions. Further, on the respective tips of the seal ring guides 5a, 5b and 6a, 6b, spaces 10a, 10b of the upper seal ring piece 1a and spaces 10c, 10d of the lower seal ring piece 1b are formed and springs 11a, 11b, 11e, 11d are provided in the spaces 10a to 10d for activation in the upward and downward directions. The respective seal ring pieces are prevented from skirmishing with each other and the upper and lower seal ring pieces move toward the inner side at the time of load so as to make narrower the clearances between seal fins 2a, 2b and corresponding rotor surface.

Description

Technical field [0001] The present invention relates to a seal ring used between rotating parts of a rotating machine such as a steam turbine. technical background [0002] In a rotating machine such as a steam turbine, for example, between the rotating circumferential surface divided by the tip of the rotor and the blade holding ring, or between the tip of the inner circumferential side of the stator and the rotor surface opposite to it, in order to connect the rotating part with A sealing comb is arranged between the opposed fixed parts for sealing, and a sealing ring supporting the sealing comb is provided. [0003] image 3 Is a schematic diagram of an existing representative seal ring. image 3 In the circumferential direction, divided pieces 21a, 21b, 21c, 21d divided into 4 pieces up, down, left, and right are arranged. In the horizontal direction, the divided pieces 21c are arranged on the left and right seal rings with support parts 23 and 24. , 21d is fixed, between the ...

AI Technical Summary

Problems solved by technology

Therefore, the urging direction of the spring 22 is inconsistent with the moving direction, and the end faces of the adjacent split pieces 21a, 21b, 21c, and 21d are separated from each other on the prescribed moving locus, and engaged abnormally, resulting in the so-called mutual interference phenomenon of the split pieces. Tablets may be stuck (occurrence of biting phenomenon)

[0005] Moreover, if such a stuck phenomenon occurs, the gap between the rotor and the rotating body will increase, causing air leakage, and there is a disadvantage that the sealing performance will be lowered.

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