Shaft seal mechanism and rotary machine provided with same

Patent metadata

Field	Value
Publication number	US-9841109-B2
Application number	US-201113818190-A
Country	US
Kind code	B2
Filing date	Oct 26, 2011
Priority date	Oct 27, 2010
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

A shaft seal structure capable of preventing a seal body of the shaft seal structure of a rotation body from being held in an inclined posture even when the seal body is inclined is provided. It includes, an accommodation body ( 9 ), a seal body ( 12 ) including thin plate seal pieces ( 20 ), and a plate body ( 17 ) covering one end in the axial direction ( 20 d ) of the seal body ( 12 ). A recessed portion ( 31 ) recessing in the axis direction, and a protruding portion projecting to the other side from the recessed portion ( 31 ) are formed on one of the plate surface ( 17 c ) of the plate body ( 17 ) and the inner wall surface ( 9 e ) of the accommodation body ( 9 ). When the protruding portion abuts the other side and a pocket (X), the recessed portion ( 31 ) communicates with the pocket (X) and the fluid low pressure region.

First claim

The invention claimed is:

1. A shaft seal mechanism for sealing a gap between a stator and a rotor of a rotary machine, and dividing the gap into a fluid low pressure region on one side of the rotor in an axial direction and a fluid high pressure region on another side of the rotor in the axial direction, the shaft seal mechanism comprising:
a housing provided in the stator and having an accommodation space extending in a circumferential direction of the rotor, the accommodation space opening toward an outer circumference of the rotor; and
a seal segment loosely accommodated in the accommodation space and moveable therein in both the axial direction and a radial direction, wherein
the seal segment includes:
a seal body including a plurality of thin plate seal pieces that overlap each other in the circumferential direction of the rotor, the seal body being accommodated in the accommodation space and extending toward the outer circumference of the rotor through the opening of the accommodation space;
a side seal plate located between the seal body and an inner wall surface of the housing at the one side of the seal body in the axial direction, the side seal plate having a plate surface that faces away from the thin plate seal pieces and faces toward the inner wall surface of the housing; and
a recessed-protruding portion formed on one of the plate surface of the side seal plate and the inner wall surface of the housing, the recessed-protruding portion including a recessed portion formed from a radially inward side toward a radially outward side and recessed to one side in the axial direction, the recessed portion including at least one radial groove extending in the radial direction, and at least one protruding portion projecting in the axial direction with respect to the radial groove, and at least a portion of the radial groove extending to be between the side seal plate and the housing,

wherein the shaft seal mechanism is configured so that, when the seal segment inclines such that a radially inner end of the side seal plate linearly contacts the inner wall surface of the housing via the protruding portion, a pocket is formed between the plate surface of the side seal plate and the inner wall surface of the housing that communicates with the fluid low pressure region through the radial groove.

2. The shaft seal mechanism according to claim 1 , further comprising:
a projecting part which is formed at a radially outward side on the one of the plate surface of the side seal plate and the inner wall surface of the housing and which projects in the axial direction with respect to the radial groove,
wherein the projecting part blocks off a connection between the fluid high pressure region and the fluid low pressure region by tightly abutting to another of the plate surface of the side seal plate and the inner wall surface of the housing when the plate surface is pressed to the inner wall surface of the housing.

3. The shaft seal mechanism according to claim 1 ,
wherein the recessed-protruding portion further includes a circumferential groove located at a radially outward side from the radial groove, the circumferential groove extending in the circumferential direction, communicating with the radial groove, and being located between the side seal plate and the housing.

4. The shaft seal mechanism according to claim 1 ,
wherein the radial groove and the protruding portion are formed only on the plate surface of the side seal plate.

5. The shaft seal mechanism according to claim 1 ,
wherein the radial groove and the protruding portion are formed only on the inner wall surface of the housing.

6. A rotary machine comprising the shaft seal mechanism according to claim 1 .

7. The shaft seal mechanism according to claim 2 ,
wherein the recessed-protruding portion further includes a circumferential groove located at the radially outward side from the radial groove, the circumferential groove extending in the circumferential direction, communicating with the radial groove, and being located between the side seal plate and the housing.

8. The shaft seal mechanism according to claim 1 , wherein
the radial groove is a plurality of radial grooves and the protruding portion is a plurality of protruding portions,
the radial grooves and the protruding portions are formed on the inner wall surface of the housing, and
the protruding portions are formed to be continuous in the circumferential direction in the radially inward side thereof.

9. The shaft seal mechanism according to claim 3 , wherein the circumferential groove is formed on the one of the plate surface of the side seal plate and the inner wall surface of the housing.

10. The shaft seal mechanism according to claim 3 , wherein the circumferential groove is formed on another of the plate surface of the side seal plate and the inner wall surface of the housing.

11. The shaft seal mechanism according to claim 1 ,
wherein the radial groove is a plurality of radial grooves and the protruding portion is a plurality of protruding portions.

Assignees

• Uehara Hidekazu
• Shinohara Tanehiro
• Nishimoto Shin
• Nakano Takashi
• Araki Masato
• Takahashi Tatsuji
• Mitsubishi Heavy Ind Ltd

Inventors

• Uehara Hidekazu
• Shinohara Tanehiro
• Nishimoto Shin
• Nakano Takashi
• Araki Masato
• Takahashi Tatsuji

Classifications

• F16J15/447 Primary

  Labyrinth packings · CPC title

• F05D2240/57

  Leaf seals · CPC title

• F16J15/3292

  Lamellar structures · CPC title

• F01D11/025 Primary

  Seal clearance control; Floating assembly; Adaptation means to differential thermal dilatations · CPC title

• F01D11/00

  Preventing or minimising internal leakage of working-fluid, e.g. between stages (sealings in general F16J {; sealing arrangements for transition ducts of combustor cans F01D9/023}) · CPC title