Shaft seal device and rotary machine

Patent metadata

Field	Value
Publication number	US-9677669-B2
Application number	US-201414769241-A
Country	US
Kind code	B2
Filing date	Feb 13, 2014
Priority date	Feb 22, 2013
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Disclosed is a shaft seal device comprising: a seal body made by layering a plurality of thin-plate seal pieces in the circumferential direction of the rotor, and a housing that is fixed to the stator, holds the seal body so as to surround the same from radially outside, and includes a first facing surface that faces the high-pressure-side edge of the seal body and a second facing surface that faces the low-pressure-side edge of the seal body. The high-pressure-side clearance between the seal body and the first facing surface is smaller than the low-pressure-side clearance between the seal body and the second facing surface, and a slope part that slopes gradually toward the high-pressure side toward the tip end, which is on the rotor side, is formed in the low-pressure-side edge of each thin-plate seal piece of the seal body.

First claim

The invention claimed is:

1. A shaft seal device that partitions a space between a rotor and a stator into a high-pressure side and a low-pressure side, the shaft seal device comprising:
a seal body that includes a plurality of thin-plate seal pieces extending toward the rotor from the stator and laminated in a circumferential direction of the rotor; and
a housing that is fixed to the stator and holds the seal body so as to surround the seal body from the outside in a radial direction, and includes a first facing surface facing a high-pressure-side edge of the seal body and a second facing surface facing a low-pressure-side edge of the seal body,
wherein the housing has a stepped portion at a tip side of a low-pressure-side side wall of the housing and at a radially inner end portion of the low-pressure-side side wall, the stepped portion being spaced apart from the seal body in a direction of an axis of the rotor,
a high-pressure-side clearance between the seal body and the first facing surface is set to be smaller than a low-pressure-side clearance between the seal body and the second facing surface,
a slope part, which gradually slopes to the high-pressure side toward a tip close to the rotor, is formed at the low-pressure-side edge of each thin-plate seal piece of the seal body, and
the tip side of the stepped portion slopes along the slope part of a thin-plate seal piece, and is formed so that a gap between the stepped portion and the slope part of the thin-plate seal piece is constant.

2. The shaft seal device according to claim 1 ,
wherein the slope part is formed from the tip to a position corresponding to an end of the second facing surface close to the rotor.

3. The shaft seal device according to claim 1 ,
wherein a high-pressure-side side plate, which defines the high-pressure-side clearance, is mounted on the high-pressure-side edge.

4. A rotary machine that includes the shaft seal device according to claim 1 .

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Uehara Hidekazu
• Nishimoto Shin
• Shinohara Tanehiro
• Oyama Hiroharu

Classifications

• F16J15/3292 Primary

  Lamellar structures · CPC title

• F01D11/001

  for sealing space between stator blade and rotor · CPC title

• F05D2240/59

  Lamellar seals · CPC title

• F16J15/44 Primary

  Free-space packings · CPC title

• F02C7/28

  Arrangement of seals · CPC title