Shaft sealing mechanism

Patent metadata

Field	Value
Publication number	US-10196987-B2
Application number	US-201515536352-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 16, 2014
Publication date	Feb 5, 2019
Grant date	Feb 5, 2019

Abstract

A shaft sealing mechanism (11) that partitions an annular space (14) that is formed between a fixed part (12) and a rotating shaft (13) into a high-pressure-side region and a low-pressure-side region, that obstructs the flow of a fluid (G), and that is provided with: a plurality of annularly laminated thin-plate seal pieces (22) that are fixed to an annular seal housing (21) that is provided to the fixed part and are in sliding contact with the rotating shaft; and an annular low-pressure-side plate (26) that is sandwiched and held such that a low-pressure-side gap (δL) is formed between the seal housing and a low-pressure-side side edge part (22d) of the thin-plate seal pieces. The thin-plate seal pieces have pressure-conduction holes (31) that are formed further to the inside in the radial direction of the rotating shaft than an inner-circumferential-side tip part (26a) of the low-pressure-side plate.

First claim

The invention claimed is:

1. A shaft sealing mechanism that, by being disposed in an annular space formed between a fixed part and a rotating shaft, partitions the annular space into a high-pressure-side region and a low-pressure-side region to prevent fluid from flowing from the high-pressure-side region toward the low-pressure-side region in the annular space in a direction of the rotating shaft, characterized in that the shaft sealing mechanism comprises:
an annular seal housing disposed at an inner circumferential portion of the fixed part;
a plurality of thin-plate seal pieces stacked and disposed annularly in a circumferential direction of the rotating shaft, each of which has an outer-circumferential-side proximal end fixed to the seal housing, an inner-circumferential-side distal end being a free end and forming an acute angle with an outer circumferential surface of the rotating shaft, and a width dimension in the direction of the rotating shaft; and
an annular low-pressure-side plate held between the seal housing and low-pressure-side side edges of the thin-plate seal pieces facing the low-pressure-side region so as to form a gap between the low-pressure-side side edges and the seal housing in the direction of the rotating shaft, wherein
each of the thin-plate seal pieces has a pressure conduction hole which is formed on an inner side of an inner-circumferential-side distal end of the low-pressure-side plate in a radial direction of the rotating shaft and alongside the low-pressure-side side edge, and allows the fluid flowing on an upper surface side of the thin-plate seal piece and the fluid flowing on a lower surface side of the thin-plate seal piece to pass therethrough.

2. The shaft sealing mechanism according to claim 1 , characterized in that
the pressure conduction hole is formed alongside the inner-circumferential-side distal end of the thin-plate seal piece.

3. The shaft sealing mechanism according to claim 1 , characterized in that
hole positions of the pressure conduction holes formed in the thin-plate seal pieces adjacent in the circumferential direction of the rotating shaft are shifted from each other.

4. The shaft sealing mechanism according to claim 1 , characterized in that
thin-plate seal pieces having no pressure conduction hole are arranged intermittently in the circumferential direction of the rotating shaft.

Assignees

• Mitsubishi Hitachi Power Sys

Inventors

• Ozaki Kohei
• Uehara Hidekazu
• Yoshida Azumi
• Oyama Hiroharu

Classifications

• F01D11/003

  by packing rings; Mechanical seals · CPC title

• F05D2240/59

  Lamellar seals · CPC title

• F04D29/10

  Shaft sealings · CPC title

• F05D2240/57

  Leaf seals · CPC title

• F16J15/22 Primary

  shaped as strands, ropes, threads, ribbons, or the like · CPC title