# US 2014/0191475 A1 · Interlocking hole pattern seal

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 2014/0191475 A1
- Document ID: US20140191475A1
- Status: Published application
- Kind: A1
- Application number: 14/005,592
- Filed: 2012-03-23
- Published: 2014-07-10
- Earliest claimed: 2011-03-24
- Assignees: Dresser-Rand Company
- Inventors: Manoj K. Gupta; Steven Nove; Thomas Soulas; Krishnaswamy Ramesh; Glenn Grosso
- Web page: https://patentgrep.com/patent/US20140191475A1

## CPC

- F01D 11/02: by non-contact sealings, e.g. of labyrinth type (for sealing space between rotor blade tips and stator F01D11/08)
- F16J 15/4472: {with axial path}
- F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D)
- F16J: PISTONS {(specially adapted for dampers F16F9/32)}; CYLINDERS; SEALINGS

## Abstract

A seal for a turbomachine is disclosed. The seal assembly includes a rotatable shaft having a stepped outer circumferential surface that defines one or more annular protrusions axially-spaced thereon. A seal is radially-offset dially-offset from the rotatable shaft and has one or more annular recesses that extend radially-outward from the inner circumferential surface of the seal. A plurality of holes are defined in both the inner circumferential surface and the one or more annular recesses of the seal, the one or more annular recesses being axially-spaced from each other and configured to receive the one or more annular protrusions in an interlocking fit.

## Claims

### Claim 1

A seal assembly for a turbomachine, comprising:
a rotatable shaft having an outer circumferential surface defining one or more annular protrusions thereon; and
a seal radially-offset from the rotatable shaft and having:
an inner circumferential surface and one or more annular recesses extending radially-outward from the inner circumferential surface, the inner circumferential surface and the one or more annular recesses defining a plurality of holes; and
an annular groove defined in a side of at least one of the one or more annular recesses, wherein the one or more annular recesses are configured to receive the one or more annular protrusions.

### Claim 2 (depends on 1)

The seal assembly of claim 1, wherein the one or more annular protrusions are equidistantly-spaced from each other along the rotatable shaft.

### Claim 3 (depends on 1)

The seal assembly of claim 1, wherein the one or more annular protrusions are non-uniformly spaced from each other along the rotatable shaft.

### Claim 4 (depends on 1)

The seal assembly of claim 1, wherein the plurality of holes is a first plurality of holes and the annular protrusions and the outer circumferential surface of the rotatable shaft define a second plurality of holes.

### Claim 5 (depends on 1)

The seal assembly of claim 1, wherein each of the plurality of holes is round.

### Claim 6 (depends on 1)

The seal assembly of claim 1, wherein each of the plurality of holes is polygonal.

### Claim 7 (depends on 1)

The seal assembly of claim 1, wherein a gap is defined between the rotatable shaft and the seal.

### Claim 8

(canceled)

### Claim 9

A method for reducing fluid leakage from a high pressure region to a low pressure region along a rotatable shaft, comprising:
rotating the rotatable shaft, the rotatable shaft having an outer circumferential surface defining one or more annular protrusions;
arranging a seal about the rotatable shaft, the seal having:
an inner circumferential surface and one or more annular recesses, wherein the inner circumferential surface and the one or more annular recesses define a plurality of holes; and
an annular groove defined in a side of at least one of the one or more annular recesses; and
seating the one or more annular protrusions within the one or more annular recesses, whereby a tortuous flowpath is defined between the rotatable shaft and the seal for obstructing fluid leakage across the seal.

### Claim 10 (depends on 9)

The method of claim 9, further comprising damping shaft vibrations with the plurality of holes.

### Claim 11 (depends on 9)

The method of claim 9, wherein the plurality of holes is a first plurality of holes and a second plurality of holes is defined in the outer circumferential surface and annular protrusions of the shaft.

### Claim 12 (depends on 11)

The method of claim 11, further comprising damping shaft vibrations and simultaneously reducing the fluid leakage with the first and second plurality of holes.

### Claim 13

A seal assembly for a turbomachine, comprising:
a rotatable shaft arranged within the turbomachine and having an outer circumferential surface defining annular protrusions that are axially-spaced from each other along an axial section of the rotatable shaft;
a seal disposed about the rotatable shaft at the axial section and having an inner circumferential surface radially-offset from the rotatable shaft, the seal defining annular recesses extending radially-outward from the inner circumferential surface, and further having an annular groove defined in a side of at least one of the annular recesses, wherein each annular recess is configured to receive at least one of the annular protrusions, and wherein the inner circumferential surface and the annular recesses define a first plurality of holes; and
a gap defined between the rotatable shaft and the seal, the gap providing a tortuous flowpath configured to impede working fluid leakage across the axial section from a high pressure side to a low pressure side.

### Claim 14 (depends on 13)

The seal assembly of claim 13, further comprising a second plurality of holes defined in the outer circumferential surface of the shaft about the axial section.

### Claim 15 (depends on 13)

The seal assembly of claim 13, further comprising a second plurality of holes defined in at least one of the annular protrusions of the shaft.

### Claim 16 (depends on 13)

The seal assembly of claim 13, further comprising a second plurality of holes defined on both the axial section of the outer circumferential surface of the shaft and at least one of the annular protrusions of the shaft.

### Claim 17 (depends on 16)

The seal assembly of claim 16, wherein the first and second plurality of holes are configured to cooperate to dampen vibrations from the rotatable shaft and reduce the working fluid leakage.

### Claim 18 (depends on 13)

The seal assembly of claim 13, wherein the turbomachine is a centrifugal compressor.

### Claim 19 (depends on 13)

The seal assembly of claim 13, wherein the turbomachine is a steam turbine.

### Claim 20

(canceled)