Labyrinth seal with tunable flow splitter

Patent metadata

Field	Value
Publication number	US-10415735-B2
Application number	US-201615179400-A
Country	US
Kind code	B2
Filing date	Jun 10, 2016
Priority date	Jun 17, 2015
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

A flow splitter includes a stepped ring and a flow restriction. The stepped ring includes a first inner wall having a first diameter, a second inner wall having a second diameter less than the first diameter, a radial step that transitions from the first to the second inner wall, and a plurality of apertures circumferentially located along the first inner wall and partially through the radial step. The first flow restriction has at least a portion thereof at a position between the first diameter and the second diameter. Further, the first flow restriction directs a flow of at least one of a gas and a fluid towards the first inner wall, and is configured to split the flow into an exit flow and a secondary flow. The exit flow exits the stepped ring via the plurality of apertures and the secondary flow proceeds downstream directed by the second inner walls.

First claim

What is claimed is:

1. A labyrinth seal system comprising:
a rotor comprising a first labyrinth knife set and a second labyrinth knife set, and
a stator comprising:
a first inner wall having a first inner diameter;
a second inner wall having a second inner diameter less than the first inner diameter, wherein at least a portion of the first labyrinth knife set is positioned between the first and the second inner diameters;
a step having a first end and a second end opposite the first end, wherein the first end of the step transitions to the first inner wall and the second end of the step transitions to the second inner wall; and
a plurality of apertures that passes partially through the step, through the first inner wall, and in an axial direction along at least a portion of an exterior surface of the second inner wall, wherein each aperture of the plurality of apertures is configured to allow at least one of a liquid and a gas from within the stator to flow through the stator, and wherein the rotor is positionable in the stator such that first labyrinth knife set is positioned within the first inner wall and the second labyrinth set is positioned within the second inner wall.

2. The labyrinth seal system of claim 1 , wherein the labyrinth seal is configured to split a flow of air leakage from the first labyrinth knife set into an exit flow that passes out of the stator via the plurality of apertures and into a secondary flow that passes over the second inner wall.

3. The labyrinth seal system of claim 1 , wherein the labyrinth seal system is configured to pressurize a second labyrinth seal via at least one aperture of the plurality of apertures.

4. The labyrinth seal system of claim 3 , wherein at least one aperture of the plurality of apertures is adjustable to modify a rate of the exit flow.

5. The labyrinth seal system of claim 1 , wherein at least one aperture of the plurality of apertures is adjustable to create a negative pressure within the second inner wall to cause the secondary flow within the second inner wall to reverse direction.

6. The labyrinth seal system of claim 1 , wherein the aperture is configured to form an upstream restriction by a slot having an aperture width greater than an aperture height.

7. The labyrinth seal system of claim 1 , wherein the labyrinth seal system is configured for a turbine engine.

8. The labyrinth seal of claim 7 , wherein the first and second labyrinth knife sets are removable from the rotor.

9. The labyrinth seal system of claim 8 , wherein the first labyrinth knife set includes at least two labyrinth knives and the second labyrinth knife set includes at least three labyrinth knives.

10. A method of manufacturing a labyrinth seal comprising:
assembling a rotor having at least one upstream labyrinth knife and at least one downstream labyrinth knife protruding from the rotor;
creating a stator having a first inner wall at a first diameter and a second inner wall at a second diameter less than the first diameter, wherein at least a portion of the first labyrinth knife is positionable between the first and the second inner diameters;
providing a plurality of holes through the first inner wall of the stator, partially though a transition from the first inner wall to the second inner wall, and in an axial direction along at least a portion of an exterior surface of the second inner wall, wherein the plurality of holes pass through the stator; and
positioning the rotor within the stator such that the at least one upstream labyrinth knife is at least partially surrounded by the first inner wall and the at least one downstream knife is at least partially surrounded by the second inner wall.

11. The method of claim 10 , wherein the labyrinth seal is configured to split an upstream flow into an exit flow and a secondary flow, and wherein the exit flow exits the stator via the plurality of holes and the secondary flow passes downstream within the second inner wall.

12. The method of claim 11 , further comprising adding an adjustable flow control structure to at least one hole of the plurality of holes, wherein the flow control structure is configured to modify a rate of the exit flow exiting the stator such that a rate of the secondary flow is also modified.

13. The method of claim 11 , wherein at least one hole of the plurality of holes is configured to form an upstream restriction by inner dimensions at a first height and a first width greater than the first height.

14. The method of claim 11 , wherein the at least one upstream labyrinth knife is configured to direct the exit flow portion of the upstream flow towards the first inner wall.

Assignees

• Rolls Royce Corp

Inventors

• Munson John
• Burnside Phillip H

Classifications

• F01D11/04

  using sealing fluid, e.g. steam · CPC title

• F01D11/02 Primary

  by non-contact sealings, e.g. of labyrinth type (for sealing space between rotor blade tips and stator F01D11/08) · CPC title

• F16J15/4472

  with axial path · CPC title

• F16L41/02 Primary

  Branch units, e.g. made in one piece, welded, riveted · CPC title