Wide differential pressure range air riding carbon seal

Patent metadata

Field	Value
Publication number	US-10234036-B2
Application number	US-201614990252-A
Country	US
Kind code	B2
Filing date	Jan 7, 2016
Priority date	Jan 12, 2015
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

An exemplary carbon seal assembly generally may include a stator fixable to a static component, such as a mechanical housing of a gas turbine engine, and a rotor fixable to a rotating component, such as a shaft of the gas turbine engine, where the rotating component is rotatable relative to the static component. The carbon seal assembly may also include a carbon ring and a spring attached thereto positioned between the stator and the rotor, where the spring may be configured to move the carbon ring fore and aft between the stator and the rotor. The carbon seal assembly may further include a diaphragm operatively attached to stator and to the carbon ring and spring combination.

First claim

What is claimed is:

1. A carbon seal assembly comprising:
a stator fixable to a static component;
a rotor fixable to a rotating component rotatable relative to the static component;
a carbon ring disposed between the stator and the rotor;
a spring configured to move the carbon ring fore and aft between the stator and the rotor;
a diaphragm operatively attached to the stator and to a combination of the spring and the carbon ring;
a casing in which at least one of the spring and the carbon ring is at least partially disposed, wherein the diaphragm is attached to the casing; and
a limit stop extending from the stator toward the rotor, the limit stop being configured to engage with the casing to limit movement of the carbon ring in the fore and aft directions and to allow high pressure air between the diaphragm and the stator;
wherein one of the casing and the limit stop has a fore stop and an aft stop extending radially from the one of the casing and the limit stop, and the other of the casing and the limit stop has a lip extending radially from the other of the casing and the limit stop in an opposite direction to the fore stop and the aft stop such that the lip is positioned between the fore stop and the aft stop.

2. The carbon seal assembly of claim 1 , wherein the static component is a mechanical housing and the rotating component is a shaft of a gas turbine engine.

3. The carbon seal assembly of claim 1 , wherein the limit stop is positioned between the casing and the stator.

4. The carbon seal assembly of claim 1 , wherein the limit stop has at least one vent hole for equalizing air pressure.

5. A gas turbine engine, comprising:
a mechanical housing;
a shaft rotatable relative to the mechanical housing; and
a carbon seal assembly having:
a stator fixed to the mechanical housing;
a rotor fixed to the shaft;
a carbon ring disposed between the stator and the rotor;
a spring configured to move the carbon ring fore and aft between the stator and the rotor;
a casing in which at least one of the spring and the carbon ring is at least partially disposed;
a diaphragm attached to the casing;
a limit stop extending from the stator toward the rotor, the limit stop being configured to engage with the casing to limit movement of the carbon ring in the fore and aft directions and to allow high pressure air between the diaphragm and the stator;
wherein one of the casing and the limit stop has a fore stop and an aft stop extending radially from the one of the casing and the limit stop, and the other of the casing and the limit stop has a lip extending radially from the other of the casing and the limit stop in an opposite direction to the fore stop and the aft stop such that the lip is positioned between the fore stop and the aft stop.

6. The gas turbine engine of claim 5 , wherein the mechanical housing and the shaft are embodied in a gearbox.

7. The gas turbine engine of claim 5 , wherein the carbon seal assembly is an air riding carbon seal or a contacting carbon face seal.

8. The gas turbine engine of claim 5 , wherein the limit stop is positioned between the casing and the stator.

9. The gas turbine engine of claim 5 , wherein the limit stop has at least one vent hole.

10. A method comprising:
attaching a diaphragm to a stator and a combination of a carbon ring and a spring to form a static assembly;
fixing a rotor to a rotating component rotatable relative to a static component; and
fixing the static assembly to the static component; and
positioning a limit stop one of radially above or radially below a casing in which the carbon ring and the spring are at least partially disposed such that a lip extending radially from one of the casing and the limit stop is positioned between a fore stop and an aft stop extending radially from the other of the casing and the limit stop;
wherein the combination of the carbon ring and the spring is positioned between the stator and the rotor such that the carbon ring is movable toward and away from the rotor.

11. The method of claim 10 , wherein the static component is a mechanical housing and the rotating component is a shaft of a gas turbine engine.

12. The method of claim 10 , further comprising positioning a limit stop between the stator and a casing in which at least one of the carbon ring and the spring are at least partially disposed.

13. The carbon seal assembly of claim 1 , wherein the carbon seal assembly is an air riding carbon seal or a contacting carbon face seal.

14. The carbon seal assembly of claim 13 , wherein the carbon seal assembly is an air riding carbon seal in which a gap is maintained between the carbon ring and the rotor.

Assignees

• Rolls Royce Corp

Inventors

• Lewis Nathan A

Classifications

• F05D2260/38

  by a spring, i.e. spring loaded or biased towards a certain position · CPC title

• F16J15/3448

  the pressing force resulting from fluid pressure · CPC title

• F01D11/025

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

• F16J15/445 Primary

  with means for adjusting the clearance · CPC title

• F16J15/3452

  the pressing force resulting from the action of a spring · CPC title