Low friction, wear resistant dry face carbon seal—seal seat assembly
A method for preparing a seal assembly for a gas turbine engine, comprising a seal comprising a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the method comprises the steps of: pre-filming a sealing surface of the seal seat with a carbon-based tribofilm; and assembling the seal seat relative to the seal in a gas turbine engine.
1. A method for preparing a seal assembly for a gas turbine engine, comprising a seal comprising a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the method comprises the steps of:
pre-filming a sealing surface of the seal seat with a carbon-based tribofilm to produce a pre-filmed seal seat having the carbon-based tribofilm on the sealing surface, wherein the pre-filming step comprises mounting the seal seat in a component rig, and contacting the seal seat in the component rig with a carbon-based member to transfer material from the carbon-based member to the seal seat and thereby produce the carbon-based tribofilm; and
assembling the pre-filmed seal seat relative to the seal in a gas turbine engine.
2. The method of claim 1 , wherein the component rig is operated to apply carbon to the seal seat at a pressure*velocity (PV) of between 1300 and 7000 psi*ft/sec for a period of at least 1 minutes.
3. The method of claim 1 , wherein the carbon-based tribofilm has a thickness of between 2 and 240 nm.
4. The method of claim 1 , further comprising the step of operating the gas turbine engine after the assembling step whereby a carbon transfer film is applied over the carbon-based tribofilm during steady state operation.
5. A pre-filmed seal seat having a sealing surface and a carbon-based tribofilm on the sealing surface, wherein the carbon-based tribofilm is applied according to the method of claim 1 .
6. The seal seat of claim 5 , wherein the carbon-based tribofilm has a coefficient of friction with a carbon-based seal of between 0.06 and 0.16.
7. The seal seat of claim 5 , wherein the carbon-based tribofilm has a thickness of between 2 and 240 nm.
8. A method for preparing a seal assembly for a gas turbine engine, comprising a seal comprising a carbon material; and a seal seat positioned for rotation relative to the seal, wherein the method comprises the steps of:
pre-filming a sealing surface of the seal seat with a carbon-based tribofilm to produce a pre-filmed seal seat having the carbon-based tribofilm on the sealing surface, wherein the prefilming step comprises contacting the seal seat mounted in a component rig with a carbon-based member to transfer material from the carbon-based member to the seal seat and thereby produce the carbon-based tribofilm; and
assembling the pre-filmed seal seat relative to the seal in a gas turbine engine.
9. The method of claim 8 , wherein the carbon-based member comprises a material selected from the group consisting of electro-graphite, carbon-graphite and mixtures thereof.