Semi-permeable media sealing an actuating shaft

Abstract

To impede soot leakage around a shaft which extends through a bore connecting volumes of differing pressures, e.g., a turbocharger turbine housing and the ambient air, a soot seal is provided to capture particulate matter while allowing the passage of gas.

Now that the invention has been described, I claim: 
     
         1 . A turbocharger with a turbine housing, a device within the turbine housing actuated by an actuating mechanism located outside the turbine housing, a shaft which is rotatably mounted in a bore extending through the turbine housing or the bearing housing for transmitting an actuating movement from the actuating mechanism to the device, wherein a sealing material is provided to seal the bore, and wherein the sealing material is gas permeable and adapted to trap soot particles. 
     
     
         2 . The turbocharger as in  claim 1 , wherein the sealing material is adapted to trap soot particles greater than 1.0 μm diameter 
     
     
         3 . The turbocharger as in  claim 1 , wherein the sealing material is adapted to trap soot particles greater than 0.05 μm. 
     
     
         4 . The turbocharger as in  claim 1 , wherein the sealing material is a porous material of which the primary component is selected from the group consisting of fiberglass, carbon, PTFE, bronze, stainless steel, nickel based alloys, titanium, copper, and aluminum. 
     
     
         5 . The turbocharger as in  claim 1 , wherein the bore is widened along a segment in which the sealing material is accommodated. 
     
     
         6 . The turbocharger as in  claim 1 , wherein the shaft is narrowed along a segment in which the sealing material is accommodated. 
     
     
         7 . The turbocharger as in  claim 1 , wherein the sealing material is provided at the device end of the bore. 
     
     
         8 . The turbocharger as in  claim 1 , wherein the sealing material is provided at the actuator end of the bore. 
     
     
         9 . The turbocharger as in  claim 1 , wherein the sealing material is provided outside the turbine housing or bearing housing, in a space between the bore and the actuating mechanism. 
     
     
         10 . The turbocharger as in  claim 1 , wherein the shaft is mounted in a bore in the turbine housing or bearing housing. 
     
     
         11 . The turbocharger as in  claim 1 , wherein the shaft is mounted in a bore in a bushing extending through the turbine housing or bearing housing. 
     
     
         12 . The turbocharger as in  claim 1 , further comprising a circumferential groove provided in at least one of said shaft and said bore, wherein at least one generally annular solid non-permeable seal member is provided in the circumferential groove. 
     
     
         13 . The turbocharger as in  claim 12 , wherein the seal member is a seal ring. 
     
     
         14 . The turbocharger as in  claim 13 , wherein the sealing material is provided between two seal rings. 
     
     
         15 . The turbocharger as in  claim 13 , wherein the sealing material is provided either outboard of the seal ring or inboard of the seal rings.