Sealing arrangement

Abstract

A sealing assembly comprises a bore in a housing, a plurality of seal rings and a shaft. The bore comprises a plurality of seats disposed at different seat radius for the seal rings. The bore comprises for each pair of adjacent seats axially inward of an inner end of the outward seat and proximate to the inward seat a chamfer extending radially inwardly over an inward axial distance. The chamfer between each pair of seats allows for the radial contraction of the seal rings upon assembly.

1 . A sealing assembly for sealing a shaft of a turbomachine in a bore of a housing, said shaft extending from a hub of a turbine wheel to a shaft bearing in said housing, the assembly comprising at least two seal rings and the bore comprising:
 a longitudinal axis extending generally from an inner end to an outer end of the bore, said outer end of the bore being adjacent said hub of the turbine wheel;   an outer seat disposed proximate to the outer end of the bore at an outer seat radius for an outer seal ring, and   an inner seat disposed axially between the outer seat and the inner end of the bore at an inner seat radius for an inner seal ring,   
     wherein
 the bore comprises axially inward of an inner end of the outer seat and proximate to the inner seat a chamfer extending radially inwardly over an inward axial distance to an inner chamfer plateau radius. 
 
   
   
       2 . The assembly of  claim 1 , the bore further comprising axially between the outer seat and the inner seat an intermediate seat at an intermediate seat radius for an intermediate seal ring and axially inward of the inner end of the outer seat and proximate to the intermediate seat a chamfer extending radially inwardly over an inward axial distance to an intermediate chamfer plateau radius. 
   
   
       3 . The assembly of  claim 1 , wherein the inner seat radius exceeds the inner chamfer plateau radius and wherein the inner seat comprises a chamfer at the outer end extending radially inwardly over an outward axial distance to the inner chamfer plateau radius. 
   
   
       4 . The assembly of  claim 1 , further comprising a radial inwardly facing annular groove disposed axially outward of the inner seat. 
   
   
       5 . The assembly of  claim 4 , wherein said annular groove is connected to a drain channel. 
   
   
       6 . The assembly of  claim 1 , the bore comprising:
 a plurality of seats disposed between said inner and said outer end of the bore at different seat radius for a plurality of seal rings, wherein of each pair of adjacent seats the seat radius of the outward seat exceeds the seat radius of the inward seat,   characterized in, that the bore comprises for each pair of adjacent seats axially inward of an inner end of the outward seat and proximate to the inward seat a chamfer extending radially inwardly over an inward axial distance.   
   
   
       7 . The assembly of  claim 6 , wherein the innermost seat comprises a chamfer at the outer end extending radially inwardly over an outward axial distance to an inner chamfer plateau radius. 
   
   
       8 . The assembly of  claim 6 , wherein the bore comprises axially outward of an outer end of the outer seat a chamfer extending radially outward over an outward axial distance from an outer chamfer plateau radius. 
   
   
       9 . A system for a turbomachine, the system comprising:
 a sealing assembly according to  claim 1 ;   a rotatable shaft, insertably positionable in the bore and comprising at least two radially outwardly opened slots; and   seal rings, positionable on the shaft, capable of being received by the slots and capable of being seated in the seats of the bore.   
   
   
       10 . The system of  claim 9 , wherein at least one of the seal rings comprises a step gap with a stop element. 
   
   
       11 . The system of  claim 9 , wherein the shaft comprises a bush, and wherein said radially outwardly opened slots are disposed in said bush. 
   
   
       12 . A turbocharger comprising:
 a compressor, comprising a compressor housing and a compressor wheel mounted in the compressor housing;   a turbine, comprising a turbine housing and a turbine wheel mounted in the turbine housing;   a shaft connecting the compressor wheel to the turbine wheel;   a bearing housing disposed between the compressor and the turbine housings, the bearing housing defining a bore that receives the shaft therethrough according to the sealing assembly of  claim 1 .   
   
   
       13 . The assembly of  claim 5 , the bore comprising:
 a plurality of seats disposed between said inner and said outer end of the bore at different seat radius for a plurality of seal rings, wherein of each pair of adjacent seats the seat radius of the outward seat exceeds the seat radius of the inward seat,   characterized in, that the bore comprises for each pair of adjacent seats axially inward of an inner end of the outward seat and proximate to the inward seat a chamfer extending radially inwardly over an inward axial distance.   
   
   
       14 . A system for a turbomachine, the system comprising:
 a sealing assembly according to  claim 8 ;   a rotatable shaft, insertably positionable in the bore and comprising at least two radially outwardly opened slots; and   seal rings, positionable on the shaft, capable of being received by the slots and capable of being seated in the seats of the bore.   
   
   
       15 . A turbocharger comprising:
 a compressor, comprising a compressor housing and a compressor wheel mounted in the compressor housing;   a turbine, comprising a turbine housing and a turbine wheel mounted in the turbine housing;   a shaft connecting the compressor wheel to the turbine wheel;   a bearing housing disposed between the compressor and the turbine housings, the bearing housing defining a bore that receives the shaft therethrough according to the sealing assembly of  claim 8 .