| 摘要 |
PROBLEM TO BE SOLVED: To provide a shaft seal that prevents oil from bearing lubrication systems from leaking into a turbine housing.SOLUTION: A shaft of a turbocharger 10 is sealed with respect to a bore 27 of a bearing housing 23 at an end of a turbine wheel 16 by one or more shaft seal rings. Conventionally these rings are seated in annular grooves provided in the shaft behind the turbine wheel. Problems can arise with this conventional shaft seal arrangement, particularly where a turbocharged engine has an engine brake valve located downstream of the turbine, and the back pressure in an exhaust line and in a turbine wheel housing can reach 7 bar. The shaft seal design of the present invention avoids use of grooves, and makes it possible to assemble a seal from ring seals with higher wear resistance and thus to maintain effectiveness of the seal over heavy use.SELECTED DRAWING: Figure 1 |
