Patent ID: 8075251

Claim:
A turbocharger comprising: a turbine wheel provided at one end of a shaft for rotation about an axis within a turbine housing; a compressor wheel mounted to the other end of the shaft for rotation about said axis within a compressor housing; the shaft rotating on bearing assemblies housed within a bearing housing located between the compressor housing and the turbine housing and provided with oil passages for delivering oil to the bearing assemblies; an hydraulic seal assembly arranged in said bearing housing around said shaft between at least one bearing assembly and the adjacent compressor or turbine housing, the hydraulic sealing fluid being oil; the hydraulic seal assembly comprising a rotary member that is rotatable about the axis and a fixed member, one of said members defining an annular projection and the other defining a radially inward open annular channel in which said projection is received such that it defines a clearance between the members for receipt of hydraulic sealing fluid, whereby rotation of the rotary member imparts a centrifugal force to the fluid, when present, so as to maintain an annulus of sealing fluid in the clearance, a sealing fluid supply for delivering sealing fluid to said channel, the supply defining a fluid inlet at which the fluid may enter the channel, the inlet being disposed in said channel at a first distance from said axis of rotation, wherein the channel is defined between a base wall and first and second substantially opposite walls that extend from the base wall towards the axis of rotation, and a sealing fluid exit in or at an end of said first wall, the inlet and exit being axially offset; a thrust bearing assembly adjacent to said hydraulic seal assembly; the hydraulic seal assembly having an oil supply inlet that is configured to receive oil from the thrust bearing assembly.