Patent ID: 8807840

Claim:
A turbocharger including: a rotating assembly including a shaft ( 52 ) and a turbine wheel ( 51 ) solidly affixed to one end of the shaft; a bearing housing including a bearing bore having an internal diameter; and a rolling element bearing assembly supported in said bearing housing, the rolling element bearing assembly comprising a first bearing and a second bearing, each of the first bearing and second bearing including: at least one inner race ( 65 , 65 C, 65 T) and at least one outer race ( 64 ), each race provided with at least one raceway, each race having a compressor end face and a turbine end face, the first bearing and second bearing arranged so that the turbine end face of the first bearing faces the compressor end face of the second bearing, and a series of rolling elements, each rolling element in contact with one of said at least one inner raceway and one of said at least one outer raceway, the rolling element bearing assembly further comprising an encapsulating sleeve ( 77 ) having an inside diameter ( 79 ) fit to the outer surface ( 72 ) of at least part of the outer circumference of the outer race of each of the first bearing and the second bearing, wherein the encapsulating sleeve ( 77 ) is non-metallic, is mechanically or chemically affixed to the radially outer surface ( 72 ) of the outer race ( 64 ), to the compressor end face of the of the outer race of the first bearing and to the turbine end face of the outer race of the second bearing, provides a thermal barrier for heat flow from the bearing housing to the outer race, and is comprised of a low thermal conductive material that provides a thermal barrier for heat flow from the bearing housing to the outer race, where low thermal conductive material refers to a material having a thermal conductivity that is low relative to the material of the bearing housing.