Patent ID: 7367190

Claim:
A supercharger with an electric motor comprising: (a) a turbine impeller rotationally driven by an exhaust gas of an internal combustion engine; (b) a turbine housing surrounding the turbine impeller; (c) a compressor impeller coupled to the turbine impeller by a shaft and rotating so as to compress an intake air; (d) compressor housing surrounding the compressor impeller; (e) an electric motor positioned between the turbine impeller and the compressor impeller so as to rotationally drive the shaft; (f) a center housing rotatably supporting the shaft and having the electric motor built-in, wherein the center housing comprises i. a housing main body; ii. a flow path forming member that is formed in a ring shape and is inserted and attached to the housing main body, and the flow path forming member comprises a first cooling structure portion and a second cooling structure portion; and iii. a cooling fluid flow path defined by the housing main body and the flow path forming member, wherein the cooling fluid flow path surrounds the electric motor; (g) a scroll chamber annularly formed within the compressor housing and discharging a compressed air; and (h) a diffuser portion extending to an outer side in a radial direction from an outlet of the compressor impeller and communicating the outlet of the compressor impeller and the scroll chamber, wherein the electric motor is arranged at a position adjacent to the compressor impeller and the cooling fluid flow path is formed so as to be adjacent to the diffuser portion, wherein the cooling fluid flow path circulates cooling fluid in an inner portion of the center housing and the first cooling structure portion is disposed at a position on an electric motor side of the cooling fluid flow path so as to cool the electric motor by heat transfer, and the second cooling structure portion is disposed at a position on a diffuser portion side of the cooling fluid flow path so as to cool the diffuser portion by heat transfer.