Patent attributes
A motor-driven supercharger is provided with a thrust bearing (30) rotatably supporting a thrust force applied to a turbine shaft (12). The thrust bearing (30) is constituted by a small-diameter disc-shaped thrust collar (32) rotating together with a turbine shaft, and a turbine side thrust bearing (34) and a compressor side thrust bearing (36) which block a movement in an axial direction of the thrust collar. The compressor side thrust bearing (36) has a small-diameter ring portion (37) including a thrust surface which is in contact with the thrust collar and has approximately an equal diameter, and a flange portion (38a) fixed to a housing (16) in the turbine side, and the small-diameter ring portion and the flange portion are arranged at different positions in an axial direction.