| 摘要 |
A turbocharger is provided with a rotor shaft, a bearing housing in which a bearing hole is formed, and a bearing member of the semi-floating type arranged in the bearing hole and supporting the rotor shaft in a rotatable state. The bearing member has a first bearing portion and a second bearing portion spaced at a predetermined interval in the axial direction of the rotor shaft, in its inner periphery. A region between the first bearing portion and the second bearing portion in the inner periphery of the bearing member, and an outer periphery of the rotor shaft constitute an oil passage for supply of lubricant oil to inside surfaces of the first and second bearing portions. Oil grooves to suppress the whirl vibration are formed in each of the inside surfaces of the first and second bearing portions. The oil grooves are closed in part. |
