Patent ID: 7168539
Filing Date: 2007-01-30
Classification: F16H

Abstract:
1. A pulley unit comprising: a pulley having an inner circumferential surface defining a through hole; a shaft having an outer circumferential surface and disposed relatively rotatable with said pulley and said shaft being concentrically arranged inside said through hole of said pulley; a one-way clutch interposed in an annular space between said inner circumferential surface of said pulley and said outer circumferential surface of said shaft said one-way clutch having an inner ring and an outer ring respectively formed by said outer circumferential surface of said shaft and said inner circumferential surface of said pulley; a ball bearing arranged adjacent to said one-way clutch in art axial direction in said annular space, said ball bearing having an inner ring and an outer ring respectively formed by said outer circumferential surface of said shaft and said inner circumferential surface of said pulley; and a roller bearing arranged adjacent to said one-way clutch in said axial direction in said annular space, said roller bearing having an inner ring and an outer ring respectively formed by said outer circumferential surface of said shaft and said inner circumferential surface of said pulley; wherein a radial internal clearance after mounting of said ball bearing is set to less than 20 μm and raceway curvatures of said inner and outer rings of said ball bearing are set to not less than 50.5% and less than 51.0%.