| 摘要 |
PURPOSE:To secure roundness and verticality and to obtain hubs with mass- productivity and its manufacture by providing an engaging part which prevents an inner and an outer ring from shifting in position relatively and axially, and coupling it in one body. CONSTITUTION:The wall thickness of the outer ring body 3 provided around the inner ring 2 is made thin enough to prevent a shrinkage from appearing in its outer circumferential surface after molding. Two inward projection parts 12 are formed on and under the inner circumferential part of the outer ring 3 while clamping the projecting streak 11 of the inner ring body 2 axially and extends almost the overall circumference of the outer ring body 3, and the projecting streak 11 of the inner ring body 2 engage the inward projection part 12 of the outer ring body 3 to prevent the inner ring body 3 and outer ring body 3 from shifting in position axially. The outer ring body 3 is formed by secondary molding following the molding of the inner ring body 2 (secondary molding). Further, the wall thickness of the inward projection part 12 provided to the outer ring body 3 is almost as thick as other parts of the outer ring body 3, and even when the projection part 12 is provided, no shrinkage appears in the outer circumferential surface of the outer ring body 3. |
