| 摘要 |
A method for forming a toothed wheel which comprises the steps of providing a circular sheet metal blank of uniform thickness, cold forming an outer peripheral portion thereof into a thickened rim of uniform generally rectangular cross-sectioned configuration having (1) an outer periphery which does not exceed the outer periphery of the toothed wheel to be formed by more than approximately two percent (2) a radial thickness at least 2.0 mm greater than the tooth height of the toothed wheel to be formed, and (3) an axial thickness at least twice the uniform thickness of said blank, the cold forming comprising progressively moving a predetermined marginal peripheral portion of the metal blank having a cross sectional outline radially inwardly and axially outwardly while the integral integrity of the metal within the cross sectional outline is maintained without merging portions of the cross sectional outline together, and cutting a series of teeth in the periphery of the thickened rim by a hobbing operation. |
