INTERNAL SPUN HUB AND METHOD OF MAKING SAME

摘要

A hub having a bore, in accordance with the present invention, is spun-roll formed of a portion of an annular sheet metal disc. The hub is formed by radially displacing a portion of the annular sheet disc outward from the bore. The so formed hub that is integral to the annular sheet metal disc forms a web having a thickness equivalent to or not less than a thickness of the annular sheet metal disc before formation of the hub. The web may be used to spun-roll form a rim having a belt receiving portion and as such a one-piece spun roll formed pulley. The web may also be used to interconnect to a rim having a belt receiving portion as a separate piece from the hub and web.During the spinning process, a shaping roller is pressed against a bore of an annular sheet metal disc which is being rotated simultaneously. The shaping roller is moved progressively, radially outward, with or without axial oscillation, against the bore of the rotating disc which displaces a portion of metal in the form of an axially extending collar. The shaping roller include various surface configurations for forming any number of various hub shapes. In addition, the spinning process may include the use of more than one shaping roller acting on the annular sheet metal disc at different times.