RACE RINGS FOR ROLLING BEARINGS AND TO ROLLING BEARINGS HAVING SUCH RACE RINGS

摘要

1357526 Bearings SKF (UK) Ltd 1 Sept 1971 [22 June 1970] 30218/70 Heading F2A A method of making a race ring for a rolling bearing comprises forming at least two ring elements, at least one of which has a concave surface 13 tapering from a maximum diameter at its junction with a cylindrical outer surface 12 to a minimum diameter at its junction with end face (14), Figs. 1-3 (not shown), to provide part of a raceway, and another of which has a concave surface 13 to provide part of the same raceway surface, assembling the two elements with their two concave surfaces forming a continuous raceway surface 11, electron beam welding the ring elements together, and finish-grinding the raceway surface 11. The ring elements may be formed, for example, by cold forming or sintering. The inner ring element of Fig. 1 is paired with another of the same dimensions with their bores co-axial and end faces (14) opposite each other. They are then welded together starting from the raceway surface and then subjected to any necessary heat treatment, e.g. case-hardening, followed by a finish-grinding to the required dimensional accuracy. Alternative embodiments feature a bevel (17) or recess (18) in the end surface (14) so as to lessen the risk of weld metal 15 projecting into the bore 11, and thus precluding much grinding. Outer race rings may be formed, Figs. 6, 7 (not shown), so as to accommodate rows of balls (21), (22) rolling on raceway (23). The inner race ring of this embodiment comprises three elements (25), (26) forming a raceway for each row of balls. A further modification includes the assembling of sintered ring elements followed by electron beam welding to provide not only a weld joint but also a melting of the raceway surface to provide on cooling a homogeneous bearing surface.