Patent ID: 6484599
Filing Date: 2002-11-26
Classification: F16H,Y10T

Abstract:
A nut unit for a ball screw drive, comprising:a sleeve-shaped nut body, said body having an inner circumferential surface and a central axis (A) and being made of an essentially rigid material; an axially extending helical groove formed in the inner circumferential surface of said nut body, said groove defining a concavely-curved support profile in said circumferential surface facing said axis (A); a one-piece, ball-guiding helix formed of strip material mounted in said helical groove, said strip material helix having a channel-shaped transverse cross section which, on the radially outer side thereof, has a convexly-curved external profile having two external flank regions separated by an external crown region and, on the radially inner side thereof, has a concavely-curved internal profile having two internal flank regions separated by an internal base region, said external profile flank regions being radial opposite said internal profile flank regions; said external profile flank regions of said helix being essentially rigidly supported by said support profile of said support groove; said support profile of said support groove physically contacting each external flank profile region of the helix over a contact zone that extends at least substantially over the total extent of the track region of the opposed curved internal profile of the helix; said contact zone extending beyond the extent of the track region of the opposed curved internal profile of the helix; said curved internal profile of said helix comprising a ball channel for receiving the balls of said ball screw drive; and said curved internal profile being shaped such that balls of an associated ball set of a predetermined nominal diameter run on bearing race tracks of said internal profile flank regions, each of which bearing race tracks lies within a track region of the respective internal profile flank region.