Patent ID: 8840444
Filing Date: 2014-09-23
Classification: B23F,Y10T

Abstract:
1. A method for machining the tooth flanks of a cylindrical crowning-modified gear by a diagonal rolling process, said gear having an axis of rotation, said method comprising: employing a worm-shaped tool having tooth flanks and an axis of rotation, said tool being modified with crowning in the direction of said axis by changing the pitch of the flanks, the crowning being positive or negative (concave crowning), producing a crowning on the gear by superimposing one portion, which results from the crowning of the tool in the diagonal process, and a further portion, which is produced by changing the axial distance between the tool and the workpiece during machining, producing a flank twist on the gear by superimposing a natural portion that is independent of how the crowning has been produced, and a further portion dependent upon the amount and profile of the crowning of the tool in the direction of its axis of rotation and upon the diagonal ratio defined by a ratio of the displacement of the tool along the tool axis of rotation and the displacement of the gear along the gear axis of rotation, wherein in order to produce a target crowning and a target twist, the natural portion of the twist is determined from the target crowning and the further portion of the twist due to matching the crowning of the tool and the diagonal ratio being determined such that as a result thereof, an actual twist is produced, and the further portion of the crowning is determined by changing the axial distance such that as a result thereof, an actual crowning is produced, comparing the target twist and crowing to the actual twist and crowning to determine any deviation therebetween and if so, providing corrected target values for twist and/or crowning, and repeating said method to achieve said target twist and crowning.