Tooth crest chamfering method of spiral bevel gear using ball end milling cutter

Abstract

A chamfering method is proposed in order to improve processing accuracy and efficiency of tooth crest chamfering of spiral bevel gear. Coordinates of discrete points of upper and lower edges of chamfering surface are calculated based on the mathematical model of tooth surface and face cone. Distances between center of ball end milling cutter and upper and lower edges are set equal to radius of the ball end milling cutter, chamfering tool path is generated by particle swarm algorithm solving, both sides of tooth crest can be chamfered simultaneously to ensure processing efficiency. Direction angle of the cutter axis is calculated based on the relationship between direction of the cutter axis and contact positions of the cutter surface. Aiming to prolong service life of cutter, direction angle varies uniformly within the feasible region and contact positions distribute evenly on the cutter surface. Pinion without tooth crest chamfering is installed on four-axis CNC machine tools, edge detector is used to detect axial and circumferential cutter positions, then chamfering experiment is completed. Widths of chamfering surface are measured on different measuring positions, maximum error is 0.08 mm compared with design width 1 mm which appears at tooth crest inner end of convex side. Measuring results show that chamfering error is much smaller than that with manual chamfering, which indicates that the chamfering method is feasible.