Research on Gear Cutter Tooth Profile for Semi-Topping: A Case of a Helical Gear

Abstract

Gear tooth tips are frequently chamfered to prevent nicks or scuffing on the tooth surface. Some of the hob cutters and pinion cutters can be chamfered but many types of cutters should be used for a particular range of tooth numbers since the amount chamfering largely varies depending on the tooth number. However, intensive efforts in the design have made it possible to produce cutters with little variation of chamfering amount for a wide range of tooth numbers. The error in the amount of chamfering by a single cutter designed by the above method can be maintained within ±10 % for gears with tooth numbers ranging from 16 to 94. It was found that three cutters of the conventional design are required for keeping the error within the same range for cutting gears within a given range of tooth numbers. The paper describes the tooth design method of the hob cutter with little variation of chamfering amount along changes in number of teeth to be machined and demonstrates that chamfering errors are maintained within practically allowable ranges for profile shift cutting or helical gear cutting with the use of this cutter.