High Accurate Robbing With Specially Designed Finishing Hobs

摘要

Load-carrying capacity of gears, especially the surface durability, is influenced by their tooth surface roughness in addition to their tooth profiles and tooth traces (Refs. 1 and 2). The harder the gears are, the smoother their tooth surfaces and the more accurately their tooth profiles should be finished in order to obtain high load-carrying capacity. Through research, the relationship between the cutting thickness (undeformed chip thickness), the size of built-up edge (BUE) and the tooth surface roughness has clarified that the number of gashes and the rake angle in hobs has an effect on the cutting thickness and the BUE formation, respectively. The cermet-tipped hobs developed by Ariura and Umezaki (Ref. 4) have excellent cutting performance with respect to wear resistance, tooth accuracy of hobbed gears and roughness of their tooth surfaces for gear blanks with hardness up to about 400HBW.