On Use of Pulsed-Electrochemical Honing to Improve Micro-Geometry of Bevel Gears

Accuracy in micro-geometry is an important issue for gears because it affects noise generation and transmission characteristics and consequently determines the operating performance and service life of the gears. Various post-manufacturing processes are required to achieve the desired level of accuracy in micro-geometry of the gears. This paper reports on use of pulsed-electrochemical honing (PECH) process to improve micro-geometry of the straight bevel gears and presents experimental optimization of three important parameters of PECH namely pulse-on time, pulse-off time, and finishing time. Seventeen experiments were conducted according to central composite rotatable approach of response surface methodology. The improvements in micro-geometry of bevel gears in terms of average percentage improvement in single pitch error, adjacent pitch error, cumulative pitch error, and in total runout were found as 34.22%, 39.58%, 13.34%, and 18.88%, respectively. These improvements are better than those achieved using constant power supply due to efficient cleaning of the narrow inter-electrode gap during pulse-off time. These improvements lead to improve the gear quality up to seven for Deutsche Normen standard. Optimized values of input parameters for achieving these results are pulse-on time (2 ms), pulse-off time (4.5 ms), and finishing time (6min).