Evaluation of the Effect of Friction in Gear Contact Stresses

Abstract

Stress analysis of gears has become a popular area of research in order to reduce failures and optimize the gear design. FrictionFriction between gears is detrimental to the gear surface contacts, but there is no effective method to determine the frictional effects on these contacts. Inclusion of friction in the study of gear contact is sparse. Also, frictionFriction depends on various other parameters, which in turn are ambiguous to evaluate. Hence, a quantitative study of frictional effects on gear contact problem is therefore essential. Thus, to solve the present problem, a dimensionless factor needs to be developed which would account for the friction in gear contact stressGear contact stress calculations. A simplified gear contact stressGear contact stress evaluation technique which includes frictionFriction needs to be developed. In this work, a 3D frictional Finite Element Method (FEM)Finite element method was employed for the gear frictional study. Also, an experimental validation was carried out using a customised experimental setup, Gear Dynamic Stress Test Rig (GDSTR). The experimental results provided a good correlation with the results of the developed 3D FE models. The results from the validated FE models showed 15–22% rise in gear contact stressesGear contact stress for increased frictional coefficients, which is significant. The FE analysis was further extended and a parametric study was carried out. A dimensionless friction factorFriction factor function was developed in this work to estimate the frictional gear contact stressesGear contact stress. The mathematically correlated Kf function was verified and its inclusion provides better frictional contact stress evaluation in gears, thus providing a simplified frictional measure in gear contact stressGear contact stress calculations.