A mixed finite element and analytical method to predict load, mechanical power loss and improved efficiency in non-standard spur gear drives

Abstract

A reasonably accurate estimation of gear power loss is desirable to maximize gear performance. The load share by teeth pair, contact stress, sliding speed, elastohydrodynamic film thickness and coefficient of friction are some of the most important contributing factors which determine frictional power losses in gears. This paper presents an improvement concept to minimize the load-related power losses (sliding and rolling power losses), which will lead to an enhancement in gear efficiency by selection of non-standard gears. The tooth thickness at the pitch circle of the pinion and gear is different in non-standard gears (kpπm > 0.5 πm and kgπm < 0.5 πm), whereas it is equal in standard gears (kpπm = kgπm = 0.5 πm). In this work, the load share-based frictional power loss and the respective mechanical efficiency have been determined for comparative performance of standard and non-standard gears. Finally, the influence of various gear and drive parameters such as gear ratio, pressure angle pinion teeth number and addendum height factor on gear efficiency has also been investigated and the results of the parametric study are discussed.