Rational Design of Spur Gears Directed to Increase Efficiency and Decrease Loss by Friction

Abstract

External parallel-axis cylindrical gears are considered as very efficient means for transmitting mechanical power, but for requirements of maximum efficiency in the current machines and equipments a precision in the procedures of calculation of power losses is necessary. In this sense, the Technical Report ISO / TR 14179-1:2001 offers formulas with empirical and theoretical bases to evaluate the gear efficiency considering gear mesh losses, windage and churning losses, and losses by bearings and seals. In particular, this article presents some results derived from a study of ISO/TR 14179-1:2001 and mathematical models described the interrelation of gear geometry, working parameters and efficiency. The results offer solution to the problem of increasing gear efficiency through a convenient relationship between the load, speed and rational gear geometry. Finally, through multiple regression a new formulation was estimated for the calculation of gear efficiency as a function of the load density, module, speed, gear ration and number of pinion teeth.