Torque loss in FZG-A10 gears lubricated with axle oils

Abstract FZG type A spur gears, lubricated with axle gear oils with high EP properties, were tested in an FZG back-to-back test rig, and their torque loss was measured for wide ranges of the input torque and speed. Several models of the load-independent and load-dependent losses of the gearbox components (gears, rolling bearings and seals), were combined into a global power loss model for the prediction of the gearbox efficiency. The average friction coefficient of the meshing gears was derived from the experimental results. A satisfactory correlation between experimental power loss measurements and the generated simulation results is observed under different operating conditions. Several aspects are discussed such as gear loss factor, friction coefficient and the influence of oil formulations.