The estimation of the losses due to friction of meshing tooth flanks is an important point in the design of gear drives. In addition to other design factors, the efficiency of a gear stage is an important criterion for selecting the type of gear and the number of gear stages in order to achieve a desired gear ratio. This manuscript deals with various approaches with which the friction losses that result from the meshing flanks of a face-gear stage can be estimated. In addition, the influence of the directions of sliding and rolling speed is investigated, which is particularly important for gear stages with axle offset, since the two velocities are not collinear. The calculation method is validated for low speeds by means of experiments on a transmission test bench.
Coefficient of frictionElastohydrodynamic lubricationFace-gearMeshing efficiencyTooth contact analysisTransmission test bench