A pathway towards energy efficiency classes for gearboxes related to superefficiency

Abstract

The energy dissipation in the lifecycle of gearboxes is often dominated by the use phase. Energy efficiency targets can accelerate technological development. For tribological contacts, the definition of superlubricity with coefficients of friction of less than 0.01 has stimulated research to reduce friction. Similarly, this potential study on the energy efficiency of gearboxes aims to push research to reduce their energy dissipation during the use phase. Different cylindrical gear geometries, gear oils, and lubrication methods are evaluated using an energy efficiency index and mean energy efficiency. Superefficiency is allocated to the technological setup of a water-containing polyglycol, an extreme low-loss gear, and minimum quantity lubrication. Its corresponding values for the energy efficiency index and mean energy efficiency depend on the particular gearbox and the underlying operating cycle. In the future, the method used in this study can be used to introduce energy classes for gearboxes and to assign energy labels.