Friction Control in Planetary Gearbox by Selecting Grease with Proper Viscosity

The paper is directed towards the selection of proper viscosity grease to be used in a gearbox. Based on the pitch line velocity, the optimum viscosity is selected. A four stage planetary gearbox is employed for the test. Different losses responsible for efficiency loss were calculated. Major loss which is friction loss was targeted. The grease viscosity influences the frictional losses in the gearbox, hence various greases with different viscosities are used and the performance is tested. The test result showed that the selection of grease with viscosity close to the optimum viscosity improves the efficiency by 1.2 %.