ABSTRACT
The purpose of a gearbox lubrication system is to provide an oil film at the contacting surfaces of working components to reduce friction. Equally as important, the lubrication system absorbs heat generated in the gearbox and dissipates it so that component temperatures do not become excessive. The viscosity index is a measure of how much the oil viscosity varies with temperature. The selection of a gear oil depends on several factors, including the unit’s operating speed and load, ambient temperatures, and which lubricants will be available at the operating site. Extreme pressure lubricants are petroleum-based oils containing special chemical additives which can increase the load-carrying capacity of gears by forming a film on the metal surfaces which provides separation when the lubrication film becomes thin enough for the asperities to contact. There are two types of lubrication systems in use: splash and forced feed. Successful splash lubrication of a gearbox is more a matter of development than analysis.
