Coal mining is the extraction of coal from inside the earth. Coal mining requires the use of heavy machineries and equipment that cut through the earth. A wide variety of gears is used in coal mining activities that are selected on two main parameters – tough reliable gearing and worm gearing. Some types of gears used in coal mining are winding gears, girth gears, planetary gears, bevel gears, spur gear, double reduction gears and gearboxes. Winding gears are normally used in cages for deep mines to allow miners to reach the pit face. Girth gears are used in sponge iron plants equipment and spares. Planetary gears are used in coal mine compressors, which reduces one-third of the compressors’ weight. Bevel gears help to reduce noise level significantly.