Essential Power Transmission Pvt. Ltd. Manufactures Worm Gear Unit. Essential Power Transmission Pvt. Ltd. Is an ISO 9001:2008 certified company. The company manufactures Standard and Customized Industrial Gear Unit. The Worm Gear Unit is compact, enclosed and are sturdy constructions combining rigidity and strength. Standard Fan Cooled Worm Speed Reducers are made from 11/8" centers to 24" centers and the ratio ranging from 10/1 to 70/1 and Horse Power Capacities up to 200 H.P.