Coal mill gearbox case study verF 2 - Hy-Pro FiltrationOct 2, 2006 . power generation unit has five or six mills. The gearboxes that run these coal mills are usually lubricated with high viscosity oil, such as ISO.coal mill gearbox,coal mill gearbox,Premium Transmission | Coal Pulverzing Mill GearboxCoal Pulverzing Mill Gearbox. RANGE. Power range upto 1200 kW kW. Sizes : 8.5 ES / 8.5 Ex / 10P (2/3 stage) Sizes : BPV-150 to BPV-250 (2 stage) Bevel-.