Oil technology has increased markedly over the last two decades, with synthetics becoming more and more prevalent. Gearbox manufacturers have continued to demand more from their designs as this technology evolves, allowing for even higher torque capacities from the same sized units.
The correct oil to use in industrial gearboxes is dependent on various factors, namely; the type of gearbox, individual manufacturer preferences and the duty cycle of the application, which considers the torque loadings, hours of operation and ambient conditions.
Bonfiglioli’s A Series of bevel-helical gearboxes, for example, specify a range of lubricants based on both the type of duty and the ambient conditions. For light duty at 20 degrees Celsius, they call for 150 viscosity mineral or synthetic oil. At 40 degrees Celsius they call for 220 viscosity mineral or synthetic oil. For heavy duty at 40 degrees Celsius ambient, Bonfiglioli calls for 320 viscosity synthetic and 460 viscosity mineral oil.
Wormboxes place different demands on lubrication, as they comprise brass for the wormwheel and steel for the balance of the components. Standard units in most mounting positions use a synthetic oil (Bonfiglioli specifies Shell Tivela S320 out of the factory), but an anti-foaming agent must be present as many units are ‘sealed for life’.
Many larger gear reducers are supplied unlubricated ex works, so it is important to get both the correct oil type for the application and the correct oil amount for the mounting position. Consider that gearboxes mounted vertically require more lubricant than those mounted horizontally (sometimes double the amount) so that the top bearings don’t run dry. In larger gearboxes, this can mean 50 or 60 litres of oil is required, which also carries with it substantial cost.
All Torque carries gear oil in bulk and is able to decant the amount required for individual applications.