New Hydrostatic Transmission Concept for Large Earth Movers

The transmission system described in this paper is basically of hydrostatic concept, with four centrifugal pumps arranged in series, series-parallel and parallel for varying torque and speed. The main departure from the conventional hydrostatic system is the application of centrifugal type pumps with low viscous oil instead of positive displacement pumps with servo operated swash plates using high viscosity oil and much higher pressures. The main objectives of the innovation thus envisaged is to minimise maintainence problems which are often encountered in practice for conventional mechanical transmission, hydrodynamic transmission and hydrostatic transmission with positive displacement type pumps. The salient features of the "New Transmission Concept" are described in the text below.