Comparison of the efficiency of the high speed low torque hydrostatic drives using bent axis motor: An experimental study

Abstract

This article is aimed at analysing the steady-state performance of four hydrostatic drives and compares their overall efficiency. The speed of the hydrostatic drives is controlled by speed controlled vane pump, variable displacement flow compensated pump, variable displacement pressure compensated pump and proportional direction controlled valve. Bondgraph simulation technique is used to model the hydrostatic drive. The relationships of the loss coefficients with the state variables obtained from the model are identified through experimental investigation. Using them, at different torque levels, the performances of the hydrostatic drives are studied on their slips, torque losses and the overall efficiencies and they are validated experimentally. It is found that hydrostatic drive using speed controlled vane pump exhibits the maximum efficiency, whereas the poorest efficiency is shown by the valve controlled system out of the four drives considered in the analysis.