Energy saving potential of load sensing system with hydro-mechanical pressure compensation and independent metering

This paper reports a systematic analysis of a load sensing system with hydro-mechanical pressure compensation and independent metering. In contrast to a conventional spool valve controlled load sensing system, the proposed load sensing system is characterised by both meter-in and meter-out pressure compensation. Quasi-static behaviour analysis is applied to three distinct load sensing systems: the meter-in pressure compensation system (MIPCS), meterout pressure compensation system (MOPCS), and pressure compensation load sensing system (PCLSS). The energy usage equation shows that minimising pump supply pressure is the only way to ensure high energy saving efficiency; proper opening modes between the meter-in and meter-out orifices of the MIPCS and MOPCS are also obtained by deducing and analysing appropriate equations. Systems parameters are then kept constant as the pump supply pressure of the three systems are compared by varying the external force. Comparison results show that the pump supply pressure of both the MIPCS and MOPCS are lower than that of PCLSS, and that the optimal metering pressure compensation method is dependent on the working mode. Taken together, the results show that a load sensing system with independent metering offers more significant energy savings than the traditional load sensing system.