Improving the efficiency of valve-controlled systems by using multi-chamber actuators
Keywords:Digital fluid power, multi-chamber actuators, throttling losses
This paper outlines how multi-chamber actuators can improve the efficiency of valve-controlled systems. Resistive control is a major source of energy losses in valve-controlled systems that share the same pump to drive multiple loads. In the proposed concept, by selecting different chambers, the load on the multi-chamber actuator can be transformed into different pressure and flow rate levels, allowing the adaptation of its load to the loads on other actuators. This can lead to a reduction of resistive control energy losses that occur between pump and actuators when driven simultaneously. Such systems are seen as an intermediate solution between resistive conventional hydraulics and throttle-less digital hydraulics. As a case study to highlight the possible efficiency improvement, a concept of a load sensing system with a conventional and a multi-chamber actuator is analysed. To determine its efficiency, the equations that describe its static behaviour are presented. Evaluating them for a set of load forces and speeds demonstrates how the load transformation occurs and how it can improve efficiency.