Differential cylinder servo system based on speed variable pump and SUM pressure control principle

摘要

In this paper an energy saving approach, which utilizes speed variable pumps to implement closed loop differential cylinder control, is presented and investigated. In the control circuit, two compound controlled speed variable pumps are used to compensate the non-symmetric flow of differential cylinder. To eliminate the cavitation and tension caused by the leakage of pump and cylinder, a sum pressure control principle was also proposed. The experiments have proved that the new system has the same technique feature as that of servo valve controlled system. Due to the elimination of all throttle elements, the system efficiency can be improved greatly.