STUDY ON STEADY FLOW FORCE OF NON-CIRCULAR OPENING SPOOL VALVE

摘要

The non-circular opening spool valve is one of the basic configurations of hydraulic valve. Its characteristic of the restriction is often a combination of several different notch forms placed axisymmetrically on spool. This type of valves is widely used to control the velocity and direction of hydraulic actuators. With spool motion, its restriction location and flow jet angle can be shifted, and therefore it is difficulty for traditional theoretic method to evaluate precisely its flow force. In this paper, the combination approaches consisting of the CFD, theoretical analysis and experiment are adopted to investigate the steady flow force in this type of valves. The numerical results shows that the steady flow force and flow rate-pressure drop characteristic on whole opening range are agreement well with that of experiment ones. The study reveals that the steady flow force hi the non-circular opening spool valve has very different characteristics with that of circular opening spool valve. This study provides a practical and very useful guidance to reduce the stroking force of hydraulic valve.