Modeling and Analysis of a Flow Divider Valve

Abstract

Flow divider valves are often used in hydraulic systems to synchronize actuators. The basic structure of the flow divider valve is by incorporating a compensating spool to maintain equal pressure drops across metering orifices. Ideally, flow divider valve splits a single source flow into two parts under a specified ratio regardless of load conditions. In practical applications, any change in load pressure will cause force imbalance on the compensating spool, which will alter the flow rates through the metering orifices and affect the control accuracy consequently. In this study, the steady and dynamic performances of a flow divider valve are simulated numerically by solving the characteristic equations. The parameters studied in this research are centering spring constant, compensating spool mass, and metering orifice area. The simulation results show that flow force is the key factor to affect the flow division accuracy. Flow division error increases with increasing the load pressure differential, centering spring constant, and metering orifice area. Even though decreasing the spring force or the metering orifice area can reduce division error, the spring force still needs to be large enough to overcome the spool static friction and the orifice area cannot be too small to lose energy efficiency. Dynamic division error increases with increasing load pressure differential and metering orifice area but with decreasing spool mass. Increasing load pressure differential, spool mass, and metering orifice area will enhance the oscillatory tendency and increase the valve settling time. The centering spring constant has no obvious effect on the valve dynamic response.