应用于数字变量马达的高速开关阀

High-speed on/off valves applied in digital displacement motor

为了研制满足数字变量马达需要的"高频响、大流量,低开阀压差,低节流损耗"高速开关阀,设计一种新型的二位三通滑阀结构的高速开关阀,采用阀套运动的结构来减小液动力有效的提升阀的开关速度,采用中位死区的结构来实现预降压和预升压以减小开阀压差.通过建立阀套的运动模型和流场动态仿真验证了该阀的快速开关性能及通流能力;同时建立单柱塞配流单元的柱塞腔压力动态模型,验证了低开阀压差的可行性,并确定最佳的中位死区长度;分析不同转速下在不同位置关阀的节流损耗及开阀压差,得到在某一转速下使节流损耗及开阀压差均很小的最佳关阀角度.理论和仿真研究表明,这种新型的二位三通高速开关阀能够满足数字变量马达对高速开关阀的需求.

The valves used in digital displacement motor(DDM)must satisfy four requirements:fast switching response,high flow rate capability,low pressure difference and low throttling losses.A novel two-position three-way spool valve with middle dead-zone and sleeve-moving structure was designed for the requirements.The steady and transient flow force of the moving sleeve decreased,which sped the valve switching.The pressure difference across the valves decreased with the help of dead-zone structure by compressing or decompressing oil in piston volume.The sleeve's kinematics and CFD model were built to verify its fast switching response and large flow rate capability.The instantaneous pressure in one piston chamber was also modeled to analyze valve-opening pressure difference and valve throttling losses at different motor speeds and valve-closing angles.The optimal dead-zone length was found by making the pressure difference small at different load conditions.These analysis reveals that there is always an optimal closing angle corresponding to different motor speeds,which makes the valve opening pressure difference and valve throttling losses all very small simultaneously.Theoretical and simulation research indicates that the novel high-speed on/off valves can greatly satisfy the requirements.