负载敏感变量泵稳态特性研究

Steady State Characteristic Analysis of the Load-sensing Pump

建立负荷传感系统稳态时的数学模型,并通过研究得出负荷传感系统存在3种稳定状态:在状态I,敏感阀阀芯位移xLS0=0,负荷传感系统工作正常;在状态II,xLS0>0,排量控制油缸腔体内的控制压力py和泵出口的压力pP相等,此时敏感阀的设定压差值ΔpSET和负载压力pL均比较低,系统处于不稳定工作状态;在状态III,xLS0<0,负载所需流量大于泵提供的流量,泵满排量供油,此时系统虽处于稳定状态,但负载敏感阀控制不起作用。在设计和使用中,应避免负荷传感系统工作在状态II和状态III。

The mathematical model of the load-sensing system was built.The operating point of the load-sensing system with a critical center spool of the load-sensing regulator was determined by three conditions.As condition I,the load-sensing regulator spool displacement xLSis always at the null position for the load-sensing regulator with a critically lapped spool.Under condition II,the control pressure py and the pump pressure pP are the same.This would occur when the system pressure differential setting ΔpSETand the load pressure pLare small.Under condition III,The demand flow is larger than the supply flow by the load-sensing pump.Condition I is the ＂normal＂ operation condition.Conditions II and III should be avoided in practice.