STRUCTURE AND FUNCTION CLSS 3.4 PRESSURE COMPENSATION VALVE Function During compound operations, if the load pressure becomes lower than the other actuator and the oil flow tries to in- crease, compensation is received. (When this happens, the other actuator being used for compund operation (right side) is at a higher load than the actuator on this side (left side)).. W A A W T a a PPA PLS1 PPA PA PA 1 2 PLS PP RKS00740 Operation If the load pressure of the other actuator (right side) becomes higher during compound operations, the oil flow in ac- tuator circuit A on this side (left side) tries to increase.
If this happens, the LS pressure PLS of the other actuator acts on spring chamber PLS1 , and reducing valve (1) and flow control valve (2) are pushed to the left in the direction of the arrow. Flow control valve (2) throttles the area of opening between pump circuit PP and spool upstream PPA , and pressure loss is generated between PP and PPA . Flow control valve (2) and reducing valve (1) are balanced in position where the difference in pressure between PLS and PA acting on both ends of reducing valve (2) and the pressure loss between PP and PPA on both sides of flow control valve (2) are the same.
In this way, the pressure difference between upstream pressure PPA and down stream pressure PA of both spools used during compund operations is the same, so the pump flow is divided in prioportion to the area of opening of notch a of each spool. 10-45 SK818-5 SK820-5 turbo