SAUER90Series Variable Pump Intermediate Position Stability Study And Control Strategy

SAUER90series axial piston pump is in itself a servo control system. It applieselectro-hydraulic proportional control, which uses servo-proportional valves to controlhydraulic cylinder and push the swash plate and alter the inclination to change the flow. Thiscontrol system can response quickly and dynamically with the high sensitivity. Meanwhile,with the improvement of sensitivity, its anti-jamming capability descends, even minorinterference can lead to the huge change, which influences the construction machinery walkhydraulic system greatly.The thesis concentrates on the SAUER90-55axial variable piston pump as well as thesystem consisted by SAUER90-55and SAUER90-55quantitative motor and utilizes forcebalance equation and flow continuity equation to construct the static mathmatical model ofSAUER90-55and the mathmatical moderl of hydraulic system consisted by variable pumpand quantitative motor, the transfer function of which will be calculated. Then the thesisanalyzes the factors that will influence the stability of SAUER90-055axial variable pistonpump. Also the corresponding dynamic model of hydraulic system will be constructed and hefacters hat influence the stability of variable pump will be analyzed. In view of the lowanti-jamming capability of electro-hydraulic proportional control, the thesis adopts pressurenegative feedback control strategy and the simulation results discloses that the pressurenegative feedback control can help to improve the stability of variable pump. Basing on thetheoretical analysis above, the thesis constructs a hydraulic test platform consisted by variablepump and quantitative motor. Taking the influential factors and pressure negative controlstrategy into consideration, the thesis start the test. The results are correspondent with thesimulation result, which shows that it is correct to adopt the control strategy.