Taking pressure compensation valve in load sensing multi-way valve as research object, based on the dynamic mathematical model, the dynamic characteristics and the law that the structure parameters affected the characteristics were analyzed. The research methods and results provide analytical tools and design documentation for the structure design and the theoretical study on the outlet pressure compensation multi-way valve.

In response to the problem of large energy waste in the loader actuator, a hybrid loader boom arm energy recovery and regeneration system is proposed, which adopts a supercapacitor as the energy storage element. Firstly, the working principle of the hybrid loader boom arm energy recovery and regeneration system is analyzed. Secondly, the mathematical model of the components is analyzed. Finally, AMESim is used to model the system. The simulation is carried out under typical working conditions with the LiuGong ZL50C loader as the simulation object and compared with the conventional system. The simulation results show that the hybrid power system does not affect the motion characteristics of the loader boom arm system compared with the conventional system. The hybrid power system can perform energy recovery regardless of the mode of operation, and the energy recovery efficiency reaches 55.7 %. When the system enters the hybrid mode, the supercapacitor SOC fluctuates less, and the energy regeneration efficiency reaches 90 %. The hybrid power system can effectively reduce engine fuel consumption and pollutant emissions, with the system's energy-saving efficiency of 44.4 % and CO, HC, and NOx emissions reduced by 41.1 %, 47 %, and 19.8 %, respectively. The system provides a reference for the research of energy-saving technology of the loaders, effectively reducing the operating cost of the loaders.

Hydraulic excavator slewing system is an important component of the excavator and its core-component is the rotary motor. When the rotary hydraulic system starts, stops, and reciprocating works, dynamic characteristic of rotary motor anti-reverse valve has a great influence for working condition of the whole system. Through researching working principle of hydraulic system anti-reverse valve, establish dynamic mathematical model of anti-reverse valve, analyze dynamic response of the model, and get the theoretical foundation of the impact of anti-reverse valve middle chamber throttle opening on hydraulic system. According to the actual working condition of the excavator slewing hydraulic system, establish the system AMESim simulation model, take different parameters of the anti-reverse valve throttle opening, conduct simulation and analysis of the anti-reverse valve characteristics, and validate throttle opening has a great influence on dynamic characteristics of the hydraulic system.

The damping characteristic of throttle valve of feedback circuit in pressure compensation system is discussed and the working principle of pressure compensation is analyzed in this paper. In order to illustrate the necessity of the existence of the throttle valve and the effect of throttle valve diameter on the stability of pressure compensation system, the system is modeled in AMESim. Through simulation and analysis, we get such a result: hydraulic shocks can be weakened without affecting its speed of response by setting a reasonable diameter of the throttle valve which plays an important role in keeping the stability of the whole system.