Study On Load Sensitive Variable Speed Flow Dividing Principle And Synchronous Drive Characteristics

Heavy equipment is an important tool of a great power,which has a huge load and requires two or more hydraulic actuators to be driven synchronously.Hydraulic flow dividing synchronous drive is one of the key technologies of heavy equipment.However,the principle of flow dividing valve has defects,which makes it difficult for the flow dividing synchronous drive system to obtain high synchronization accuracy under time-varying eccentric load and flow change conditions,which limits the application of flow dividing synchronous drive in high-precision occasions and can not meet the requirements of high-precision variable speed synchronous drive.This paper designs a load sensitive variable speed synchronous drive system,and innovates the structure of the flow dividing valve.The dividing principle of "variable speed dividing-compensation-partial load equalization" is put forward and the highprecision flow dividing mechanism is expounded under time-varying partial load and variable speed conditions.The principle of load sensitive variable displacement pump and new flow dividing valve is described and analyzed in load sensitive variable speed synchronous drive system.In order to deeply understand the working principle of the load sensitive variable speed synchronous drive system and the new dividing valve,the relationship between the parameters of the key hydraulic components of the system is studied.The mathematical models of the load sensitive variable pump,variable speed flow divding valve,pressure compensation valve and hydraulic cylinder are established,and the different effects of time-varying partial load on the flow dividing error and synchronization error are analyzed.Based on AMESim,two cylinder synchronous drive systems with load sensitive variable speed dividing,self-adjusting flow dividing valve and load independent flow distribution are established respectively.Under static partial load,time-varying partial load and variable speed conditions,the synchronous driving characteristics of load sensitive variable speed dividing sysytem are compared and studied,and the main factors and laws affecting the synchronization accuracy are revealed.The simulation results show that,compared with the traditional self-adjusting flow dividing valve synchronization system,the load sensitive variable speed synchronization control has the advantages of high efficiency,adjustable speed and wide speed range;the load independent flow distribution synchronization control system has poor anti bias load ability because of the independence between the two branches and no flow compensation mechanism.Through the research in this paper,the ability of the flow dividing valve and its synchronous control system to resist dynamic and static unbalanced loads and flow changes has been improved.The simulation results show that the dividing error and synchronization error can be controlled within 0.1% and 1% respectively.The research of this paper will lay a theoretical foundation for the design of high-precision flow dividing valve,provide a scheme for high-precision hydraulic synchronous drive under bad conditions,and promote the development of high-precision flow dividing valve and its synchronous system.There are 88 figures,10 tables and 90 references in this paper.