Research On Flow Characteristics And Buffer Structure Of Swashplate Piston Hydraulic Transformer

In the field of hydraulic transmission,constant pressure-network readjustment system（CPR）can recover the load energy effectively,reduce energy consumption and improve the system energy efficiency.As the core component of the system,the hydraulic transformer can control the hydraulic actuator without throttling loss.Therefore,the theoretical research on hydraulic transformer is helpful to improve the efficiency of CPR,and has certain theoretical significance and practical application value.Based on the analysis of the flow characteristics of swashplate piston hydraulic transformer,how to alleviate the phenomenon of pressure shock is studied in this paper.On the basis of consulting a large number of literatures,this paper first describes the research status and application of different types of hydraulic transformers.At the same time,the application and development of pressure buffer structure of hydraulic components are summarized,which lays a theoretical foundation for the application of buffer structure in hydraulic transformer.Secondly,the working principle of swashplate piston hydraulic transformer is described,and its mathematical model is established according to the structure of the target hydraulic transformer,the influence of variable pressure angle on displacement,instantaneous flow,flow fluctuation and variable pressure ratio of hydraulic transformer is analyzed,and the key variable pressure angle is determined,which lays a foundation for the research of buffer structure.Then,the differential equation of oil pressure in the piston cavity with buffer structure is established and transformed into the pressure increment equation of the piston cavity.A triangular slot buffer structure applied to hydraulic transformer is proposed,and given different depth angle and width angle,the relation curve between the size of the buffer structure and the pressure change of the plunger cavity is obtained,and the influence law of the buffer structure on the pressure change of the piston cavity is obtained,and the optimal size of triangular groove buffer structure for each distribution window is determined.Finally,the internal flow field models of swashplate piston hydraulic transformer under different pressure angles are established.Based on user defined function and dynamic grid technology,the transient simulation analysis of oil pressure in piston cavity of hydraulic transformer is carried out by using ANSYS software.The pressure distribution law of the internal flow field of the swashplate piston hydraulic transformer is obtained.The analysis results show that the buffer structure designed in this paper can improve the pressure shock phenomenon of hydraulic transformer effectively.