Performance Research And Optimization Of Heavy-duty Hydraulic Automatic Transmission Torque Converter Based On Parametric Desig

Heavy-duty hydraulic automatic transmissions are extensively utilized in heavy-duty transportation machinery,construction machinery,and other equipment.Due to its high technical barriers,intricate design,and lengthy development period,domestic independent research capabilities for heavy-duty hydraulic automatic transmissions are currently weak and lack theoretical support.This study aims to develop a systematic design theory for guiding the development and modification of heavy-duty hydraulic automatic transmissions by breaking through the core technology.To achieve this,this study conducted research on parametric design methods,work performance analysis and optimization of torque converter in heavy-duty hydraulic automatic transmission.Based on the systematic analysis of the powertrain in heavy-duty hydraulic automatic transmission and the structure and working principles of the torque converter,and according to the characteristics of high power and high torque of the torque converter,a parametric design method of torus based on double elliptical arcs and a parametric design method for blades based on B-spline curves are proposed.The relationships between the design parameters of torque converter and its geometric model parameters are established,and the shape control of the torque converter’s geometric model can be realized by changing the design parameters.Based on the parametric design method of torque converter,the 3D automatic forming software of torque converter is developed.According to the design parameters in the parametric design method,the interface is developed,and the interface program is established to transmit the parameter values from the dialogue to the software core.Function modules such as parameter checking,parameter mathematical calculation and 3D modeling are integrated in the framework of the center scheduling software.The 3D model of the torque converter can be obtained immediately by inputting the design parameters in the automatic forming software,which greatly shortens the development period of the torque converter.Based on the 3D model of the torque converter generated by the automatic forming software,the performance of the torque converter is studied by the flow field analysis method.The flow field analysis model of the torque converter is established based on computational fluid dynamics,the parameters of external characteristic of the torque converter are obtained through the transient flow field analysis,and the flow characteristics of the internal flow field of the torque converter are revealed.Analyzing the flow field solutions,it is found that the working performance of the torque converter is insufficient.There are local high pressures and large-scale eddies in the internal flow field that are not conducive to hydraulic transmission.In order to enhance the operational efficiency and performance of the torque converter,it is imperative to optimize its design and improve the flow characteristics of the fluid field.Optimal design has been implemented to address the performance deficiencies of the torque converter.By conducting sensitivity analysis on the design parameters of the torus and blades,this study clarifies the degree of influence that different parameters have on torque converter performance,thereby distinguishing significant influencing factors.The interdependence between the two factors is analyzed,revealing the internal laws of interaction among design parameters.Based on this analysis,a response surface model is established to optimize torque converter design.After optimization,the stall torque ratio of the torque converter has been increased by 21.2%,while the stall pump torque coefficient has been improved by 13.3%.Moreover,the maximum efficiency before and after optimization remains stable at approximately 86.7%.