Structure Design And Finite Element Analysis Of Hydro-mechanical Continuosly Variable Transmission

Tractors,the commonly tool in agricultural production,which power come from the engine.Then it transfer to the bridge through the transmission.Transmissions,as a bridge in the total running process,transmit torque all the constantly.Which key parts and the gearbox’s properties,such as strength、stiffness and life,will affect the working efficiency of the tractor inevitably.Hydro-mechanical Continuously Variable Transmission rely on hydraulic drive control speed regulation and the combination of mechanical transmission to realize step-less variable speed.It has the merits of the high transmitted power and high transmission efficiency at the same time.The transmission device which used on the high power vehicles not only can improve the power performance and fuel economy,but also can reduce the complexity of the operation.Above all,it has good practical value.This paper based on the independent research and development design of Nanjing agricultural university institute of technology in power tractor hydraulic mechanical automatic transmission on the experimental prototype.After performed the prototype’s disassembly and assembly experiment and the analysis of the gearbox vibration test,the design of the hierarchical casting gearbox is put forward,which can integrate control system integration.In the end,All parts modeling of HMCVT and the virtual assembly were made by Solid works.And the finite element analysis on gearbox and output shaft were made by ANSYS Workbench.The main research points were shown as below:1.Based on the HMCVT laboratorial bench,the components of the bench was analyzed.The disassembly and assembly process of the HMCVT was described detailedly.Many significant parts of prototype vibration velocity was tested.On the basis of measured vibration speed in different case,the reliability of the gear-casing could be assessed.2.The total transmission composition and different section transmission line of HMCVT was described in details,which included the institutions of the double plant row.Solid works,a kind of modeling software,was used to complete all parts of HMCVT modeling and virtual assembly and interference checking,which make basis for following analysis of the finite element.3.The simplified hierarchical gearbox assembly model was exported into ANSYS Workbench,where could made the finite element statics analysis and modal analysis.On the basis of the finite element statics analysis results of the gearbox in HM1,the strength and stiffness of the layering gearbox could be accessed.According to the modal analysis results of gearbox,the stability of the layering gearbox could be accessed.The analysis outcome showed that all the gear casing stiffness,strength and stability meet the requirements.4.Fatigue life of the finite element analysis of the HMCVT output shaft could be worked out.According to the analysis result of the Safety Factor、Life and Damage of the output shaft,whether it would happen to the fatigue damage could be judged.The analysis results showed that the output shaft meet the fatigue safety design requirements.