The Optimal Design Of Key Parts Of Transmission System Of Baja Racing Car

The Baja competition requires the team must design and manufacture their own Baja racing car to meet the requirements.However,most of the participating teams are college students,and the design and manufacturing methods of the vehicles have certain deficiencies,resulting in the failure of the key parts of the transmission system of the participating vehicles during the race.In this paper,the key parts of the transmission system of a Baja racing car are taken as the research object.Firstly,the three-dimensional modeling is established and then the optimal design is carried out through simulation static stress analysis and modal analysis.Finally,the matching of the optimized key parts is verified by virtual prototype simulation software in order to improve the reliability and lightweight of the key parts of the transmission system.1.According to the design parameters of the failed key parts of the original vehicle,the key parts are modeled,and then the failure causes and failure locations of the key parts of the original vehicle are analyzed.The results show that: the stress at the joint of the driving half shaft rod and the spline is too large;the stress at the joint of the bearing seat of the reducer box and the bolt of the box is too large;and the single tooth stress of the reduction gear and differential planetary gear is too large.2.Simulation analysis software can be used to design and optimize complex parts repeatedly to obtain the optimal solution,so as to achieve the purpose of saving cost and reducing R & D cycle.(1)Through the reliability simulation design and optimization of the parts,the reliability of the parts can meet the requirements of the maximum strength running state of the transmission system.(2)Material with better performance was selected for lightweight simulation design and optimization: TC4 titanium alloy was used for driving half shaft,7075-T6 aluminum alloy for reducer box,20 Cr Mn Ti for secondary driven gear of deceleration and differential planetary gear.After repeated simulation and optimal design,the final results are as follows: the minimum safety coefficient of drive axle is raised from 0.9 to2.9,the reducer box is raised from 0.6 to 2.0,the secondary driven gear of deceleration is raised from 1.0 to 4.6,and the differential planetary gear is raised from 0.9 to 3.3.(3)Through modal analysis,it can be concluded that the natural frequencies of the boxes on both sides of the reducer are concentrated between 3650Hz～8300Hz and230Hz～2500Hz respectively,and the natural frequencies of the differential housing,half-shaft gear and planetary gear assembly are respectively concentrated between5500Hz～13000Hz and 19700Hz～62600Hz.The natural frequencies between each other are neither equal nor multiples,and are much larger than the ground excitation frequency.Through the simulation and optimization of the key parts of the transmission system,the results show that the optimization results meet the requirements of material strength and the principle of lightweight racing car,and there is no resonance in the work,which meets the demanding requirements of the race.3.The three-dimensional model is simplified and imported into ADAMS simulation environment,and the transmission system simulation analysis is carried out in four different stages—starting acceleration condition,stable operation condition,braking condition and circulation condition to verify the feasibility and rationality of the optimal design of key parts of the transmission system of Baja racing car.The research in this paper provides a theoretical basis and a scientific and reasonable method for the optimal design of key parts of the transmission system of Baja racing car,and also provides some references for the design and manufacture of the transmission system of Baja racing car.