Research On Gear Dynamics Of Electric Vehicle Transmission Considering Tooth Surface Accuracy

As one of the most commonly used transmission modes,gear transmission is widely used in industrial production,transportation,aerospace,instrumentation and other industries because of its light weight and high efficiency.In recent years,with the development of electric vehicles,it is urgent to study the gear transmission system applied to work condition of variable speed of electric vehicles.Based on the international scientific and technological cooperation project "Research on Key Technologies of Electric Vehicle Lightweight and Power Transmission System"(2014DFA80440)and the National Natural Science Foundation project "AccuracyOriented Dynamic Design Theory and Experimental Study of Large Coincidence Gears"(51775156),this paper optimized the design of gears in the electric vehicle motor-two-speed transmission system,and analyzed concretely the factors affected single degree of freedom spur gear transmission system.Also,this paper established a general dynamic model of gear transmission by using concentrated mass method,and a numerical simulation was performed on the model.In order to analyze the influence of gear surface roughness on the dynamic characteristics of gear system and further balance the relationship between tooth surface accuracy and processing cost,this paper studied on the dynamic characteristics of gear system from the angle of random roughness of tooth surface.According to fractal theory,a mathematical model of rough gear surface with random roughness has been established for gears in transmission.In addition,combined the above mathematical model,this paper researched and analyzed the influence of tooth surface roughness on the gear dynamics in grinding process by the numerical simulation method in the singledegree-of-freedom gear dynamics model,and the influence of tooth surface roughness on the dynamic response of the system at different rotational speeds.At the same time,on the condition of the corrugation of gear tooth surface,this paper established a model of gear transmission the static error including corrugation by using fractal theory,researched the influence of tooth surface roughness on the dynamic characteristics of the system.Based on the parameters of the whole vehicle,the parameters of the driving motor suitable for the two-gear active drive system are matched.Then on the condition of optimizing the parameters of the gear system,designed the interval parameters.Finally,the roughness parameters were designed by using the dynamic method.