Design And Study On Wear Characteristics Of Chain Transmission System Of Transfer

The toothed chain is also called silent chain,because of its high transmission accuracy,low noise and excellent wear resistance,it has been widely used in the field of mechanical transmission.This paper is supported by National Natural Science Foundation project “Variation Theory and Key Design Technology of Silent Chain(51775222)” and Science and Technology Development Project of Jilin Province “Key Technology Research on the Timing Chain System of Passenger Vehicle Hybrid Engine(20200401136GX)”,designed and analyzed the chain drive system for the transfer case of a four-wheel drive vehicle.This paper described the current research status of the chain drive system for the transfer case,explained the research significance of the thesis,and analyzed the switching process of the vehicle drive mode under electromechanical control for the transfer case structure of the four-wheel drive vehicle in a timely manner,and designed the chain drive system for the transfer case.The chain drive system selected the inner-outer compound meshing Hy-Vo chain.The paper designed the parameters of the inner-outer compound meshing chain plate and the involute tooth profile sprocket,and carried out the system layout design,established a three-dimensional model of the system.By establishing a multi-body dynamic model of the toothed chain system,the dynamic characteristics of the system are studied,and the system’s motion trajectory,chain plate angular velocity change is analyzed separately;The contact force characteristics between sprocket and chain plate,chain plate and pin and pin are analyzed.The simulation results show that the design of the transfer case chain transmission system fully meets the smoothness requirements of its motion,and the overall motion and mechanical characteristics of the system can meet the expected design requirements.In order to study the inherent characteristics of the system and to explore whether the system will be affected by resonance during operation,a finite element modal analysis was carried out on the chain drive system.The static analysis of the driving sprocket,the driven sprocket and the overall chain transmission system under prestress was carried out,and based on this,the prestressed modal analysis was carried out,The first six modes and natural frequencies are extracted and analyzed.Through the free modal analysis of the integral chain drive system,the results are compared with the modal analysis results under the condition of prestress,in order to explore the influence of stress stiffening on the chain drive system,and analyze the influence law of prestress on the natural frequency of the system.In order to study the wear characteristics of the transfer case chain,the transfer case chain system that has passed the 30,000-kilometer road test was disassembled,the chain length change after the test was studied,the wear elongation rate of the chain was calculated,and the test The latter chain system conducts microscopic scanning analysis,and mainly observes the position of the bright band of the chain plate and the pin shaft and the position of the pin shaft crack by electron microscopy to study its wear characteristics.To sum up,this paper proposes the design and analysis method of the transfer case chain transmission system,and carries out the simulation analysis and wear characteristics study of the chain system,which enriches the design theory of the transfer case chain system of the four-wheel drive vehicle.The NVH analysis of the transfer case chain system has laid the foundation,which has reference significance for the further complete localization of the chain transfer case.