Analysis Of Contact Stress Of Roller And Roller Pin And Their Structure Optimization

In the field of engineering and mechanics,because contact problem is complexity with nonlinear owning to material deformation,load and the influence of the change in the contact area. it has always been an object that people want to conquer. We usually use the mathematical analytical method and numerical method to solve contact problem, use mathematical analytical method solve the nonlinear problem is difficult to obtain the exact solution, conventional numerical method need multiple iterations, it will occupy more resources and time. The finite element need to establish a geometric model and load boundary conditions, using simple problem instead of a complex problem solving, the problem is simplified, so it is widely used in the contact problem solving.The research object of this article is the CAM mechanism of diesel injection pump,the emphasis is the phenomenon of uneven stress on the roller pin when the roller contact with roller pin. This phenomenon can lead to early fatigue wear of the roller and roller pin, seriously affect the working performance and service life of the fuel injection pump mechanism. As a result, the next we will put the problem as the research background, 3d entity modeling was carried out on the wheel and the roller pin, and import it into ANSYS software to analyze their stress and strain, the results showed that on the linear area of the roller pin contact with the roller had an obvious stress concentration phenomenon on both ends, the wear and tear of roller pin position is consistent with the engineering practice.In order to improve the situation, we put forward three ways of optimization for this structure, Optimize the cylindrical of roller pin separately and optimize the wheel inner hole and optimize the wheel and the roller pin at the same time. Results show that, in this way we can alleviate the edge effect effectively, improve the status of the stress distribution is not uniform on the roller pin. By analyzing the convex metric size of the roller and roller pin in different conditions of load type fix, the larger the load, the larger the convex metric.Finally, we analyze the different heat treatment methods and performance of the Crl2 steel of roller’s materials under different heat treatment, different materials were analyzed by finite element software that roller contact with the pin, after we get the surface stress distribution in the process of roller pin, we can know Cr12 is better than 17CrNiMo6.