Parametric Design And Finite Element Analysis Of Car Differential

As an important transmission part of a car, differential's role is to make the two sides of driving wheels rotate at different speeds, and ensure the them roll only in order to meet the vehicle driving kinetic requirements, when the car is turning or driving on uneven pavement.First of all, it did the design and calculation of the differential gears according to the given parameters of a car combined with the symmetric cone planetary gear differential design theory and got the basic and formal parameters of the geometric models; Then made a precise three-dimensional parametric modeling to the bevel gear of differential in the way of drawing spherical involute based on CATIA software which has powerful surface modeling function. Planetary gear and axle gear of differential have mutually perpendicular axes and they share the same module and pressure angle. It also did parametric modeling to the differential case and other parts of differential using the three-dimensional scanning point cloud and its assembly relationship with the differential gears. Each component of differential has independent parametric system which are associated by their mutual assembly relationship. Comparing to the traditional design process of differential, three-dimensional parametric modeling process is more simple and efficient, and can shorten the design cycle since you can modify the geometry rapidly according to the following simulation results.It carried out finite element analysis to the main components of the differential——planetary gear and axle gear. The assembled geometries of differential gears were imported into the finite element software ABAQUS based on its data interface, selected right cell type and mesh technology which must be appropriate for contact nonlinear finite element analysis, exerted two different boundary condition and loads, it would generate two sorts of finite element contact models which appropriate for static contact analysis and dynamic contact analysis respectively. The finite element analysis simulated the condition that the car is in the first gear, or generating the maximum torque,driving straightly.The results of the two kinds of analysis are consistent, and illustrated the engaged state of differential gears, contact force and contact area, the distributing condition of contact stress, tooth root bending stress. Then, it proposed the improvements aiming to the design of the geometries according to the analysis results.It did modal analysis to the differential gears, calculated the top ten natural frequencies and mode shapes which provide the theoretical basis for avoiding resonance in practice. Finally it made a summary of the full text and gave some lacks and prospects of the research.