A New Method For Contact Interface Topology Optimization And Their Application In Roller Bearings

As an important mechanical transmission part,the performance of bearings directly affects the safety and stability of the machine.The research shows that un-uniform distribution of pressure at contact interface is the main reason causes of premature bearing failure.Through the tiny modification of contact interface can improve the contact pressure distribution effectively and increase the reliability of bearings.So how to determine the modification value of bearing contact interface is an vital way to improve the reliability of bearings.The roller generatrix is main modification object in traditional bearing modification design,and there are two kinds of modification methods: recognizing Lundberg logarithmic curve as the ideal modification characteristic curve or using contact deformation to estimate modification value.The traditional modification methods unable to suit modification design of bearing contact interface very well in complex working conditions,and it is need iteration calculation repeatedly to get ideal roller modification value,which will consume lots of time and computing resources.Aiming at the shorting comings of traditional modification methods,elastic contact interface modification theory is developed in this article based on elastic mechanics and contact finite element method,e the characteristic curve and repeated structural reanalysis is no longer to defined,the ideal result can get only by the low order linear calculation,also,the application of cylindrical roller bearing modification is studied,the main research work is as follows:(1)The establishment of linear programming model,used in the elastic contact areas modification to achieve the best pressure distribution: Taking contact pressure as the optimization target,a linear programming model based on minimax model is established under the condition that the contact structures satisfies force equilibrium and deformation compatibility,through two numerical examples,the validity of the modification theory for the contact modification of elastic structures is verified.(2)The modification equations is extended from local contact coordinate system to the global coordinate space: Aiming at the complex structure or multi contact domain,based on the transformation between local coordinate and global coordinate,the mathematical relationship between the contact nodes modification value and the contact force is derived,the linear programming model is used to calculate the modification of contact nodes in the global coordinate system,and the validity of the modification theory is verified by numerical simulation.(3)The modification of misalignment mesh in contact interface is solved: When mesh is misaligned in contact interface,the virtual contact nodes is constructed using Lagrange interpolation function,the contact nodes force of one structure is assigned to another structure contact nodes by a certain weight coefficient to achieve two structures contact nodes alignment in virtual way,the numerical examples are given to verify the validity of the modification theory.(4)The cylindrical roller bearing modification new method is established considering the axial and circumferential coupling: The nodes modification on the initial contact generatrix of the maximum load roller is taken as independent variables,all the maximum load roller contact nodes modification value of the roller along the axial and circumferential contact area is taken as state variable,The calculation method of modification of the roller generatrix and the coupling of the maximum load roller and it's contact nodes with the corresponding raceway are explored.Taking cylindrical roller bearing as numerical case to simulation analysis,the results indicate that the edge effect of cylindrical roller bearings is eliminated,and the roller stress distribution is better,the validity of the modification method in bearing modification is verified.