Some Design Issues and Optimum Design of Rolling Element Bearing

Abstract

Minimum weight, long fatigue life and adequate film thickness are some of the key design objectives in the optimum design of rolling element bearing (REB). The design approach by considering bearing envelope, fatigue life and wear life results in a low cost bearing. The weight, dynamic load capacity and Elasto-hydrodynamic (EHD) minimum film thickness of bearing are considered as some of the important design objectives. In the present study the above design objectives are optimized by using single objective and multi-objective optimization approach along with some realistic kinematic constraints. In single objective optimization problem the fatigue life is considered to be the prime objective, whereas for multi-objective optimization all the three design objectives are optimized simultaneously for the deep groove ball bearing. Both the nonlinear constrained single objective and multi-objective optimization problem has been solved using Particle Swarm Optimization algorithm and a hybrid PSO-TLBO algorithm. The contact stress and the thickness of outer and inner races have been introduced as new constraints in the formulation of the optimization problem. The PSO-TLBO algorithm uses a rank based constraint handling approach for efficient handling of different constraints. The results of the optimizations have been compared with the established available results. A constraint violation study has been carried out to prioritize the constraints. A convergence study has been performed to identify the key design variables. Encouraging results in terms of objective function values and CPU time have been reported in this study. A statistical test was performed to test the superiority of the proposed algorithm. In order to comprehend the changes in objective functions a response analysis is performed on the critical design variables. In addition, the optimum design variables obtained through the design optimization of the deep groove ball bearing are used for development of a CAD model. Then the stress analysis is performed