The purpose of this study is to determine the stress distribution of uncoated and coated ball bearings by using finite element analysis. The coatings used in this study are titanium nitride (TiN), titanium carbide (TiC) and chromium nitride (CrN) with a thickness of 5 microns. A contact analysis has been performed on ball bearings to compare the performance between coated and uncoated ball bearings. Boundary loads of 5000 N is used for contact analysis. This study tries to establish a simple, two-dimensional expression for the elastic deformation with the inner ring and ball bearing as a angular or curvature model in terms of the geometry of the coating contact surfaces. The coating of ball and raceway surfaces is a requisite but difficult factor to be determined during design, so it is desirable for engineering to understand the effect of surface coating on the motion of ball and subsurface stresses in bearing. For contact analysis, the maximum contact pressure and maximum stress on the coating, inner ring and ball bearing have been used for comparison. The results of this study show that, among other coatings, TiC provides the best protection for the ball of the ball bearing. This is because the low Poisson's ratio of TiC in other coated ball bearings helps reduce the stress on the ball bearing, even though TiC has the lowest Young's modulus in the coating. When a lower boundary load is applied, high COF will also cause an abnormal increase in the maximum stress on the contact surface between the coated or uncoated ball and the inner ring of the ball bearing.

This study is an analytical evaluation of contact and wear on ball bearings using the finite element method. Ball bearings are used in various sectors, such as in the automobile, turbine and aircraft engine industries, to reduce rotational friction and support radial loads. Nevertheless, ball bearings often experience failure due to wear as a consequence of contact pressure. The contact between the ball bearing components will affect the surface of the balls, and the inner and outer rings. Therefore, the main objective of this study was to examine the stress distribution and elasto-plastic deformation in order to analyse the contact between the ball bearing components. Most of the existing contact and wear models for ball bearings only take into account the elastic model. However, an analytical evaluation of contact and wear using an elastic model, while ignoring plastic deformation, is inaccurate. In this study, a contact analysis was performed using elasto-plastic models of a ball bearing, and the results were validated using data from a previous research. Boundary loads of between 100 N to 800 N were applied and plasticity values of 550 MPa, 1050 MPa, 1550 MPa and 2050 MPa were used to analyse the contact behaviour. As the boundary load increased, the maximum contact pressure and displacement of the ball bearing increased. As the plasticity, E2 rose higher, the maximum plastic strain was lowered proportionally.

Contact pressure has a great influence on the realiability and the life of ball bearings. However, most of the previous contact and wear model mainly focussed on the elastic model. In this paper, considering the contact between ball bearing and inner ring, both elastic and elasto-plastic contact model are established to investigate the contact behaviour on ball bearing. Three types of materials have been used to compare the contact behaviour which are bearing steel, silicon nitride and aluminium oxide. Aluminium oxide experienced highest maximum contact pressure for elastic model while silicon nitride experienced highest maximum contact pressure for elasto-plastic model. The stress contour of elastic model was elliptical shape while elasto-plastic model was elliptical shape before the material yields.