Experimental Stress Analysis of Spherical Roller Bearing for High-Speed Trains Using Photoelasticity

Most studies on bearing stress analysis have considered single row rolling elements. In this study, the stress behavior of a spherical roller bearing with two rows of rolling elements is investigated. Photoelastic experimental hybrid method, is applied to investigate the interior and contact stresses of high-speed train bearings under combined axial and radial loads. The experimental results show that the bearing under investigation has the capability of sustaining high loads. The sharing of the loads between the two rows of rollers was found to contribute to excellent load bearing capabilities. It is also shown that the barrel-shaped roller has an influence on the stress concentrations and their distributions on the bearing races. At low radial and axial loads, the stresses on the races result from the bulging out section of the roller. As load is increased, the roller deforms and race stress occur at the ends of the roller, which now act like a punch. Only half of the bearing structure was found to be highly stressed. At position 3, the few isochromatic fringes on rollers and inner race shows that low stress concentrations occur on them. A comparison of the results from spherical roller bearing (SRB) and tapered roller bearing (TRB) showed that the stresses induced at the bearing races of the TRB bearing have higher magnitudes than those of SRB. This observation can be attributed to the two rows of rollers in SRB. High stress concentrations often lead to crack initiation and spall growth. Therefore, the low stresses on the SRB makes them more suitable for applications involving heavy loads.