Influence of race thickness on contact stress of inner and outer races of angular contact ball bearing using photoelastic experimental hybrid method

In recent years, there has been greater demand for higher spindle speeds in majority of moving and rotating parts. As a result, one of the important issues among bearings is to meet the requirement for high performance under severe operational conditions. Stress analysis remains one of the fundamental steps in the analysis of the performance of bearings since stress concentrations are known to often lead to bearing failures. Experimental systems that permit measurements of stresses on bearing races remain a great challenge to many researchers. This explains why studies involving analysis of stresses on the bearing races are not common in open literature. To overcome this challenge, a photoelastic experimental device with the capability of applying combined axial and radial forces was used to measure the stresses induced on the races of a proposed angular contact ball bearing (ACBB). The proposed ACBB was designed with a larger outer race thickness. The influence of race thickness on stress behavior as well as deformations has not been experimentally investigated. Through photoelastic experimental hybrid method (PEHM), biaxial loading was applied to an ACBB. The critical regions with high stress concentrations were identified. The contact stress magnitudes were also extracted. Contact stresses were found to be slightly higher on the inner races than on outer races. For all loading conditions, the location of the maximum value of contact stress was at position 0, situated at the base of the bearing housing. This was followed by 1R, 1L and finally 2R and 2L. The notation 1R and 1L means location of bearing ball on right and left of position 0 at the base of bearing housing. The results showed that the proposed design with larger outer race thickness led to decrease in the contact stresses. This decrease was explained on the basis of high stiffness and reduced deformations. These findings can give important guidelines on bearing designs for advanced engines operating at severe conditions such as increased spindle speeds.