This paper presents an integrated thermo-mechanical model for analyzing angular contact ball bearings (ACBBs) operating under oil-jet lubrication. The proposed approach enables a comprehensive analysis of both the mechanical and thermal behavior of the ACBB system. The proposed formulation employs a quasi-static approach to accurately calculate contact loads and heat generation, taking into careful consideration variations in internal clearance resulting from factors such as surface pressure, centrifugal forces, and thermal expansion. For the thermal analysis, a refined thermal network model is utilized. The proposed thermal model incorporates a newly derived correlation for the drag coefficient under oil-jet lubrication, which is obtained through high-fidelity computational fluid dynamics simulations. The validity of the proposed model is confirmed through comparison with experimental data. Furthermore, extensive simulations are conducted to investigate the impact of bearing fit-up and thermal variations on the performance of ACBBs.

Rolling bearing fatigue life is an essential criterion in industrial equipment design and manufacturing and requires precise maintenance and replacement predictions. ISO/TS 281:2007 and 16281:2008 are commonly used for angular contact ball bearing (ACBB) fatigue life calculations, but they do not account for the characteristics of individual bearing elements under combined loading conditions. This study proposes an enhanced formula for calculating fatigue life modification factors that considers individual element-specific contact loads and resulting film thickness variations. The proposed fatigue life formula provides longer life predictions than the conventional method of determining modification factors based solely on maximum contact loads. This difference is particularly noticeable in low-speed and/or heavy-loading applications. Analysis conducted using the proposed fatigue life formula on various factors affecting fatigue life revealed that fluid kinetic viscosity coefficients, temperature-associated density changes, and changes in radial loads and rotational speeds could significantly impact the fatigue life of ACBBs. The proposed fatigue life formula is expected to increase the accuracy of ACBB fatigue life predictions.