<p>The distribution of heat generation and operating temperature are crucial factors affecting the performance and useful service life of angular contact ball bearings. A thermodynamic real-time coupling analytical model is established in this work to illustrate alterations in the bearing structure, internal load, and the sliding and rotation of the ball correlated with temperature fluctuations. The temperature rise and heat generation of angular contact ball bearings under combined loads are accurately calculated. The simulation of the temperature rise in bearings is conducted based on this model, and the effectiveness of the model is validated through simulation experiments. The simulation results of the distribution of heat generation are compared between thermodynamic real-time coupling and thermodynamic sequential coupling, with a focus on the transient thermal characteristics of bearings and the effect of load on their steady-state thermal characteristics. The precision of temperature simulation through thermodynamic real-time coupling is significantly higher than that through thermodynamic sequential coupling. Axial load mainly affects heat generated by the sliding and rotation of the ball on the inner raceway, while radial load predominantly affects the heat generation of the ball due to sliding on the inner and outer raceways. The findings of the work can guide the design and performance evaluation of angular contact ball bearings and provide support for temperature simulation.</p>