Possibility of cooling the rotor of an electric traction motor by bidirectional air flows

Introduction. The performance reliability of electric vehicles (EVs) is an important factor in evaluating their suitability for widespread adoption. The reliability and lifespan of an EV depend on several critical factors including the motor, battery pack, controllers, and thermal management systems. The problem addressed in this paper is to cool down the rotor of permanent magnet synchronous motor efficiently using new combined cooling methods. Goal. Determination of the effectiveness of the combined rotor cooling method, which includes a bidirectional airflow circulating through a designed fan and oil circulation in the hollow shaft. Methodology. The solution was carried out using CFD (computational fluid dynamics) analysis. Results. A numerical model of a new combined cooling method for the rotor, which taking into account heat generation in the rotor and the thermal influence of the stator and bearing units, based on heat flow equations that consider its laminar or turbulent nature, was developed and studied. Scientific novelty. Based on the analysis of the rotor’s numerical model, a fan design was proposed that allows for effective heat dissipation by creating bidirectional airflow circulation. Practical value. The developed model can be used for further research on the dynamic thermal parameters of the rotor and evaluation of heat dissipation efficiency, which will optimize the heat and mass transfer processes within the motor, enhance its operational efficiency, and ensure the stability of its performance in various operating modes.