• An active housing cooling jacket integrated with SG-PM is proposed for PMSM thermal management. • The SG-PM layer creates an auxiliary heat-transfer path without changing the main cooling structure. • Comparative simulations with a conventional aluminum-based HCJ show lower motor temperatures. • The proposed design improves thermal uniformity and reduces localized hot spots in stator and windings. • A practical and manufacturable cooling solution is demonstrated for EV and industrial PMSM applications. Electric motors (EMs) are key components of electric vehicles (EVs). Therefore, effective thermal management is essential for enhancing the reliability and performance of Permanent Magnet Synchronous Motors (PMSMs). In conventional PMSM cooling jacket designs, the cooling channels are typically arranged around the stator housing, enabling more direct heat removal. As a result, the end-winding regions are cooled only indirectly and do not fully benefit from the cooling system. To address this limitation, this study introduces an innovative active housing liquid cooling jacket integrated with a silicon gelatin potting material (SG-PM) layer on both end sides of the housing cooling jacket (HCJ) to improve both conductive and convective heat transfer paths. Although the SG-PM layer does not directly contact the end windings, it improves heat dissipation indirectly by reducing thermal resistance within the housing and forming an additional conductive bridge from the stator/winding region toward the cooling channels. The modification does not alter the primary stator-to-coolant heat transfer path, but introduces an auxiliary conduction path to enable improved heat transfer toward the aluminum cooling channels. A 3D transient thermal simulation of a 40 kW PMSM was performed using an ethylene glycol-water mixture (EG/W, 50/50%) as the coolant, with a flow rate of 10 L/min, an inlet temperature of 60°C, and four fluid flow channels in the HCJ. The temperatures of the stator core and windings were reduced more effectively compared with a conventional HCJ design, confirming a significant improvement in overall heat dissipation. The SG-PM layer improved the thermal interface, resulting in better thermal uniformity and enhanced heat transfer. Furthermore, to validate the proposed HCJ performance, a comparative thermal analysis was conducted between the conventional aluminum-based HCJ and the SG-PM integrated HCJ, where the proposed design exhibited lower temperatures and more uniform temperature distribution in the stator and winding regions. The results demonstrate that activating previously non-functional regions of the HCJ can improve temperature distribution and reduce localized hot spots without modifying the primary cooling mechanism. Therefore, the proposed SG-PM-based HCJ concept provides a practical and manufacturable solution for PMSMs, offering improved thermal stability and higher efficiency for EV and industrial motor applications.
Ahmed et al. (Fri,) studied this question.