Study of the Thermal Performance of Oil-Cooled Electric Motor with Different Oil-Jet Ring Configurations

Hao Yang, Fan Wu, Jinhao Fu, Junxiong Zeng (), Xiaojin Fu, Guangtao Zhai and Feng Zhang ()
Additional contact information
Hao Yang: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Fan Wu: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Jinhao Fu: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Junxiong Zeng: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Xiaojin Fu: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Guangtao Zhai: Vehicle Engineering Institute, Chongqing University of Technology, Chongqing 400054, China
Feng Zhang: College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China

Energies, 2025, vol. 18, issue 16, 1-22

Abstract: This study investigates the thermal performance of an oil-jet-cooled permanent magnet synchronous motor (PMSM), with a particular focus on end-winding heat dissipation. A high-fidelity numerical model that preserves the full geometric complexity of the end-winding is developed and validated against experimental temperature data, achieving average deviations below 7%. To facilitate efficient parametric analysis, a simplified equivalent model is constructed by replacing the complex geometry with a thermally equivalent annular region characterized by calibrated radial conductivity. Based on this model, the effects of key spray ring parameters—including orifice diameter, number of nozzles, inlet oil temperature, and flow rate—are systematically evaluated. The results indicate that reducing the orifice diameter from 4 mm to 2 mm lowers the maximum winding temperature from 162 °C to 153 °C but increases the pressure drop from 205 Pa to 913 Pa. An optimal nozzle number of 12 decreases the peak winding temperature to 155 °C compared with 162 °C for 8 nozzles, while increasing the oil flow rate from 2 L/min to 6 L/min reduces the peak winding temperature from 162 °C to 142 °C. Furthermore, a non-uniform spray ring configuration decreases maximum stator, winding, spray ring, and shaft temperatures by 5.6–9.2% relative to the baseline, albeit with a pressure drop increase from 907 Pa to 1410 Pa. These findings provide quantitative guidance for optimizing oil-jet cooling designs for PMSMs under engineering constraints.

Keywords: PMSM; oil-jet cooling; spray ring design; end-winding thermal management; cooling performance; temperature uniformity (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2025
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.mdpi.com/1996-1073/18/16/4302/pdf (application/pdf)
https://www.mdpi.com/1996-1073/18/16/4302/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:18:y:2025:i:16:p:4302-:d:1723219

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().