Tooth coil windings, in particular when using a double layer structure, present opportunities for in-slot liquid cooling. Since the windings are not overlapping, access to the slot from the end section for coolant liquids is enabled. In this paper, a solution for in-slot and in-stator direct oil cooling for a tooth coil winding machine is presented. The coils are pre-wound on bobbins and inserted on the stator teeth. The novelty of the design consists in the integration of the cooling, using a thermally conductive epoxy resin to create the channels within the slot as well as the positioning of the stator yoke cooling channels. A 50 kW machine for an automotive traction ap-plication is designed, manufactured and tested. Conjugate heat transfer simulations are used in the design process in combination with finite element analysis for the loss mapping. The thermal model is verified with measurements at 6 l/min oil flow and 17.5 A/mm $^{2}$ continuous and 35 A/mm $^{2}$ 30 s peak. The thermal model is then used to establish a continuous operating point of 25 A/mm $^{2}$ .

中文翻译：

---

牵引用槽内油冷齿圈绕线永磁电机的设计与验证

齿形线圈绕组，特别是在使用双层结构时，为槽内液体冷却提供了机会。由于绕组不重叠，因此冷却液可以从端部进入槽。在本文中，提出了一种用于齿形线圈绕线机的槽内和定子内直接油冷却的解决方案。线圈预先缠绕在骨架上并插入定子齿上。该设计的新颖之处在于冷却的集成，使用导热环氧树脂在槽内创建通道以及定子磁轭冷却通道的定位。设计、制造和测试了用于汽车牵引应用的 50 kW 机器。在设计过程中使用共轭传热模拟并结合有限元分析进行损失映射。热模型通过在 6 l/min 油流量和 17.5 A/mm $^{2}$ 连续和 35 A/mm $^{2}$ 30 s 峰值下的测量进行验证。然后使用热模型建立 25 A/mm $^{2}$ 的连续工作点。