## 5 Performance Testing  
### Principle Prototype Development  
For the stator core processing of the axial flux permanent magnet motor, this paper employs a winding method. The process begins by fixing the lJ22 material of a specified width onto the material support mechanism. Since the lJ22 material tends to bend, it is directly sent to the leveling mechanism for flattening after passing through the support mechanism. Following this, the lJ22 material is slotted using a press. Finally, the slotted material enters the winding mechanism, where the automatic winding process is completed. The motor stator, processed through these steps, is shown in Figure 30.  
For the windings of the axial flux permanent magnet motor, an automated winding process has been employed. It should be emphasized that although multi-wire winding was incorporated in the electromagnetic design, its practical implementation poses significant  
Figure 30: Motor stator core. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Parameter Name** & **Before Optimization** & **Post-Optimization** & **Unit** \\ \hline Width of stator notch \(b_{0}\) & 5 & 4.8 & mm \\ \hline Stator groove depth \(h_{\text{s}}\) & 5.4 & 5.2 & mm \\ \hline Thickness of stator yoke \(h_{\text{sy}}\) & 2.1 & 2 & mm \\ \hline Thickness of permanent magnet \(t_{\text{m}}\) & 5 & 4.8 & mm \\ \hline Air gap length \(h_{\text{g}}\) & 0.5 & 0.4 & mm \\ \hline Slot filling rate \(K_{\text{sf}}\) & 0.68 & 0.74 & / \\ \hline Opposite maximum electromotive force \(E_{\text{l,max}}\) & 11.3 & 11.9 & V \\ \hline Stator yoke is magnetically dense \(B_{\text{sy}}\) & 1.4 & 1.42 & T \\ \hline _Stator teeth are magnetically dense \(B_{\text{st}}\)_ & 1.8 & 1.83 & T \\ \hline Average electromagnetic torque \(T_{\text{ele\_avg}}\) & 2.7 & 3.2 & N.m \\ \hline Effective mass \(m_{\text{ele}}\) & 0.606 & 0.599 & kg \\ \hline Torque density \(S\) & 4.45 & 5.34 & N.m/kg \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Motor parameters and performance comparison table. challenges. Therefore, in the finite element model, a single-wire equivalent was modeled by appropriately modifying the wire diameter and reducing the number of parallel winding wires to one, ensuring consistency in simulation results. In the actual manufacturing process, single-wire winding is implemented. Given the spatial constraints imposed by the motor's compact size, each coil is initially wound individually on a dedicated fixture. Subsequently, coils belonging to the same phase are joined through welding to form the complete phase windings. An example of a single coil is shown in Figure 31a, while Figure 31b illustrates the B-phase windings after the winding and welding process on the fixture. Once all three-phase windings are completed, they are sequentially assembled onto the stator core, resulting in the stator assembly depicted in Figure 31c. Finally, the assembled windings undergo an immersion paint curing process to enhance their insulation properties and strengthen the stator assembly's durability. For the rotor of the motor, the rotor bracket, permanent magnets, assembly tooling base, and top cover are initially fabricated and prepared. Subsequently, the rotor is assembled by systematically integrating these components. The assembly process begins with positioning the rotor bracket onto the assembly tooling base. The permanent magnets are then arranged in accordance with the polarity configuration detailed in the electromagnetic design specifications. These magnets are secured to the rotor bracket using a specialized adhesive to ensure stability and alignment. Finally, the top cover of the assembly tooling is securely installed to complete the rotor assembly. Figure 32 illustrates the rotor prior to the installation of the top cover. Figure 31: Coil winding and assembly: (**a**) single coil; (**b**) B-phase winding of the motor on the winding fixture; (**c**) motor stator assembly.