<p>The deformation of each part of the motor.</p>

The air gap between the stator and rotor of an electric motor is a crucial parameter that influences its performance. A well-designed tolerance can effectively control the size of the air gap, which results from the accumulation of machining deviations. Using the air gap as an assembly functional requirement, a polyhedral model was developed to represent the assembly deviation transfer path. The effects of thermal loads under actual operating conditions were considered, and thermal deformation was incorporated into the deviation transfer path analysis. By applying Minkowski summation and intersection operations, the cumulative errors of the assembly polyhedron were determined, and the impact of thermal deformation on the assembly errors in the motor was analyzed. A multi-objective tolerance optimization model was developed, with processing and quality loss costs as the objective functions. Considering thermal deformation, a multi-objective particle swarm optimization algorithm was employed to optimize the tolerances of the motor’s critical components, providing a novel theoretical method and technical reference for assembly error analysis and tolerance optimization in electric motors.电动机定子与转子之间的气隙（air gap）是影响其运行性能的关键参数。合理设计的公差可有效管控气隙尺寸，而气隙尺寸由加工偏差（machining deviations）的累积效应所决定。以气隙作为装配功能要求（assembly functional requirement），本研究构建了多面体模型以表征装配偏差传递路径（assembly deviation transfer path）。研究考虑了实际运行工况下的热载荷（thermal loads），并将热变形（thermal deformation）纳入偏差传递路径分析（deviation transfer path analysis）之中。通过应用闵可夫斯基和（Minkowski summation）与交运算（intersection operations），确定了装配多面体的累积误差，并分析了热变形对电动机装配误差（assembly errors）的影响。本研究构建了以加工与质量损失成本（processing and quality loss costs）为目标函数（objective functions）的多目标公差优化模型（multi-objective tolerance optimization model）。结合热变形因素，采用多目标粒子群优化算法（multi-objective particle swarm optimization algorithm）对电动机关键零部件的公差进行优化，为电动机装配误差分析与公差优化工作提供了全新的理论方法与技术参考。