高速异步主轴电机的热分析与冷却结构设计

高速主轴电机是电主轴的关键核心部件，电机发热直接影响电主轴的加工精度和运行可靠性。以一台10万转主轴异步电机为例，对高速异步主轴电动机进行深入的热分析，设计高效的散热冷却结构，确保主轴电机的可靠平稳运行。确定主轴电机的主要热源，研究转子转速、转子表面粗糙度对主轴电机风摩损耗的影响规律；考虑旋转磁场和谐波对铁耗计算的影响，采用齿轭分区的有限元法提高仿真精度，分析电机铁耗的分布规律。基于流体力学对电机进行3D热仿真，对比主流的周向螺旋型和轴向Z字型两种冷却结构的冷却效果，确定高效的冷却结构设计方案，并进一步采用转子铁心开空气槽的设计方案，增加转子铁心与转轴之间的热阻，提高电机的散热能力，确保电机的转轴温升在安全范围内，最后校核转子结构的机械强度，保证主轴电机运行的可靠性。

Thermal Analysis and Cooling Structure Design for High Speed Asynchronous Spindle Motor

The high speed spindle motor is the crucial component of motorized spindle. The heating problem of motor directly affects the machining accuracy and operation reliability of motorized spindle. Taking a 100 000 r/min spindle asynchronous motor as an example, the thermal analysis and efficient cooling structure design are carried out to ensure the reliable and stable operation of the spindle motor. The main heat source of the spindle motor is determined and the influence of rotor speed and rotor surface roughness on the air friction loss of the spindle motor is studied. Considering the influence of rotating magnetic field and harmonics on the calculation of iron loss, the teeth and yokes of the stator are separately modelled in the finite element method to improve the simulation accuracy and analyze the distribution law of motor iron loss. The 3D thermal simulation of the motor is carried out based on hydrodynamics, and an efficient cooling structure design scheme is determined by comparing the cooling effects of the mainstream circumferential spiral and axial Z-shaped cooling structures. Furthermore, a design scheme of opening air slots in the rotor core is proposed, which increases the thermal resistance between the rotor core and the shaft and improves the heat dissipation capacity of the motor to keep the temperature rise of the rotating shaft within a safe range. Finally, the mechanical strength of the rotor structure is checked to ensure the reliable operation of the spindle motor.