Xi Xiaofei, Sun Yan, Wang Xudong, Xin Yuanxu, Yang Yong
School of Electrical Engineering, Shanghai Dianji University, Shanghai 201306, China.
Micromachines (Basel). 2022 Jun 11;13(6):931. doi: 10.3390/mi13060931.
The micro-claw pole stepper motor is widely used in the field of camera modules and VR focusing. The influence of torque ripple on positioning accuracy becomes more obvious with a decrease in motor volume. In order to reduce the torque ripple of the micro-claw stepper motor and increase the load capacity of the motor, the torque of the motor is simulated by using finite element software. Firstly, the influences of four parameters, namely air gap, magnet thickness, claw thickness and claw height, on the detent torque and holding torque of the claw permanent magnet stepper motor are obtained through the Taguchi experiment. The Signal-to-noise ratio (SNR) of each factor to the response was calculated and the degree of influence of the four parameters on the detent torque and holding torque of the micro-claw pole permanent magnet stepper motor was determined. Then, the optimal value of each factor to reduce the detent torque and increase the holding torque was obtained through optimization analysis. Finally, experiments were carried out to test the holding torque of the motor, and the accuracy of the results was verified by comparing the test values with the simulation values. According to the analysis of the paper, the response delta of air gap to detent torque is the largest, reaching 5.99, and that to holding torque is 0.73. The response delta of the magnet thickness to the detent torque is 5.87, and the response delta to the holding torque is 1.52. The optimized parameters obtained by optimization analysis reduce the detent torque of the motor by 26.74% and increase the holding torque by 18.35%. It is found that air gap and permanent magnet thickness have the greatest influence on the detent torque and holding torque of a micro-claw permanent magnet stepper motor, followed by claw thickness and claw height. Among them, the air gap has more influence on the detent torque than on the holding torque, and the thickness of the permanent magnet has more influence on the holding torque than on the detent torque.
微爪极步进电机广泛应用于相机模块和VR对焦领域。随着电机体积的减小，转矩脉动对定位精度的影响变得更加明显。为了降低微爪步进电机的转矩脉动并提高电机的负载能力，利用有限元软件对电机的转矩进行了仿真。首先，通过田口实验得到气隙、磁体厚度、爪厚和爪高这四个参数对爪极永磁步进电机的定位转矩和保持转矩的影响。计算了各因素对响应的信噪比，并确定了这四个参数对微爪极永磁步进电机定位转矩和保持转矩的影响程度。然后，通过优化分析得到了各因素降低定位转矩和提高保持转矩的最优值。最后，进行实验测试电机的保持转矩，并将测试值与仿真值进行比较，验证结果的准确性。根据论文分析，气隙对定位转矩的响应增量最大，达到5.99，对保持转矩的响应增量为0.73。磁体厚度对定位转矩的响应增量为5.87，对保持转矩的响应增量为1.52。通过优化分析得到的优化参数使电机的定位转矩降低了26.74%，保持转矩提高了18.35%。研究发现，气隙和永磁体厚度对微爪永磁步进电机的定位转矩和保持转矩影响最大，其次是爪厚和爪高。其中，气隙对定位转矩的影响比对保持转矩的影响更大，永磁体厚度对保持转矩的影响比对定位转矩的影响更大。
