In order to improve the speed of machine tool spindle and overcome the rapidly wearing off of the conventional electric brush in the rotary ultrasonic machining, research on non-contact power transmission system which based on the principle of electromagnetic induction has been conducted. Through the mutual inductance coupling theory and the simulation on Maxwell electromagnetic simulation software, the non-contact rotary electromagnetic coupling mechanism is established and the influence factor on the transfer efficiency of the rotary mutual inductance, such as rotation speed, inter-stage magnetic gap, matching compensation and the ultrasound frequency has been explored. It demonstrates that transfer efficiency of the energy from the primary to secondary forward load can achieve 80% with proper selection of matching parameter and magnetic gap at a high rotary speed. The electricity intensity in the coil and the magnetic flux shows no significant difference with the acceleration of the rotary speed, while the efficiency decreased with the magnetic gap. Furthermore, it shows that the coupling has an optimal frequency within the input frequency range of the ultrasonic excitation, where the transfer efficiency goes up initially and then turns backward as frequency increased. The research provides a reference for the optimal design of the ultrasonic spindle.%为解决超声加工中传统的接触式能量传输方式存在电刷磨损快且主轴不能高速旋转的问题,根据电磁感应原理,建立了非接触能量传输系统的互感理论模型,基于Maxwell平台构建了系统的仿真计算模型,通过旋转电磁耦合实验机构对仿真模型进行验证,获得了旋转转速、级间磁隙、超声频率以及谐振匹配参数对系统能量传递效率的影响规律. 仿真与实验结果表明:超声系统实现高速旋转时,非接触能量传输装置的输入和输出功率能量传递效率可达80%,初、次级线圈绕组电流密度和磁芯磁通密度随旋转转速的增加并无显著变化,传递效率的下降与磁隙近似成线性关系,传递效率随着频率呈现先升后降,对输入信号的频率具有选频作用. 应用规律可为电磁感应式超声主轴进行优化设计.
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