Support Stiffness of Magnetic Bearing Based on Unequal Magnetic Circuit Area Design Method
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摘要:
磁悬浮转子需同时满足抗干扰与共振隔离需求,为了从磁悬浮轴承结构角度奠定设计基础,基于磁悬浮轴承结构参数对支承刚度的影响,对高刚度磁悬浮轴承设计方法展开研究. 首先,通过磁悬浮轴承刚度解析式推导,分析磁悬浮轴承结构参数对支承刚度的影响因素,确定支承刚度优化方向;其次,提出高刚度磁悬浮轴承设计方法,分析支承刚度的优化效果;最后,通过转子固有频率测试及压缩机升频实验,验证所提出方法的可行性. 结果表明:在压缩机样机中,磁悬浮轴承采用不等磁路面积结构,在齿轭宽度比为1.2时,可使轴承在最恶劣工况,即对应最大控制电流时,支承刚度较常规等磁路面积结构提高了25%,压缩机在工况运行区间有效避免共振,为工程应用中磁悬浮轴承刚度优化设计提供参考.
Abstract:The magnetic suspension rotor needs to meet the requirements of anti-interference and resonance isolation at the same time, in order to lay the design foundation from the perspective of magnetic bearing structure, the design method of high stiffness magnetic bearing is studied based on the influence of magnetic bearing structural parameters on support stiffness. Firstly, through the derivation of the analytical formula of the stiffness of the magnetic bearing, the influencing factors of the structural parameters on the support stiffness are analyzed, and the optimization direction of the support stiffness is determined; Secondly, the design method of high stiffness magnetic bearing is proposed, and the optimization effect of support stiffness is analyzed; Finally, the feasibility of the proposed method is verified by rotor natural frequency test and compressor frequency rise experiment. The results show that in the compressor prototype, when the magnetic bearing adopts the structure of unequal magnetic circuit area with the tooth yoke width ratio 1.2, the support stiffness of the magnetic bearing under the worst working condition, that is, the maximum control current, can improve by 25% compared with the equal magnetic circuit area, and the compressor can effectively avoid resonance in the operating range, which provides a reference for the optimization design of the support stiffness of magnetic bearing in engineering application.
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