China Mechanical Engineering ›› 2021, Vol. 32 ›› Issue (08): 901-907.DOI: 10.3969/j.issn.1004-132X.2021.08.003

Previous Articles     Next Articles

Dynamics Characteristics of Rotor Systems under Magnetic Bearing Excitation

LI Shengyuan;ZHENG Longxi   

  1. School of Power and Energy, Northwestern Polytechnical University, Xi’an,710072
  • Online:2021-04-25 Published:2021-05-10

磁轴承激励下转子系统动力学特性

李胜远;郑龙席   

  1. 西北工业大学动力与能源学院,西安,710072
  • 通讯作者: 郑龙席(通信作者),男,1970年生,教授、博士研究生导师。研究方向为航空发动机燃烧与流动,新概念航空航天推进技术,航空发动机强度、振动与可靠性。E-mail:zhenglx@nwpu.edu.cn。
  • 作者简介:李胜远,男,1992年生,博士研究生。研究方向为航空发动机转子动力学。E-mail:lshy@mail.nwpu.edu.cn。

Abstract: To analyze the vibration mechanism of the rotor systems excited by magnetic bearings, a calculation model for dynamics characteristics of a double-disk rotor system was established by using one-dimensional finite element method. The dynamics behaviors of rotor system under different types of magnetic bearing excitations were studied. Results show that the co-rotating sweep frequency exciting forces excite forward whirl mode of the rotor systems, while the counter-rotating sweep frequency exciting forces excite backward whirl mode. In both cases, the rotor system whirls in a circular trajectory. The unidirectional harmonic exciting force may be decomposed into the sum of co-rotating and counter-rotating exciting forces, therefore both of the backward whirl and forward whirl modes of the rotor system are excited and the rotor system whirls with an elliptical trajectory under the effect of unidirectional harmonic sweep exciting force. Under bi-directional harmonic sweep exciting forces, the whirl direction and whirl trajectory of the rotor system depend on the phase difference of the two exciting forces. Research results provide a theoretical basis for the selection of excitation scheme of magnetic bearings when evaluating the stability of rotor systems of high-pressure compressor.

Key words: rotor system, magnetic bearing, harmonic excitation, forward whirl, backward whirl

摘要: 为分析磁轴承激励下转子系统的振动机理,应用一维有限元方法建立了双盘转子系统动力学特性计算模型,研究了不同类型磁轴承激励下转子系统的动力学行为。研究结果表明:同向旋转的扫频激励力激发了转子系统的正进动模态,而反向旋转的扫频激励力激发了转子系统的反进动模态,两种情况下转子系统均以圆轨迹进动;由于单向简谐激励力可以分解为同向旋转激励力和反向旋转激励力之和,因此在单向简谐扫频激励力作用下,转子系统的反进动和正进动模态均被激发,转子系统以椭圆轨迹进动;在双向简谐扫频激励力作用下,转子系统的进动方向和进动轨迹取决于两个激励力的相位差。研究成果为评估高压压缩机转子系统稳定性时磁轴承激励方案的选取提供了理论依据。

关键词: 转子系统, 磁轴承, 简谐激励, 正进动, 反进动

CLC Number: