新型轴向被动磁轴承-Halbach磁体阻尼器一体化优化设计关键技术研究

磁悬浮轴承利用电磁力实现定子与转子之间的无接触支承，具有高转速、长寿命的优点，是高速旋转机械的核心部件，其按照磁力是否可控，分为主动磁轴承和被动磁轴承，前者具有刚度阻尼可控的优点，但控制系统复杂、可靠性低；而后者无需控制系统，具有功耗低和可靠性高的显著优势，应用广泛，但其存在阻尼小的缺陷，针对这一问题，本项目提出了一种新型轴向被动磁轴承-Halbach磁体阻尼器一体化结构（APMBD），所设计的新型空心杯转子将轴向被动磁轴承与阻尼器的转子部分集成，由定子永磁体与杯形转子的多个"齿"实现支承；由Halbach磁体和杯形转子上的阻尼套实现阻尼，不仅可以提供足够的刚度，而且对转子振动具有良好的阻尼能力，大大提高了可靠性，本项目建立了APMBD结构的数学模型，提出了相应的优化设计方法，同时研制实验样机，并进行综合性能测试，为APMBD在基于高速电机的鼓风机和压缩机等领域的应用提供了必要的理论基础。

Magnetic bearings can suspend rotor by magnetic forces between stator and rotor. They have such advantages as no wearing, without lubrication and less maintenance, have been widely used in high-speed rotary machines. According to the control mode of magnetic force，they can be classified into two types, active bearings and passive bearings. The former possesses controllable stiffness and damping character, whereas it suffers from complex control system and low reliability. The latter has several advantages over conventional active magnetic bearings because of no energy input, low power loss and high reliability. So they have expanded the applications in flywheel, pumps, compressor drives, and so on. However, it is lack of damping. Based on the previous work, a novel integrated structure of axial passive magnetic bearing and damper (APMBD) is proposed in this subject. The cup-shaped rotor is designed to integrate passive rotor and damper rotor. The suspended forces can be realized by stator permanent magnet and teeth of cup-shaped rotor and the damping force can be realized by Halbach magnetized array and a damping sleeve on the cup-shaped rotor. This integrated structure can not only provide adequate stiffness, but also good damping ability for the rotor. Therefore, the reliability is improved greatly. Mathematical models are established and the finite element method (FEM) is applied to analyze force and damping of APMBD in this project. Then the optimization design method is presented. An experimental setup is developed to measure the stiffness and damping characteristics of the proposed APMBD, which is the necessary theoretical basis for its application in the blowers and compressors with high speed motor.