轴流式磁悬浮人工心脏泵磁悬浮轴承系统设计

System design of magnetic bearings in an axial-flow artificial blood pump

人工心脏泵要求体积小、质量轻、功耗低。为契合上述要求,实现人工心脏泵转子的五自由度全悬浮,采用径向永磁轴承和轴向电磁轴承相结合的磁悬浮系统,在对轴流式人工心脏泵转子受力分析的基础上,提出了低功耗和单轴向电磁轴承这两种磁悬浮轴承系统结构设计方法,给出了采用这两种方法进行结构设计时,径向永磁轴承和轴向电磁轴承的设计原则。比较来看,采用单轴向电磁轴承结构设计方法虽然会增加电磁轴承的功耗,但是大大降低了系统的体积和质量;简化系统结构和电磁轴承的控制复杂性,更具优势。根据单轴向电磁轴承设计方法,设计并加工一台轴流式磁悬浮人工心脏泵原型机,成功实现转子的五自由度稳定悬浮,验证了所提方法的可行性,为磁悬浮人工心脏泵的结构设计提供参考依据。

The artificial blood pump has to meet the following advantages,small volume and mass and low power consumption.Radial permanent magnetic bearings（RPMBs） and axial electromagnetic bearings（AEMBs） were employed in the magnetic levitated artificial blood pump to suspend the rotor in five degree of freedoms（DOFs） and to meet the above requirements.According to the mechanical equilibrium condition of the blood pump rotor,two structure design methods were presented for the magnetic levitated system of the blood pump.One can be called the low power consumption design method and the other can be called the single axial EMB design method.The design principals of radial PMB and axial EMB in the two methods were given.Compared with the first method,the second method simplifies the blood pump structure and the axial EMB＇s controller,and greatly reduces the pump volume and mass,though it maybe require more power consumption.A prototype axial-flow magnetic levitated blood pump was designed and manufactured according to the second method.Experimental results showed that the rotor was successfully and stably suspended in five DOFs by radial PMBs and only one axial EMB.These results showed that the magnetic bearing system structure design method presented is feasible.This study will provide references to the structure design of the magnetic levitated artificial blood pump.