流道型轴流血泵支承结构设计与分析

目的:为了改善电磁轴承结构复杂、体积偏大，液力轴承承载力小、不能在较大负载下工作的弊端，提出一种流道型磁液悬浮轴流血泵，提高血泵承载能力。方法:流道型轴流血泵轴向采用永磁力进行支承，径向采用转子叶轮的流道结构产生的液力悬浮；利用Ansys对轴向瞬态磁场进行仿真，对磁力变化进行研究，利用Fluent对不同开槽方向、角度、深度的径向液力进行仿真，对液力变化进行研究。结果:根据轴向磁力随位移的变化，得出磁力最大为2.9 N，楔形开槽结构倾斜角为28°，开槽数为5，槽深0.36 mm，叶顶间隙为0.40 mm，性能达到最优，能满足人体使用。结论:流道型轴流血泵相对于普通磁液悬浮血泵有更高的承载力，较好的悬浮性能，为轴流血泵的优化研究提供了新的思路。

Design and analysis of the support structure of flow-channel type axial-flow blood pump

Abstract: Objective To alleviate the problems of electromagnetic bearings (complex structure, large volume) and hydraulic bearings (small bearing capacity, no longer able to work under large loads), a flow-channel type magnetic fluid suspension axial-flow blood pump is proposed to improve the bearing capacity of blood pump. Methods The flow-channel type axial-flow blood pump was supported by permanent magnetic force in the axial direction, and the hydraulic suspension generated by the flow channel structure of the rotor impeller was used in the radial direction. The axial transient magnetic field was simulated by Ansys for studying the changes of magnetic forces, and Fluent was used to simulate radial hydraulic forces with different slotting directions, angles and depths, thereby investigating the changes of hydraulic forces. Results The analysis on the changes of axial magnetic forces with displacements revealed that the proposed blood pump had the most excellent performance, when the maximum magnetic force, the inclination angle of the wedge-shaped slotted structure, the number of slots, the depth of the slot and the tip clearance were 2.9 N, 28°, 5, 0.36 mm and 0.40 mm, respectively, meeting the requirements of application in human body. Conclusion The flow-channel type axial-flow blood pump has higher bearing capacity and better suspension performances than the ordinary magnetic fluid suspension blood pump, which provides a new idea for the optimization of axial-flow blood pump.