Study On Homopolar Hybrid Magnetic Bearing For Axial Maglev Blood Pump

Heart failure has become a global epidemic,threatening for the patients' life.Although heart transplantation is the most sustainable treatment for the end-stage heart failure patients,with limitations in donor availability,therefore,artificial heart pumps(referred to as blood pump)in particular play a key role in the management of advanced heart failure.The maglev blood pump with the characteristics of no mechanical contact,eliminating the mechanical wear and friction,can reduce blood damage.Therefore,it has great significance to study on the maglev blood pump for patient transplant.At present,the research on the maglev blood pump has got a certain achievements at home and abroad,and a few maglev blood pumps have been used for clinical application.However,according to the relative research and clinical data,maglev blood pump has some drawbacks,such as large support structure,high power consumption and low reliability of blood pump caused by complex control system,which limits the transplantation.Therefore,the research on blood pump bearing system has become a key and difficult point of the maglev blood pump.The main contents of this paper are as follows:(1)A homopolar hybrid magnetic bearing for axial maglev blood pump is presented in this paper to overcome its shortcoming,such as a large volume,high power consumption and complex control system.Equivalent magnetic circuit method is adopted to design the magnetic circuit,and the structure of a homopolar hybrid magnetic bearing is designed.(2)Simulation and analysis on the 3D magnetic field of the hybrid magnetic bearings are carried out using the Finite Element Method(FEM).Magnetic field distribution,bearing characteristics and coupling characteristics of radial and axial edge effect of the homopolar hybrid magnetic bearing are also discussed.(3)The blood pump experimental apparatus is designed and fabricated,and test rig is also constructed.Measurement experiments of magnetic field distribution and supporting parameters are carried out,achieving static stable suspension.Design and analysis methods and suspension experiments of the hybrid magnetic bearing system of axial flow maglev blood pump are presented in this paper.Results show that the hybrid magnetic bearing system adopting two homopolar hybrid magnetic bearing is feasible,meeting the requirements of a short axial size,low power consumption and simple control for the axial flow blood pump.