Research On Permanent Magnetic Bearing Of Maglev Heart Pump

Ventricular assistant device,VAD (Heart Pump) is a device instead of heart partly or entirely. Traditional heart pump has frication in places with physical contact, which always lead hemolysis and thrombus. In order to solve these problems, the author did research on magnetic bearings system. Permanent magnetic bearing was used for the radial levitation and axial was electromagnetic ones. The system can realize levitation on five-degree. The result gives us a direction on research of VAD.The main contents of this article as follows:1,According to the structure characteristics of Axial-flow heart pump, we designedthe structure of radial permanent magnet bearings.2,Several modeling of permanent magnetic bearings, such as static magnetic circuit model, common model, the equivalent magnetic charge method and the finite element method were analyzed and compared. Finite element method was chosen to establish radial permanent magnetic bearing stiffness and capacity mathematical model.3,Requirement of radial stiffness was determined according to the principle of electromagnetics and rotor dynamics, which would be must above when we designed the radial permanent magnet bearings. The author used Femm and Matlab compile a computer program and realized a computer interface of permanent magnetic radial bearing, on which optimized the magnet parameters to meet the stiffness required.4,According to force analysis of the heart pump bearings -rotor system, designed axial-flow pump open-heart model. The axial force generated by the radial bearing was experimented .At last the heart pump achieved radial and axial full suspension.