Research On The Analytical Magnetic Force Model Of Permanent Magnet Bearings Andpermanent Magnet Guideway

Permanent magnet bearings(PMB) and permanent magnet guideway(PMG) were magnetic force mechanism by using magnetic field force to suspend a rotor or a straight motion body, applied to rotary and reciprocating machine respectively .owing to they have the advantages of simple in the structure, reliability in work, cheaper in cost, frictionless, no power consumption, without pollution, long life, suit with high speed and high precision machine, vacuum and some of the special conditions, and therefore they have abroad application foreground in many kinds of fields. Therefore it is important to research on its magnetic field and magnetic force systematically.At present, the theory analysis and design of permanent magnet levitation was far from enough, primary reason was that the previous study mostly aimed at bi-magnetic rings PMB,while new configuration of PMB was studied scantily; and that the previous research mostly on the complicated numerical calculation model , but it was short of explicit magnetic force analytical model of PMB and PMG ,and can't guide the structural design and optimum of PMB and PMG .So magnetic force explicit analytical models of PMB and PMG are built with very important theory significance and practical value for guidance the structural design and optimum of PMB and PMG.Analytical magnetic force model studied magnetic field and magnetic force by math and physics idea, and expressed by completely mathematical formula. Based on other's achievement and connected with rare earth permanent material property as well as the structure character of PMB and PMG, obvious analytical models of magnetic force for PMB and PMG were investigated by principle of linear superposition, conformal transformation method, equivalent magnetic charge method, magnetic circuit method, virtual work theory method, virtual image method, direct integral method, and the different combination of those methods, and the correctness of the models were validated by ANYSIS10.0 calculation and test, theoretical foundation was supplied for guidance the structural design and optimum of PMB and PMG. The main research as follows:(1) The magnetic force obvious analytical models of radial magnetic bi-annular-nesting -shaped PMB were established by conformal transformation method, equivalent magnetic charge method, magnetic circuit method and virtual work theory method, and the feasibility of the model was validated by test.(2) Based on analysis the magnetic energy and magnetic conductance of magnetic rings gap, connected with rare earth permanent material property as well as the principle of magnetic-flux equivalency, the axial and radial magnetic force obvious analytical models of axial placement bi-annular-shaped PMB were founded by virtual work theory method, and the correctness of the models were validated by test.(3) The new structure of radial magnetization multi-annular-nesting-shaped PMB was designed, which can make good use of magnetic energy and have larger load capacity. Based on magnetic force analytical models of radial magnetization bi-annular-nesting-shaped PMB as well as the structure character of radial magnetization multi-annular-nesting-shaped PMB and principle of linear superposition, magnetic force analytical models of radial magnetization multi-annular-nesting-shaped PMB were built, and the correctness of the models were validated by ANYSIS10. 0.(4) The new structure of axial placement multi-annular-shaped PMB was designed, which has larger load capacity. Based on analysis the magnetic conductance of magnetic rings gap and rare earth permanent material property, the axial and radial magnetic force obvious analytical models of axial placement multi-annular-shaped PMB were founded by virtual work theory method.Tests prove that the calculated values by the model are found to be basically in agreement with those actually-measured.(5) Based on magnetic energy shared by two permanent magnet and virtual work theory method, connected with the structure character of two parallel rectangle-section permanent magnet, the magnetic force analytical models of two parallel rectangle-section permanent magnet were founded, the models were applicable for the design and calculation of PMG and PMB. Tests prove that the model have upper calculation precision.(6) Based on the method of electric current virtual image and permanent magnet equivalent electric current model, regarded magnetization magnetizer effect as PM virtual image in magnetizer, the law of PM virtual image in plane magnetizer and virtual image calculation method which is simply and has upper calculation precision were derived, and test validate the magnetic force of a pair parallel permanent magnet rings and PMG affixed to a plane magnetizer.(7) Based on the magnetic force analytical models of two parallel rectangle-section permanent magnet and the law of PM virtual image in plane magnetizer, connected with the structure character of PMG, the levitation and guidance magnetic force analytical models of PMG were obtained, and and the feasibility of the model was validated by test.Investigative results indicates that the magnetic force of PMB and PMG is proportion to the second power of residual magnetism induction density, and that the magnetic force increases with the increment of the section and longitudinal size of permanent magnet, the number of the magnetic rings as well as total magnetic conductance of magnetic circuit, and decreases with the increment of gap between permanent magnet, in a normally movement space ,magnetic force increases with the increment of permanent magnet opposite displacement.