Design,Analysis And Experimental Research Of The Laminated Redundant Axial Magnetic Bearing

With the high-tech magnetic technology applications in the field of ultra high-speed ultra-precision machining,aerospace and other more widely.With the continuous improvement of magnetic technology,maglev system reliability requirements have become increasingly,therefore,the reliability of magnetic bearings has become a key factor affecting its wide application.How to further improve the reliability of magnetic bearings is the focus of current research.And hardware redundancy is one of the most important ways to improve system reliability.Magnetic bearings are often used for high-speed rotation,under the high speed of heating problem is very outstanding.Heat loss not only increases energy loss,causes the stator of the magnetic bearing to be thermal-expanded to deform,thus affect the positioning precision of the bearing system,it also leads to a reduction in the reliability of the whole maglev system.A magnetic bearing system by the radial magnetic bearing and axial magnetic bearing work togethe,theradial magnetic bearing has self-redundancy and the stator is made of silicon steel sheet,which not only improves the self-redundancy but also reduces the eddy current loss in high-speed rotation.However,the axial magnetic bearing itself does not have redundancy and is an integral structure.The eddy current loss generated in the working process is large,which leads to the rise of system temperature,affects the positioning accuracy of the whole system and reduces the reliability of the system.Therefore,it is of great significance to study axial magnetic bearing with high redundancy and low heating characteristics to improve the reliability of the whole magnetic system.In this paper,the main research work and innovative results are as follows(1)For the axial magnetic bearing,a new structure with high redundancy and low heating characteristics is proposed--laminated redundant axial magnetic bearing structure.The proportional relation between the redundancy of magnetic bearing and current margin,the space utilization ratio of lamination,mechanical properties and heat output is presented,it lays the foundation for the structural design of laminated redundant axial magnetic bearings.(2)Theoretical study,simulation and experimental study on redundancy,bearing capacity and heat generation of laminated redundant axial magnetic bearings.And compared with the integrated concentric multi-ring redundant axial magnetic bearing.The results show that the laminated redundant axial magnetic bearing improves the redundancy and reduces the heat output of the system at the expense of certain electromagnetic force.The research results provide the basis and reference data for the high reliability magnetic bearing(3)The strategy and control method for redundant reconstruction of laminated redundant axial magnetic bearings under different failure conditions are studied,and according to the principle of invariable stiffness and damping of magnetic suspension bearing before and after failure,determine the impact of the redundant reconstruction and the control parameters of the maglev bearing.(4)Degree of freedom magnetic system was put forward the general model of constraint theory,through the model to reduce the degrees of freedom of the system,discusses the structure design of the structure size and degree of freedom the relationship between constraints,and using the model,build a set of experiment platform.the redundancy reconstruction and temperature field distribution of the overlapping redundant axial magnetic bearings under different failure conditions were verified by experiments.The experimental results verify the correctness of the theory and the simulation calculation.The practicability of the laminated redundant axial magnetic bearing proposed in this paper is verified,which has certain theoretical and practical significance.