Study On The Coupling Law Of Multi-physical Field Of Magnetic-liquid Double Suspension Bearing

Magnetic-Liquid Double Suspension Bearing(MLDSB)introduces hydrostatic support into the magnetic suspension.Mainly supported by magnetic suspension,auxiliary supported by hydrostatic support,the double suspension form of electromagnetic and support is established.MLDSB can greatly improve the capacity and stiffness of bearings.The thermal deformation of the pole caused by the heat loss of the coils of MLDSB can reduced the gap between the rotor and the stator,and the probability and degree of impact-rub can be increased,and then the operation stability and service life of MLDSB will be reduced severely.The coil heat loss is not only related to the magnetic pole material and current,but also affected by the cooling effect of the fluid and the change of air gap/liquid film thickness,which is a magnetic-liquid-thermal-solid multi-physical field coupling problem.So the multi-physical field model of MLDSB is established in this paper,and then the magnetic-liquid-thermal-solid coupling is solved,the flow field characteristics of magnetic pole/coil surrounding is explored,the heat transfer path of copper loss and the heat loss distribution regularity is revealed,the distribution regularity of temperature rise and thermal deformation of the stator poles under different operation parameters is explored.The main research contents of this paper are as follows:(1)The multi-physical field model of MLDSB is established and the ICEM is used to reasonably mesh the bearing and the bearing boundary conditions is determined,and then the magnetic-liquid-thermal-solid coupling is solved.The characteristics of flowing law surround the magnetic pole/coil,temperature distribution of the bearing and thermal deformation of stator and the rotor is explored,and then the heat transfer path of copper loss and the heat loss distribution regularity is revealed.(2)The influence of current,oil inlet pressure,rotor speed,number of magnetic poles,coil turns and wire diameter on temperature rise,stator thermal deformation,oil film temperature and fluid cooling efficiency of MLDSB was simulated by the single variablemethod.(3)The orthogonal test method is used to select representative data points within the limited range of research parameters and establish the orthogonal test table.Combined with ANSYS simulation,the simulation data of each parameter combination were obtained and processed.Combined with range analysis and variance analysis,the effects of structural parameters of MLDSB on bearing temperature rise and stator thermal deformation were cleared.(4)The PIV system was used to observe the internal flow field of the MLDSB,and the test results were compared with the simulation results to verify the feasibility of the simulation idea and the reliability of the simulation results.