Research On Transmission Performance Of Cylindrical Permanent Magnet Eddy Current Governor With Misalignment

Permanent magnet eddy-current adjustable speed drive(PMEASD)is a kind of motor speed-regulating and energy-saving equipment for fans and pumps,with its advantages of no rigid connection to transmit torque,wide speed range,high efficiency,and energy-saving,it has become one of the best choices for upgrading power consumption facilities such as fan and water pump.The misalignment of the cylinder PMEASD will cause uneven air gap width,which can cause the air gap magnetic field to distort,change the radial force,and stimulate an unbalanced magnetic pull(UMP).The existence of the above factors often affects the PMEASD’s transmission performance and aggravate the PMEASD vibration.Therefore,in this paper,the ALT490 S cylindrical PMEASD is taken as the research object,and the transmission performance of the misaligned cylindrical PMEASD is studied using theoretical analysis and finite element analysis,and the relationship between vibration signal and misaligned state of cylinder PMEASD is studied on an experimental platform,which provides a reference for the theoretical improvement and engineering application of PMEASD.The mathematical model of the radial force and the UMP in the cross-section of the cylindrical PMEASD was established by using the permeability correction method and Maxwell stress method.Considering the axial length,the mathematical model in-plane is extended to three-dimensional space.The influence of synthesis misalignment on the magnetic conductivity correction coefficient is analyzed,and the torque calculation formula of PMEASD is deduced theoretically.The effects of misalignment on the transmission performance of PMEASD were analyzed using Ansoft Maxwell’s 2D and 3D transient magnetic field finite element simulation modules.Simulations in a two-dimensional plane verify the correctness of the mathematical model;three-dimensional simulations focus on the influence of misalignment on the magnetic field distribution and output torque of the PMEASD is analyzed.The vibration test platform is established and artificially set the misalignment state to obtain the vibration signal.The program for the acquisition and processing of vibration signals is compiled using Lab VIEW.From the time domain,frequency domain,and timefrequency domain,the changes in vibration signals with misalignment were analyzed.