Study On High Speed Magnetic Transmission And Liquid Magnetic Coherence Of Magnetic Coupling

Magnetic pumps are widely used in pharmaceutical,aerospace and other fields because of no leakage.High speed of magnetic pumps can improve efficiency and reduce volume.Magnetic coupling is the key component of Magnetic pump.However,the “wet”Eddy current loss,magnetic field distribution,the fluid-magnetism coupling are still not clear.In this paper,the cylindrical radial magnetized magnetic coupling is taken as the research object and the characteristics of high-speed magnetic transmission and fluid-magnetism coupling are studied which is of great engineering significant to improve efficiency of high-speed pump and scholar value to the theory of high-speed magnetic transmission.The main work and research results are as follows:1.It was systematically summarized of development of magnetic coupling at home and abroad.The static magnetic field and transient magnetic field were com Pared and the distribution of the induced magnetic field was obtained.The results show that: the bigger rotating velocity is,the stronger the introduced magnetic field is and the original magnetic field is increasingly weakened with faster drop.The largest drop is 1.7% at 10000 rpm.2.The 2D model of the cylindrical radial magnetized magnetic coupling was established.The torque was simulated with consideration of introduced magnetic field and the influence of slip angle,rotating velocity on the torque was analyzed.The results show:(1)The torque increases with the increasing of slip angle and its value is biggest at 15°(180°/n,n is the number of magnet pairs which is 12 in this paper.)which is same with that not considering introduced magnetic field.(2)As the rotating speed increases,the transmission torque is approximately linearly reduced and the smaller the slip angle is,the greater the effect of the speed on the torque is.3.The magnetic field generating device was designed,and NaCl solution of different mass concentration was made.It was innovation to research the influence of magnetic field on viscosity and conductivity of conducting liquid by experiment.The results are as follows:(1)the magnetic field makes the liquid conductivity bigger,however,when it is to a certain degree,the value of conductivity may even decline.(2)the viscosity of deionized water and NaCl solution are increasing with the increase of magnetic field and then tend to be steady.(3)The more particles in the solution there are,the greater the viscosity value is affected by magnetic field.4.The “wet” state magnetic coupling model was set up.The eddy current loss generated by isolation cover made by different material and liquid medium with different conductivity was calculated.On the above basis,the influence of rotating speed,conductivity isolation material,number of magnet pairs,thickness of isolation on Eddy current loss was researched.The results show:(1)Eddy current loss is increasing with the increase of liquid conductivity.(2)The higher the conductivity of isolation cover is,the larger the eddy current loss is and the eddy current loss generated by isolation cover made by 1Cr18Ni9 Ti is two times than that of TC4.(3)The eddy current loss increases first and then decreases with the increase of the rotating speed,and there is a maximum value and a minimum value.In the vicinity of 4000 rpm,the value reaches the maximum and reaches the minimum at8000 rpm.The eddy current loss is reduced by 82.43% when the rotating speed is 8000 rpm com Pared to 4000 rpm.(4)The influence of magnet pairs on eddy current loss is different at different rotating speed.At 1000rpm~7000rpm,there is a maximum and minimum value of eddy current loss.When the number of magnet pairs is 8,the eddy current loss is the largest,and the eddy current loss is the smallest when the number of magnet pairs is 12.At7000rpm~10000rpm,the eddy current loss has a minimum value with the increase of the number of magnet poles,and the eddy current loss is lowest at 12.In addition,as the number of magnetic poles increases,the extreme value of the eddy current loss tends to move in the direction that the rotating speed is small.(5)The more thickness the isolation is,the larger the eddy current loss is.The influence law of rotating speed on eddy current loss is same at different thickness.5.A high speed magnetic transmission test rig was designed and set up which lays the foundation of related experiment.