| Magnetic coupling is the key component of high speed magnetic pump,which leakage characteristic meets the requirements of energy conservation and environmental protection in modern industrial production process.In addtion,high efficiency transmission characteristic makes it widely used in the emerging industry.Based on the wet dynamic magnetic coupling test-bed,the numerical simulation and experimental methods were used to study the influence of the magnetic torque,eddy current loss,temperature field and cooling medium on the transmission performance of the magnetic coupling.The main contents and achievements of the study are as follows.?1?Using Ansoft Maxwell,a 2D ideal model of magnetic coupling was established to calculate the vector magnetic potential of half rotating period with different magnetic rotation angles to solve the static magnetic torque.It is concluded that the period of the absolute value of the magnetic vector potential and the maximum magnetic induction intensity is 4?/p?p is the number of magnetic pole?,and the period of static magnetic torque is 2?/p,which maximum value is at?/p.Maxwell 3D was used to optimize the simulation calculation.Then the result is Tmax3D=535.65N·m,Tmax2D=585.04N·m,TmaxEmpirical formula=502.43N·m.The influence of the magnetic coupling structure on the static magnetic torque was analyzed.The result shows that the longer the axial length is,the larger the maximum magnetostatic torque is.The magnetic force line distribution can be optimized by embedding the yoke in the gap of 1°5°,and the magnetic material can be saved.The maximum magnetic torque decreases with the increase of gap.?2?The eddy current loss of magnetic coupling and the magnetic induction intensity of isolation cover at different angles and speeds were calculated by Maxwell 2D transient field,and regression analysis was carried out.The results show that the eddy loss of the same angle increases nonlinearly with the increase of speed.The eddy current loss of the same angle fluctuates with time around a fixed value periodically.Due to the variation of magnetic induction intensity on the isolation cover,the eddy loss changes periodically with the magnetic rotation angle,and the period is 4?/p.The maximum magnetic torque of Maxwell 2D transient field is smaller than the maximum static magnetic torque.The influence factors of the eddy current loss were analyzed,and?35?pStainless steel>?35?pTitanium alloy>?35?pPlexiglasslexiglass was obtained at same speed and same magnetic rotation angle.The larger the conductivity of the isolating cover material is,the greater the eddy current loss is.The eddy current loss caused by saturated salt water is greater than that caused by dielectric water,but the eddy current loss caused by saturated salt water is small by order of magnitude.?3?Based on ANSYS Workbench,multi-field coupling calculation of magnetic coupling was carried out.Firstly,Maxwell's transient field and transient temperature field were coupled.The results show that the temperature of the isolation cover is the highest.When the rotation speed is less than 2300r/min,the temperature rise of the isolation cover increases linearly,and the temperature increases abruptly within 2300r/min2900r/min.The convection heat transfer of air and water can effectively control the temperature rise at low speed,while the temperature rise is still obvious but improved.The flow field and temperature field of the cooling circuit were calculated by CFX,and the stress and deformation of the isolating sleeve of different materials were calculated by coupling with the static temperature and structural fields.The results show that the pressure of the swirling water body at the inner wall of the inner magnetic steel and the inner wall of the isolation cover is low,while the center pressure of the bottom of the isolation cover is large.There are a large number of vortices in the inlet water cavity and the outlet water cavity.The surface temperature of the water surface contact with the inner wall of the isolating cover is stratified along the axial direction.The maximum circumferential layer with the highest temperature is at the nozzle of the isolating cover.With the speed increasing,the highest temperature of the circle moves along the direction of the bottom of the isolating cover,and the highest temperature of the cooling water is gradually increased.The stress and deformation of the isolation cover made by stainless steel is dominated by the temperature field,while those of the isolation cover made by titanium alloy is dominated by the pressure and the temperature.The stress and deformation of the isolation cover made by organic glass is dominated by the pressure distribution of the flow field.The bearing capacity of the organic-glass isolation cover,which deformation at bottom is the largest,is less than the metal isolation cover.The deformation decreases circularly from the center to the circumference.?4?The wet dynamic magnetic coupling test-bed was built for the first time.The dynamic characteristics of the rated load and rated speed,the influence factors of the energy loss of the magnetic coupler and the temperature test in different positions were carried out.When the load is fixed,the torque T1 increases with the increase of speed,but the increase trend is smaller when the speed is greater,which means that the maximum torque of the magnetic coupling is constant.The loss of the magnetic coupling is related to the speed,and almost has little to do with the load.The carrying capacity of the same magnetic coupling increases with the increase of rotation speed.The efficiency is constant.It increases slightly with the increase of speed.The longer the axial length of the magnetic coupling is,the greater the load capacity is.The shorter the axial length is,the higher the transmission efficiency is.The relationship between eddy current loss and rotational speed is nonlinear,which shows as?35?ptest=2.72574×10-6n1.87559.The influence of isolation sleeve material,medium water and saturated salt water on eddy current loss is verified.The temperature of the isolation cover on the same cylinder is increased along the direction far away from the bottom of the isolation cover.The rise of temperature of isolation cover at low speed is not obvious while that of high speed is rapid. |
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