Study On Working Performance Of Speed-control Slotted-type Asynchronous Magnetic Coupler Under Different Operating Conditions

Speed-control slotted-type asynchronous magnetic coupler(SSAMC)is a new type of transmission device combining a variety of technologies.It can transmit torque without contact and has the characteristics of flexible start,overload protection,seismic isolation,allowing alignment error and so on.If the the air-gap thickness is adjusted,the output speed can be controlled,and when the SSAMC is applied to pumps and fans for speed regulation,it can achieve better energy conservation effect.In view of the many advantages of the SSAMC,it has high academic value and practical engineering value for its theoretical research.Contents about the SSAMC are mainly studied as follows:Firstly,the electromagnetic torque and adjustable-speed relation model are analyzed and calculated.The magnetic circuit of SSAMC is analyzed and all magnetic resistance is calculated by equivalent magnetic circuit method.According to Kirchhoff's law and introducing the Carter's coefficient,the magnetic flux density of SSAMC is obtained.Based on that,the expression of electromagnetic torque is deduced.Based on the load characteristics of constant load,variable load and constant power load,the adjustable-speed relation models under different load conditions are deduced and solved,respectively.Secondly,the speed control performance and influence factors of SSAMC are simulated and analyzed.The critical slip is about 17% when the output torque of SSAMC under different air-gap thicknesses reaches the maximum.The output power of SSAMC under different air-gap thicknesses has a maximum,and with the increase of air-gap thickness,the corresponding slip is also increasing when the output power reaches the maximum.The speed control performance of the SSAMC under different load conditions is different.By comparison,the performance of the SSAMC under variable load is optimal.With the increase of the number of slots and poles,the speed control performance of the SSAMC gradually decreases,and with the increase of the pole-arc factor,the speed control performance of the SSAMC remains unchanged.Thirdly,The dynamic characteristics of the SSAMC are simulated and analyzed.The output speed of SSAMC under different conditions decreases gradually with the increase of air-gap thickness.Meanwhile,the induced current density and the eddy current loss increases.When the air-gap thickness is invariant,the output speed of SSAMC will decrease as the increase of constant load,variable load factor and constant power load,while eddy current loss will gradually increase.The decrease of air-gap thickness will result in the increase of axial force,and when the thickness reduced is less than 3mm,the axial force increase sharply.The axial force of the SSAMC will be affected by the air-gap thickness and slip,while the effect of the air gap thickness on the axial force is significantly stronger than the effect of the slip.Finally,the work performance test platform is developed.The transmission performance of SSAMC is tested.The torque change rule under non-load condition and the mechanical characteristic curves of SSAMC under different air-gap thickness are obtained.The speed control performance of the SSAMC under constant load and variable load condition is tested,respectively.The relationship between the air-gap thickness and the output speed,slip and speed difference of SSAMC under different input speeds is measured.By comparison,it is found that the measurement results agree well with the results obtained from the calculation and simulation.