Study On The Transmission Characteristics For 110kW Fixed Gap Magnetic Coupling

In this paper,the 110kW fixed gap magnetic couplings for "Yu Kun" fresh water pump is taken as the research object,and the fact that the magnetic couplings manufacturer only provides the transmission characteristic parameters of the rated working point without the non-rated transmission characteristic parameters of magnetic couplings.The analytical calculation of the transmission characteristics,the finite element simulation analysis and the test methods have been carried out to compensate the study on the transmission characteristics of the magnetic couplings.The conclusions of the paper will provide technical support for the use,design and manufacture.First the fixed gap magnetic coupling working principle,features,structure are introduced.The system of the No.3 magnetic couplings fresh water pump is briefly introduced,and the parameters of the magnetic couplings are given.The prototype is provided for the theoretical analysis.Secondly with the theory of constant magnetic field,the analytical model of the standard type magnetic coupling has been established.And by solving the analytical model of magnetic coupling,the transmission torque expression has been got;for the fixed gap magnetic coupling,copperplate thickness and air-gap size are highly nonlinear with the torque coefficient;transfer torque is highly linear with slip;in the engineering coefficient of Russell's for the transmission torque can be neglected.And then combining with 110kw fixed gap magnetic coupling parameters,simulation analysis has been finished with Maxwell 16.0.Field intensity distribution,magnetic induction intensity distribution,the density of the eddy current distribution of the magnetic coupling magnetic components,loss power and torque values have been got.Copper plate eddy current density increases with the increasing of slip.Torque value has a linear relation with the slip.Loss power is nonlinear with the slip.Having set up a 110kw magnetic coupling test bench for 110kw the fixed gap magnetic coupling has got the four synchronous speed 750 rpm,1000 rpm,1500 rpm and 3000 rpm test data.The ratio of the torque and the slip rate is increasing with the synchronous speed.The ratio of the power and the slip rate is increasing with the synchronous speed.If synchronous speed is constant,the ratio of torque and the slip rate,the ratio of the power and slip rate ratio are constant.The lager synchronous speed will pass the larger torque and power with the same slip rate,so the fixed gap magnetic coupling is suitable for working under high speed working conditions.Finally,the finite element simulation data,analytical model data and experimental data have been compared.Analytical data and the simulation data compared with the experimental data are within 20%which is satisfied with engineering requirements;with the increasing of slip,analytical model data and simulation data are more and more close to the test data.Analytical data is more close to the test data than the simulation data,and the minimum deviation rate between test data and analytical data is within 1%.And the power-speed characteristic of the magnetic coupling has been predicted by the comparison.In this paper,the analysis of magnetic coupling transmission characteristics has laid foundation for marine applications.