| With the continuous improvement of modern mechanical transmission structure,the development of coupling is also advancing towards the direction of high transmission efficiency,safety,reliability and easy assembly.Radial permanent magnet coupling is a new type of coupling which has been developed rapidly and widely used at present.Its main and follower rotor non-contact structure characteristics can ensure the efficiency and safety of transmission process.The corresponding structure design and working characteristics analysis have high research value.In the process of manufacture and installation,the misalignment errors between the main and follower rotors of radial permanent magnet coupling are easy to occur,resulting in transmission instability,low efficiency,large vibration of axle center,and even structural damage.In this paper,the transmission characteristics and vibration characteristics of the radial permanent magnet coupling with installation errors are analyzed and calculated,and the installation accuracy of the radial permanent magnet coupling is determined.Firstly,the structure characteristics of the radial permanent magnet coupling and the misalignment form of the traditional coupling are introduced,and the expression form of the installation error of the radial permanent magnet coupling is obtained.Two-dimensional magnetic field analysis by Ansoft Maxwell shows that the existence of axial errors will lead to a downward trend in the magnetic line density and magnetic induction intensity of the air gap between the main and follower rotor of the system.The existence of coaxiality errors and parallelism errors will lead to obvious non-uniform changes in the magnetic line distribution and magnetic induction intensity.Then the influence of each error on the transmission process of the system is obtained by three-dimensional transient torque analysis.Secondly,the mathematical model of the radial permanent magnet coupling is established by using the Coulomb’s law of magnetic charge,and the calculation formula of the torque is deduced for different types of installation errors.The correctness of the formula is verified by comparing the calculated value of the formula with the stable transfer torque value obtained from the simulation analysis.According to the calculation results of the formula,the influence of installation errors on the transmission torque of the system under different structural parameters is analyzed,and the installation accuracy of the coupling system with different sizes is obtained to ensure the normal transmission.Finally,the dynamic model of radial permanent magnet coupling system with installation error is established by using Lagrange equation of dissipative system from the angle of energy.According to the actual parameters,the dynamic equation is established by ODE45 method of Matlab,and the bifurcation diagram of the system varying with the error value and the displacement response diagram under different error value are solved numerically.The installation precision of the stable transmission of the system is obtained.The degree also validates the feasibility of the established dynamic model. |
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