Research On The Nonlinear Dynamics Of Metal Belt Transmission With Rare-earth Permanent Magnets

Belt driving is a traditional mechanical transmission mode which is widely used in many fields. It has irreplaceable advantages because the distance and angle can be adjusted between the two shafts of belt driving, and the belt can be replaced by a variety of flexible materials. Belt driving research has never been stopped since it came into being. The early research mainly focused on its structures with different structures of flexible bodies and belt pulleys. With the development of science and wide application in computers, the scientific research has becoming much more accessible to the essence of things. As far as the belt driving is concerned, the object of the research has concentrated on mass and complicated non-linear in belt driving. With much function of belt driving having been improved with the research of the characteristics, a lot of new-style belt driving devices have been developed. The metal belt driving with rare-earth permanent magnets is a new belt transmission whose permanent magnets are fixed between two transmission pulleys in particular arranged ways, so that the friction between metal band and belt pulley can be increased. Thus it can reach the enhancement of transmission power and transmission accuracy of belt driving.This paper mainly studies the issues of dynamics property of metal belt transmission with rare-earth permanent magnets. With the existence of magnetic force, the problem of the metal band vibration in transmission has been highlighted. As to the property change of metal belt transmission caused by introducing magnetic force, we analyze firstly in simple dynamics. Then assisted by rare-earth magnet, we acquire Euler equation through analyzing property of metal belt driving with flexible body friction transmission. We testified the effective improvement of drive power in metal belt with the assisting of the permanent magnet force, after analyzing the action of magnetic fields using the method of finite element analysis.In this paper, the effect of magnetic force by magnetic field is simplified into magnetic damping and external magnetic excitation. Considering the viscoelastic property and geometric non-linearity of metal band, we established three equations:nonlinear dynamical equation reflecting the transverse vibration of the metal band in axial movement, differential equation describing the transverse nonlinear forced vibration and differential equation explaining the non-linear parametric vibration of the band. This paper analyzes the steady-state frequency-amplitude response of the non-linear forced vibration of the metal band under magnetic force in axial movement by using viscoelastic constitutive function, and the response of non-linear parametric resonant vibration. It also discusses the steady-state frequency-amplitude response under systematic resonant vibration, as well as the influence of non-linear coefficient, magnetic excitation amplitude and viscoelastic coefficient, and explores the steady property of response curves. The results of the paper include the following aspects:as the values of non-linear coefficient and viscoelastic coefficient increase, or as the amplitude of magnetic excitation decreases, the steady-state amplitude of the metal band will decrease, the influence of viscoelastic coefficient on high-order mode is bigger than its influence on low-order mode, it doesn't hold that the higher the magnetic field intensity the better, because the increase in the amplitude of magnetic excitation results in a sharp increase in the vibration amplitude of the transmission system which leads to the lose of the stability of the transmission system, and the systematic stability can be enhanced by raising the speed of the transmission system; a proper increase in magnetic damping can also improve the systematic stability.This paper analyzes the vibration performance of metal belt through finite element analysis method. The vibration power of metal belt increases as the excitation magnitude of the external world, and then the stress of metal belt is also increased. But the vibration of metal belt will down with the higher speed of running. The entire conclusions are testified by the experiments.Introducing magnetic force will exert great influence on belt driving system in metal belt transmission institute. Utilizing rare-earth magnet in metal belt transmission strengthens the traction of belt driving system by means of theoretical research, numerical simulation, and experimental studies. As a result, transmission power will be greatly increased compared with the previous equipment. However, the introduction of magnetic force also increases the vibration of the metal belt and decreases the stability of the metal belt transmission. All these problems mentioned above can be resolved through the scientific selection of the metal belt and the pulley material, the range of operating speed, the design and earth magnet structure and the arrangement of them on the pulley belt.This paper lays a solid foundation for the further research on the metal belt driving with magnets and provides an approach for the development of new transmission system.