| Magnetic coupler is a new type of speed control equipment,which has the characteristics of light load start,overload protection,isolation vibration,zero leakage,energy saving and environmental protection.It has a wide application prospect in power generation,metallurgy,sewage treatment,mining and cement,pharmaceuticals,chemical industry and other heavy torque industries.In order to overcome the shortcomings of the existing magnetic coupling technology,a new type of composite magnetic coupling structure is proposed.It could enlarge the area of the induction magnetic field at the same time from the axis/radial.Aiming at the special working environment,the mine composite magnetic coupler is taken as the object,the modeling of permanent magnet coupled transmission is taken as the main line.With the aim of the safety,high efficiency,energy saving,environmental protection,smooth transmission and reduction of unit specific volume of transmission power,the key issues of the main structure design,parameter design and test platform design of the composite magnetic coupler are studied.Specific research work is described below:1)Based on the structural characteristics and operating characteristics of the existing cylinder and plate magnetic couplers,a composite magnetic coupler is proposed based on the principle of permanent magnet eddy current transmission.In addition,copper conductor of it cut the magnetic line of force in the radial direction and on its end face to increase electromagnetic damping.In this way,transmission power could be substantially improved in a condition of identical volume or size;moreover,in the case that the transmission power was at a certain value,both volume and size of such a coupler could be reduced to decrease the space it occupied.2)One of the most important defects of composite magnetic coupler is that the magnetic flux leakage is large,and the particularity of the structure makes it difficult to calculate the magnetic flux leakage.Therefore,the accurate calculation of magnetic flux leakage in various parts of the composite magnetic coupler is meaningful.Considering the magnetic leakage effect,the equivalent magnetic circuit network model of composite magnetic coupler is established.Then the formula for calculating the leakage coefficient of the magnetic coupler is obtained.Compared with the traditional three-dimensional finite element method,the equivalent network modeling process of composite magnetic coupler considering magnetic flux leakage is simple and the calculation time is short.3)According to the structural characteristics of a new type of composite magnetic coupler,the calculation formula of air gap magnetic field is established by applying the method of "field" as "road".Based on the superposition of current,the current is converted to the surface of copper conductor,and the induced electromotive force is integrated in the circumferential direction.The electromagnetic torque model of the space magnetic field is established.Under the same volume condition,compared with the ordinary double disc magnetic coupler,the torque of the composite magnetic coupler is larger.Compared with hard rock boring machine equipped with the same capacity asynchronous motor,the rigid rock boring machine equipped with composite magnetic coupler has wider linear working area and softer mechanical characteristics,so it has more overload protection ability.4)Based on improved response surface methodology,combined MAXWELL ANSOFT and Design Expect 8.0 softwares,the multi factor and multiple response value two times orthogonal rotating combination test was designed to optimize the structural parameters of the composite magnetic coupler,so as to find the optimal structure layout and parameters of the composite magnetic coupler.5)In order to eliminate the influence of eddy current heat on the output torque,a three-dimensional finite element analysis method based on magneto thermal coupled field is proposed for the three-dimensional magnetic field simulation of a composite magnetic coupler.The model of permanent magnet thermal coupling is built by combining Ansoft Maxwell and Ansys Workbench software to analyze the influence of vortex heat on the properties of copper conductor and permanent magnet.The thermal power generated by the eddy current is introduced into the temperature field of the Transient Thermal module as a heat source load,and the performance parameters of the composite magnetic coupler are corrected by the simulation results of the temperature field.6)The design of composite magnetic coupler test platform system,in order to test the magnetic leakage effect,magnetic transmission characteristics,mechanical properties,magnetic thermal coupling characteristics,and verify the improved results of response surface optimization,based on the experimental data,the conclusions are as follows:composite magnetic coupler with high transmission efficiency,the mechanical characteristics of soft.Have good ability of magnetic soft start and overload protection ability. |
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