The existing heat dissipation research on double disk magnetic couplers ignores the coupling influence of electromagnetic temperature–stress and other multiphysics fields, and the error between the calculation and analysis results and the measured values is large. Therefore, a multi-parameter optimization method for heat dissipation structures of double disk magnetic couplers based on orthogonal experimental design is proposed. Based on the double disk magnetic coupler model, a three-dimensional finite element model based on fluid–solid–heat coupling is established, with the axial air gap length, input motor speed, the thickness of the permanent magnet in the magnetizing direction, the thickness of the copper plate, the number of fins of the heat dissipation plate and the length of the fins of the heat dissipation plate as design variables. Six-factor and three-level simulation experiments are designed with the minimum temperature of the heat dissipation plate as the objective function, and additionally, orthogonal experiments were designed according to the actual working conditions by selecting the optimal combination of parameters and modifying the model to perform physical tests. The results show that the variables that have the most significant impact on heat dissipation performance from high to low are as follows: axial air gap length, input motor speed, the length of the fins of the heat dissipation plate, the thickness of the permanent magnet in the magnetizing direction, the number of fins of the heat dissipation plate and the thickness of the copper plate. The increase in axial air gap length can effectively reduce the temperature rise, and the maximum decrease can reach 9.76%. Under the same conditions, the input motor speeds are set to 300 r/min, 400 r/min, 500 r/min, 600 r/min and 700 r/min, respectively, and the simulation results are in good agreement with the physical test results, with a maximum error of 4.8%. The error between the simulation result and the physical test result is only 1.9% under the optimal combination of parameters obtained by the orthogonal experiment, which verifies the correctness of the optimization model. In conclusion, the study is of reference significance for the parameter optimization of the heat dissipation structure of the double disk magnetic coupler.

In order to effectively solve the current problems of magnetic couplers such as large area and complex internal coil, the Halbach array magnetic coupler was proposed. According to the specific characteristics of the hybrid magnetic coupler structure, the mathematical model of air gap magnetic flux density is established by using the combination of electric circuit and electromagnetic field solution. Based on the current superposition, the current is converted to the surface of the copper conductor, and the electromagnetic torque model of the space magnetic field is established by integrating the induced electromotive force along the circumferential direction. In order to verify the correctness of theoretical analysis, the 1:4 prototype was designed and manufactured. Then simulation verification and experiment measurement on its mechanical behaviour are performed. The results show that the maximum error of theoretical value, simulation value and test value is 9.3%. Under the same volume size, the output torque of Halbach array magnetic coupler is increased by 16.1% compared with the ordinary disk magnetic coupler. The research could provide the reference for the design and experimental research of magnetic coupler.

A new inhibition method was proposed for the problem of harmonic of radial electromagnetic force during the operation of the composite magnetic coupler. In order to suppress its radial electromagnetic force, a radial permanent magnet rotor eccentricity method is proposed, and a three‐dimensional finite element model is established. Based on the Maxwell tensor method, the radial electromagnetic force of the composite magnetic coupler is analysed, and the mathematical expression of its radial electromagnetic force is established, Maxwell stress tensor was used to analyse the radial electromagnetic force in a composite magnetic coupler and to establish the mathematical equation for the radial electromagnetic force. In order to suppress the radial electromagnetic force, a method based on rotor eccentricity in a radial permanent magnet was proposed. A prototype of a composite magnetic coupler with a rated power of 5 kW was designed to test its output torque under load. The results showed that the simulated curve was consistent with the tested curve, with a maximum numerical error of 8.9%. The tested values of the output torque before and after eccentricity were compared, and the results showed that the output torque remained basically unchanged after the eccentric structure was adopted and that the torque pulsation was significantly reduced.

Abstract-Aiming at the dynamic measurement stability problem of electromechanical transmission system under harsh environments such as heavy-load starting, severe wear, and severe pollution, an improved non-dominated sorting genetic algorithm II (NSGA-II) double-disk magnetic coupler multiobjective optimization algorithm is proposed. This algorithm is designed to achieve the coordinated optimization of high power and low amplitude, while enhancing the measurement accuracy of key performance indicators. Taking a 55-kW double-disk magnetic coupler prototype as an example, the response surface method based on a full factorial experiment is used to reveal the interaction of core parameters such as input speed, the length of air gap, and pair of permanent magnets on the nonlinear influence of transmission power and vibration amplitude. The NSGA-II multiobjective optimization algorithm model based on deep regression and density adaptation is constructed, using polynomial fitting and the improved NSGA-II for optimization, which addresses the issue that traditional struggle to achieve a global optimal solution. Compared with the traditional NSGA-II algorithm and transmission test, the effectiveness of the improved algorithm is verified. The optimal structural parameter combination is obtained through analytic hierarchy process (AHP) decision-making and box-plot comprehensive analysis: input speed is 1054.8 rmin, length of air gap is 3.4 mm, and pair of permanent magnets is 5. The research results show that the transmission power of the optimized double-disk magnetic coupler is increased by 38.1 %, the vibration amplitude is reduced by 26.4 %, and its transmission characteristics and vibration characteristics are significantly improved.

In order to effectively solve the problems of large impact vibration and frequent overload of hard rock roadheader at present, a new magnetic coupler based on flexible transmission technology is proposed. Combined with the structural characteristics of the new magnetic coupler, the mathematical model of air-gap magnetic field is established by using the method of “field” and “circuit”. Based on the superposition of current, the current is converted to the surface of copper conductor, and the induced electromotive force is integrated along the circumferential direction, and the electromagnetic torque model of space magnetic field is established. Based on the above, a prototype is designed and manufactured, and its mechanical characteristics are simulated, analyzed and tested. The results show that the difference between theoretical value, simulation value and experimental value is less than 10% at the same slip rate. Compared with the asynchronous motor with the same capacity, the new magnetic coupler has wider linear working area and softer mechanical characteristics, so it has stronger overload protection capability. This study can provide application reference for mechanical equipment with large start-up impact and frequent overload.