| Industrial robots are the core equipment for our country’s industrial upgrading of intelligent manufacturing and play an important role in our country’s economic and social development.The permanent magnet synchronous motor is a power output component installed in the body of an industrial robot.A lightweight,high-overload output motor has been developed.Through the "small horse-drawn big cart",the weight of the industrial robot body is reduced,and the gap and deformation errors of multi-joint gears are reduced.is an important way to improve the accuracy and load capacity of industrial robots.In the process of reducing the weight of the motor and improving the power-to-quality ratio,the excessive temperature rise of the motor is the main bottleneck.Aiming at the problem of excessive temperature rise in the end windings of permanent magnet synchronous motors,this paper proposes a motor thermal management program that strengthens convection heat transfer.The temperature rise of the motor is explored through electromagnetic field and temperature field simulation,and a test platform is established to test the motor,and finally the motor overload output capacity is verified.The main research contents and conclusions are as follows:(1)A two-dimensional electromagnetic field simulation model and a three-dimensional temperature field simulation model of the motor were established,and the source and distribution of the motor loss were analyzed,and they were applied as a heat source to the corresponding components for temperature simulation.Aiming at the motor overload requirements and working environment of industrial robots,the simulation explored the effects of different multiples of overload current and ambient temperature on the motor temperature rise.The investigation found that the copper loss of the winding is the largest part of the motor loss,the temperature field of each component in the motor is not balanced in all directions,and the end winding is the highest temperature rise area in the motor.In order to solve the heat dissipation problem of the motor end windings,a fan-based forced air cooling system is proposed,and the internal temperature distribution characteristics of the motors with different cooling methods are simulated and compared.(2)According to the principle of motor-to-dragging,a motor-to-dragging test platform was established through the process of equipment selection,communication connection,upper computer program writing,etc.,and the torque and speed test,continuous overload temperature rise test,thermal model test,etc.were completed respectively.Effective torque load temperature rise test.By comparing with the actual temperature rise curve,it is found that the finite element simulation model is closer to the actual situation than the thermal model and its derived temperature rise curve,which verifies the accuracy of the simulation results.(3)Combining the analysis of simulation and actual test results,it is found that,compared with the natural cooling motor,the maximum steady-state temperature rise of the forced aircooled motor under rated conditions is reduced by 33.7℃;the forced air-cooled motor can continue under the condition of 130% current load Compared with the natural cooling motor,the operation is increased by 20%;at higher overload current(150%～300%),the running time of the forced air-cooled motor is extended by 33%～65%.The research results show that the forced air cooling system can effectively reduce the maximum temperature rise of the motor by improving the convective heat transfer capacity of the casing surface,further increase the power density of the permanent magnet synchronous motor,increase the continuous overload output capacity of the motor,and extend the high overload condition The running time provides a new idea to realize the lightweight of permanent magnet synchronous motors and industrial robots. |
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