Key Technologies Of Light-duty For Permanent Magnet Torque Motors Used For Laser Communication Platform

Due to the particularities of the aerospace field, high reliability and light-duty are the most important requirements for aerospace equipment rather than that in ordinary industrial field. The light-duty requirement is mainly related to the mass and the volume of parts from aerospace equipment. On the view of motors, it is the best choice that the one has light-duty design under the same torque. Therefore, the permanent magnet torque motor(PMTM) which has good performance and high torque density attracts great attention. Balancing the aspects of volume, mass and performance, the PMTM is superior with these properties and benefit to light-duty for aerospace equipment.The motor used for two-dimensional track gimbal equipment of laser communication is focused on in this thesis. We found that the volume decreasing of motor on pitching axis, especially the decrease of the axial length, will make a good contribution on the load decreasing of azimuth axis motor. The load reduction has a positive effect on the designs of azimuth axis motor which could be as smaller as possible in size. Based on the above discussions, we can conclude that the light-duty of pitching axis motor will benefit to the mass reduction of whole two-dimensional track gimbal equipment, and it would to be lighter than the pristine one. So the researches related to the light-duty technology of the direct drive PMTM are meaningful and will facilitate the development of the laser communication or other aerospace equipment.In this thesis, the motor is designed according to the needs of the laser optical equipment. The design what we concerned is the light-duty of the motor. Focusing on this target, we researched the strategy of light duty and used the new special materials with advanced properties to design the light-duty motor. During this process, we study the light-duty effect on motor based on the new special iron and permanent magnet materials. Meanwile, the effect of main dimentions of the motor on the light duty is studied. Finally the optimal approach is obtained considering the factors above.The material of FeCo is used for the structure of the motor. However FeCo is too fragile to process as the traditional laminations, and it is easy to defect during the process of superposition. These two aspects may affect the reliability of the laser communication. Therefore we research the effect of both traditional laminatied FeCo and novel integral FeCo on the iron loss of the PMTM used for laser communication platform. The results show that it is better to replace the traditional laminatied FeCo with novel integral FeCo. Besides the integral structure can simplify the processing and improve the reliability.Considering the direct-drive PMTM for laser communication that used in space, the special environment, other than on earth, will be bad for heat dissipation. So the researches related to heat dissipation are necessary. On the other hands, the temperature increment of motor will cause the variation of working parameters and the thermal stress that will affect the strength of mechani cal structure. Thus, the temperature analysis within the light-duty motor was carried out. By analyzing the working parameters of motor dependent on the temperature, the limited working time of motor on each state are confirmed and evaluated. Furthermore the thermal stress distribution on each working state is also given out based on the temperature results.Consequently, the final design of the direct drive PMTM which used on aerospace equipment is confirmed. Based on this design, a comprehensive physical and full stress method that combined the thermal stress from temperature elevated and mechanical stress is proposed to calculate and analyzethe full-scale effects on the direct drive PMTM, which will be used in aerospace. In addition, the limited working times of the motor at every state are confirmed.Finally, in order to verify the rationality of the light-duty procedure, the prototype based on the final contrivable conditions and the testing platform are built, a series of measurements including the back-EMF, output torque, iron loss and temperature rising that related to properties of the prototype are carried out respectively, moreover, the testing or revising method are given out.Trying the best use of the existing experimental conditions to simulate the actual operation of the motor with respect to laser communication platform, the result of calculation and the result of experiment are basically identical and mutual authentication, further confirming the design of the direct drive PMTM is correct and scientific.