大型磁悬浮控制力矩陀螺可重复锁紧装置高刚度高阻尼实现及微动运行机理研究

Large-sized magnetically suspended control moment gyros are developed in recent years to meet the need of the large satellite platforms, space stations and other national key projects. Due to the intensive vibration and shock during launch, locking device is mandatory to maintain the magnetically suspended rotor supported by electromagnetic force. To ensure flywheel to be suspended in the orbital phase, the link between stator and rotor created by locking device must be completely released. The repeated locking device with high stiffness and damping for magnetically suspended large inertia rotor and its fretting operation mechanism is investigated. First, based on combinatorial optimization strategy, the locking device is optimized with high locking stiffness and damping as objective functions. Subsequently, the fretting testing machine is established by using environmental mechanics tests to simulate launch vibration. The composite fretting behavior in locking contact surface is investigated and the fretting damage is inhibited based on fretting map theory. Finally, according to gyro system performances, response spectra and fretting displacement, wear morphology and elemental composition, the protection functions are evaluated. This work will provide the necessary theoretical basis for space station construction. It will also promote the settlement of the common scientific issues in vibration and space tribology areas.

大型磁悬浮控制力矩陀螺是应大型卫星平台、空间站等国家重大专项的亟需而发展起来的新型姿控机构。由于航天器发射主动段存在激烈振动与冲击，为保护电磁力弹性支承的磁悬浮转子，在发射主动段必须采用锁紧装置对其进行锁紧，入轨后还需解除原有的锁紧关系，使其处于自由状态以便悬浮工作。本项目首次对大惯量磁悬浮惯性执行机构用可重复高刚度高阻尼锁紧装置及其微动运行机理展开研究。首先，采用组合优化策略，以锁紧刚度和阻尼综合最优为目标，对锁紧装置进行双目标多学科优化。随后，采用环境力学实验模拟卫星发射振动工况，建立锁紧装置微动实验平台，对锁紧面内的复合微动行为进行研究，并基于微动图理论对微动损伤进行抑制。最后，从陀螺系统性能、振动频谱响应和微动位移响应、磨损形貌和元素成分三个角度，分别对其性能、宏观和微观保护效果进行评价。本项目的研究为我国空间站建设提供必要的理论基础，同时促进振动和空间摩擦学领域共性问题的解决。

针对大型磁悬浮控制力矩陀螺用可重复锁紧保护技术，本课题主要完成以下工作。.锁紧装置与转子系统优化。开展了可重复抱式锁紧装置研究，并对一体式碳纤维弹片和分立式弹片两种释放机构进行了详细力学分析和优化设计。通过有限元法计算释放机构对约束变量的灵敏度，选择灵敏度较高的结构参数作为优化设计变量，考虑结构强度、解锁力和一阶共振频率，对两种释放机构进行优化。环境力学实验表明，两种锁紧装置能够对转子系统实施有效保护。在此基础上，考虑磁悬浮转子锁紧状态下一阶共振频率，对转子进行多学科优化。.发射主动段微动行为研究。采用正弦扫频振动和随机振动模拟发射振动工况，利用电涡流位移传感器测量锁紧接触副处的微动位移，发现斜面锁紧副处存在包含切向和径向的复合微动。通过嵌入一橡胶减振垫，避免赫兹接触，从而抑制了斜面锁紧副的微动损伤。在平面锁紧副处，增加锁紧力可减小微动位移，从而使切向微动从滑移区移动至部分滑移区，避免了切向微动损伤。同时增加接触刚度，使平面锁紧副基体材料相近或相同，避免微滑发生。两者共同作用，抑制了平面锁紧副的复合微动损伤。.磁悬浮转子系统锁紧保护效果检测方法。首先，通过对比分析磁悬浮转子-锁紧装置在环境力学实验前后的测试性能数据，判断两者是否工作正常。其次，利用加速度计和电涡流位移传感器分别检测陀螺系统频谱响应和转子振动位移，对锁紧装置宏观保护效果进行评价。最后，采用扫描电子显微镜和能量色散谱仪分析锁紧面的磨损形貌和元素成分，对锁紧面微观保护效果进行评价。.磁悬浮敏感陀螺及其高精度磁轴承探索性研究。提出了3种陀螺方案、12种球面磁阻力磁轴承和19种洛伦兹力磁轴承，并选择其中部分方案进行了样机加工和实验验证。针对显式洛伦兹力磁轴承气隙磁密均匀性较差，基于磁路顺磁效应、聚磁效应、叠加效应原理，将磁密均匀性从现有30%提升至0.3%，大幅提高了陀螺输出力矩精度和姿态敏感精度。