用于质量特性参数测量的新型气浮扭摆台

常规扭摆台采用滚动轴承和扭杆振动结构，纵向尺寸大、测量精度低、抗倾覆力矩小，不能满足质量特性参数综合试验台的要求，必须对其进行结构的分析和优化。本文提出交叉弹簧板结构替换扭杆，减少了扭摆台纵向尺寸，分析和实验表明该结构具有和扭杆相同的振动效果。将滚动轴承替换为气浮轴承，提高了抗倾覆力矩，测量精度最高达0.1%；采用有限元法对柱坐标系下修正的雷诺方程进行仿真计算，研究气浮轴承结构参数对承载能力和抗倾覆力矩的影响规律，确定了给定轴承外径下的最优几何参数。实验表明，改进的试验台提高了测量精度和振动稳定性，对卫星等飞行体质量特性参数的测量有重要的意义。

New Kind of Gas Bearing Torsion Pendulum Used for Mass Property Parameters Measurement

The conventional torsion pendulum adopts a rolling bearing and torsion bar vibrating structure. It suffers from excessive length in the vertical direction, low measurement accuracy, poor load capacity, and poor anti-overturning moment, and it cannot meet the requirements of a comprehensive test platform for mass property parameters. The cross-shaped spring block structure is proposed to replace the torsion bar structure, and the size of the torsion pendulum is reduced in the vertical direction. Analysis and experiment prove that the new structure has the same effect as the torsion bar. As the rolling bearing is replaced by the gas bearings, the anti-overturning moment of the torsion pendulum is improved and measurement accuracy reaches up to 0.1%. The finite element method is adopted to simulate the re-corrected Reynolds equation under a cylindrical coordinate system,and then the influence of basic gas bearings structural parameters on load capacity and anti-overturning moment is studied. Finally, the optimized geometrical parameters of a given outer radius bearing are determined. Experimental results demonstrate that the improved test-bed improves the measurement accuracy and vibration stability. It is significant for mass property parameters measurement of spacecraft, such as satellites.