一种用于机载设备的高精度转动型柔性铰链
收稿日期: 2012-03-23
修回日期: 2012-06-27
网络出版日期: 2013-03-29
基金资助
国家自然科学基金(50975007,51105014)
A Precise Rotational Flexure Pivot for Airborne Equipment
Received date: 2012-03-23
Revised date: 2012-06-27
Online published: 2013-03-29
Supported by
National Natural Science Foundation of China (50975007, 51105014)
传统铰链应用于机载设备时会产生摩擦、磨损、接触面热梯度等问题,而利用材料变形产生运动的柔性铰链可避免此类缺陷,获得高性能的同时,降低维护成本。现阶段使用的交叉簧片柔性铰链无法满足某些超精密航空机载设备的定位精度要求,因此将交叉点推广到任意位置以改善性能。首先,考虑机械接口,建立了广义交叉簧片柔性铰链的刚度和轴漂模型,从而分析了各个参数与刚度及轴漂的关系,并评估了由于加工因素造成的簧片不等长给性能带来的影响,得到了具有等值刚度和较小轴漂特性的柔性铰链。然后,通过有限元仿真验证了所分析特性的有效性。最后,通过组合提出了一种更大行程的复合柔性铰链,当转角为15°时,且在垂直力作用下,轴漂小于3 μm,精度优于在国外已得到应用的蝶形铰链。
刘承平 , 赵宏哲 , 毕树生 , 徐熠 . 一种用于机载设备的高精度转动型柔性铰链[J]. 航空学报, 2013 , 34(3) : 694 -702 . DOI: 10.7527/S1000-6893.2013.0108
Current joints used for airborne equipment suffer from problems of friction, wear, and thermal gradients. Flexure pivots, on the other hand, achieve their motion by the deflection of their flexible members, so the performance increases and the cost reduces. At present, the cross-spring pivot cannot satisfy the positioning requirements for some ultra-precision airborne equipment. Consequently, the intersection point is generalized to arbitrary position in order to improve the performance. Firstly, considering the mechanical interface, a model for the generalized cross-spring pivot is developed. The relationships between stiffness/accuracy and design parameters are analyzed, and the influence is evaluated of two different length leaves resulting from manufacturing errors on its performance. Therefore, a flexure pivot with constant stiffness or small center shift is obtained. Furthermore, the characteristics revealed by the analysis model are verified by finite element analysis (FEA). Finally, taking the advantage of building block method, a complex flexure pivot with higher precision is proposed. When the rotational angle is up to 15° and a vertical load is applied, the center shift of the complex flexure pivot is less than 3 μm, and its precision is even better than the butterfly pivot, which is extensively utilized abroad.
Key words: flexure pivot; stiffness; center shift; precision machine; airborne equipment
[1] Howell L L. Compliant mechanisms. New York: Johm Wiley & Sons, Inc., 2001: 136-162.
[2] Smith S T. Flexures: elements of elastic mechanisms. New York: Gordon and Breach Science Publishers, 2000: 193-198.
[3] Henein S, Spanoudakis P, Droz S, et al. Flexure pivot for aerospace mechanisms. Proceedings of 10th European Space Mechanisms and Tribology Symposium. 2003:1-4.
[4] Huang J, Ge W J, Yang F. Topology optimization of the compliant mechanism for shape change of airfoil leading edge. Acta Aeronautica et Astronautica Sinica, 2007, 28(4): 988-992. (in Chinese) 黄杰, 葛文杰, 杨方. 实现机翼前缘形状连续变化柔性机构的拓扑优化. 航空学报, 2007, 28(4): 988-992.
[5] Zago L, Mayor J M, Droz S, et al. High-accuracy hexapods for the alignment of secondary mirrors of advanced astronomical telescopes. Neuchatel: CSEM, 2004.
[6] Li H X, Ding Y L, Hui S W, et al. Design of compliance factor experiment setup for single-axis flexure hinge. Optics and Precision Engineering, 2011, 19(7): 1552-1559. (in Chinese) 李海星, 丁亚林, 惠守文, 等. 单轴柔性铰链柔度系数试验装置的设计. 光学精密工程, 2011, 19(7): 1552-1559.
[7] Chen G M, Han Q. Deep-notch elliptical flexure hinges. Optics and Precision Engineering, 2009, 17(3): 570-575. (in Chinese) 陈贵敏, 韩琪. 深切口椭圆柔性铰链. 光学精密工程, 2009, 17(3): 570-575.
[8] Hu J F, Zhang X M. Active vibration control and its simulation of a novel 2-DOF flexible parallel manipulator. China Mechanical Engineering, 2010, 21(17): 2017-2020. (in Chinese) 胡俊峰, 张宪民. 一种新型两自由度柔性并联机械手的主动振动控制及其仿真. 中国机械工程, 2010, 21(17): 2017-2020.
[9] Trease B P, Moon Y M, Kota S. Design of large-displacement compliant joints. ASME Journal of Mechanical Design, 2005, 127(4): 788-798.
[10] Fowler R M, Howell L L, Magleby S P. Compliant space mechanisms: a new frontier for compliant mechanisms. Mechanical Sciences, 2011, 2(2): 205-215.
[11] Zelenika S, DeBona F. Analytical and experimental characterisation of high-precision flexural pivots subjected to lateral load. Precision Engineering, 2002, 26(4): 381-388.
[12] Jensen B D, Howell L L. The modeling of cross-axis flexural pivots. Mechanism and Machine Theory, 2002, 37(5): 461-476.
[13] Riverhawk Company. Flexural pivot catalog. 2004:1-6.
[14] Wittrick W H. The properties of crossed flexural pivots and the influence of the point at which the strips cross. The Aeronautical Quarterly, 1951, 2: 272-292.
[15] Awtar S, Slocum A H, Sevincer E. Characteristics of beam-based flexure modules. Journal of Mechanical Design, 2007, 129(6): 625-639.
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