Study on Performance of an Air Spring Isolator for Large-Scale Precision Optical Micro-Vibration Isolation

To realize high payload and ultra-low frequency isolation characteristics and effectively restrain the influence of microvibration in the environment on the accuracy of large precision/ultra-precision optical instruments, a high precision analysis method for the performance of air spring isolators is presented. The analysis method that combining theory with simulation studies the structural stiffness and material stiffness characteristics of an air spring isolator respectively, which effectively solves the problem that the traditional theoretical models could not guide the optimization design and precision machining of air spring isolators accurately due to their neglecting of the elastic membrane material stiffness. The analysis results show that the stiffness and stiffness ratio of the elastic membrane increase with the rise of inflatable pressure in the chamber. Structural designs of large chamber volume and small bearing area, the working pattern of high inflatable pressure, as well as material parameters of large cord angle and a small distance from cord to the neutral surface of the elastic membrane, are beneficial to reduce the stiffness of the air spring isolator. The research is beneficial to realize the low stiffness and ultra-low frequency isolation of air spring isolators.