Finite Element Analysis for Connection Mechanism in Macro-Micro Platform

Connection mechanism is a key component in macro-micro platform which can achieve high acceleration, ultra-high precision positioning and a long stroke. The paper presents a connection mechanism combining with a voice coil motor (VCM) and a piezoelectric stack actuator (PSA). The connection mechanism was investigated by mechanical analysis, related property indices, and some preliminary studies were as following: in the beginning, static analyses in multi-cases were carried out to ensure a solid foundation for the connection mechanism. The maximum deformation and stress were obtained for a validation evidence of structural reliability. Stress and deformation distribution were disclosed, and the relevant change trends of the maximum stress and deformation in multi-cases were obtained. However, the connection mechanism is employed to realize high acceleration, while to achieve ultra-high precision positioning. Since resonance between connection mechanism and other bodies must be avoided. It is convenient and economic to do modal analysis by ANSYS, and then the intrinsic frequency of connection mechanism will be obtained. The results indicate the connection mechanism has a higher resonance frequency than others. Though there are realization of the solid foundation and avoiding resonance, some environmental factors have hindered ultra-high precision positioning such as the relative air humidity, temperature and so on. Since the temperature up to 100℃ from heating problem of VCM inevitably produces a great deal of heat energy which can bring thermal deformation and stress, it is obliged to explore thermal deformation and stress distribution of connection mechanism by thermal- structure characteristic analysis. Thermal deformation and stress change trends under different temperature loads are revealed, which will provide a support for ultra-high precision. It is expected that finite element simulation can be an effective tool to realize the design of ultra-high precision connection mechanism in high acceleration positioning. 