ABSTRACT
The fabrication of micro-textures on free-form surface with high precision is vital for the development of hi-tech industries, such as aero-space, defense industry, micro-electronics industry and biological engineering. It is still difficult to manufacture micro-textures on free-form surface by using multi-axis machine tool. In order to solve the problem, a multi-DOF micro-feed mechanism is proposed to provide the capability of fabricating micro-textures to obtain better quality, which can be installed on the machine tool. Structure design, kinematics modeling and finite element simulation for the proposed multi-DOF micro-feed mechanism are explored. Firstly, two-layer structure with parallel top platform and nested bottom platform are proposed to form the multi-DOF micro-feed mechanism and parallel top platform and nested bottom platform are connected in series. Secondly, the nested bottom platform is designed with four groups of bridge-type displacement amplifier to form nested structure of XOY coordinate plane, which is used to generate movements along X and Y directions. Thirdly, parallel top platform is constructed based on four leg parallel mechanism and is composed of supporting platform, installing platform, three groups of symmetrical parallel branched chain and one middle branched chain which is perpendicular to the XOY plane. The symmetrical branched chain is designed by combining the series form of multi axis and single axis flexure hinge. The rotation movements of 3-DOF are generated in parallel top platform by piezoelectric transducer. Thus, the multi-DOF micro-feed platform is established based on the hybrid compliant mechanism. Finally, static and dynamic analysis is conducted by using the finite element method to verify output motions of multi-DOF micro-feed mechanism. The results show that the designed multi-DOF micro-feed mechanism is satisfied.
