Design and application of a flexure-based oscillation mechanism for surface texturing

Micro-textures on tribological interfaces act as micro hydrodynamic bearings that can enhance hydrodynamic lubrication and reduce friction. In this paper, an oscillation mechanism (OM) is employed to generate micro-textures on piston surfaces. The OM is composed of a piezo-actuator and a flexure-based (FB) mechanism in the form of a parallel and symmetric structure with eight circular notch-type hinges. The conceptual design of the FB mechanism is illustrated first. Its stiffness and resonant frequencies are mathematically modeled and verified through FEA. Then, the generation process of micro-textures is analyzed and the relationship between the processing parameters and the parameters of the micro-texture shapes are graphically illustrated. Performance tests of the FB mechanism are also conducted to measure the its output displacement, resonant frequencies and stiffness. Finally, preliminary experimental results confirm that the generated micro-textures on cylindrical surfaces are in accordance with the simulated geometries.