Mechanical Properties Characterizations of Elastomer Pads and Control of a 3-DOF Rubber-Bearing Stage

As products are required with higher precision, vibration control becomes more important for precision machining and inspection. Controlled positioning stages with both fast positioning and relative vibration eliminated have been widely used as critical subsystems in precision manufacture and metrology. Recently, elastomeric bearings, which had been widely used in the seismic engineering, have been integrated into precision stage design due to their inherent stiffness anisotropy. With the incorporation of rubber bearing, stages can be designed to have the same function as these much larger compliant mechanisms-based designs. This provides possible advantages in the precision positioning. However, the behavior of elastomeric bearings depends on mechanical properties of materials, geometry, and operating conditions. It is important to perform essential characterization for fully taking the advantage of this approach. In this work, essential static and dynamic characterizations of elastomeric bearing structures are performed under different preloads and actuating frequencies. The stiffness, damping, and natural frequencies are evaluated. In parallel, a 3-DOF elastomeric bearing stage is design, realized, and controlled based on the characterized results. The experimental results indicate that it can achieve an 80 Hz controlling bandwidth and an 80 nm and 2urad travelling resolutions.