Highly damped single-chamber pneumatic vibration isolator using effects of thermal conductivity in the air volume

Abstract

Contemporary pneumatic isolators have dual-chamber design with metered orifices between the chambers. This arrangement produces the energy dissipation necessary to avoid excessive resonance vibration. However, this leads to reduced isolation performance compared to a single-chamber isolator of equivalent total volume. Analysis shows that, while the dynamic process of the air compression in the pneumatic chamber is adiabatic for geometric parameters usually employed in vibration isolators, substantial dissipation of mechanical energy can be achieved by introducing certain thermally conductive features into the chamber. That makes practical a single-chamber design with sufficient damping. The paper presents the optimization of the geometry of thermally conductive features aimed at maximizing the loss factor at the resonance frequency of the isolation system. Experimental results illustrate the concept and demonstrate the increased isolation effect.