35. Development of a Vibration Isolator Using Air Suspensions with Slit Restrictions

A new vibration isolator using four air suspensions is proposed. Each air suspension consists of a cylinder, a piston which is connected to a supported object, a reservoir tank, and a slit restriction fabricated as the narrow airflow channel and installed between the cylinder and the reservoir tank. Its damping force is proportional to velocity, and its damping coefficient is constant and independent of oscillating amplitude. The damping coefficient corresponds to clearance, length, and width of the slit restriction. Tuning equivalent damping ratio of an isolator in order to minimize the maximum transmissibility in translational mode, maximum transmissibility is reduced about 1.6 even if the rotational mode also oscillates. Experimental results almost coincide with numerical results. The maximum transmissibility of the translational mode and the rotational mode is not varied even if the oscillating amplitude is varied because of the linearity of the damping characteristics of the applied slit restriction.