Vibration isolators work by decoupling an object from the source of vibration, thereby reducing the transmission of vibrational energy. Their primary function is to absorb or dissipate mechanical energy that could otherwise cause unwanted motion, noise, or damage.
There are several types of vibration isolators, each employing different principles. Passive isolators, like rubber mounts, springs, or air springs, rely on material properties to absorb energy. Rubber mounts, for instance, deform under load, converting kinetic energy into heat. Springs use their elasticity to store and release energy, effectively lengthening the natural period of vibration, which helps to move it away from the excitation frequency. Air springs achieve isolation by trapping a volume of air, whose compressibility provides a soft, cushioning effect.
Active vibration isolators, on the other hand, use sensors, actuators, and control systems to dynamically counteract vibrations. Sensors detect the vibration, and the control system sends signals to actuators (like piezoelectric devices or electromagnetic shakers) to generate opposing forces, effectively canceling out the unwanted motion.
The effectiveness of a vibration isolator depends on several factors, including the mass of the isolated object, the stiffness and damping properties of the isolator, and the frequency of the incoming vibration. Ideally, an isolator is designed to have a natural frequency significantly lower than the disturbance frequency, which allows it to filter out most of the vibrational energy.