In vibration analysis, a dynamic vibration absorber, or vibration neutralizer, is a tuned spring-mass system which reduces or eliminates the vibration of a harmonically excited system. Rotating machines such as engines, motors, and pumps often incite vibration due to rotational imbalances. A dynamic absorber can be affixed to the rotating machine and tuned to oscillate in such a way exactly counteracts the force from the rotating imbalance. This reduces the possibility that a resonance condition will occur, which can cause rapid catastrophic failure. Properly implemented, a dynamic absorber will neutralize the undesirable vibration, which would otherwise reduce service life or cause mechanical damage.
Dynamic absorbers differ from tuned mass dampers in that dynamic absorbers do not require any damping to function satisfactorily. Damping can, however, be introduced to increase the range of frequencies for which the dynamic absorber is effective.