Isolation and Absorption of Machinery Vibration.

The isolation of machinery vibration from rigid and nonrigid substructures is described in uncomplicated terms. One- and two-stage mounting systems, single and multiple antivibration mountings, and beamlike and platelike substructures are examined. A machine and the intermediate mass of a two-stage mounting system are considered to be supported by flanges or feet to demonstrate the loss in isolation that can occur if the flanges are not rigid but are multiresonant because of their poor design. The use of conventional dynamic absorbers to reduce the vibration of such structural members as beams rails and stanchions and circular plates bulkheads is discussed. A novel dynamic vibration absorber is described that comprises a damped circular plate loaded centrally by a lumped mass and clamped at its perimeter to the vibrating item or structure of concern. Author