Damped dynamic vibration absorber

A combination comprising:

• a pump installation having a pump comprising an impeller secured to a pump shaft for rotation about axis of rotation;
• a housing surrounding said impeller and having a fluid inlet and fluid outlet;
• a plurality of bearings carried by said housing with said pump shaft journaled within said bearings;
• means for connecting said housing to a foundation;
• said pump generating a disturbing force having a periodic component normal to said shaft at a frequency proportional to the rotational velocity of said shaft and generating a resultant periodic force normal to a portion of said pump with said portion experiencing a periodic lateral displacement relative to said foundation in response to said resultant force;
• a vibration absorber having a plurality of distinct elastic means secured to said pump for permitting lateral elastic movement of a portion of said elastic means relative to said pump;
• independent inertia means secured to said portion for lateral movement therewith;
• energy dissipative means for damping movement of said inertia means relative to said pump;
• said elastic means, inertia means and energy dissipative means each having, respectively, a preselected stiffness, mass and damping ratio sufficient for said absorber to generate a periodic compensation force acting on said portion out of phase with said disturbing force to attenuate the periodic displacement of said portion wherein said elastic means comprises a plurality of elastic members and means for rigidly securing said elastic members to said apparatus with said elastic members arranged around said apparatus in a plane generally normal to said axis of rotation,
• wherein said inertia means comprises an annular mass secured to each of said elastic members,
• wherein said energy dissipative means comprises a squeeze film damper.