Vibration damper for rotating shaft

Abstract

A vibration damper has a pair of rollers that engage a shaft rotating about its longitudinal axis while being supported at its ends on centers. The rollers transmit shaft vibrations to the piston rod of a hydraulic or pneumatic cylinder in such a manner that the piston rod dampens the vibrations.

Having described my invention, I claim:  
     
         1 . A vibration damper for an elongated workpiece rotating about an axis, and vibrating in a direction lateral to said rotating axis, comprising: 
 at least one workpiece-engaging roller supported for rotation about an axis parallel to a workpiece-rotating axis;    mechanical means connected to said roller for moving the roller into engagement with the rotating workpiece to rotate therewith, and for moving with the workpiece in a direction lateral to said rotating axis as the workpiece is vibrating;    a fluid cylinder having a reciprocally, resiliently mounted piston rod, movable with respect to said cylinder;    said mechanical means being connected to said piston rod and said roller to resist a radial motion of the roller carried by the workpiece.    
     
     
         2 . A vibration damper as defined in  claim 1 , in which the piston rod reciprocates along an axis that intersects the rotating axis of the workpiece.  
     
     
         3 . A vibration damper as defined in  claim 1 , including a plurality of rollers each supported for engaging the workpiece, said mechanical means being operative to move said plurality of rollers toward the workpiece, and being connected to the piston rod to resist a vibrational movement of the workpiece.  
     
     
         4 . A vibration damper as defined in  claim 3 , in which the plurality of rollers engage the workpiece in equal angularly spaced locations about the workpiece.  
     
     
         5 . A vibration damper for an elongated workpiece rotating about an axis and moving in a vibrational movement in a direction lateral to said rotating axis, comprising: 
 a base;    a cylinder mounted on the base and having a piston rod movable in a direction transverse to the rotating axis of a workpiece;    a slide plate connected to the piston rod so as to be movable therewith;    a first arm, and first pivot means connecting the first arm to the base for a pivotal motion, the first arm having a camming slot;    a first cam roller carried by the slide plate and received in the camming slot of the first arm, such that as the slide plate moves toward the workpiece, the first arm swings along a first path of motion about said pivot means toward the workpiece;    a first floppy bracket, and pivot means connecting the first floppy bracket to the first arm to swing the arm toward the workpiece as the first arm swings in said first path of motion;    a pair of spaced rollers carried on the first floppy bracket to engage the workpiece on a first side thereof;    a second arm and second pivot means connecting the second arm to the base for a pivotal motion, the second arm having a camming slot;    a second cam roller carried by the slide plate and received in the camming slot of the second arm such that as the slide plate moves toward the workpiece, the second arm swings along a second path of motion about said second pivot means toward the workpiece;    a second floppy bracket and pivot means connecting the second floppy bracket to the second arm to move toward the workpiece as the second arm swings in said second path of motion; and    a pair of spaced rollers carried on the second floppy bracket to engage the workpiece on a second side thereof whereby a vibrational movement of the workpiece is transmitted from the rollers on the floppy brackets to the first arm and the second arm, and then to the slide plate and the piston rod such that the piston rod resists said vibrational motion.