Torsional vibration absorber system

A system for absorbing torsional vibration in a shaft which is drivingly rotated about an axis and wherein the shaft is exposed to torsional disturbances during rotation and wherein the disturbances are substantially regularly spaced throughout each revolution of the shaft, the system comprising:

• means defining at least one cavity of circular cross section for rotating with a rotating shaft as the shaft rotates about its axis of shaft rotation, the cavity being arranged in such a relation to the shaft so that its circular cross section is substantially normal to the axis of shaft rotation;
• a cylindrical rolling element positioned within each cavity so as to be free to roll along the walls of its corresponding cavity in a pendulum action in response to the torsional disturbances to which the shaft is exposed;
• and
• wherein the cylindrical rolling element is related to its corresponding cavity and to the torsional disturbances desired to be absorbed by the system in accordance with the equation:
• N.sup.2 =r.sub.w.sup.2 r.sub.3 /[r.sub.g.sup.2 +r.sub.w.sup.2 ][r.sub.1 -r.sub.w ]
• wherein N is within about .+-.15% of the number of torsional disturbances per revolution of the shaft, r.sub.w is the radius of the rolling element, r.sub.g is the radius of gyration of the rolling element, r.sub.1 is the radius of the cavity, and r.sub.3 is the radial distance of the cavity from the axis of rotation of the shaft.

A system for absorbing torsional vibration in an internal combustion engine having multiple cylinders and a shaft which rotates about an axis in response to power pulses generated within the engine cylinders and wherein the power pulses create torsional disturbances in the shaft which are substantially regularly spaced throughout each revolution of the shaft, the system comprising:

• means associated with the rotating shaft of the engine for defining an elongated cavity which rotates with the shaft about the axis of shaft rotation, the cavity being arranged in such a relation to the shaft that the longitudinal axis of the cavity is substantially parallel with the axis of shaft rotation;
• a rolling element positioned within the elongated cavity so as to be free to roll forwardly and rearwardly with respect to the direction of rotation of the shaft along the interior wall of the cavity in a pendulum action in response to the torsional disturbances created in the shaft during the rotation thereof;
• and
• wherein each rolling element is related to its corresponding cylindrical cavity and to the engine with which the system is used in accordance with the equation:
• N.sup.2 =r.sub.w.sup.2 r.sub.3 /[r.sub.g.sup.2 +r.sub.w.sup.2 ][r.sub.1 -r.sub.w ]
• wherein N is within about .+-.15% of the number of power pulses per revolution of the engine shaft, r.sub.w is the radius of each rolling element, r.sub.g is the radius of gyration of the element, r.sub.1 is the radius of the cavity, and r.sub.3 is the radial distance of the cavity from the axis of rotation of the shaft.