Low frequency torsional vibration damper

A method of making a torsional vibration damper, the method comprising:

• providing a hub that includes a plurality of protrusions on either an outermost surface thereof or an innermost surface thereof, the plurality of protrusions being spaced apart from one another;
• providing an inertia member sized to fit adjacent to either the outermost surface or the innermost surface of the hub having the plurality of protrusions;
• machining into each of the plurality of protrusions of the hub a first pocket portion comprising a first partial-pipe shaped receptacle;
• machining into a surface of the inertia member that is adjacent to either the outermost surface or the innermost surface of the hub having the plurality of protrusions, a plurality of second pocket portions spaced apart from one another that each comprise a second partial-pipe shaped receptacle;
• mating the hub and the inertia member with each first pocket portion aligned with one of the second pocket portions thereby defining a plurality of pockets;
• and
• positioning a plurality of elastomeric members, one each, in the plurality of pockets;
• wherein each of the plurality of elastomeric members has a first flange and a second flange at opposing axial ends separated by a core section.

A method of making a torsional vibration damper, the method comprising:

• molding a hub having a plurality of spaced apart protrusions on either an outermost surface thereof or an innermost surface thereof, wherein each protrusion includes a first partial-pipe shaped receptacle recessed therein;
• molding an inertia member sized to fit adjacent to either the outermost surface or the innermost surface of the hub having the plurality of protrusions, wherein the inertia member includes a plurality of spaced apart second partial-pipe shaped receptacles recessed into a surface thereof that is adjacent to either the innermost surface or the outermost surface of the hub having the plurality of protrusions;
• mating the hub and the inertia member with each first partial-pipe shaped receptacle aligned with one of the second partial-pipe shaped receptacles thereby defining a plurality of pockets;
• and
• positioning a plurality of elastomeric members, one each, in the plurality of pockets;
• wherein each of the plurality of elastomeric members has a first flange and a second flange at opposing axial ends separated by a core section.

A torsional vibration damper comprising:

• a hub;
• an inertia member disposed concentric with and spaced radially outward or radially inward from the hub;
• wherein the hub and inertia member define a plurality of pockets therebetween;
• and
• a plurality of elastomeric plugs, each having a first flange and a second flange at opposing axial ends separated by a core section, one each seated in each of the plurality of pockets;
• wherein each of the plurality of pockets includes a central rib portion on both the hub and the inertia member seated against the core section of one of the plurality of elastomeric plugs, thereby operative coupling the hub and the inertia member for rotation together.