Torsional vibration damper spoke design
Torsional vibration dampers (TVDs) having a plurality of spokes designed to withstand both torsional and bending forces and vibrations are disclosed. The spokes, which connect a central member to a peripheral rim, include a first end coupled to an outer radial surface of the central member; a second end coupled to an inner radial surface of the rim; and four concave surfaces extending between the first end and the second end. The concave surfaces may be concave from the first end to the second end and may also be concave laterally from front to back or side to side. A TVD having a hub with spokes having one or more concave surfaces is also disclosed herein. A method of designing the spokes for the hub is also disclosed.
1. A torsional vibration damper comprising:
a hub; and
an inertia member concentric about the hub with an elastomeric member operatively positioned therebetween;
wherein the hub comprises a plurality of spokes extending from an outer radial surface of a central member to an inner radial surface of a peripheral rim, each of the plurality of spokes comprising:
a first end coupled to the outer radial surface of the central member;
a second end coupled to the inner radial surface of the peripheral rim;
a first concave surface extending between the first end and the second end and facing an axial direction;
a second concave surface extending between the first end and the second end and facing opposite the first concave surface;
a third concave surface extending between the first end and the second end and between the first concave surface and the second concave surface; and
a fourth concave surface extending between the first end and the second end and between the first concave surface and the second concave surface, wherein the fourth concave surface faces generally opposite the third concave surface.
2. The torsional vibration damper of claim 1 , wherein, for each of the plurality of spokes, the first concave surface and the second concave surface are concave extending from the first end to the second end.
3. The torsional vibration damper of claim 2 , wherein, for each of the plurality of spokes, the first concave surface and the second concave surface are additionally concave extending from the third concave surface to the fourth concave surface.
4. The torsional vibration damper of claim 2 , wherein, for each of the plurality of spokes, at least one concavity of at least one of the first concave surface, second concave surface, third concave surface, and fourth concave surface is defined by an arc of a circle.
5. The torsional vibration damper of claim 1 , wherein, for each of the plurality of spokes, the third concave surface and the fourth concave surface are concave extending from the first end to the second end.
6. The torsional vibration damper of claim 5 , wherein, for each of the plurality of spokes, the third concave surface and the fourth concave surface are generally flat extending from the first concave surface to the second concave surface.
7. The torsional vibration damper of claim 1 , wherein the third concave surface faces generally perpendicular to the axial direction.
8. The torsional vibration damper of claim 1 , wherein, for each of the plurality of spokes, a width of the second end is smaller than the first end.
9. The torsional vibration damper of claim 1 , wherein, for each of the plurality of spokes, the first end has a shape that conforms to the outer radial surface of the central member, and the second end has a shape that conforms to the inner radial surface of the peripheral rim.
10. A front end accessory drive system comprising the torsional vibration damper of claim 1 mounted to a crankshaft for rotation therewith.