Elastomeric teetering hinge
The invention generally relates to two-bladed turbine nacelles and associated teetering hinges. In certain embodiments, the invention provides a hinge assembly encompassing a hub and two double elastomeric teeter bearings. In some aspects, the bearings are self-contained elements that can be preloaded in a controlled manner prior to their incorporation into the larger assembly.
1. An assembly, the assembly comprising:
a hub; and
at least two elastomeric teeter bearings, positioned at openings in said hub,
wherein each of the at least two elastomeric teeter bearings comprises a plurality of elements each having a plurality of metal shims and elastomeric layers, the plurality of elements being housed between a shell and a polygonal sleeve,
wherein each of the plurality of elements has an essentially flat first end that faces one side of the polygonal sleeve, and
wherein each element is operably configured to be assembled in the hub in two different positions, said positions differing by an angle of 90 degrees.
2. The assembly of claim 1 , wherein the teeter bearings are preloadable teeter bearings.
3. The assembly of claim 2 , wherein the teeter bearings are self-contained.
4. The assembly of claim 3 , wherein the teeter bearings are operably configured to not transfer a preload to said hub.
5. The assembly of claim 1 , wherein the teeter bearing are operably configured for mounting on one of two opposite ends of a T-shaped turbine shaft head, the ends corresponding to openings in said hub.
6. The assembly of claim 1 , wherein each element within the plurality of elements is independently preloadable.
7. The assembly of claim 1 , wherein each element within the plurality of elements can be individually removed from the teeter bearing.
8. The assembly of claim 1 , wherein the teeter bearing further comprises one or more sliding bearings operably configured to receive a force from an element within said plurality of elements.
9. The assembly of claim 1 , wherein the essentially flat first end is received in cavity in the polygonal sleeve.
10. The assembly of claim 2 , wherein the ratio between a radial and an axial preload can be obtained consistently with an external load.
11. The assembly of claim 2 , wherein a preload can be changed during an operation of the assembly.
12. The assembly of claim 2 , wherein the preloadable teeter bearings are preloaded by independently preloading each of the plurality of elements.
13. The assembly of claim 12 , wherein the shell comprises a plurality of segments, and wherein each of the plurality of elements is independently preloaded by independently preloading each of the plurality of segments.
14. The assembly of claim 12 , wherein each of the plurality of elements is independently preloaded by providing wedges disposed between the first ends of the plurality of elements and the sleeve, and second ends of the plurality of elements and the shell.
15. The assembly of claim 14 , wherein at least some of the wedges are coupled to the second ends of the plurality of elements.