Lower bearing assembly for disconnectable turret
A turret mooring system for a vessel comprises a turret which is rotatably connected to the vessel and comprises a lower end, a buoy which is anchored to the sea floor and is releasably connectable to the lower end, and a bearing assembly which is positioned between the buoy and the vessel when the buoy is connected to the turret. In this manner, horizontal mooring loads acting on the buoy are transmitted through the bearing assembly to the vessel.
1. A turret mooring system for a vessel which comprises:
a turret which is rotatably connected to the vessel and comprises a lower end;
a buoy which is anchored to the sea floor and is releasably connectable to the lower end; and
a bearing assembly which is positioned between the buoy and the vessel and is capable of directly contacting the surfaces thereof when the buoy is connected to the turret;
wherein horizontal mooring loads acting on the buoy are transmitted through the bearing assembly to the vessel.
2. The turret mooring system of claim 1 , wherein the bearing assembly comprises a bearing ring which is supported on one of the vessel and the buoy.
3. The turret mooring system of claim 2 , wherein the bearing ring is comprised of a self-lubricating material.
4. The turret mooring system of claim 2 , wherein the bearing ring is comprised of a polymer material.
5. The turret mooring system of claim 2 , wherein the bearing ring is comprised of a fiber reinforced polymer material.
6. The turret mooring system of claim 2 , wherein the bearing ring comprises a plurality of bearing segments.
7. The turret mooring system of claim 2 , wherein the bearing assembly further comprises:
a bearing support ring which is connected to one of the vessel and the buoy; and
a reaction ring which is positioned concentrically relative to the bearing support ring and is adapted to engage the other of the vessel and the buoy;
wherein the bearing ring is disposed between the bearing support ring and the reaction ring.
8. The turret mooring system of claim 7 , wherein the bearing support ring includes a circular first ring which in cross section comprises a groove that is adapted to receive at least a portion of the bearing ring.
9. The turret mooring system of claim 8 , wherein the bearing support ring further comprises a circular second ring which is positioned concentrically relative to the first ring and is connected to both the first ring and one of the vessel and the buoy.
10. The turret mooring system of claim 9 , wherein the second ring is positioned concentrically around the first ring and is connected to the vessel.
11. The turret mooring system of claim 7 , wherein the reaction ring includes a circular retainer ring which in cross section comprises a pocket that is adapted to receive at least a portion of the bearing ring.
12. The turret mooring system of claim 11 , wherein the pocket comprises an overlay which is comprised of a corrosion-resistant material.
13. The turret mooring system of claim 11 , wherein the reaction ring further comprises an annular bumper which is connected to the retainer ring and is adapted to engage the other of the vessel and the buoy.
14. The turret mooring system of claim 13 , wherein the bumper comprises a curved outer surface.
15. The turret mooring system of claim 7 , further comprising means for preventing the reaction ring from rotating relative to the other of the vessel and the buoy.
16. The turret mooring system of claim 15 , wherein the preventing means comprises:
a number of pins which are pivotably connected to the reaction ring; and
a number of corresponding slots which are formed in the other of the vessel and the buoy;
wherein the pins are pivotable from a first position in which they are clear of the slots to a second position in which they are engaged by the slots.