Bearing assembly for a marine turbine shaft, and marine turbine including such a bearing assembly
View Patent ↗To recover the axial forces transmitted by a rotating shaft, a bearing assembly includes a plurality of distributed bearing units. Each bearing unit comprises: a stationary base; a resilient member having a stationary portion and a portion that is completely movable in a main direction of the forces to be supported; and a bearing surface that defines, together with the shaft, a water film. The bearing surface is connected to the movable portion. The minimum radius of the bearing surface is between 1 m and 3 m. The resilient member and the base define at least one water chamber. A plurality of ducts are arranged so as to connect the chambers together, thereby defining a closed circuit.
1. A bearing assembly for absorbing axial force transmitted by a rotating marine turbine shaft about an axis of rotation, the bearing assembly comprising a plurality of bearing units distributed about the axis of rotation, each bearing unit comprising:
a stationary base;
a resilient member having a stationary portion rigidly connected to the base and a portion that is generally movable in a main direction of the forces to be supported;
a bearing surface suitable for defining, together with the shaft, a volume for receiving a liquid film, the bearing surface being connected to the movable portion of the resilient member, wherein the liquid film is a water film, a minimum radius of the bearing surface is between 1 m and 3 m, the resilient member and the stationary base define at least one chamber containing water, surfaces of the resilient member and the base in contact with water comprising a rustproof material, and
the bearing assembly further comprises a plurality of ducts configured for circulating water, each duct being arranged so as to connect at least two chambers together, the ducts and the chambers defining a closed circuit extending about the axis of rotation.
2. The bearing assembly according to claim 1 , wherein the movable portion moves generally in a parallel direction with respect to the axis of rotation and the bearing surface is perpendicular to the axis of rotation.
3. The bearing assembly according to claim 1 , wherein the bearing surface is linked to a single movable portion.
4. The bearing assembly according to claim 1 , wherein the bearing surface is linked to a plurality of movable portions belonging to a plurality of bearing units respectively.
5. The bearing assembly according to claim 1 , wherein the bearing surface comprises a material having a hardness greater than 800 Hv.
6. The bearing assembly according to claim 5 , wherein the bearing surface comprises a ceramic material.
7. The bearing assembly according to claim 1 , wherein the base comprises a plate having a generally annular shape and in that each duct is formed by holes extending in the base.
8. The bearing assembly according to claim 1 , wherein the resilient member forms a resiliently deformable membrane.
9. The bearing assembly according to claim 1 , wherein each chamber comprises a portion having a generally toroid shape optionally having a circular cross-section.
10. The bearing assembly according to claim 1 , wherein the resilient member comprises a plate consisting of a sheet.
11. The bearing assembly according to claim 10 , wherein the resilient member comprises a stainless steel sheet.
12. The bearing assembly claim 1 , wherein the resilient member comprises a part forming the movable portion and the stationary portion.
13. The bearing assembly according to claim 12 , wherein at least one bearing unit comprises a partially spherical projection so as to form a point connection between the resilient member and the base.
14. The bearing assembly according to claim 1 , comprising:
between 10 and 20 bearing units.
15. The bearing assembly according to claim 14 , comprising:
16 bearing units.
16. A marine turbine comprising:
at least one bearing assembly according to claim 1 ; and
a turbine equipped with the rotatable shaft about the axis of rotation.
17. The marine turbine according to claim 16 , wherein the water film has a thickness of less than 0.10 mm.
18. The marine turbine according to claim 17 , wherein the water film has a thickness of less than 0.06 mm.
19. The marine turbine according to claim 16 , comprising:
two bearing assemblies, the two bearing assemblies being coaxial with the axis of rotation, the two bearing assemblies being situated at a distance from each other so as to define a housing for a shaft flange.