Device for lubricating a component in a turbomachine

1. A lubrication device for lubricating a shaft bearing in a turbojet, the device comprising:

an annular component support part mounted on stationary elements and defining a lubrication chamber around the shaft bearing; and

an annular cover including an oil inlet for lubricating the shaft bearing, the annular cover having a radial end face mounted in a sealed manner on a radial end face of said annular support part, sealing being provided by an annular gasket mounted between the support part and the cover, said cover including an annular enclosure for feeding pressurizing and cooling air, the enclosure is fed at its upstream end by ducts formed through the support part and having their downstream ends opening out around the annular gasket, wherein

the device includes means for providing a flow of pressurizing and cooling air between the radial end face of the support part and the radial end face of said cover around said annular gasket.

2. A lubrication device according to claim 1 , wherein

the annular gasket is mounted between cylindrical bearing surfaces of the support part and of the cover, and

the means for providing a flow of pressurized and cooling air opens out in a vicinity of the annular gasket at an interface between said cylindrical bearing surfaces.

3. A lubrication device according to claim 1 , wherein the means for providing a flow of pressurized and cooling air comprises an annular channel formed in the radial end face of the cover facing the downstream ends of the ducts in the support part, and includes orifices in alignment with said ducts and opening out into said enclosure.

4. A lubrication device according to claim 3 , wherein said annular channel opens out to an interface between cylindrical bearing surfaces of the support part and of the cover via a chamfer in a peripheral edge of the radial end face of the support part.

5. A lubrication device according to claim 1 , wherein an axially-extending annular gap is formed between the radial end face of the support part and the radial end face of the cover level with the downstream ends of the ducts in the support part.

6. A lubrication device according to claim 5 , wherein an annular channel is formed by a chamfer in a peripheral edge of the radial end face of the support part, said chamfer interconnecting the axially-extending gap and an interface of cylindrical bearing surfaces of the support part and of the cover.

7. A lubrication device according to claim 6 , wherein the annular channel communicates with the enclosure of the cover via at least one hole in the radial end face of the cover.

8. A lubrication device according to claim 5 , wherein another sealing gasket is mounted in the axially-extending annular gap and includes orifices for passing pressurizing and cooling air, the orifices are in alignment with the ducts in the support part.

9. A turbojet, comprising:

a turbine whose shaft is guided by a bearing fitted with lubrication means,

wherein the lubrication means include a lubrication device according to claim 1 .

10. A lubrication device, comprising:

an annular component support part having a radial end face and defining a lubrication chamber around a component;

an annular cover having a radial end face disposed to the radial end face of the annular support part, the annular cover including

an inlet configured to lubricate the component, and

an annular enclosure configured to feed air;

an annular gasket configured to seal the annular component support part and the annular cover; and

an annular channel configured to provide a flow of the air around the annular gasket.

11. A lubrication device according to claim 10 , wherein

the annular gasket is mounted between cylindrical bearing surfaces of the annular component support part and of the annular cover, and

the annular channel opens out in a vicinity of the annular gasket at an interface between the cylindrical bearing surfaces.

12. A lubrication device according to claim 10 , wherein

the annular component support part includes ducts, and

the annular channel is formed in the radial end face of the annular cover facing downstream ends of the ducts, and includes orifices in alignment with the ducts and opening into the annular enclosure.

13. A lubrication device according to claim 12 , wherein the annular channel opens out to an interface between cylindrical bearing surfaces of the annular component support part and of the annular cover via a chamfer in a peripheral edge of the radial end face of the annular component support part.

14. A lubrication device according to claim 10 , wherein

the annular component support part includes ducts, and

an axially-extending annular gap is formed between the radial end face of the annular component support part and the radial end face of the annular cover level with downstream ends of the ducts.

15. A lubrication device according to claim 14 , wherein the annular channel is formed by a chamfer in a peripheral edge of the radial end face of the annular component support part, the chamfer interconnecting the axially-extending gap and an interface of cylindrical bearing surfaces of the annular component support part and of the annular cover.

16. A lubrication device according to claim 15 , wherein the annular channel communicates with the enclosure via at least one hole in the radial end face of the annular cover.

17. A lubrication device according to claim 14 , wherein another sealing gasket is mounted in the axially-extending annular gap and includes orifices to pass the air, the orifices are in alignment with the ducts.

18. A lubrication device according to claim 10 , wherein the air is at a higher pressure than the pressure inside the lubrication chamber.

19. A lubrication device according to claim 10 , wherein the air is at a higher pressure than the pressure outside the lubrication device.

20. A turbojet, comprising:

a turbine whose shaft is guided by a bearing fitted with a lubrication device according to claim 10 .