Drainage system for gas turbine supporting bearings

• US 20040037696A1
• Filed: 08/25/2003
• Published: 02/26/2004
• Est. Priority Date: 07/03/2000
• Status: Active Grant

• Current Assignee: Nuovo Pignone Holding SPA (Baker Hughes Company)
• Original Assignee: Nuovo Pignone Holding SPA (Baker Hughes Company)
• Inventors: Signori, Andrea, Frosini, Franco
• Granted Patent: US 6,893,208 B2
• Time in Patent Office: Days
• US Class Current: 415/112
• CPC Class Codes: F01D 25/16 Arrangement of bearings; Supporting or mounting bearings in casings bearings per se F16C
• CPC Class Codes: F01D 25/18 Lubricating arrangements of machines or engines in general F01M
• CPC Class Codes: F02C 7/06 Arrangements of bearings bearings F16C; Lubricating of turbo machines F01D25/18; of machines or engines in general F01M
• CPC Class Codes: F16C 2360/23 Gas turbine engines in general F02C
• CPC Class Codes: F16C 33/10 Construction relative to lubrication lubrication in general F16N
• CPC Class Codes: F16C 33/1045 Details of supply of the liquid to the bearing

Abstract

A drainage system for gas turbine supporting cushions or bearings, in particular for the second supporting bearing, consisting of a central shaft (20), surrounded by a series of supporting studs (21), which result, in their turn, with connection to a container housing (22) for studs (21), a sleeve (23) for containing the second supporting bearing of the turbine and a series of pipes (24, 25), respectively for the entry and drainage of the lubrication and cooling oil; the system consists of, in addition, a series of lateral seals (26), provided in positions facing the second supporting bearing, which create a pressure difference which permits the oil to pass under pressure within the drainpipes (25) at a well sustained speed.

Claims

1. System of drainage for the supporting bearings of gas turbines, of the type incorporating at least one central shaft (20), surrounded by a series of means of support (21), which result, in their turn, with attachment to a containment housing (22) of those means of support (21), a sleeve (23) for the containment of at least one of the aforementioned support bearings of the turbine and a plurality of pipes (24, 25), respectively, for entry and drainage of lubrication and cooling fluids, characterised by the fact of incorporating, in addition, a series of lateral seals (26), provided in correspondence with a space (10) intended to contain the aforementioned supporting bearing, which creates a pressure difference, which permits the aforementioned fluids to pass from the interior of the aforementioned drainage pipes (25) at pressure and/or sustained speed.

2. System of drainage for the supporting bearings of gas turbines as in claim 1, characterised by the fact that the aforementioned sleeve (23) includes, further, a plurality of lateral chambers (27), at least one chamber for the accumulation of fluids under pressure (28), apertures (29) for connection between the lateral chambers (27) and the aforementioned drainage pipes (25) for the fluids, in a way in which the aforementioned accumulation chamber (28) receives at least a portion of the flow, which is drained from the turbine by gravity.

3. System of drainage for the supporting bearings of gas turbines as in claim 2, characterised by the fact that, within the aforementioned accumulation chamber (28), the fluid reaches a pressure corresponding to a predetermined speed of flow, in such a way that the same fluid may overflow within the aforementioned drainpipe (25).

4. System of drainage for the supporting bearings of gas turbines as in claim 3, characterised by the fact that the greater part of the fluid is confined within the aforementioned accumulation chamber (28), which surrounds the containment sleeve (23) of the aforementioned supporting bearing.

5. System of drainage for the supporting bearings of gas turbines as in claim 4, characterised by the fact that the aforementioned accumulation chamber (28) presents an internal overpressure, which produces an ejection of fluid at an elevated speed, obliging that fluid present within the aforementioned accumulation chamber (28) to flow into the drainage pipe (25).

6. System of drainage for the supporting bearings of gas turbines as in claim 5, characterised by the fact that the aforementioned phenomenon of ejection provokes the emission of jets of fluid in correspondence with the predetermined portions (30) of elements attached to the aforementioned central shaft (20), with the running of motor fluid or the overflowing of that motor fluid from the aforementioned lateral chambers (27).

7. System of drainage for the supporting bearings of gas turbines as in claim 5, characterised by the fact that the aforementioned phenomenon of ejection of fluid permits a consequential overflowing of the flows of fluid, which pass from the interior of the aforementioned turbine and are drained to the exterior (F) thanks alone to the force of gravity, it having to be said that the quantity of fluid which comes from the aforementioned lateral seals (26) is a further quantity of fluid which flows from the aforementioned lateral chambers (27) for the purpose of cooling.

8. System of drainage for the supporting bearings of gas turbines as in claim 1, characterised by the fact that the aforementioned lateral seals (26) are constituted of floating rings.

9. System of drainage for the supporting bearings of gas turbines as in claim 7, characterised by the fact that the dimensions of the aforementioned containment sleeve (23) of the supporting bearings and of the relative piping are reduced to the minimum, while the fact of extracting energy from a pressurised fluid present within that sleeve (23) of the supporting bearing is optimised.

10. System of drainage for the supporting bearings of gas turbines as in claim 1, characterised by the fact that the aforementioned drainage pipes (25) are positioned lower and substantially at the centre of the aforementioned containment sleeve (23) of the supporting bearings, in a way which reduces to the minimum at least one axial dimension of the aforementioned sleeve (23), with respect to the recognised manner.

11. System of drainage for the supporting bearings of gas turbines as in claim 10, characterised by the fact that the aforementioned axial dimension is constituted by the sum of the axial length of the aforementioned bearing and of the aforementioned lateral seals (26) with the addition of at least one space corresponding to a narrow chamber, positioned between the aforementioned supporting bearing and the aforementioned lateral seals (0.26).

12. System of drainage for the supporting bearings of gas turbines as in claim 11, characterised by the fact that the radial dimensions are reduced, with respect to the recognised manner, insofar that it is no longer necessary to install a fluid collection chamber, external to the aforementioned system, in which to increase the level of the fluid and obtain sufficient potential energy to balance out the loss of pressure in the pipes (24, 25) and the fluidodynamic resistance.

13. System of drainage for the supporting bearings of gas turbines as in claim 1, characterised by the fact that the aforementioned lubrication and cooling fluid is constituted from oil under pressure.