Rotary kinetic fluid motors or pumps – Including destructible – fusible – or deformable non-reusable...
Reexamination Certificate
1999-09-08
2001-10-23
Verdier, Christopher (Department: 3745)
Rotary kinetic fluid motors or pumps
Including destructible, fusible, or deformable non-reusable...
C415S214100
Reexamination Certificate
active
06305899
ABSTRACT:
THE FIELD OF THE INVENTION
This invention relates to gas turbine engine and is particularly concerned with the manner in which at least some of the constituent parts of a casing of such an engine are joined to each other.
BACKGROUND OF THE INVENTION
The core of a modern axial flow gas turbine engine is typically enclosed by a casing that comprises a number of coaxial annular cross-section portions that are connected in series. Conventionally, each of the casing portions is provided with a radially outwardly extending annular flange at each of its axial extents. The flanges of adjacent casing portions are maintained in engagement with each other by bolts that extend through suitably located and aligned holes is in the flanges.
In the compressor and turbine sections of such an engine, annular arrays of rotor blades are contained within the casing. During engine operation, these rotor blade arrays rotate at very high speeds. If any of the rotor blades should suffer a structural failure, they travel at high speed in a generally radially outward direction to impact the casing section adjacent thereto. In the interests of safety, the casing must be sufficiently strong to contain such failed blades. However, this is a more difficult task if the failed blades are located adjacent the previously mentioned flanges joining adjacent two casing portions. If one of the casing portions is less rigid than the other, there can be a tendency for that casing portion to be radially deflected to a greater extent than the other. This brings about the imposition of shear loads upon some of the bolts joining the casing portions and their eventual failure. High pressure gases normally present within the casing then tend to urge the flanges apart, so in turn exerting tensile loads upon the remaining bolts and in some cases, causing their failure also.
If adjacent casing section flanges are urged apart in this manner, there is, of course, an increased likelihood of the non-containment by the casing of failed rotor blades and associated debris.
One way in which this problem could be tackled is by the strengthening of one of the casing portions so that its rigidity is increased to a level similar to that of the casing portion adjacent thereto. However, this results in a significant increase in the weight of the casing portion which is a undesirable feature in aircraft-mounted gas turbine engines.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a gas turbine engine casing portion having enhanced rigidity with a minimal weight penalty.
According to the present invention, a gas turbine engine includes a casing enclosing a rotary stage of aerofoil blades, said casing comprising two axially adjacent annular cross-section portions, one of which is provided with a flange located at one of its axial extents for connection to a corresponding flange provided on the other casing portion, one of said flanges being of generally L-shaped cross-section in a circumferential direction so as to comprise radially outwardly and axially extending portions and the other being generally radially outwardly extending, said radially outwardly extending portions of said flanges axially abutting each other and said axially extending portion of said L-shape flange locating adjacent and radially outwardly of the radial extent of said other flange, said radially outwardly extending axially abutting flange portions being positioned radially outwardly of and in radial alignment with said rotary stage of aerofoil blades.
The whole of said generally L-shaped cross-section flange may be integral with said casing portion.
Alternatively, said flange comprises a part that is integral with said casing portion and a part that is mechanically attached to said integral part.
Said part mechanically attached to said integral part is preferably a ring of substantially L-shaped cross-section configuration.
Said ring may be divided into two semicircular parts.
Said ring and said integral part may be attached to each other by bolts, said ring and integral part having apertures to receive said bolts.
REFERENCES:
patent: 1525647 (1925-02-01), Haughey
patent: 1819086 (1931-08-01), Friend
patent: 2885768 (1959-05-01), Shinn
patent: 3387820 (1968-06-01), Smith
patent: 3490748 (1970-01-01), Hoffman
patent: 3529905 (1970-09-01), Meginnis
patent: 3741680 (1973-06-01), Killman et al.
patent: 3807891 (1974-04-01), McDow et al.
patent: 4208777 (1980-06-01), Walsh et al.
patent: 4684320 (1987-08-01), Kunz
patent: 5096377 (1992-03-01), Catte et al.
patent: 5273396 (1993-12-01), Albrecht et al.
patent: 5314303 (1994-05-01), Charbonnel et al.
patent: 5462403 (1995-10-01), Pannone
patent: 5503490 (1996-04-01), Melton
patent: 5520508 (1996-05-01), Khalid
patent: 5562408 (1996-10-01), Proctor et al.
patent: 511690 (1953-12-01), None
patent: 624777 (1949-06-01), None
patent: 902942 (1962-08-01), None
patent: 2111129 (1983-06-01), None
patent: 2115487 (1983-09-01), None
patent: 2260786 (1993-04-01), None
patent: 52-68611 (1977-06-01), None
British Search Report for GB 9820226.0, Dated May 26, 1999.
Manelli Denison & Selter PLLC
Rolls-Royce plc
Taltavull W. Warren
Verdier Christopher
LandOfFree
Gas turbine engine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gas turbine engine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gas turbine engine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2579761