This invention relates to turbine engines with exhaust nozzles, and more particularly to struts used to control the positions of exhaust nozzles during operation of turbine engines.
The configuration of some exhaust nozzles for turbine engines (for example, those on jet aircraft) can be adjusted to accommodate changing engine conditions by changing the position of one or more adjustable flaps in the exhaust nozzle. A strut connects an adjustable flap to an actuator which controls the flap position. In a conventional design, a strut indicated at 10 in
The present invention resides in one aspect in a strut which includes a rod having a body member which has two opposite ends, with a first rod end at one end of the body member and a second rod end at the other end of the body member. The first rod end defines a first mounting aperture having a first interior surface, and there is a first ball member disposed in the first mounting aperture to form a first spherical plain bearing. The second rod end defines a second mounting aperture having a second interior surface, and there is a second ball member disposed in the mounting aperture to form a second spherical plain bearing. At least one of the first spherical bearing and the second spherical bearing does not include an outer ring.
The present invention resides in another aspect in a method of making a ball member. The method includes forming powdered chromium-cobalt alloy into an unfinished ball member having a rounded outer surface and an interior bore; machining the unfinished ball member using wire EDM to provide a machined ball member; and jig grinding a chamfer onto the machined ball member.
The present invention resides in another aspect in a method of making a strut. This method includes providing a rod which includes a body member having two opposite ends, a first rod end at one end of the body member and a second rod end at the other end of the body member, wherein the first rod end defines a first mounting aperture and the second rod end defines a second mounting aperture. The method further includes disposing a first ball member into the first mounting aperture without an outer ring to form a first spherical plain bearing; and disposing a second ball member in the second mounting aperture to form a second spherical plain bearing.
A strut shown generally at 100 in
As is shown in
As is shown in
As is shown in
The dry lubricating films 116 and 126 may be the same as each other or different from each other, and may comprise any suitable dry lubricating material. For example, the dry lubricating films 116 and 126 may be polytetrafluoroethylene (PTFE) or a variation thereof, a molybdenum disulfide-type film, or a graphite-type film, or any other suitable dry lubricant, and may be adhered to a surface by means of a binder or by high intensity impingement on the surface. The present invention is not limited to the use of a dry lubricating film, however, as the interior surface and/or the ball surface may be defined by lubricious materials such as bronze, oil impregnated bronze, and the like.
In various embodiments, one or both of the rod ends 110 and 120 are formed from a high-temperature alloy, such as a nickel-chromium alloy. In one embodiment, the rod ends 110 and 120 are formed from an INCONEL® (a registered trademark of Huntington Alloys Corporation, a Delaware corporation with a place of business at 3200 Riverside Drive, Huntington, W.V.) alloy, e.g., INCONEL® 718.
In certain embodiments, one or both of the ball members 112, 122 are formed from a high-temperature alloy, such as a chromium-cobalt alloy. In one embodiment, one or both of the ball members 112, 122 are formed from a STELLITE® (a registered trademark of Deloro Stellite Holdings Corporation, a Delaware corporation with a place of business at 555 N. New Ballas, Ste. 305, St. Louis, Mo.) alloy, e.g., STELLITE® 3.
In a particular embodiment, the ball member 122 is formed from powdered metal which is molded and compacted using hot isostatic compaction, and the compacted powder is then sintered to form an unfinished ball member. The unfinished ball member is then machined to achieve the final dimensional features using a CNC (computer numerical control)-controlled wire EDM (Electrical Discharge Machining) process. In one embodiment, the chamfer 122b is machined using a jig grinder. However, the invention is not limited in this regard, and in other embodiments, the ball member 122 may be formed by other means. In various embodiments, the ball members 112 and 122 may be formed from the same material and using the same general process as each other, or from different materials and/or in by different processes from each other.
To assemble the strut 100, the ball members 112 and 122 are Roll staked into the respective mounting apertures 110a and 120a, for example, as shown in
The strut 100 is useful in a variety of applications, including in exhaust nozzles of gas turbines, for example, in the divergent exhaust nozzle on a jet aircraft.
The terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
Although the invention has been described with reference to particular embodiments thereof, it will be understood by one of ordinary skill in the art, upon a reading and understanding of the foregoing disclosure, that numerous variations and alterations to the disclosed embodiments will fall within the scope of this invention and of the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/228,202, filed on Jul. 24, 2009, the contents of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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61228202 | Jul 2009 | US |