This invention relates to roller bearing assemblies and bearing linkages for use in aircraft applications and, more particularly, to roller bearing assemblies and bearing linkages used within an actuation system of an aircraft assembly.
The wings of fixed wing aircraft typically include slats movably arranged along a leading edge of each wing and flaps movably arranged along a trailing edge of each wing. By selectively extending, retracting, and deflecting the slats and flaps, aerodynamic flow conditions on a wing are influenced to increase lift generated by the wing during takeoff or decrease lift during landing. During take-off, for example, the leading edge slats are moved forward to extend an effective chord length of the wing and improve lift. During cruise portions of flight, the leading edge slats and trailing edge flaps are placed in a retracted position to optimize aerodynamic conditions.
The leading edge slats are fixedly mounted on tracks, and aircraft wings carry an actuation mechanism to extend the leading edge slats to increase lift at slow speeds for landing and takeoff, and then retract the leading edge slats again during cruise. The wings also include a series of roller style bearings that engage and guide the tracks as the leading edge slats are extended and retracted. The tracks may have multiple configurations such as, for example, general I-beam and Pi-beam shapes. Track roller bearings and side load rollers or pins are employed to center and support the track under load conditions. The wing also includes actuation systems for positioning the slats and flaps.
The present invention resides in one aspect in an aircraft wing which comprises a wing structure, a slat panel mounted on a track, and an actuator mechanism on the wing structure coupled to the track for moving the slat panel between a deployed position and a retracted position. A plurality of track roller bearings is mounted on the wing structure, rotatably contacting the track, and a plurality of side roller bearings is mounted on the wing structure rotatably contacting at least one side of the track.
The present invention resides in another aspect in an aircraft wing comprising a wing structure, a slat panel mounted on a track, and an actuator mechanism on the wing structure and coupled to the track for moving the slat panel between a deployed position and a retracted position. The actuator mechanism includes a shaft rotatably mounted on the wing structure, an actuator arm coupled to the track by a bearing linkage, and an actuator lever coupled to the shaft by a bearing linkage and to the actuator arm by a bearing linkage. There are a plurality of track roller bearings on the wing structure, the track roller bearings rotatably contacting the track, and a plurality of side roller bearings rotatably contacting at least one side of the track. At least one bearing linkage comprises a spherical plain bearing.
The present invention resides in another aspect in an actuation system for deploying and retracting a lift assisting device of a wing of an aircraft. The actuation system comprises a track pivotally coupled to a lift assisting device, an actuator coupled to the track, and a plurality of track roller bearings rotatably contacting the track to guide the track along an arcuate path. The track roller bearing comprises an outer ring having inner bearing surfaces, an inner ring having outer bearing surfaces, a shield disposed about shoulder portions of an outer diameter of the outer ring and extending to an outer diameter of the inner ring, and a seal located under the shield and retained against an outward facing surface of the inner ring.
An aircraft indicated generally at 10 in
An actuation system 26 engages the track 18 to selectively move the slat panels 16 relative to the leading edge section 14 as indicated by arrow B in response to flight control signals, i.e., the slat panels 16 move between a retracted position (indicated in solid line) and an extended or deployed position (indicated by dashed lines). In the retracted position (e.g., cruise position) the slat panel 16 is located against the leading edge section 14 of the wing structure 12a, and in the extended position (e.g., take-off and landing position) the slat panel 16 is deployed downwardly and forwardly away from the leading edge section 14 of the wing structure 12a thus effectively increasing a surface area of the wing 12 to vary the lift-enhancing characteristics of the wing. During deployment and retraction, the track 18 moves in an arcuate path along the arcuate axis A.
In one embodiment, the actuation system 26 on the aircraft 10 includes a shaft 28 rotatably mounted on the wing structure 12a. An actuator lever 30 is mounted on the shaft 28, and the actuator lever 30 is coupled to the track 18 via an actuator arm 32 having a first end 32a and a second end 32b. The first end 32a is pivotally coupled to the actuator lever 30 at a bearing linkage 34, and the second end 32b is pivotally coupled to the front portion 18a of the track 18 at a bearing linkage 36. The shaft 28 extends along the leading edge section 14 of the wing structure 12a and operates a plurality of actuator levers (similar to lever 30) coupled to the plurality of slat panels 16. The shaft 28 rotates in response to flight control commands, rotating in a first direction to extend the slat panels 16 and rotating in a second direction to retract the slat panels.
A plurality of track roller bearings 38 is mounted on the wing structure 12a such that the track roller bearings are disposed about a top surface 18c and a bottom surface 18d of the track 18. The track roller bearings 38 are in rotational contact with the top and bottom surfaces 18c, 18d of the track 18 to guide the track in a path along arcuate axis A during deployment and retraction. In one embodiment, the plurality of track roller bearings 38 includes a first pair of roller bearings 40 and 42 and a second pair of roller bearings 44 and 46, which are positioned to provide rolling support to the track 18 by bearing against the top and bottom surfaces 18c, 18d. It should be appreciated that it is within the scope of the present invention to include more or less than the illustrated two pairs of track roller bearings. For example, three roller bearings may be disposed about one or both of the top surface 18c and bottom surface 18d of the track 18. Multiple load conditions are experienced at the track during operation that may be carried and distributed to the wing structure 12a of the aircraft 10 by the track roller bearings 38. The track roller bearings 38 may comprise needle style rollers and/or self lubricating rollers. In one embodiment, a mounting web 48 in the wing structure 12a encloses at least a portion of the track 18. In some aircraft 10, the mounting web 48 extends into a fuel tank 12b disposed within the wing structure 12a.
In one embodiment indicated in
In another embodiment, any of side surfaces 18h, 18i, 18j, and 18k may be supported and/or guided by side rollers of the type described with reference to
In various embodiments, each bearing linkage (designated as 34, 36, 20, 24a, or 24b) may comprise one or more spherical plain bearings and/or one or more bushings. In one embodiment shown in
The inner ring member 64 and outer ring member 66 may be made from various materials. For example, the outer ring member 66 may be fabricated from titanium or steels such as 17-4PH®, 15-5PH®, PH13-8Mo®, AISI Type 300 or 400 series stainless material, or the like, and the inner ring member 66 may be made from titanium or stainless steels such as AISI Type 440C, AISI Type 52100, Custom 455®, Custom 465® (CUSTOM 455 and CUSTOM 465 are registered trademarks of CRS Holdings, Inc., Wilmington, Del., USA), AISI Type 422 stainless surface-treated with a nitriding process such as, for example, the AeroCres® process (AEROCRES is registered trademark of RBC Aircraft Products, Inc., Oxford, Conn. USA), XD-15NW steel (a trademark of Aubert & Duval, Tour Maine Montparnasse 33, avenue du Maine F-75015 Paris, France), Cronidur 30® (available from FAG OEM and Handel AG of Germany), or corrosion resistant steel such as 17-4PH, 15-5PH, PH13-8Mo, or the like. Optionally, the inner ring member 64 may be surface-treated for increased hardness. The inner ring member 64 may optionally be coated with chrome plate, thin dense chrome, tungsten carbide, chrome carbide, aluminum oxide, or other suitable material having a desired hardness. While particular materials for the inner ring member 64 and outer ring member 66 are disclosed, the invention is not limited in this regard, and in other embodiments any other suitable material may be used.
The liner 68 and the liner 64c both have a low coefficient of friction on the sliding surfaces and are referred to herein as self-lubricating liners. A bearing having a self-lubricating liner is referred to herein as a lined bearing or a self-lubricating bearing. In one embodiment, a self-lubricating liner comprises a fabric in which PTFE (polytetrafluoroethylene) fibers are interwoven with bondable glass, graphite, polyester, or other aramid fibers such that the PTFE fibers are at least partially exposed on one side of the fabric and the bondable glass, graphite, polyester, or aramid fibers are at least partially exposed on the other side of the fabric. The fabric structure is flooded with resin, which holds the fibers in place. The fabric is then bonded to the metal substrate, e.g., to the inner ring member 64, with an adhesive resin. This type of self-lubricating liner 68 is referred to as a flooded liner, since the working surface of the fabric is flooded with binding resin. The flooded liner provides a locking of the PTFE fibers for strength and resistance to cold flow, bearing surfaces which are almost entirely PTFE, and a surface which is bonded to the metal substrate of the bearing, e.g., to the convex surface 66a. While a self-lubricating liner comprising glass/graphite/polyester/aramid fibers/PTFE has been described, the invention is not limited in this regard, and in other embodiments other suitable liners may be used for lubricating effect, without departing from the broader aspects of the present invention. For example, in another embodiment, the self-lubricating liner 68 may molded and comprised of PTFE, glass, graphite, polyester, or aramid fibers in a thermosetting composite resin made from polyester, urethane, polyimide, epoxy, phenolic, or other type of resin.
Alternatively, the bearing linkage 20 may comprise bushings, such as the bushings 80, 82 as shown in
In one embodiment illustrated in
The track roller bearing 38 may be coupled to the mounting web 48 about the track 18. In one embodiment, the track roller bearing 38 is coupled to the mounting web 48 using opposing bushings 92, a mounting pin 94, and a nut 96. The opposing bushings 92 facilitate the mounting of the track rollers (e.g., either needle rollers 98 or self-lubricating rollers). The nut 96 may be a castellated nut to allow adjustment to the track 18 at fit-up. In one embodiment, the track roller bearing 38 includes a plurality of the needle rollers 98 (e.g., two rows of needle rollers in a double channel design) between an outer ring 100 and an inner ring 102. In one embodiment, the needle rollers 98, the outer ring 100, and/or the inner ring 102 are comprised of hardened stainless steel such as, for example, AISI Type 52100, AISI Type 440C, AISI Type 422 stainless steel treated with a nitriding process (AeroCres®) (AEROCRES is registered trademark of RBC Aircraft Products, Inc., Oxford, Conn. USA), XD-15NW, Cronidur 30®, or the like. The needle roller bearings may employ grease to lubricate the bearings. Such grease includes, for example, Aeroshell grease 33, Mobilgrease 28, Aerospec 200 grease, or Aeroplex 444 grease, but the invention is not limited in this regard, and any suitable grease may be used.
In another embodiment, a track roller bearing comprises a lined track roller bearing 200 which, as illustrated in
As shown in
Optionally, the lined track roller bearing 200 may include seals 253 that are retained against the flanges 236 and/or the flange 246 by respective shields 260 and 270 disposed about shoulder portions 216 and 218 of an outer diameter of the outer ring 210 and extending to an outer diameter 223 of the inner ring 220. The seals 253 are fabricated from acetal, nylon, Delrin®, Celcon® with or without lubricant fillers such as PTFE, polyester, ultra high molecular weight polyethelene (UHMWPE), or other thermoplastic material. The shields 260, 270 may be constructed of various steels, for example, 301, 302, 304, 316, 17-4PH, 17-7PH, 15-5PH, or PH13-8Mo corrosion resistant steels. The shields 260 and 270 reduce friction and inhibit dust and other contaminates from entering and compromising contact between the bearing surfaces 212, 214 of the outer ring 210 and bearing surfaces 222, 224, 226, and 228 of the inner ring 220.
As shown in
As shown in
As shown in
In certain applications, it is also desirable to employ inner rings 410 manufactured from 17-4PH steel, and it is further desirable to employ outer rings 400 of AISI Type 422 stainless steel. In one embodiment, each of the outer rings 400 of the track roller bearings is comprised of AISI Type 422 stainless steel that has been subjected to a nitriding hardening process (e.g., the aforementioned AeroCres® process). Outer rings 400 comprised of AISI Type 422 stainless steel with nitriding hardening are preferred for superior corrosion resistance and performance as compared to outer rings manufactured of 440C steel.
In any of the foregoing embodiments, the drive mechanism and structural joints for the leading edge slats contain bushings and spherical bearings to accommodate mounting, rotation, and misalignments in the drive mechanism and structural joints.
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 spirit and scope of this invention and of the appended claims.
This application is a continuation-in-part of U.S. application Ser. No. 12/201,062, entitled “Actuation System for a Lift Assisting Device and Roller Bearings Used Therein,” filed Aug. 29, 2008, now pending, which claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application Ser. No. 60/992,746, entitled “Lined Track Roller,” filed Dec. 6, 2007, the disclosures of which are incorporated by reference herein in their entireties.
Number | Date | Country | |
---|---|---|---|
60992746 | Dec 2007 | US |
Number | Date | Country | |
---|---|---|---|
Parent | 12201062 | Aug 2008 | US |
Child | 13053945 | US |