WO2006094145A9 - Train d'atterrissage a mecanisme articule d'extension en longueur - Google Patents

Train d'atterrissage a mecanisme articule d'extension en longueur Download PDF

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Publication number
WO2006094145A9
WO2006094145A9 PCT/US2006/007477 US2006007477W WO2006094145A9 WO 2006094145 A9 WO2006094145 A9 WO 2006094145A9 US 2006007477 W US2006007477 W US 2006007477W WO 2006094145 A9 WO2006094145 A9 WO 2006094145A9
Authority
WO
WIPO (PCT)
Prior art keywords
over
landing gear
strut
center
bogie beam
Prior art date
Application number
PCT/US2006/007477
Other languages
English (en)
Other versions
WO2006094145A1 (fr
Inventor
Anthony J Barr
Original Assignee
Goodrich Corp
Anthony J Barr
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Goodrich Corp, Anthony J Barr filed Critical Goodrich Corp
Publication of WO2006094145A1 publication Critical patent/WO2006094145A1/fr
Publication of WO2006094145A9 publication Critical patent/WO2006094145A9/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C25/00—Alighting gear
    • B64C25/32—Alighting gear characterised by elements which contact the ground or similar surface 
    • B64C25/34—Alighting gear characterised by elements which contact the ground or similar surface  wheeled type, e.g. multi-wheeled bogies
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C25/00—Alighting gear
    • B64C25/001—Devices not provided for in the groups B64C25/02 - B64C25/68
    • B64C2025/008—Comprising means for modifying their length, e.g. for kneeling, for jumping, or for leveling the aircraft

Definitions

  • the invention herein described relates generally to landing gear for large aircraft and more particularly to a landing gear including an articulated length extension mechanism.
  • Landing gear for large aircraft heretofore have employed a telescoping shock-absorbing strut to which a multi-wheel truck (bogie beam) is attached.
  • Such landing gear usually are equipped with some form of positioning mechanism to orientate the truck when the strut is fully extended and aircraft weight is removed. This provides a predictable position of the assembly to ensure internal and external landing gear clearances are respected during and after landing gear extension and retraction.
  • the present invention enables a landing gear to be equipped with a mechanism that isolates a hydraulic pitch trimmer outside of the landing loop thereby eliminating the need for complex hydraulics normally associated with articulated landing gear designs equipped with pitch or trimmers or other articulating actuators.
  • a landing gear for an aircraft comprises a shock strut including a cylinder and a piston telescopically movable in the cylinder, a multi-axle bogie beam connected to the lower end of the shock strut piston at a first pivot connection, an articulated strut connected between the bogie beam and shock strut cylinder for controlling the pitch of the bogie beam, an over-center linkage connected between the articulated strut and the shock strut cylinder, and an externally powered actuator connected to the over-center linkage for moving the over-center linkage between the over-center locked position and other another position articulating the bogie beam from an end of take-off position to a stowage position, whereby the bogie beam can be properly angularly positioned relative to the shock strut for retraction into an aircraft landing gear bay.
  • the articulated strut includes a lower strut pivotally connected at its lower end to the bogie beam at a location spaced from the first pivot connection between the bogie beam and shock strut piston, and an upper strut connected at one end to the lower strut at a second pivot connection and at its other end to the shock strut cylinder that allows for movement of the upper strut whereby the position of the second pivot connection between the upper and lower struts can be changed relative to the shock strut cylinder.
  • the over-center linkage includes first and second links pivotally connected to one another for movement into and out an over-center locked position, the over-center linkage, when in the over-center locked position, cooperating with the upper strut to restrain movement of the second pivot connection relative to the shock strut cylinder, whereby the bogie beam will be caused to pivot when the shock strut piston extends out of the shock strut cylinder during take-off, and the over-center linkage, when not in the over-center locked position, allowing movement of the second pivot connection whereby the bogie beam can be pivoted relative to the shock strut piston without corresponding extension or retraction of the shock strut piston.
  • the upper strut may be pivotally connected to the shock strut cylinder and may form a fixed triangular structure with the over-center linkage when the over- center linkage is in its over-center locked position.
  • At least one of the first and second links of the over-center linkage may include an extendible member biased toward a retracted position, which biased extendible member compensates for rocking movement of the bogie beam during landing and takeoff when the over-center linkage is in its over-center condition.
  • the extendible member may include an actuator pressured to its retracted position.
  • the externally powered actuator may be connected to the first and second links at a pivot connection therebetween, and may include an end-of- stroke stop that defines the over-center stop position of the over-center linkage.
  • the over-center linkage when in its over-center locked position, may be cooperative with the lower strut to rotate the bogie beam to a forward axle up position as the shock strut piston is extended during take-off of the aircraft.
  • a landing gear is characterized by a mechanism that isolates an actuator used to position the bogie beam for stowage outside of the landing loop, thereby eliminating the need for complex hydraulics normally associated with articulated landing gear equipped with pitch trimmers or other articulating actuators.
  • the mechanism may comprise an articulated strut connected between a bogie beam and a shock strut cylinder for controlling the pitch of the bogie beam, an over-center linkage connected between the articulated strut and the shock strut cylinder, and an externally powered actuator connected to the over-center linkage for moving the over-center linkage between the over-center locked position and other another position articulating the bogie beam from an end of take-off position to a stowage position, whereby the bogie beam can be properly angularly positioned relative to the shock strut for retraction into an aircraft landing gear bay.
  • a method of articulating a landing gear of an aircraft comprises the steps of isolating outside of the takeoff/landing loop an actuator used to position a landing gear bogie beam for stowage, thereby eliminating the need for complex hydraulics normally associated with articulated landing gear equipped with pitch trimmers or other articulating actuators; and after take-off of the aircraft with the landing gear shock strut extended, operating the actuator to move the bogie beam to its position for stowage thereby allowing the landing gear to be retracted into a landing gear bay of the aircraft.
  • the isolating step may include using an linkage connected between an articulated strut and cylinder of the shock strut to isolate the actuator from the take-off/landing loop.
  • Fig. 1 is a side elevational view of a landing gear according to the invention, shown during take-off.
  • Fig. 2 is a view similar to Fig. 1 , showing the landing gear during landing. perspective view of the landing gear of Fig. 1 , shown in a retracted position.
  • Fig. 3 is a view similar to Fig. 1 , showing the landing gear during forward wheel removal.
  • Fig. 4 is a view similar to Fig. 1 , showing the landing gear in an extended articulated position.
  • a main landing gear according to the invention is indicated generally at 10.
  • the illustrated landing gear is particularly intended for large multi-wheel aircraft comprising nose landing gear, fuselage-mounted, multi-wheeled landing gears, and/or wing-mounted, multi-wheeled landing gears.
  • the landing gear system arrangement may perform one or more of the following basic functions: (a) to distribute aircraft loads onto the ground 1 , (b) to carry the aircraft during ground maneuvers, (c) to enable effective braking, (d) to contribute to a clean aerodynamic shape in flight, (e) to ensure safe aircraft transition from flight to ground and from ground to flight, and (f) to achieve an acceptable passenger and crew comfort during take-off, landing and ground maneuvers.
  • the landing gear 10 may be a cantilever-type with a shock strut 14 fitted with a multi-wheel truck 16, also referred to herein as a bogie.
  • the truck 16 includes a truck (bogie) beam 18 that carries two or more axles 20 for respective pairs of wheels 22. In the illustrated embodiment, two axles are employed to provide a four wheel truck. The number of wheels and/or axles may be varied as desired for a given application.
  • the shock strut 14 may be of any suitable construction.
  • the shock strut may be a single-stage oleo-pneumatic type in which nitrogen gas and oil are unseparated and perform gas spring and shock dampening functions as is conventional in the art.
  • the shock strut as is typical, may comprise a single piece outer cylinder 24 into which a piston 26 (sliding member) strokes.
  • the shock strut preferably is inclined with an aftward angled rake in the gear down position as shown in Fig. 1.
  • the upper end of the shock strut may be attached by any suitable means to the frame structure of the aircraft, usually in a manner that allows the gear to rotate upwardly into a landing gear bay of the aircraft.
  • the landing gear typically will be equipped with a retraction actuator, such as the retraction actuator 30 (Fig. 4), for retracting the landing gear into the bay and also for extending the gear, i.e., for moving the gear between stowed and unstowed positions.
  • the landing gear is equipped with torque links 32 and 34 that are attached by suitable pivot connections between the outer cylinder 24 of the shock strut 14 and the bogie beam 18, for example, on the aft side of the shock strut.
  • the torque links transmit pivoting torque from the strut piston 26 and bogie beam to the outer cylinder 24, and into the aircraft.
  • the torque links are articulated to accommodate shock strut stroking.
  • the strut piston 26 at its lower end forms a fork 56 to which the bogie beam 18 is attached with a pivot pin 58.
  • the fork is provided with lugs for attachment of brake rods (one shown at 62) for reacting brake torque from brakes (not shown) associated with the wheels.
  • the landing gear 10 is equipped with an articulated length extension mechanism 66.
  • FIG. 1 generally comprises an articulated strut 68 connected between the bogie beam 18 and shock strut cylinder 24 for controlling the pitch of the bogie beam, an over-center linkage 70 connected between the articulated strut 68 and the shock strut cylinder 24, and an externally powered actuator 72 connected to the over-center linkage for moving the over-center linkage between the over-center locked position (Fig. 1) and other another position (Fig. 4) articulating the bogie beam from an end of takeoff position to a stowage position, whereby the bogie beam can be properly angularly positioned relative to the shock strut for retraction into an aircraft landing gear bay.
  • the articulated strut 68 includes a lower (vertical) strut 76 pivotally connected at its lower end to the bogie beam 18 at a location 78 spaced from the first pivot connection 58 between the bogie beam and shock strut piston, and an upper (horizontal) strut 80 connected at one end to the lower strut at a second pivot connection 82 and at its other end to the shock strut cylinder 24 that allows for movement of the upper strut whereby the position of the second pivot connection 82 between the upper and lower struts can be changed relative to the shock strut cylinder.
  • the illustrated vertical and horizontal struts are links that are attached by suitable pivot connections between the outer cylinder 24 of the shock strut 14 and the bogie beam 18.
  • the pivot connection 78 between the vertical strut and the bogie beam is proximate the end of the bogie beam opposite the end to which the lower torque link 34 is attached, i.e., at the forward side of the shock strut.
  • the over-center linkage 70 includes first and second links 86 and 88 pivotally connected to one another for movement into and out an over-center locked position seen in Fig. 1.
  • the over- center linkage when in the over-center locked position, cooperates with the upper strut 80 to restrain movement of the second pivot connection 82 relative to the shock strut cylinder 24, whereby the bogie beam 18 will be caused to pivot when the shock strut piston 26 extends out of the shock strut cylinder during take-off, and the over-center linkage.
  • the over-center linkage allows movement of the second pivot connection 82 whereby the bogie beam can be pivoted relative to the shock strut piston without corresponding extension or retraction of the shock strut piston.
  • the second link 88 of the over-center linkage includes an extendible member biased toward a retracted position, which biased extendible member compensates for rocking movement of the bogie beam during landing and takeoff when the over-center linkage is in its over-center condition.
  • the extendible member may include, as shown, an actuator pressured to its retracted position, which may be referred to as a rocking bogie actuator.
  • the pivot connection 82 between the vertical and horizontal struts may provide the pivotal connection of the first link 86 to the strut link assembly (the "first link” is also referred to herein as the "articulation over-center link”).
  • the other end of the first link is pivotally connected to one end of the rocking bogie actuator 88 and to one end of the articulation actuator 72.
  • the other ends of the rocking bogie actuator and articulation actuators are pivotally connected to the shock strut cylinder 24 at different points along the length of the shock strut cylinder.
  • hydraulic pressure from an external source such as an aircraft's hydraulic system
  • the articulation actuator 72 for extension or retraction
  • actuator being, for example, a hydraulic cylinder and piston assembly.
  • the rocking bogie actuator 88 which may also be a piston and cylinder assembly, is always pressured (biased) to retract in the illustrated embodiment.
  • the articulation actuator 72 receives a constant hydraulic pressure to the fully retracted position. This creates a fixed triangulated structure being supported vertically by the rocking bogie actuator 88.
  • the rocking bogie actuator is always pressured to retract as above mentioned.
  • An over-center condition is created between the rocking bogie actuator and the articulation over-center link, with mechanical stops between the components serving to support the structure.
  • the fixed triangular structure is connected to the bogie beam 18 via the vertical strut 76.
  • the structure can react against the shock strut gas spring to support and pivot the aircraft around the aft wheels.
  • the shock strut 14 will extend as the weight of the aircraft is lifted off the shock strut.
  • the bogie beam 18 will rotate and maintain the rear wheels of the truck in contact with the runway for a longer period of time, as is often desired, as is depicted in Fig. 1.
  • the articulation actuator 88 is effectively taken out of the loop by the over-center condition of the rocking bogie actuator 88 and the articulation over- center link 86.
  • the fixed triangular structure, vertical strut, bogie beam and shock strut function as a four-bar linkage with three revolute joints and one prismatic or slide joint. Linear movement of the shock strut piston effects rotation of the bogie beam between the positions seen in Figs. 1 and 2.
  • the articulated length extension mechanism 66 allows for jacking of the forward wheels to replace a flat tire without compressing the shock strut.
  • the angular movement of the bogie beam 18 is accommodated through extension of rocking bogie actuator 88.
  • hydraulic damping can be applied to the extension and retraction strokes of the articulation actuator. This will reduce inertia loads and noise at stroke extremes.
  • the articulation actuator can be located outside of landing loop thereby to reduce complex hydraulic systems necessary for previously proposed designs. This also reduces cost and weight.
  • the articulated length extension mechanism can be applied to all types of aircraft including multi-axle bogies.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Transmission Devices (AREA)

Abstract

Un train d'atterrissage (10) est doté d'un mécanisme (66) qui isole un compensateur d'inclinaison hydraulique (72) à l'extérieur de la boucle du train d'atterrissage éliminant ainsi l'hydraulique complexe associée normalement à des conceptions de train d'atterrissage articulé dotées de compensateurs d'inclinaison ou d'autres actionneurs d'articulation. Le mécanisme comprend une jambe articulée (68) reliée entre un balancier (18) et un cylindre de jambe élastique (24) afin de réguler l'inclinaison du balancier, une liaison centrale (70) reliée entre la jambe articulée et le cylindre de jambe élastique, ainsi qu'un actionneur (72) alimenté extérieurement et relié à la liaison centrale pour placer la liaison centrale sur la position verrouillée centrale ainsi qu'une autre position articulant le balancier depuis une extrémité de position de décollage jusque dans une position de repli, de manière que le balancier peut être positionné angulairement correctement par rapport à la jambe élastique pour permettre un relevage à l'intérieur de la soute du train d'atterrissage d'un avion.
PCT/US2006/007477 2005-03-02 2006-03-02 Train d'atterrissage a mecanisme articule d'extension en longueur WO2006094145A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US65796105P 2005-03-02 2005-03-02
US60/657,961 2005-03-02

Publications (2)

Publication Number Publication Date
WO2006094145A1 WO2006094145A1 (fr) 2006-09-08
WO2006094145A9 true WO2006094145A9 (fr) 2009-01-08

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102712363A (zh) * 2009-10-23 2012-10-03 梅西耶-道提有限公司 转向架止挡块
US11091252B2 (en) 2019-07-30 2021-08-17 Safran Landing Systems Canada Inc. Aircraft multi-wheel truck beam positioner

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8448900B2 (en) * 2010-03-24 2013-05-28 The Boeing Company Semi-levered landing gear and associated method
GB2483472B (en) 2010-09-08 2012-08-15 Messier Dowty Ltd Aircraft landing gear
US9481452B2 (en) 2010-11-22 2016-11-01 The Boeing Company Hydraulic actuator for semi levered landing gear
US8939400B2 (en) 2011-02-21 2015-01-27 The Boeing Company Air-ground detection system for semi-levered landing gear
US8998133B2 (en) 2011-04-01 2015-04-07 The Boeing Company Landing gear system
GB2510412C (en) * 2013-02-04 2021-08-25 Messier Dowty Ltd Aircraft landing gear pitch trimmer actuator with variable damping
US9090342B2 (en) * 2013-10-04 2015-07-28 Goodrich Corporation Rocking bogie mechanism
EP3009348B8 (fr) 2014-10-16 2017-03-29 Safran Landing Systems UK Limited Ensemble de train d'atterrissage d'avion
EP3269637B1 (fr) * 2016-07-12 2021-12-08 Goodrich Corporation Agencement de train d'atterrissage
US10384767B2 (en) 2017-01-25 2019-08-20 The Boeing Company Single axle, semi-levered landing gear with shortening mechanism
US10597146B2 (en) * 2017-02-28 2020-03-24 The Boeing Company Aircraft landing gear having a lever assembly, aircraft including the same, and related methods
US10625849B2 (en) 2017-04-11 2020-04-21 The Boeing Company Levered landing gear with inner shock strut
US10800516B2 (en) 2017-06-02 2020-10-13 The Boeing Company Semi-levered shrink landing gear
US11161599B2 (en) 2018-01-26 2021-11-02 The Boeing Company Landing gear strut assembly and method therefor
US10981646B2 (en) 2018-07-30 2021-04-20 The Boeing Company Landing gear shrink link mechanism

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4720063A (en) * 1985-09-30 1988-01-19 The Boeing Company Main landing gear with variable length drag brace
FR2688190A1 (fr) * 1992-03-03 1993-09-10 Messier Bugatti Train d'atterrissage relevable.

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102712363A (zh) * 2009-10-23 2012-10-03 梅西耶-道提有限公司 转向架止挡块
US11091252B2 (en) 2019-07-30 2021-08-17 Safran Landing Systems Canada Inc. Aircraft multi-wheel truck beam positioner

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