• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to an aircraft landing gear comprising a box (1) intended to be connected to the aircraft, a sliding rod (3) slidably engaged in the box by the lower opening, which carries at least one wheel to its lower end, a diaphragm (7) carried by a support (8) hooked to the upper wall of the box to cooperate sealingly with an inner wall of the sliding rod, so as to define a first chamber (C1) under the diaphragm to the interior of the rod completely filled with hydraulic fluid, and a second chamber (C2) above the diaphragm partially filled with hydraulic fluid, a rolling needle (10) integral with the sliding rod and penetrating into a calibrated orifice (12). ) of the diaphragm to define a calibrated fluid passage between the first and the second chamber, and angular connection means for imposing an angular position of the sliding rod relatively to the caisson. According to the invention, the undercarriage comprises at least one pallet (20) attached to the end of the rolling needle to extend inside a portion filled with hydraulic fluid of the second chamber.
    公开号:FR3036095A1
    申请号:FR1554229
    申请日:2015-05-12
    公开日:2016-11-18
    发明作者:Jerome Fraval；David Frank
    申请人:Messier Bugatti Dowty SA；
    IPC主号:
    专利说明:

    [0001] The invention relates to an aircraft undercarriage equipped with shimmy damping means. BACKGROUND OF THE INVENTION Landers having a housing in which a sliding rod is telescopically slidable are known. The lower end of the sliding rod carries an axle or a bogie to receive one or more wheels. Suspension means are formed between the box and the sliding rod to absorb shocks during landings and suspend the aircraft during the rolling thereof. In general, the rod is connected to the box by a compass whose branches allow the free insertion of the rod in the box while preventing a rotation of the sliding rod in the box. In landing vehicles equipped with wheel orientation means, the compasses are not directly connected to the casing, but to a member rotatably mounted on the casing (such as an external collar mounted around a lower part of the casing, or still an internal rotating tube mounted inside the casing). The angular position of the rotating member is controlled by a hydraulic or electrical steering command which, by the compasses, imposes the angular position of the sliding rod, and therefore the wheels. It is known that the undercarriages are subject to oscillations called shimmy, which result in particular from a coupling of flexion and torsion modes of the undercarriage. These oscillations tire the undercarriage and can lead to catastrophic situations, in case of resonance input. Various damping means for these oscillations are known, such as, for example, the arrangement of anti-shimmy valves in hydraulic steering controls, or shimmy dampers on the compass articulation.
    [0002] OBJECT OF THE INVENTION The object of the invention is to propose an aircraft landing device equipped with an alternative system for purely passive shimmy damping.
    [0003] PRESENTATION OF THE INVENTION With a view to achieving this object, an aircraft landing gear comprising a caisson intended to be connected to the aircraft and defining a substantially cylindrical cavity delimited by an upper wall and having an opening is proposed. lower; - A sliding rod engaged in sealingly sliding in the box by the lower opening, which carries at least one wheel at its lower end; A diaphragm carried by a support hooked to the upper wall of the box to cooperate sealingly with an inner wall of the sliding rod, so as to define a first chamber under the diaphragm inside the rod completely filled with hy - 20 hydraulic, and a second chamber above the diaphragm partially filled with hydraulic fluid; - A portion filled with hydraulic fluid of the second chamber, being secured to the end of a rolling needle integral with the sliding rod and penetrating into a calibrated orifice of the diaphragm to define a calibrated fluid passage between the first and the second chamber; - Angle connecting means for imposing an angular position of the sliding rod relative to the box. According to the invention, the undercarriage comprises at least one pallet fixed to the end of the rolling needle to extend inside. Thus, if torsional oscillations during which the sliding rod oscillates angularly in the box 3 develop, due in particular to the flexibility of the angular connection means, the pallet will begin to oscillate angularly in the hydraulic fluid, this will generate a resistive torque on the pallet contributing to the damping of these oscillations, and helping to counter a possible tendency to the shimmy of the undercarriage. This resistive torque, due to the viscous friction generated by the angular displacement of the pallet in the fluid, is generated automatically and in a purely passive manner. For undercarriages whose angular connection means between the sliding rod and the casing include an orientation control, this damping is available even when the steering control is inactive, for example following a failure of the steering wheel. of the orientation control. Preferably, the pallet comprises edges which extend facing an inner wall of the support to present therewith a reduced clearance at least when the wheels are in the straight rolling position of the aircraft. BRIEF DESCRIPTION OF THE FIGURES The invention will be better understood in the light of the following description of a particular embodiment of the invention, with reference to the figures of the appended drawings in which: FIG. in schematic section of an aircraft undercarriage according to the invention; Figure 2 is a cutaway perspective view of the undercarriage of Figure 1; - Figure 3 is a sectional view along the line A-A of Figure 1 of the tubular diaphragm carrier and the pallet of the undercarriage of Figure 1; - Figure 4 is a view similar to Figure 1 35 of an alternative embodiment of the invention.
    [0004] DETAILED DESCRIPTION OF AN EMBODIMENT OF THE INVENTION With reference to the figures, a typical aircraft undercarriage generally comprises a casing 1 attached to the aircraft structure and defining a cylindrical cavity delimited by a wall. upper 2, and having an opening at its lower end. A sliding rod 3 is slidably engaged in the casing 1 by its lower opening. To do this, the box 1 carries a lower bearing 4 against which slides an outer wall of the sliding rod 3, while the sliding rod 3 carries a movable upper bearing 5 which slides against an inner wall of the box 1. The end lower of the sliding rod 15 3 here carries two wheels 6. In addition, a diaphragm 7 is carried by a support 8 fixed to the upper wall 2 of the box 1. The diaphragm 7 delimits in the sliding rod 3 a first chamber C1 filled with hydraulic fluid. A second chamber C2 extending into the sliding rod 3 and the casing 1 over the diaphragm 7 is partially filled with hydraulic fluid, the remainder of the second chamber C2 being filled with pressurized gas. A third chamber C3 filled with hydraulic fluid extends between the sliding rod 3 and the casing 1, between the bearings 4 and 5. A calibrated passage (not shown here) is provided at the upper bearing 5 to implement fluidic communication rooms C2 and C3. A rolling needle 10 carried by a needle holder 11 integral with the sliding rod 30 3 extends through a calibrated orifice 12 of the diaphragm 7. In a manner known per se, the rolling needle 10 comprises longiline grooves 13 of variable depth which make it possible to vary the section of fluid passage between the chambers C1 and C2 as a function of the depression of the sliding rod 3 in the casing 1.
    [0005] In a manner known per se, the undercarriage is equipped with a device for controlling the angular position of the sliding rod 3 relative to the casing 1, for example a compass 14 whose arms 14a and 14b are articulated between they are articulated respectively to the sliding rod 3 and to the casing 1. In landers with steerable wheels, the upper limb 14b of the compass is not hinged directly on the casing 1, but on a pivoting member mounted to rotate on the casing 10 its, like a collar rotatably mounted around the box, or a rotating tube rotatably mounted within the box, and whose angular position is controlled by an orientation command. All this is well known and is only recalled to situate the scope of the invention.
    [0006] According to the invention, a paddle 20 is fixed to the end of the rolling needle 10 to extend inside the support 8, in a portion of the second chamber C2 filled with hydraulic fluid. During torsional oscillations of the landing gear during which the sliding rod 3 oscillates angularly inside the casing 1, in particular because of the flexibility of the compass 14, the paddle 20 oscillates angularly in the hydraulic fluid in which it bathes, which generates on the pallet 20 a resistant torque due to the viscous friction which, through the rolling needle 10, tends to dampen the angular oscillations of the sliding rod 3 in the casing 1. We obtain thus an internal damping to the undercarriage, purely passive, available even if the orientation control is not active. According to a particular aspect of the invention illustrated in FIG. 3, when the wheels 6 (not shown in FIG. 3) are in the straight rolling position (which is always the case in the undercarriages without a steering control , or, for landing gear with orientation device, when it is in the neutral position), the edges 21 of the pallet 20 extend facing an inner wall of the support 8 with a reduced clearance adapted to provide greater depreciation. Preferably, the edges 21 of the pallet 20 are in the form of a cylindrical sector whose outer wall extends facing the inner wall of the support 8 with a reduced clearance. According to an alternative embodiment illustrated in FIG. 4, the landing gear comprises no rolling needle, and the pallet 120 is now fixed to the diaphragm 107 to extend into the first chamber C1. In the same way, when torsion oscillations of the undercarriage in which the sliding rod 103 angularly oscillates inside the box 101, in particular because of the flexibility of the compass 114, the pallet 120 oscillates angularly in the hydraulic fluid in which it bath, which generates on the pallet 120 a resistive torque due to viscous friction 20 which, through the rolling needle 110, tends to dampen the angular oscillations of the sliding rod 103 in the casing 101. an internal damping to the undercarriage, purely passive, available even if the steering control is not active.
    权利要求:
    Claims (3)
    [0001]
    REVENDICATIONS1. An aircraft landing gear comprising: - a box (1) intended to be connected to the aircraft and defining a substantially cylindrical cavity delimited by an upper wall (2) and having a lower opening; - A sliding rod (3) slidably engaged in the box by the lower opening, which carries at least one wheel at its lower end; - a diaphragm (7) carried by a support (8) hooked to the upper wall of the box to cooperate sealingly with an inner wall of the sliding rod, so as to define a first chamber (Cl) under the diaphragm to the inside the rod completely filled with hydraulic fluid, and a second chamber (C2) above the diaphragm partially filled with hydraulic fluid; - A rolling needle (10) integral with the sliding rod and penetrating into a calibrated orifice (12) of the diaphragm to define a calibrated fluid passage between the first and the second chamber; - Angle connecting means for imposing an angular position of the sliding rod relative to the box; characterized in that the undercarriage comprises at least one pallet (20) attached to the end of the rolling needle to extend within a portion filled with hydraulic fluid of the second chamber.
    [0002]
    2. Landing gear according to claim 1, in which the pallet (20) has edges (21) which extends opposite an inner wall of the support (8) with a reduced clearance, at least when the wheel of the undercarriage is in the rectilinear rolling position of the aircraft.
    [0003]
    3. Landing gear according to claim 2, wherein the edges (21) are cylindrical sector-shaped 3036095 8 having an outer wall which extends with a reduced clearance facing an inner wall of the support (8).
    类似技术:
    公开号 | 公开日 | 专利标题
    EP3093238B1|2018-10-10|An aircraft undercarriage with shimmy-damping means
    CA2730586A1|2010-01-28|Mechanical device for inclination control
    FR2598676A1|1987-11-20|AIRCRAFT TILLER WITH TILTING BEAM AND REDUCED SIZE
    EP3085988B1|2018-09-12|Pneumatic suspension device
    EP0447307B1|1994-05-11|Hydraulic damper and elastohydraulic return device composed of such a damper
    EP0554147A1|1993-08-04|Suspension assembly for a heavy vehicle, especially for an endless track vehicle
    CH685378A5|1995-06-30|Rotary tool carrier head weight compensator for drilling machine
    FR2962974A1|2012-01-27|SHIMMY COMPACT ATTENUATOR FOR AIRCRAFT LANDING TRAIN
    CA2977277C|2019-11-19|Aircraft landing gear equipped with a shimmy attenuation device
    US2557274A|1951-06-19|Cross wind undercarriage for airplanes
    FR2689062A1|1993-10-01|Two-stage suspension arranged in series for a motor vehicle called auto-suspension.
    US2275372A|1942-03-03|Shock absorbing structure for airplane landing gears
    TWI571395B|2017-02-21|The suspension of the wheel
    FR2608518A1|1988-06-24|Swing-arm suspension for a set of two wheels of a vehicle and unitary suspension and shock-absorbing system for such a suspension
    FR2559715A1|1985-08-23|HYDROPNEUMATIC SYSTEM OF ADJUSTABLE HEIGHT FOR A VEHICLE
    FR2993623A1|2014-01-24|Shock absorber device for use in e.g. motor cycle, has non-return valve located in external container to control flow of fluid from external container towards shock absorber and coaxially placed around adjustment unit
    TWM506053U|2015-08-01|Suspension structure of vehicle wheel
    FR2580356A1|1986-10-17|FLUID-FILLED PAD
    FR2933951A1|2010-01-22|Movable frame inclination controlling device for vehicle i.e. tricycle, has accelerometer measuring transverse acceleration of frame, and control circuit activating locking units when transverse acceleration exceeds predetermined threshold
    FR2982843A1|2013-05-24|LITTER WITH LOWER LOWER PART
    FR2541944A1|1984-09-07|OLEOPNEUMATIC SUSPENSION WITH TOTAL DAMPENING
    FR3002998A1|2014-09-12|HYDRAULIC SHOCK ABSORBER, IN PARTICULAR FOR A VEHICLE SUSPENSION DEVICE.
    EP1074406A1|2001-02-07|Improved device for a front wheel suspension of a motor vehicle
    FR2781185A1|2000-01-21|Suspension system for front directional wheels of motor vehicle, comprises quadrilateral that is vertically deformable and triangle formed from components with pivoting axis of wheel
    FR2805871A1|2001-09-07|A double piston damper with fluid recharge chamber to replace losses in the working chambers
    同族专利:
    公开号 | 公开日
    US20160332726A1|2016-11-17|
    EP3093238B1|2018-10-10|
    FR3036095B1|2017-05-26|
    US10005547B2|2018-06-26|
    EP3093238A1|2016-11-16|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US2366697A|1940-10-24|1945-01-09|Dowty Equipment Ltd|Aircraft alighting gear|
    GB555500A|1942-02-23|1943-08-25|Inv S Aeronautiques & Mecaniqu|Improvements in or relating to aeroplane landing gear|
    US3056598A|1958-04-18|1962-10-02|Short Brothers & Harland Ltd|Under-carriage shock absorbers for aircraft|
    EP0246949A1|1986-05-13|1987-11-25|Messier-Hispano-Bugatti |Aircraft landing gear provided with a swivelling beam and having small overall dimensions|
    GB2482154A|2010-07-21|2012-01-25|Ge Aviat Systems Ltd|Compact shimmy damper for aircraft landing gear|
    GB8803134D0|1988-02-11|1988-03-09|British Aerospace|Aircraft undercarriage unit|CN107021212B|2017-03-03|2019-03-19|中国民航大学|A kind of plate turning type magnetorheological shimmy damper for undercarriage|
    CN109319099B|2018-11-29|2021-07-09|中国航空工业集团公司沈阳飞机设计研究所|Extension stroke becomes oilhole undercarriage buffer|
    CN109552603A|2018-12-01|2019-04-02|江苏鸿鹄无人机应用科技有限公司|A kind of unmanned plane landing and buffering device|
    KR102200201B1|2019-04-16|2021-01-11|백남용|Drone with morphological transformation in the air and underwater|
    US11255398B2|2020-01-13|2022-02-22|Goodrich Corporation|Multi-actor damping systems and methods|
    法律状态:
    2016-05-20| PLFP| Fee payment|Year of fee payment: 2 |
    2016-11-18| PLSC| Search report ready|Effective date: 20161118 |
    2017-05-23| PLFP| Fee payment|Year of fee payment: 3 |
    2017-06-23| CD| Change of name or company name|Owner name: MESSIER-BUGATTI-DOWTY, FR Effective date: 20170518 |
    2018-05-22| PLFP| Fee payment|Year of fee payment: 4 |
    2019-04-19| PLFP| Fee payment|Year of fee payment: 5 |
    2020-04-22| PLFP| Fee payment|Year of fee payment: 6 |
    2021-04-21| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1554229A|FR3036095B1|2015-05-12|2015-05-12|AIRCRAFT IMPELLER EQUIPPED WITH SHIMMY DAMPING MEANS.|FR1554229A| FR3036095B1|2015-05-12|2015-05-12|AIRCRAFT IMPELLER EQUIPPED WITH SHIMMY DAMPING MEANS.|
    EP16163934.9A| EP3093238B1|2015-05-12|2016-04-05|An aircraft undercarriage with shimmy-damping means|
    US15/151,593| US10005547B2|2015-05-12|2016-05-11|Aircraft undercarriage with shimmy-damping means|
    [返回顶部]