Aircraft landing gear leg, aircraft landing gear with such a landing gear leg, and aircraft with at least one such landing gear leg.

Description

[0001] The present invention relates to the field of landing gear and more particularly to the integration of a battery into an aircraft landing gear. BACKGROUND OF THE INVENTION

[0002] Aircraft equipped with retractable landing gear, cargo bays for storing these landing gear while the aircraft is in flight, and hatches for closing these bays are known. A landing gear typically comprises a leg with one end connected to an aircraft structure and a second end fitted with an axle on which wheels are mounted for maneuvering the aircraft on the ground (towing, braking, steering, etc.). At least one of the wheels is equipped with a brake comprising friction elements, such as discs, some of which are integral with the wheel and others with a stator, and a hydraulic cylinder arranged to exert sufficient force on the friction elements to prevent the wheel from rotating.

[0003] In normal operation, the landers are typically deployed using a hydraulic circuit with hydraulic components designed to work sequentially to unlock and open the lander hatches, then unlock and / or deploy the landers, and possibly close and relock at least some of the hatches. The hydraulic circuit also includes hydraulic components designed to control the braking of the lander wheels.

[0004] In the event of a hydraulic system failure, backup systems are in place to ensure the opening of the hatches and / or the deployment of the landing gear and / or the braking of the wheels. These backup systems may include a hydraulic power reserve designed to supply, in emergency mode, the wheel brakes and the actuators for unlocking the landing gear and hatches.

[0005] This energy reserve includes one or two hydraulic accumulators which are generally housed in the holds near the landing gear due to their size, mass and regulations (European Union Aviation Safety Agency, Federal Aviation Administration...) which require physical separation between the accumulator and the equipment surrounding it of a distance of up to 1.54 meters to mitigate any risk of explosion.

[0006] However, integrating the batteries into the cargo holds proves complicated due to the limited space available in said cargo holds.

[0007] We also know of the installation of fixed hydraulic accumulators in the landing gear leg and document GB 520995 A1 illustrates this state of the art. SUBJECT OF THE INVENTION

[0008] The invention aims to provide a solution that at least partially remedies the aforementioned drawbacks. SUMMARY OF THE INVENTION

[0009] For this purpose, we propose a leg for aircraft landing gear comprising a box arranged to absorb landing forces and equipped with a cavity in which is housed an energy accumulator in the form of a cartridge insertable into this cavity.

[0010] Thus, the housing serves two functions: absorbing the landing forces and housing the energy accumulator. Furthermore, the housing can be configured to mechanically protect the accumulator.

[0011] In particular, the accumulator is hydraulic.

[0012] In particular, the accumulator is an electrochemical battery.

[0013] According to a particular embodiment of the invention, the leg comprises a rod forming a shock absorber sliding in the box, one end of the rod carrying at least one wheel.

[0014] According to one variant of the invention, the leg comprises a balance beam articulated on the box and a shock absorber connecting the balance beam to the box, one end of the balance beam carrying at least one wheel.

[0015] The invention also relates to an aircraft landing gear comprising such a leg.

[0016] The invention also relates to an aircraft comprising at least one such landing gear.

[0017] In particular, the lander's box is hinged to a structure of the aircraft.

[0018] The invention further relates to a method for emergency deployment of such a lander using the accumulator integrated into the lander's leg. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The invention will be better understood in light of the following description, which is purely illustrative and not limiting, and should be read in conjunction with the accompanying figures, among which: [Fig.1 ] there figure 1 is a schematic view of an aircraft including retractable landing gear; [ Fig.2 ] there figure 2 is a schematic view of the aircraft landing gear illustrated in the figure 1 ; Fig.3 ] there figure 3 illustrates a leg, according to a particular embodiment of the invention, of one of the landers illustrated in the figure 2 ; Fig.4 ] there figure 4 illustrates a variant of the leg shown in the figure 3 . DETAILED DESCRIPTION OF THE INVENTION

[0020] As illustrated in the figure 1 , the invention is described here in application to an aircraft 1 comprising two main landing gear 10 and an auxiliary forward landing gear 50.

[0021] With reference to the figure 2 The main landing gear 10 is articulated on a structure of the aircraft 1 around an axis X10, X10' substantially parallel to a direction of forward movement of said aircraft 1, between a deployed position illustrated here and a retracted position in which the main landing gear 10, 10' is received in a bay that can be closed by a hatch 11, 11'. Double-acting hydraulic cylinders 12, 12' are attached to the main landing gear 10, 10' and allow them to be maneuvered between the deployed and retracted positions. The main landers 10, 10' are held in the retracted position by latching boxes 13, 13' equipped with hooks 13.1, 13.1' which engage with olives attached to the main landers 10, 10' when the latter reach the retracted position. The release of the hooks 13.1, 13.1' is controlled by hydromechanical unlocking actuators (not shown) which are here integrated into the latching boxes 13, 13'.

[0022] Similarly, hydraulic cylinders (not shown) are attached to hatches 11, 11' and allow them to be maneuvered between an open position for deploying and retracting the main landing gear 10, 10', and a closed position for closing the cargo bays. Hatches 11, 11' are held in the closed position by latching brackets 14, 14' attached to the aircraft structure 1. The latching brackets 14, 14' are equipped with hooks 14.1, 14.1' that engage with locking tabs attached to the hatches 11, 11' when the latter reach the closed position. The release of the hooks 14.1, 14.1' is controlled by hydromechanical release actuators (not shown) which are integrated into the latching brackets 14, 14'.

[0023] The jacks 12, 12' used to maneuver the main landers 10, 10' are controlled by a distributor D 12, D 12' connected to a pressurized fluid source P. The unlocking actuators allowing the locking boxes 13, 13', 14, 14' to be deactivated are controlled by a valve V 13, V 13', V 14, V 14' connected to the pressurized fluid source P.

[0024] The auxiliary landing gear 50 is articulated to the structure of the aircraft 1 around a Y-axis 50 substantially orthogonal to a direction of forward movement of said aircraft 1, between a deployed position illustrated here and a retracted position in which the auxiliary landing gear is received in a compartment that can be closed by hatches 51. A double-acting hydraulic cylinder 52 is coupled to the auxiliary landing gear 50 and allows it to be maneuvered between the deployed and retracted positions. The auxiliary landing gear 50 is held in the retracted position by a latching housing 53 equipped with a hook 53.1 that engages a locking olive attached to the auxiliary landing gear when the latter reaches the retracted position. The release of the hook 53.1 is controlled by a hydromechanical unlocking actuator (not shown) which is integrated into the latching housing 53.

[0025] Similarly, hydraulic cylinders (not shown) are attached to the hatches 51 and allow them to be maneuvered between an open position, enabling the deployment and retraction of the auxiliary landing gear 50, and a closed position, closing the cargo bays. The hatches 51 are held in the closed position by a latching housing 54 attached to the structure of the aircraft 1. The latching housing 54 is equipped with a hook 54.1 that engages locking tabs attached to the hatches 51 when the latter reach the closed position. The release of the hook 54.1 is controlled by a hydromechanical unlocking actuator (not shown), which is integrated into the latching housing 54.

[0026] The cylinder 52 used to maneuver the auxiliary lander 50 is controlled by a distributor D 52 connected to the pressurized fluid source P. The unlocking actuators allowing the locking boxes 53, 54 to be deactivated are controlled by a valve V 53, V 54, connected to the pressurized fluid source P.

[0027] With reference to figures 2 And 3 The main landers 10, 10' comprise a leg 20, 20' having a rigid box 21, 21' in which slides a telescopic rod 22, 22' forming a shock absorber. One end of the rod 22, 22' is provided with an axle on which at least one wheel Rf, Rf' is mounted for rotation. The wheel Rf, Rf' is equipped with a brake which is controlled by a distributor D Rf, D Rf' connected to the pressurized fluid source P.

[0028] The box 21, 21' is generally triangular in shape and has a base that is articulated on the structure of the aircraft 1 by means of two pivots 21.1, 21.2, 21.1', 21.2' with axis X 10 , X 10 ', the apex opposite the base constituting a housing in which the rod 22 slides.

[0029] The base of the casing 21, 21' extends along an axis X 21, X 21' substantially parallel to the axis X 10 and comprises, according to the invention, a cavity 21.3, 21.3' in which a hydraulic accumulator 30, 30' is fully housed. The cavity 21.3, 21.3' and the accumulator are generally cylindrical in shape and extend coaxially along the axis X 21, X 21'. An outer surface of the accumulator 30, 30' is shaped to cooperate with an inner surface of the cavity 21.3, 21.3' so as to achieve a short centering of the accumulator 30, 30' within said cavity 21.3, 21.3'. The outer surface will, for example, comprise three bosses spaced at 120 degrees and forming a substantially cylindrical bearing surface. A centering plate locked by a segment provided at one end of the cavity 21.3, 21.3' ensures the immobilization of the accumulator inside said cavity 21.3, 21.3'.

[0030] The accumulator 30, 30' here has a diameter approximately equal to 120 millimeters and a length approximately equal to 570 millimeters for a useful internal volume approximately equal to 6 liters.

[0031] The end of cavity 21.3, 21.3' opens onto one side of housing 21, 21' and allows the accumulator 30, 30' to be inserted like a removable cartridge into said cavity 21.3, 21.3'. A shutter 31, 31', which can be attached to the accumulator 30, 30', closes cavity 21.3, 21.3' in order to isolate said accumulator 30, 30' from the outside and thus protect it from external damage (water spray, gravel, etc.). It should also be noted that housing 21, 21' is dimensioned to withstand landing forces and that this dimensioning allows it to resist a potential bursting of the accumulator 30, 30'.

[0032] The accumulator 30, 30' forms a reservoir of pressurized fluid connected to: to all or part of the hooking boxes 13, 13' so as to allow the release of the hooks 13.1, 13.1' and therefore the deployment of the main landers 10, 10' in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said hooking boxes 13, 13'; and / or to all or part of the hooking boxes 14, 14' so as to allow the release of the hooks 14.1, 14.1' and therefore the opening of the hatches 11, 11' in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said latching boxes 14, 14'; and / or to all or part of the wheel brakes R f , R f ' so as to allow the braking of said wheels R f , R f ' and therefore the slowing down and keeping the aircraft 1 stopped in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said wheel brakes R f , R f ' . .

[0033] The accumulator 30, 30' thus forms an emergency power source to supply the attachment boxes 13, 13', 14, 14' and / or the wheel brakes R f , R f ' in the event of failure of the aircraft's main power supply circuit 1.

[0034] The accumulator 30, 30' is here connected to the unlocking actuators of the docking boxes 13, 13', 14, 14' via a rigid tube 32, 32' passing through the shutter 31, 31' and which is fixed to the housing 21, 21'. The rigid tube 32, 32' has a first end connected to an output port of the accumulator 30, 30', and a second end connected to a flexible tube 33, 33' allowing the deployment and retraction of the lander 10, 10'.

[0035] The 30, 30' battery can also be connected: to the hooking box 53 so as to allow the release of the hook 53.1 and therefore the deployment of the auxiliary landing gear 50 in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said hooking box 53; and / or to the hooking box 54 so as to allow the release of the hook 54 and therefore the opening of the hatches 51 in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said hooking box 54; and / or to any wheel brakes equipping the landing gear 50 so as to allow the braking of these wheels and therefore the slowing down and holding at rest of the aircraft 1 in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said any wheel brakes.

[0036] The accumulator 30, 30' will then form an emergency power source to supply the hook boxes 53, 54 and / or the wheel brakes of the auxiliary landing gear 50 in the event of failure of the main power supply circuit of the aircraft 1.

[0037] There figure 4 This illustrates a 10" main landing gear, which is simply a variant of the 10, 10' main landing gear. The 10" main landing gear comprises a 20" leg with a rigid 21" box section, the upper end of which is hinged to the aircraft structure 1 along the X-axis 20, and a 22" outrigger arm hinged to a lower end of the 21" box section along a Y-axis 21 substantially orthogonal to the direction of travel of aircraft 1. One end of the 22" outrigger arm has an axle on which the wheels Rf are mounted for rotation. A 23" shock absorber connects the 21" box section to the 22" outrigger arm.

[0038] The 21" box is generally T-shaped, comprising a straight upper part articulated to the aircraft structure 1 by means of a pivot 21.1" with axis X 10, and a straight lower part comprising, according to the invention, a cavity 21.3" in which a hydraulic accumulator 30" is fully housed. The cavity 21.3" and the accumulator 30" are generally cylindrical in shape and extend coaxially along an axis Z 21". An outer surface of the 30" accumulator is shaped to cooperate with an inner surface of the 21.3" cavity so as to achieve short centering of the accumulator within said 21.3" cavity. The outer surface will, for example, include three bosses spaced at 120 degrees and forming a substantially cylindrical bearing surface. A centering plate, locked by a segment formed at one end of the 21.3" cavity, secures the accumulator within said 21.3" cavity.

[0039] The 30'' battery here has a diameter of approximately 100 millimeters and a length of approximately 410 millimeters for a useful internal volume of approximately 3 liters.

[0040] The end of the 21.3" cavity opens onto the lower end of the 21" housing and allows the 30" accumulator to be inserted as a removable cartridge into said 21.3" cavity by dismantling the 22" balance wheel. A shutter (not shown) which can be attached to the 30" accumulator closes the cavity in order to isolate said 30" accumulator from the outside and thus protect it from external aggressions (splashes of water, gravel, etc.).

[0041] Similar to the 30 accumulator, the 30'' accumulator forms a reservoir of pressurized fluid connected to: to all or part of the hooking boxes 13, 13' so as to allow the release of the hooks 13.1, 13.1' and therefore the deployment of the main landers 10, 10' in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said hooking boxes 13, 13'; and / or to all or part of the hooking boxes 14, 14' so as to allow the release of the hooks 14.1, 14.1' and therefore the opening of the hatches 11, 11' in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said latching boxes 14, 14'; and / or to all or part of the wheel brakes R f , R f ' so as to allow the braking of said wheels R f , R f ' and therefore the slowing down and keeping the aircraft 1 stopped in the event of failure of the pressurized fluid source P or of the hydraulic circuit linking said pressurized fluid source P to said wheel brakes R f , R f ' . .

[0042] The 30" accumulator thus forms an emergency power source to power the attachment boxes 13, 13', 14, 14' and / or the wheel brakes Rf, Rf' in the event of failure of the aircraft's main power supply circuit 1.

[0043] The 30" accumulator is connected to the unlocking actuators of the 13, 13', 14, 14' attachment boxes via a rigid pipe passing through the box 21 at the top (at the X axis 10) or at the bottom (at the Y axis 21") and which runs up along the box to be connected to a flexible pipe allowing the deployment and retraction of the 10" lander.

[0044] Such an arrangement of 30, 30', 30" accumulators offers the following advantages: installation of the accumulators 30, 30', 30" closer to the attachment boxes 13, 13', 14, 14' and the wheel brakes R f , R f '; freeing up space and induced constraints on other equipment arranged in the holds receiving the landing gear 10, 10', 10"; compliance with regulatory requirements imposing a physical separation between emergency equipment of a distance of at least 1.54 meters to mitigate the risk of explosion (CS 25.795 certification).

[0045] Preferably, batteries requiring little or no maintenance should be chosen, especially when battery replacement requires dismantling the balance wheel, as is the case for the 10" lander.

[0046] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0047] Although the 30, 30', 30'' accumulators are hydraulic here, they can also be electric and thus take the form of batteries (for example of electrochemical type), particularly when the brake and / or the unlocking system of the landing gear and / or hatches is electric.

[0048] The term "casing" refers to any part of the landing gear capable of absorbing landing forces and enclosing a housing for the accumulator, whether it be the casing of the shock-absorbing cylinder forming the leg itself, a rocker arm, or another element of the landing gear. The auxiliary landing gear 50 may thus include a leg with a casing hinged to the aircraft structure and containing an integrated accumulator.

[0049] The 30, 30' accumulator can be connected to any actuator present in a lander, such as a claw jack used in place of a hook box.

Claims

1. Strut (20, 20', 20'') for aircraft (1) landing gear (10, 10', 10''), comprising a casing (21, 21', 21") arranged to take up landing forces and provided with a cavity (21.3, 21.3', 21.3") in which an energy accumulator (30, 30', 30'') is housed, characterised in that the accumulator is in the form of a removable cartridge which can be inserted in the cavity.

2. Strut (20, 20', 20'') according to claim 1, wherein the accumulator (30, 30', 30'') is hydraulic.

3. Strut (20, 20', 20'') according to claim 1, wherein the accumulator (30, 30', 30'') is an electrochemical battery.

4. Strut (20, 20') according to any one of the preceding claims, comprising a rod (22, 22') forming a damper sliding into the casing, an end of the rod carrying at least one wheel.

5. Strut (20") according to any one of claims 1 to 3, comprising a rocker arm (22') articulated on the casing (21'') and a damper (23'') connecting the rocker arm to the casing, an end of the rocker arm carrying at least one wheel.

6. Aircraft (1) landing gear (10, 10', 10'') comprising a strut (20, 20', 20") according to any one of claims 1 to 5.

7. Aircraft (1) comprising at least one landing gear (10, 10', 10'') according to claim 6.

8. Aircraft (1) according to claim 7, wherein the casing (21, 21', 21'') of the landing gear (10, 10', 10'') is articulated on a structure of the aircraft.

9. Method for emergency deployment of a landing gear (10, 10', 10'') according to claim 6, using the accumulator (30, 30' , 30'') integrated in the strut (20, 20', 20'') of the landing gear.