Aircraft landing gear actuator device.

Abstract

Aircraft landing gear actuator device (0), comprising an electric cylinder (1) having a sleeve (1f), an electric motor (M) and a rod (1b) sliding under the effect of the electric motor (M) between first and second positions of the rod (1b) relative to the sleeve (1f), the electric cylinder (1) having a first length (L1) when the rod (1b) is in its first position and a second length (L2) when the rod (1f) is in its second position. The actuator device comprises a sleeve (2) in which the sleeve (1f) is slidably mounted between a nominal position and an emergency position and a locking system (3) adopting: - a locked configuration where the sleeve (1f) is held in the nominal position; and - an unlocked configuration in which the sleeve (1f) can slide in the sleeve (2). FIGURE OF THE ABSTRACT: [Fig. 1]

Description

Title of the invention: Aircraft landing gear actuator device.

[0001] BACKGROUND OF THE INVENTION

[0002] The present invention relates to the field of actuator devices intended to actuate aircraft landing gear.

[0003] Some aircraft landing gear actuator devices include an electric actuator having a sleeve, an electric motor, and a rod slidably mounted relative to the sleeve under the effect of the electric motor between first and second positions of the rod relative to the sleeve.

[0004] Such an electric cylinder has a variable length between a first length when the rod is in its first position and a second length when the rod is in its second position, the first length being less than the second length.

[0005] The variation in length of the cylinder makes it possible to control a movement of the landing gear, for example to move a landing gear leg between a retracted leg position (making it possible to limit the drag during the flight of the aircraft) and a deployed leg position (making it possible to support the aircraft moving on the ground, the leg partly supporting the weight of the aircraft).

[0006] In the event of a malfunction of the electric motor, the electric cylinder is then blocked, its length being invariable which blocks the landing gear in a given current position.

[0007] This can cause safety problems for the aircraft.

[0008] SUBJECT OF THE INVENTION

[0009] The invention aims in particular to provide a landing gear actuator device making it possible to alleviate all or part of the aforementioned problems of the prior art. Summary of the invention

[0010] To this end, according to the invention, there is provided an aircraft landing gear actuator device, comprising an electric cylinder comprising a sleeve, an electric motor and a rod mounted to slide relative to the sleeve under the effect of the electric motor between first and second positions of the rod relative to the sleeve, the electric cylinder having a first length when the rod is in its first position and a second length when the rod is in its second position, the first length being less than the second length.

[0011] The landing gear actuator device according to the invention is essentially characterized in that it comprises a sheath in which the sleeve of the electric cylinder is mounted to slide between a nominal position and an emergency position and a locking system selectively adopting:

[0012] - a locked configuration in which the locking system maintains the liner in its nominal position, preventing relative sliding between the liner and the sheath; and

[0013] - an unlocked configuration in which the locking system allows the sliding of the sleeve inside the sheath between the nominal position and the emergency position.

[0014] The actuator device according to the invention is particularly advantageous in that it allows, in the event of failure of the cylinder or failure of the cylinder control, to adopt an emergency mode, that is to say an operating mode of the actuator device in which the locking system is in the unlocked configuration to allow the sleeve to slide in the sheath.

[0015] Thus, in the emergency mode, that is to say when the locking system is in the unlocked configuration, the actuator device allows a variation in the length of the actuator device without having to actuate the electric cylinder.

[0016] In such an emergency mode, the variation in length of the actuator device is permitted even if the cylinder, the cylinder motor or the cylinder control exhibit a mechanical or electrical malfunction such that the electric cylinder is blocked or uncontrollable.

[0017] In nominal operating mode, that is to say when the locking system is in the locked configuration, the sleeve of the electric cylinder is held fixedly in the sleeve, and the length variation control of the actuator device is made possible only by controlling the electric motor to vary the length of the electric cylinder.

[0018] In this nominal operating mode, only the variation in length of the electric actuator makes it possible to control the movement of the landing gear relative to a structure of the aircraft which carries the landing gear.

[0019] In emergency mode, that is to say when the locking system is in the unlocked configuration, the cylinder sleeve is then axially detached from the sleeve and the sliding of the cylinder sleeve in the sleeve is then possible.

[0020] Thanks to the invention, the sliding of the cylinder sleeve in the sheath allows a variation in the length of the actuator device independently of the variation in length of the electric cylinder and independently of the operating state of the electric cylinder.

[0021] By means of the actuator device according to the invention, the landing gear leg can be moved from the retracted leg position to the deployed leg position. understood when the electric cylinder of the actuator device can no longer be correctly controlled to adapt its length.

[0022] According to a second aspect, the invention relates to an aircraft landing gear comprising a landing leg, a main pivot around which said leg is pivotally mounted between a retracted leg position and a deployed leg position, the gear comprising an actuator device according to any one of the embodiments of the invention.

[0023] More particularly, said aircraft landing gear actuator device according to the previous embodiment is arranged in such a way that: - when the sleeve is in the nominal position with the cylinder rod placed in one of said first or second positions relative to the sleeve, then the landing gear leg is in the retracted leg position; and so that

[0024] - the landing gear leg is in the extended leg position when the the cylinder rod is placed in any position between said first and second positions and the sleeve is placed at a distance from the nominal position, between the nominal position and the emergency position.

[0025] This embodiment is particularly advantageous in that it implies that the sliding amplitude of the sleeve in the sheath is provided so that even if the rod of the electric cylinder is kept locked in that of the first or second positions which corresponds to the retracted leg position when the sleeve is in the nominal position, the sleeve can nevertheless be slid in the sheath to a position of the sleeve (for example the emergency position) such that the actuator device authorizes the movement of the landing leg from the retracted leg position to the deployed leg position.

[0026] Thanks to the invention, by placing the locking system of the actuator device in the unlocked configuration, the normal amplitude of movement of the landing gear leg remains total between the retracted leg and deployed leg positions, regardless of the current length adopted by the electric cylinder and this even if this current length of the cylinder begins to vary involuntarily (for example under the effect of an uncontrolled command of the cylinder).

[0027] As long as the locking system is maintained in the unlocked configuration, the liner remains free to slide in the sheath, allowing a full range of movement of the leg between its retracted and deployed positions.

[0028] The invention greatly improves the safety of the aircraft since it allows, in the event of an operating incident of the jack, to adopt an emergency mode allowing the leg to be deployed, regardless of the operating state of the electric jack and the control of the electric jack.

[0029] According to another aspect, the invention relates more generally to an aircraft comprising an actuator device according to any one of the embodiments of the actuator device according to the invention.

[0030] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention. Brief description of the drawings

[0031] Reference will be made to the accompanying drawings, among which:

[0032] [Fig-1] [Fig.l] shows the actuator device 0 according to the invention while its sleeve If is in nominal position and that the rod of the cylinder 1b is in its first position, the cylinder here having a length Ll, the length of the actuator measured between its ends 1a and 2a being here suitable for maintaining the landing leg in a position called retracted leg;

[0033] [Fig.2] [Fig.2] shows the actuator device 0 according to the invention while the sleeve If has been released and is free to slide relative to the sleeve 2, the sleeve If here being moved away from its nominal position and it is between the nominal position and the emergency position, the rod of the cylinder 1b being in an intermediate position between first and second positions of the rod 1b relative to the sleeve If, ​​the freedom of sliding of the sleeve If relative to the sleeve allowing (as will be seen later) the passage of the landing gear leg from the retracted leg position to the deployed leg position under the effect of gravity exerted on the leg alone (the actuator device 0 is here in emergency mode);

[0034] [Fig.3] [Fig.3] illustrates an aircraft 100 comprising a landing gear 30 comprising right and left main landing gears 30, 31 and a front landing gear 32, each of these gears comprising its own gear actuator device 0 according to the invention (for reasons of clarity, only the actuator device 0 of the right main landing gear 30 is shown, the leg of this gear 30 being in its deployed position). DETAILED DESCRIPTION OF THE INVENTION

[0035] With reference to Figures 1 to 3, the invention essentially relates to an actuator device 0 for landing gear 30 of aircraft 100.

[0036] The invention also relates to the landing gear 30 comprising an actuator device 0 according to any one of its embodiments.

[0037] More particularly, as can be understood from [Fig. 3], the landing gear 30 of aircraft 100 comprises a landing gear leg 30a, a main pivot 30b around which said leg 30a is pivotally mounted between a retracted leg position and a deployed leg position.

[0038] The invention also relates to an aircraft 100 comprising one or more landing gears 30 comprising the actuator device 0 according to the invention.

[0039] The actuator device 0 according to the invention comprises an electric cylinder 1 comprising a sleeve If, ​​an electric motor M and a rod 1b mounted to slide relative to the sleeve If under the effect of the electric motor M between first and second sliding positions of the rod 1b relative to the sleeve If.

[0040] The motor M, which is here a motor comprising a rotor and a stator, is here mechanically connected to the rod If by means of a screw / nut system M10 such that rotation of the rotor of the motor M causes a relative movement between the screw and the nut of the screw / nut system and an axial movement of the rod 1b relative to the sleeve If along an axis AA.

[0041] This axis AA is a longitudinal axis of a sheath 2 in which the sleeve If is located.

[0042] Here the M10 screw and nut are symbolized in dotted lines on either side of the AA axis.

[0043] In the present case, the screw extends over a major longitudinal portion of the jack 1, the screw penetrating into the nut to drive it in longitudinal displacement along the axis AA as soon as the screw is set in rotation under the effect of the motor M.

[0044] The nut is itself mechanically connected to the rod 1b of the jack in such a way that the nut and the rod of the jack 1b move together along the axis AA and along the screw (the screw extends into a longitudinal internal recess of the rod 1b).

[0045] Alternatively, it could be arranged so that the nut of the screw / nut system M10 is rotated by the motor M10 and the screw is fixedly connected to the rod 1b of the jack, the nut then being secured to the motor M along the axis AA while the screw and the rod 1b slide together along the axis AA as a function of the rotation of the nut.

[0046] The electric cylinder 1 has a first length L1 when the rod 1b is in its first position and a second length L2 when the rod If is in its second position.

[0047] The first length L1 is less than the second length L2.

[0048] As seen in [Fig.l], the first and second lengths Ll, ​​L2 are measured between terminal ends of the electric cylinder 1.

[0049] The first length L1 of the electric cylinder 1 corresponds to the length L1 of the cylinder 1 when the rod 1b is in its first position relative to the sleeve If, ​​that is to say when the electric cylinder is compacted.

[0050] The second length L2 of the electric cylinder 1 corresponds to the length L2 of the cylinder 1 when the rod 1b is in its second position relative to the sleeve If, ​​that is to say when the electric cylinder is extended.

[0051] The first and second positions of the rod 1b relative to the sleeve If are illustrated in [Fig.l], the second position of the terminal end of the rod 1b being shown diagrammatically in dot-and-dash lines with the second length L2 being greater than the first length LL

[0052] The jack 1 can, as illustrated in [Fig.2], adopt any length in intermediate Ll' between said first and second lengths Ll, ​​L2, this cylinder being a linear and telescopic electric cylinder.

[0053] As illustrated in Figures 1 and 2, the actuator device 0 according to the invention also comprises: - said sheath 2 in which the sleeve If of the electric cylinder 1 is slidably mounted between a nominal position and an emergency position; and - a locking system 3.

[0054] This locking system 3 is arranged to selectively adopt: - a locked configuration, illustrated in [Fig.l], in which the locking system 3 maintains the sleeve If in its nominal position by preventing relative sliding between the sleeve If and the sheath 2; and - an unlocked configuration, illustrated in [Fig.2], in which the locking system 3 allows the sleeve If to slide inside the sheath 2 between the nominal position and the emergency position.

[0055] More particularly, the locking system 3 is arranged in such a way that when it is in the unlocked configuration, the sleeve If is then free to slide in the sheath 2 between the nominal position and the emergency position.

[0056] In [Fig.2], the current length of the jack 1 is a length Ll' which is included between said first and second lengths L1, L2, the locking system 3 being in the unlocked configuration, the sleeve If being in an intermediate position relative to the sheath 2, at a distance from the nominal position and between the nominal and emergency positions.

[0057] The actuator device 0 is particularly advantageous in that it allows, in the event of failure of the cylinder 1 or failure of the cylinder control, to adopt an emergency mode, that is to say an operating mode of the actuator device 0 in which the locking system is in the unlocked configuration to allow free sliding of the sleeve If in the sheath 2.

[0058] Thus, in the emergency mode of the actuator device 0 (i.e. when the locking system is in the unlocked configuration, as in [Fig.2]), this device 0 allows a variation in the length of the actuator device without having to actuate the electric cylinder 1.

[0059] In such an emergency mode, it is therefore not necessary to be concerned with the state of the motor M of the jack 1, the general state of the jack 1, from both a mechanical and electrical point of view, or the control of the jack 1.

[0060] The variation in length of the actuator device 0 in emergency mode is therefore independent of the state of the motor M or of the cylinder 1 since the sleeve If is axially detached from the sheath 2.

[0061] As understood from figures 1 and 2, the motor is preferably placed inside the jacket which increases the compactness of the device 0 while preserving the motor M.

[0062] One end 1a of the rod 1b has a first attachment point 1a intended to be pivotally assembled with an attachment zone of an aircraft landing gear leg 30a.

[0063] This attachment point 1a is here formed from a widened portion of the rod having a central bore suitable for receiving a pivot for connection with the leg of the landing gear.

[0064] One end of the sheath 2 which is distal to the rod 1b has a second attachment point 2a intended to be pivotally assembled with a structural zone of the aircraft 100.

[0065] This second attachment point 2a is here formed from an end portion of the sheath which is locally widened and which has a central bore suitable for receiving a connecting pivot with an area of ​​the structure of the aircraft.

[0066] The actuator device 0 is such that: - when the locking system 3 is in the locked configuration (as is the case in [Fig.l]) and the motor M is supplied with a signal Sx, then the motor M forces a displacement of the first attachment point 1a relative to the second attachment point 2a by sliding the rod 1b relative to the sleeve If; and that - when the locking system 3 is in the unlocked configuration then a movement of the first attachment point 1a relative to the second attachment point 2a is permitted by sliding of the sleeve 1f relative to the sheath 2 under the effect of a force of bringing together or separating said first and second attachment points 1a, 2a relative to each other.

[0067] The variation in spacing between the first attachment point 1a formed at one end of the rod 1b of the jack 1 and the second attachment point 2a formed at one end of the sleeve 2 can be done:

[0068] - Either solely by variation of the length of the electric jack 1 under the effect of the engine M, when the locking system 3 is in the locked configuration with the sleeve If held in the nominal position; - Either by displacement of the sleeve If relative to the sheath 2 under the effect of forces applied between the first and second attachment points 1a, 2a, while the locking system 3 is in the unlocked configuration with the sleeve If free to slide into its nominal and emergency positions.

[0069] As soon as the locking system 3 is in the unlocked configuration, that is to say that the actuator device is in emergency mode, then the actuation of the motor M as well as the current length LU adopted by the jack 1 have no effect on the variation in spacing between the first attachment point 1a and the second attachment point 2a.

[0070] The forces applied between these first and second attachment points 1a, 2a being here sufficient to vary the spacing between these attachment points 1a, 2a.

[0071] The landing gear leg, to the extent that it is otherwise free to pivot around the main pivot 30b, can then move towards its deployed position by controlling the variation in spacing between the attachment points 1a, 2a.

[0072] The aircraft landing gear actuator device is arranged so that:

[0073] - when the sleeve If is in the nominal position with the rod 1b of the cylinder 1 placed in one of said first or second positions relative to the sleeve If, ​​then the leg 30a of the landing gear 30 is in the retracted leg position; and so that

[0074] - the leg 30a of the landing gear 30 can be in the leg position deployed when the rod 1b of the cylinder 1 is placed in any position located between said first and second positions and the sleeve If is placed at a distance from the nominal position, between the nominal position and the emergency position.

[0075] In summary, in emergency mode, that is to say when the locking system 3 is in the unlocked configuration, the landing gear 30 can then deploy freely under the effect of gravity, and thus cause a variation in the length of the actuator device by sliding its sleeve in the sheath.

[0076] When the locking system is in the unlocked configuration, the actuator device allows the landing gear leg to move from the retracted leg position to the deployed leg position.

[0077] Under the effect of gravity, the leg pivots towards its deployed leg position and the length of the actuator device then begins to vary under the effect of forces applied by the landing leg 30 to the actuator device.

[0078] Preferably, the actuator device 0 comprises a control connector 2d of the electric cylinder 1 carried by the sheath 2.

[0079] The control connector 2d comprises a first group G1 of electrical contacts for powering the motor and possibly for controlling it or measuring characteristics of its state.

[0080] The electric cylinder 1 comprises a second group G2 of electrical contacts.

[0081] At least some of the electrical contacts of the first group G1 of electrical contacts are:

[0082] - electrically connected to at least some of the electrical contacts of the second group G2 of electrical contacts when the jacket is in nominal position relative to the sheath (as in [Fig.l]); and are

[0083] - electrically disconnected from said electrical contacts of the second group G2 of electrical contacts when the jacket is moved away from its nominal position towards the emergency position (as in [Fig.2]).

[0084] The disconnection of contacts of the first and second groups Gl, G2, when the sleeve If is moved to its emergency position makes it possible to electrically decouple the motor M of the jack 1 from the control connector 2d.

[0085] This decoupling between contacts of groups G1 and G2 makes it possible to avoid a risk of damage to motor M when device 0 is in emergency mode.

[0086] This embodiment makes it possible, for example, to limit the risk of electromechanical incident by transmission of electrical power from or to the electric cylinder.

[0087] The electrical state of the control system which makes it possible to control the cylinder 1 / the motor M therefore has no effect on the state of the cylinder since the contacts connecting the cylinder 1 to the control connector 2d are disconnected by the sliding of the sleeve If towards its emergency position.

[0088] More particularly, as is apparent from Figures 1 and 2, some of said electrical contacts are pins 2c and at least some other of said electrical contacts are female sockets 1c.

[0089] The actuator device 0 comprises several pairs Pxl, Px2 of electrical contacts, each given pair of electrical contacts comprising a pin 2c and a female socket le which are:

[0090] - nested when the If sleeve is in its nominal position to establish a electrical connection through the given pair of electrical contacts; and which are - disjointed from each other when the sleeve If is moved from its nominal position to its emergency position to prevent any electrical connection through the given pair Pxl, Px2 of electrical contacts.

[0091] The actuator device 0 further comprises an anti-rotation device RI, R2 preventing any rotation of the sleeve If of the electric cylinder 1 inside the sheath 2 at least when the sleeve If of the electric cylinder 1 is in its nominal position relative to the sheath 2.

[0092] Thus, the anti-rotation device RI, R2 makes it possible to maintain an alignment between the electrical contacts of the first and second groups Gl, G2 in order to be able to maintain the electrical connections between the contacts of the first and second groups of contacts at least as long as the sleeve If is in its nominal position.

[0093] More particularly, the anti-rotation device RI, R2 is arranged so that the passage of the sleeve If of the electric cylinder 1 into the nominal position is authorized only if said sleeve If is in a predetermined orientation around a longitudinal axis AA of said sleeve 2 in which electrical connections between electrical contacts of the first and second groups Gl, G2 are authorized.

[0094] Thus, the anti-rotation device RI, R2 can be used as a key to make so that when the cylinder 1 is mounted in the sleeve, the cylinder sleeve can only adopt a single orientation allowing contact between the electrical contacts of the first and second groups G1, G2.

[0095] This makes it easier to assemble the jack in the sleeve 2 while ensuring that the electrical contacts are not damaged and that there is an electrical connection of the motor M that conforms to a predetermined connection plan.

[0096] Thus, even after switching device 0 to its emergency mode, maintenance teams can easily reconnect motor M by simply replacing the cylinder sleeve in its nominal position with respect to sleeve 2.

[0097] The anti-rotation device may for example comprise male R2 and female RI shapes which are complementary to one another and which can be fitted into one another only when the sleeve If is in said predetermined orientation position relative to the sheath, this orientation position preferably being unique.

[0098] For example, as shown diagrammatically in Figures 1 and 2, the male shape R2 may be a lug carried by the sheath 2, this male shape being oriented towards a zone for receiving the jacket If in the sheath.

[0099] The female form RI may be a groove or a perforation formed on an external surface of the liner.

[0100] This female form RI is arranged to be able to slide relative to the lug R2 by translation of the jacket If relative to the sheath 2 along a longitudinal axis AA of said sheath 2, while the lug R2 is in lateral abutment against at least one of the edges of the groove or perforation RL.

[0101] It would of course be possible to reverse these male and female shapes, the male shape R2 being able to be formed on the external surface of the sleeve while the female shape RI, complementary to the male shape RI, could be formed in the sheath by being oriented towards a zone for receiving the sleeve If in the sheath 2.

[0102] As understood from Figures 1 and 2, a first chamber 2h can be defined in the sheath 2, the first chamber 2h having a variable volume when the sleeve If slides relative to the sheath 2.

[0103] A first vent 2el is formed between the first chamber 2h and an external zone of the actuator device to allow the passage of fluid between the first chamber 2h and the external zone of the actuator device to generate a braking force for the movement of the jacket If relative to the sheath 2.

[0104] This braking is done by a loss of load in the flow of fluid circulating through said at least one first vent 2el during the sliding of the sleeve If in the sheath 2.

[0105] Preferably, a second vent 2e2 is formed between the first chamber 2h and the external area of ​​the actuator device to allow a second fluid passage between the first chamber 2h and the external area of ​​the actuator device.

[0106] The first sleeve If here comprises a radially widened annular portion Ifl which supports a first seal Ij extending all around the radially widened annular portion Ifl and sliding in a sealed manner against an internal surface of the sheath 2 which delimits said first chamber 2h.

[0107] The first seal Ij is arranged in such a way that on a first part of a sliding path of the liner If relative to the sheath 2 the two vents 2e 1, 2e2 are placed on the same side of the first seal Ij and that on a second part of the sliding path distinct from said first part of the sliding path, the first seal Ij is located between said first and second vents lel, le2 so as to obtain a total fluid passage section between the first chamber and the external zone of the actuator device which is greater on the first part of the sliding path of the liner If than it is on the second part of the sliding path of the liner If.

[0108] In this way, said braking force of the movement of the jacket If with respect to the sheath 2 generated by the passage of fluid between the first chamber and the external zone of the actuator device is lower on the first part of the trajectory than it is on the second part of the trajectory.

[0109] In the present case, when the jacket is moved in the sheath 2 in a direction in which the actuator device is extended, the first part of the trajectory takes place at the start of the extension of the device and the second part of the trajectory takes place at the end of the extension of the device.

[0110] For a given constant speed of movement of the liner in the sheath, the braking force of the movement of the liner If with respect to the sheath 2 is greater on the second part of the trajectory than it is on the first part of the trajectory, while the actuator device lengthens.

[0111] This allows the actuator device in emergency mode to quickly extend while the sleeve is moving on the first part of the trajectory and then to slow down on the second part of the trajectory so as to limit an intensity of shock when the sleeve reaches the end of its travel in the sleeve, i.e. when the landing gear leg approaches its deployed leg position.

[0112] The vents 2el, 2e2 thus allow rapid deployment of the leg followed by progressive damping of the speed of deployment of the leg as it approaches its deployed leg position.

[0113] Thus, the actuator device 0 according to the invention placed in an emergency mode allows the free deployment of the leg 30a of the landing gear 30 while limiting the risk of shocks when the leg approaches its deployed leg position.

[0114] More precisely, a second seal 2j is fixed in a bore of the sleeve 2 and extends around an area of ​​the sleeve If placed in front of the portion Ifl of the sleeve If which is radially widened.

[0115] Thus, the volume of the first chamber 2h decreases when the sleeve If slides in the sheath in a direction allowing the elongation of the actuator device 0.

[0116] Preferably, in order to amplify the difference between the braking forces on the first and second parts of the sliding trajectory of the liner If in the sheath 2, the fluid passage section through the first vent 2e 1 is less than the fluid passage section through the second vent 2e2.

[0117] We will now present a particular embodiment of the locking system 3 implemented in Figures 1 and 2.

[0118] This locking system 3 comprises: - a locking finger 3a movable between a locking position of the liner If in said nominal position of the liner and an unlocking position in which said at least one locking finger 3a is moved away from the liner If to allow the liner If to slide relative to the sheath 2.

[0119] The locking finger 3a in the locking position being arranged to extend into a recess lf2 of the sleeve If placed in the nominal position of the sleeve.

[0120] The locking system 3 also includes: - an elastic means 3al for returning the locking finger 3a to the unlocking position; and

[0121] - a locking ring 3b slidably mounted along and around a portion central part of the sheath 2 between a position for holding the locking finger 3a in its locking position and a position for releasing the locking finger 3a in which the locking ring 3b allows the locking finger 3a to move towards its unlocking position.

[0122] The sheath 2 comprises a central portion and an external portion which together define an annular space in which the ring 3b slides between its holding and release positions.

[0123] A third annular seal 3j extends between an internal surface of the ring and the central portion of the sheath to allow sealing sliding between this ring 3b and the central portion of the sheath 2.

[0124] A fourth annular seal 4j extends between an external surface of the ring 3b and the external portion of the sheath to allow sealing sliding between this external surface of the ring 3b and the annular external portion of the sheath 2 in which the ring 3b slides.

[0125] Thus, when the ring 3b slides relative to the sheath 2, the joints Ij and 2j allow the fluid contained in chamber 2h to escape only via vents 2e 1 and 2e2.

[0126] The seals 3j and 4j make it possible to limit contamination of the locking system by agents external to the actuator device.

[0127] In [Fig. 1], the locking finger 3a is in the locking position, the locking ring 3b being in the position for holding the locking finger 3a to prevent it from moving to the unlocking position.

[0128] In [Fig.2], the locking finger 3a is in the unlocked position under the effect of the thrust generated by the elastic means 3al for returning the locking finger 3a to the unlocked position, the locking ring 3b then being in its position for releasing the locking finger 3a.

[0129] The locking system 3 also comprises: - a return spring 3d of the locking ring 3b arranged to return the locking ring 3b towards the release position of the locking finger 3a; and - an electromechanical actuator 3c provided with receivers of a control signal 3f.

[0130] The electromechanical actuator 3c is adapted to switch from a func nominal operation to an emergency operating configuration as a function of said control signal 3f.

[0131] As illustrated in [Fig.l], the electromechanical actuator 3c in the nominal operating configuration is mechanically engaged with the locking ring 3b to hold the ring 3b in the position of holding the locking finger 3a in its locking position.

[0132] As illustrated in [Fig.2], the electromechanical actuator 3c in the emergency operating configuration authorizes the passage of the ring from the position for holding the locking finger 3a to the position for releasing the locking finger 3a in which the locking ring 3b authorizes the passage of the locking finger 3a to its unlocking position.

[0133] As seen in Figures 1 and 2, the actuator device comprises several locking fingers 3a regularly distributed around the sleeve If.

[0134] These fingers are moved together under the effect of the movement of the locking ring 3b from its holding position where it holds all the locking fingers 3a in their respective locking positions to its position of release of each of the locking fingers.

[0135] The ring 3b comprises an internal annular chamfer 3b 1 arranged to come into contact with each at least one locking finger in order to push it towards its position for locking the liner when the ring 3b is moved from the position for releasing the locking finger 3a towards the position for holding the locking finger 3a.

[0136] Preferably, the device 0 comprises a visual indicator T observable from a peripheral zone of the actuator device 0 which is observable in only one of said release position or holding position of the locking finger 3a that the ring can adopt.

[0137] In the present case, this visual indicator is constituted by an external portion of the ring 3b which is visible when the ring is in the release position, as illustrated in [Fig.2].

[0138] This visual indicator T, which is visible here only after the actuator device 0 has switched to the emergency configuration, allows a person carrying out maintenance to identify that the electromagnetic actuator 3c has been commanded to authorize the switch of the actuator device 0 to the emergency mode, the ring being pushed towards its release position.

[0139] Under the effect of the spring 3d, the ring remains in this release position even if relative movements between the sleeve If and the sheath 2 have occurred after the actuator device 0 has switched to emergency mode.

[0140] This visual indicator T is valuable for maintenance teams who can thus check the correct operation of the actuator device 0 and the landing gear 30 before repositioning the actuator device 0 in its nominal mode.

[0141] The visual indicator T, depending on whether it is visible or not from outside the device 0, serves as a memory of a switch to emergency mode.

[0142] To allow the actuator device 0 to return to its nominal mode, the maintenance personnel must first replace the sleeve If in its nominal position so as to reestablish the electrical connections between the electric cylinder 1 and the control connector 2d, then they must force the ring 3b to slide from its release position (visible in [Fig.2]) to its position for holding the locking finger 3a in the locking position of the sleeve (If) in the nominal position of the sleeve (the holding position adopted by the ring is visible in [Fig.l]).

[0143] During this movement of the ring 3b towards its position for holding the locking finger 3a, the internal annular chamfer 3b 1 pushes each of the locking fingers towards its position for locking the liner in its nominal position.

[0144] The landing gear 30 preferably comprises a leg lock Vx 30a arranged to selectively adopt: - a leg locking configuration in which the Vx lock holds the leg in the retracted leg position by preventing movement of the leg to the extended leg position; and - a leg release configuration in which the Vx lock allows the leg to move from the retracted leg position to the deployed leg position.

[0145] Such a lock Vx is for example coupled to a hatch of the landing gear 30 which remains closed to keep the leg 30a retracted in an internal volume of the aircraft fuselage and which is open when the lock Vx goes into the unlocking configuration to allow the leg 30 to exit from the internal volume of the fuselage so that the leg can move to the deployed leg position.

[0146] The landing gear according to the invention 30 comprises a control unit UC arranged to selectively adopt a nominal control mode and an emergency control mode.

[0147] The control unit UC in nominal control mode is arranged to generate a control signal for switching the lock Vx to the unlocking configuration, so that the lock Vx authorizes the leg to move to the deployed leg position, followed by the landing gear control signal Sx transmitted to the motor M to move the rod 1b of the cylinder 1 to its second position (the second position of the rod 1b being the position adopted by the rod 1b when the leg 30a of the landing gear 30 is in the deployed position and the sleeve If is maintained in the nominal position with respect to the sheath 2).

[0148] The control unit UC in emergency control mode is arranged to generate the control signal for switching the lock Vx to the unlocked configuration, so that the lock authorizes the leg 30 to move to the deployed leg position, followed by a signal 3f for controlling the locking system 3 of the actuator device 0 such that the locking system 3 switches to its unlocked configuration to authorize the free sliding of the sleeve If relative to the sheath 2.

[0149] The leg 30 subjected to gravity generates forces on the actuator device 0, the length of which begins to change since the sleeve If is axially detached from the sheath.

[0150] In the event that the screw / nut system is reversible, a forced extension of the actuator device 0 by deployment of the landing leg 30 under the effect of gravity could cause the rotation of the motor M which would then generate electrical power at the connectors of the motor M.

[0151] For this purpose, connectors of the motor M can be electrically connected to one or preferably several electrical heating resistors such that in the event of generation of electrical power generated by the motor M, said resistor(s) transform this electrical power generated by the motor into thermal energy which can be dissipated for example via a heat exchange surface in contact with this or these electrical heating resistors.

[0152] Thanks to the actuator device 0 which allows, in emergency mode, the sliding of the cylinder sleeve with respect to the sheath, the risk of high electrical power being generated by the motor M under the effect of the elongation of the actuator device 0 is minimized.

[0153] Therefore the amount of energy generated by the motor and having to be dissipated is minimized.

[0154] In summary, the actuator device 0 is arranged to adopt a nominal operating mode and an emergency operating mode.

[0155] In the nominal operating mode of the actuator device, the sleeve If of the cylinder 1 is locked in its nominal position relative to the sleeve 2 under the effect of the locking system 3 in the locked configuration, the movement of the landing gear leg between the retracted leg and deployed leg positions is done exclusively by actuation of the motor M of the electric cylinder 1 by a landing gear control signal Sx.

[0156] This signal Sx is transmitted to the motor M via the control connector 2d of the electric cylinder 1 and via the electrical contacts connecting the connector 2d to the motor of the cylinder M while the sleeve If of the cylinder 1 is in its nominal position relative to the sleeve 2.

[0157] In emergency operating mode of the actuator device, the sleeve If of the cylinder 1 is released from its nominal position relative to the sleeve 2 under the effect of the locking system 3 moving into the unlocked configuration.

[0158] The sleeve If can then slide freely in the sheath 2 between its nominal and emergency positions depending on the movement of the leg 30a of the landing gear between the retracted leg and deployed leg positions.

[0159] As soon as the locking system 3 is in the unlocked configuration, the movement of the leg is carried out, without the need to actuate the motor M, by sliding the sleeve in the sheath under the effect of gravity which is applied to the leg 30a.

[0160] An advantage of this solution is that when the actuator device is in emergency operating mode the elongation of the actuator device can vary even when the motor is blocked.

[0161] The deployment of the leg 30 is always possible in emergency mode and this even if the screw / nut system connecting the motor M to the rod 1b is not reversible or if an element of the kinematic chain driving the rod 1b relative to the sleeve If is blocked.

[0162] Of course, the invention is not limited to the embodiments described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0163] In particular, although the locking system 3 presented comprises one or more locking fingers to selectively hold the liner in its nominal position, it could be envisaged to replace these fingers with another selective locking system such as a claw locking system coming separately. selectively secure the sleeve to the sheath depending on whether one wishes to move the locking system from its locked configuration to its unlocked configuration where the sleeve can slide freely in the sheath 2.

[0164] It could also be imagined that the solenoid 3c could act directly in place of the locking fingers 3a by doing away with the locking ring.

[0165] Other variations could also be considered for switching the locking system to its unlocked configuration.

[0166] For example, while the release of the locking fingers 3a is here initiated by a signal 3f transmitted to the solenoid, it could alternatively be arranged so that the transition of the locking system 3 to its unlocked configuration is initiated by any other device which makes it possible to carry out the same unlocking command.

[0167] For example, the electromechanical actuator could be replaced by a mechanical actuator actuated mechanically, for example by cable, this mechanical actuator being able to act: Either on a ring actuating mechanism to control its passage from the holding position to the release position; Either directly on the locking ring 3b to push it towards its release position.

[0168] It is also possible to envisage a cable which would act directly on a locking finger 3a, without requiring the locking ring 3b.

Claims

Claims

1. Aircraft landing gear actuator device (0), comprising an electric cylinder (1) comprising a sleeve (If), an electric motor (M) and a rod (1b) mounted to slide relative to the sleeve (If) under the effect of the electric motor (M) between first and second positions of the rod (1b) relative to the sleeve (If), the electric cylinder (1) having a first length (L1) when the rod (1b) is in its first position and a second length (L2) when the rod (If) is in its second position, the first length (L1) being less than the second length (L2),characterized in that the actuator device comprises a sheath (2) in which the sleeve (If) of the electric cylinder (1) is mounted to slide between a nominal position and an emergency position and a locking system (3) selectively adopting: - a locked configuration in which the locking system (3) maintains the sleeve (If) in its nominal position by preventing relative sliding between the sleeve (If) and the sheath (2); and - an unlocked configuration in which the locking system (3) allows the sleeve (If) to slide inside the sheath (2) between the nominal position and the emergency position.,

2. Actuator device according to claim 1, in which a control connector (2d) of the electric cylinder (1) is carried by the sheath (2), the control connector (2d) comprising a first group (G1) of electrical contacts for supplying the motor, the electric cylinder (1) comprising a second group (G2) of electrical contacts, at least some of the electrical contacts of the first group of electrical contacts being electrically connected to at least some of the electrical contacts of the second group (G2) of electrical contacts when the sleeve is in the nominal position relative to the sheath and being electrically disconnected from said electrical contacts of the second group of electrical contacts when the sleeve is moved away from its nominal position towards the emergency position.

3. An actuator device (0) according to claim 2, wherein some of said electrical contacts are pins (2c) and at least some other of said electrical contacts are sockets (1e), the actuator device (0) comprising several pairs (Pxl, Px2) of electrical contacts, each given pair of electrical contacts comprising a pin (2c) and a socket (1e) which are nested when the jacket (If) is in its nominal position to establish an electrical connection through the given pair of electrical contacts and which are disjointed from each other when the jacket (If) is moved away from its nominal position to its emergency position to prevent any electrical connection through the given pair (Pxl, Px2) of electrical contacts.

4. Landing gear actuator device (0) according to any one of claims 1 to 3, further comprising an anti-rotation device (RI, R2) preventing any rotation of the sleeve (If) of the electric cylinder (1) inside the sheath (2) at least when the sleeve (If) of the electric cylinder (1) is in its nominal position relative to the sheath (2).

5. Landing gear actuator device (0) according to claim 4, wherein the anti-rotation device (RI, R2) is also arranged so that the passage of the sleeve (If) of the electric cylinder (1) into the nominal position is authorized only if said sleeve is in a predetermined orientation around a longitudinal axis (AA) of said sleeve (2) in which electrical connections between electrical contacts of the first and second groups (Gl, G2) are authorized.

6. Landing gear actuator device (0) according to any one of claims 1 to 5, wherein one end (la) of the rod (1b) has a first attachment point (la) intended to be pivotally assembled with an attachment zone of an aircraft landing gear leg (30a) and one end of the sleeve which is distal with respect to the rod (1b) has a second attachment point (2a) intended to be pivotally assembled with a structural zone of the aircraft, the actuator device being such that - when the locking system (3) is in the locked configuration and the motor (M) is powered then the motor forces a movement of the first attachment point (la) relative to the second attachment point (2a) by sliding the rod (1b) relative to the sleeve (If);and that - when the locking system (3) is in the unlocked configuration then a movement of the first attachment point (la) relative to the second attachment point (2a) is authorized by sliding of the sleeve (If) relative to the sheath (2) under the effect of a force of bringing together or separating said first and second points; attachment (la, 2a) relative to each other.

7. Landing gear actuator device (0) according to any one of claims 1 to 6, in which a first chamber (2h) is defined in the sleeve (2), the first chamber (2h) having a variable volume during the sliding of the sleeve (If) relative to the sleeve (2), a first vent (2e 1) being formed between the first chamber (2h) and an external zone of the actuator device to allow the passage of fluid between the first chamber and the external zone of the actuator device to generate a braking force on the movement of the sleeve (If) relative to the sleeve (2).

8. Landing gear actuator device (0) according to claim 7, in which a second vent (2e2) is formed between the first chamber (2h) and the external zone of the actuator device to allow a second fluid passage between the first chamber and the external zone of the actuator device, the first sleeve (If) comprising a radially enlarged annular portion (If 1 ) which supports a first seal (Ij) extending all around the radially enlarged annular portion (If 1 ) and sliding in a sealed manner against an internal surface of the sheath (2) which delimits said first chamber (2h),said first seal (Ij) being arranged in such a way that on a first part of a sliding path of the liner (If) relative to the sheath (2) the two vents are placed on the same side of the first seal and that on a second part of the sliding path distinct from said first part of the sliding path, the first seal (Ij) is located between said first and second vents (lel, le2) so as to obtain a total fluid passage section between the first chamber and the external zone of the actuator device which is greater on the first part of the sliding path of the liner (If) than it is on the second part of the sliding path of the liner (If).,

9. Actuator device according to any one of claims 1 to 8, in which the locking system (3) comprises: - a locking finger (3a) movable between a locking position of the sleeve (If) in said nominal position of the sleeve and an unlocking position in which said at least one locking finger (3a) is spaced from the sleeve (If) to allow the sliding of the sleeve (If) relative to the sheath (2), the locking finger (3a) in the locking position being arranged to extend into a recess (lf2) of the sleeve placed in the nominal position of the sleeve; - an elastic means (3al) for returning the locking finger (3a) to the unlocking position; - a locking ring (3b) mounted to slide along and around a central portion of the sheath (2) between a position for holding the locking finger (3a) in its locking position and a position for releasing the locking finger (3a) in which the locking ring (3b) allows the locking finger (3a) to pass to its unlocking position; - a return spring (3d) of the locking ring (3b) arranged to return the locking ring (3b) to the position for releasing the locking finger (3a);and - an electromechanical actuator (3c) provided with receivers of a control signal (3f), the electromechanical actuator (3c) being adapted to pass from a nominal operating configuration to an emergency operating configuration as a function of said control signal (3f), the electromechanical actuator (3c) in the nominal operating configuration being mechanically engaged with the locking ring (3b) to maintain the ring in the position for holding the locking finger (3a) in its locking position and the electromechanical actuator (3c) in the emergency operating configuration authorizing the passage of the ring from the position for holding the locking finger (3a) to the position for releasing the locking finger (3a) in which the locking ring (3b) authorizes the passage of the locking finger (3a) to its unlocking position.;

10. Actuator device according to claim 9, comprising a visual indicator observable from a peripheral zone of the actuator device which is observable in only one of said release position or holding position of the locking finger (3a) which can be adopted by the ring (3b).

11. Actuator device according to any one of claims 1 to 10, in which the motor (M) is mechanically connected to the rod (If) via a screw / nut system (M10) such that rotation of the motor (M) causes a relative movement between the screw and the nut of the screw / nut system and a movement of the rod (1b) relative to the sleeve (If).

12. Landing gear (30) of an aircraft (100) comprising a landing gear leg (30a), a main pivot (30b) around which said leg (30a) is pivotally mounted between a retracted leg position and a deployed leg position, the landing gear comprising an actuator device according to any one of claims 1 to 11.

13. An aircraft (100) landing gear (30) according to claim 12, wherein said aircraft landing gear actuator device is arranged such that: - when the sleeve is in the nominal position with the cylinder rod placed in one of said first or second positions relative to the sleeve then the landing gear leg is in the retracted leg position; and so that - the landing gear leg is in the extended leg position when the cylinder rod is placed in any position between said first and second positions and the sleeve is placed at a distance from the nominal position, between the nominal position and the emergency position.

14. An aircraft (100) comprising an aircraft landing gear (30) according to any one of claims 12 or 13.

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