Device for actuating a thrust reverser with an antideployment body

Abstract

The invention relates to a device for actuating a thrust reverser, comprising mobile thrust-reversing elements (1) carried by a nacelle in order to move between a retracted position and a deployed position, the actuating device comprising: two actuators mounted on the nacelle and connected to a motor and to mobile thrust-reversing elements in order to manoeuvre same in a retraction or deployment direction over a course of the actuators between a retracted position and a deployed position of the mobile thrust-reversing elements; locks for locking the mobile thrust-reversing elements in the retracted position; and antideployment bodies (11,12,13,16) associated with the actuators in order to ensure free operation of the actuators in the direction of retraction and to ensure that the actuators are retained in the direction of deployment, the antideployment bodies being designed to ensure free operation of the actuators in the direction of deployment over part of the course of the actuators corresponding to a shift from a position of over-retraction of the mobile thrust-reversing elements to a position of retraction of the mobile thrust-reversing elements.

Description

[0001] Actuation device for a thrust reverser with an anti-deployment mechanism

[0002] The present invention relates to an actuation device for a thrust reverser, and a method of using this actuation device.

[0003] Actuation devices for a thrust reverser are known, comprising moving thrust reverser elements, generally two moving thrust reverser elements, carried by a nacelle to move between a retracted position and a deployed position. The actuation device includes actuators mounted on the nacelle and connected on one side to a motor, and on the other side to the moving thrust reverser elements to maneuver them in a direction of retraction or deployment over a stroke of the actuators between a retracted position and a deployed position of the thrust reverser elements, and locks ensuring that the moving thrust reverser elements are held in the retracted position, and constituting means of retaining the thrust reverser against unintentional deployment in flight.The thrust reversing elements tend to deploy naturally under the aerodynamic forces to which they are subjected until they reach their fully extended position. Due to the inertial effect of the moving parts constituting the actuation mechanism, the arrival of the thrust reversing elements at the deployment stops generates a dynamic shock that is detrimental to the nacelle structure. To control the deployment time and avoid this impact shock at the deployment stops, it is necessary to control the deployment speed of the actuators. However, in the event of a failure in the actuator control or a mechanical break in the mechanical transmission chain of the actuation mechanism, the thrust reversing elements can deploy at excessive speed and generate an impact upon reaching the stop.To guard against these degraded scenarios, it is known to equip actuation devices with anti-deployment mechanisms configured to ensure free operation of the actuators in the retraction direction and to retain them in the deployment direction. The anti-deployment mechanism generates friction that increases with the tensile force exerted on the actuator.

[0004] The introduction of this anti-deployment device, however, creates another problem that must be addressed: when the thrust reverser is in the closed position, the anti-deployment device blocks the actuator's movement in an undesired position. This is incompatible with the thrust reverser's structural design, since the force path ensuring the locking of the thrust reversing moving element passes through the actuator, whereas the desired position is a retracted position for the thrust reversing moving elements, in which they are in contact with at least one primary lock. A primary lock is, by definition, a lock through which the force path ensuring the locking of the thrust reversing moving element passes.One aim of the invention is to provide an actuation device for a thrust reverser capable of avoiding the risks of high-speed impact on the deployment stops while ensuring that in the closed position the force path for locking the doors passes through the primary locks and not through the actuator.

[0005] To achieve this goal, a thrust reverser actuation device is proposed, comprising at least one movable thrust reverser element carried by a nacelle to move between a retracted position and a deployed position, the actuation device comprising: at least one actuator mounted on the nacelle and connected on one side to a motor,and on the other hand, to said at least one movable thrust reversing element to maneuver it in a direction of retraction or deployment over a stroke of said at least one actuator comprising between a retracted position and a deployed position of said at least one retracted and movable thrust reversing element; at least one lock to block said at least one movable thrust reversing element in the position; and at least one anti-deployment device associated with said at least one actuator to ensure free operation of said at least one actuator in the direction of retraction and to ensure restraint of said at least one actuator in the direction of deployment,in which said at least one anti-deployment device is configured to ensure free operation of said at least one actuator in the deployment direction over a portion of the stroke of said at least one actuator corresponding to a transition from an over-retraction position of said at least one thrust reversing moving element to a retraction position of said at least one thrust reversing moving element. For the purposes of this invention, a retraction position is understood to be a position of the thrust reversing moving elements in which they are in contact with a so-called primary lock, i.e., a lock through which passes the force path ensuring the door's locking mechanism, and an over-retraction position is understood to be a position in which the thrust reversing moving elements are abutted against the nacelle beyond the retraction position.

[0006] The anti-deployment device is characterized by its passive movement over a specific range of motion between the over-retraction and retraction positions; that is, it does not introduce friction during this portion of the travel. This characteristic of the anti-deployment device ensures that, when the thrust reverser is in the closed position, the force required to lock the doors is channeled through the primary locking mechanisms designed for this purpose, and not through the actuator of the actuation device.

[0007] According to other features of the invention taken separately or in combination: the device comprises a motor directly associated with each actuator; the device comprises a motor associated with several actuators by means of mechanical transmission members; the device comprises at least one first actuator driven by a motor, and at least one second actuator driven by the first actuator; the device comprises at least two actuators having different strokes or actuation speeds; said at least one lock is electrically controlled; said at least one lock is hydraulically controlled; the motor is an electric motor; the motor is a hydraulic motor.

[0008] According to another aspect of the invention, it relates to a method of using the device defined above, in which, starting from a deployed position of said at least one thrust reversing member, the method comprises the steps of: commanding said at least one actuator in a retraction direction of said at least one thrust reversing member to maneuver it in a retraction direction, until said at least one thrust reversing member has reached an over-retraction position, ensuring a closure of said at least one lock, and commanding said at least one actuator in a deployment direction until a part of said at least one lock carried by said at least one thrust reversing member is in contact with a part of said at least one lock carried by the nacelle.

[0009] Thus, on the one hand the lock is operated under conditions facilitating this maneuver, and on the other hand the actuator is finally free of any constraint when the moving thrust reversal elements are in the closed and locked position.

[0010] Other features and advantages of the invention will become apparent from the following description of a preferred, non-limiting embodiment of the actuation device according to the invention, with reference to the accompanying figures, among which:

[0011] Figure 1 is a partially cutaway schematic perspective view of a gondola equipped with the actuation device according to the invention. Figure 2 is an exploded schematic representation of a part of an actuator according to the invention.

[0012] Figure 3 is a schematic cross-sectional view along line lll-lll of Figure 2. Figure 4 is a schematic diagram illustrating the movements of a thrust reversing moving element resulting from the use of the actuation device according to the invention.

[0013] Figure 5 is a diagram illustrating the relative position of the parts of a primary lock as a function of the position of the thrust reversing moving element.

[0014] With reference to the figures, the actuation device according to the invention is intended for the operation of movable thrust reversing elements, here two doors 1, carried by a platform 2 to pivot about axes 3, between a retracted position and a deployed position. The actuation device comprises two actuators 4 mounted on the platform and each having an axis 5 connected to a motor, here an electric motor 6 connected to a power unit 24 itself connected to a control unit 23 also connected to sensors, in particular a door position sensor 22, and a motor sensor 27, intended to provide the control unit 23 with the information necessary for the proper functioning of the actuation device, in particular with regard to the position of the doors 1.Each actuator 4 has one end articulated to the body of the nacelle 2 and an opposite end articulated to a door 1, either directly or by a connecting rod also articulated to a nut 9 mounted on a ball screw 8. The position of the output nut 9 of the actuator 4 is determined by the rotation of the shaft 5 connected to the electric motor 6 by a flexible mechanical transmission cable 7.

[0015] Each actuator 4 further includes an anti-deployment element comprising: a toothed wheel 11 mounted freely on the shaft 5 and associated with a ratchet 16 fixed in an articulated manner to the housing 17 of the actuator; a friction plate 13 disposed between the toothed wheel 11 and a support plate 12 fixed on the shaft 5. The toothed wheel 11, the friction plate 13 and the support plate 12 are held tightly against each other between a front bearing 14 and a rear bearing 15.

[0016] The gear 11 has a single tooth 18 projecting from a smooth lateral surface 19. The tooth 18 has one ramped side 25 and an opposite side with a steep front 26. The operation of the anti-deployment device is as follows:

[0017] - When the shaft 5 is rotated in the direction of retraction, shown in Figure 3 by an arrow R, with each turn the pawl 16 moves up the ramp 25 and falls back down on the side of the face 26. The toothed wheel 11 rotates with the support plate 12 without slipping. The shaft 5 rotates freely.

[0018] When the shaft 5 is rotated in the direction of deployment, shown in Figure 3 by arrow D, as long as the pawl 16 slides on the smooth side wall 19, the gear 11 rotates with the support plate 12 without slipping. The shaft 5 rotates freely. However, when the pawl 16 comes to a stop against the front 26, the gear is locked in rotation and the support plate slides relative to the gear 11, rubbing against the friction plate 13. The rotation of the shaft is braked. According to the invention, the actuator is configured so that the unbraked rotation corresponds to the portion of the stroke between the over-retraction position and the retraction position. For this purpose, the angular position of the tooth 18 is calculated as a function of the pitch of the ball screw 8 and the diameter of the gear 11 so that the steep front 26 of the tooth 18 comes to rest on the pawl 16 when the nut 9 is in the retraction position (position A in figure 4).

[0019] In addition, the actuation device includes, in a manner known per se, primary locks comprising hooks 20 fixed to each of the doors 1 and arranged to couple, when retracting the push reversing moving elements, with hooks 21 carried by a pivoting arm brought elastically back to a closed position of the lock and associated for opening with an actuator not shown.

[0020] Figure 4 is a diagram that illustrates the movements of nut 9 during rotation of axis 5. The letter A illustrates the retraction position of the doors and the letter B illustrates the over-retraction position, while the letter 0 illustrates the end-of-travel position of the doors during deployment.

[0021] During deployment, starting from point A, the nut 9 is first moved to the over-retraction position B (only a few millimeters from the retraction position A), which creates a gap between the hooks 20 and 21 just sufficient to allow the hooks 21 to disengage in the direction of the lock opening. The shaft 5 is then driven in the deployment direction until the thrust reversing moving elements 1 reach the end-of-stroke stop designated by the letter O.

[0022] During a retraction, starting from point O, the nut 9 is first moved in a retraction direction until the nut 9 reaches the over-retraction position B. The primary locks are then closed and the nut 9 is moved in the deployment direction to the retraction position A. As illustrated by figure 5, in this position the hooks 20 and 21 are in contact with each other and are therefore under load while the actuators are unloaded.

[0023] Of course the invention is not limited to the embodiment described and is susceptible to variant embodiments without departing from the scope of the invention as defined by the claims.

[0024] In particular, although the device according to the invention has been illustrated with a single electric motor for both door actuators, the invention can be realized with a hydraulic motor and / or by providing an electric motor associated with each actuator, the motor 6 being in direct mechanical transmission, or by means of a reduction with the main shaft 5 of the actuator 4.

[0025] Although the invention has been described in relation to an actuation device comprising a single lock per door, the invention can be implemented with several associated locks according to combinations appropriate to the specifications concerning the implementation of the thrust reversal system.

[0026] Similarly, although no mention has been made of synchronization between the movements of the two doors, such synchronization, regardless of its embodiment, can be added without the resulting device falling outside the scope of the invention.

[0027] Although the invention has been described in relation to doors arranged symmetrically, an actuation device can be made having thrust reversing moving elements that open asymmetrically.

[0028] Although the invention was developed in the context of researching a solution applicable to a small aircraft, such as a business jet, it can be applied to large aircraft.

Claims

DEMANDS Thrust reverser actuation device comprising at least one thrust reversing movable element (1) carried by a nacelle (2) to move between a retracted position and a deployed position, the actuation device comprising: at least one actuator (4) mounted on the nacelle and connected on one side to a motor (6), and on the other side to said at least one thrust reversing movable element to maneuver it in a direction of retraction or deployment over a stroke of said at least one actuator between a retracted position and a deployed position of said at least one thrust reversing movable element; at least one lock (20,21) to lock said at least one thrust reversing movable element in the retracted position;and at least one anti-deployment device (11, 12, 13, 16) associated with said at least one actuator to ensure free operation of said at least one actuator in the retraction direction and to ensure restraint of said at least one actuator in the deployment direction, characterized in that said at least one anti-deployment device is configured to ensure free operation of said at least one actuator in the deployment direction over a portion of the stroke of said at least one actuator corresponding to a passage from an over-retraction position (B) of said at least one thrust reversing moving element to a retraction position (A) of said at least one thrust reversing moving element. Device according to claim 1, characterized in that it comprises a motor directly associated with each actuator. Device according to claim 1, characterized in that it comprises a motor (6) associated with several actuators (8) by means of mechanical transmission members (7). Device according to claim 1 characterized in that it comprises at least one first actuator driven by a motor, and at least one second actuator driven by the first actuator. A device according to claim 1, characterized in that it comprises at least two actuators having different strokes or actuation speeds. A device according to any one of claims 1 to 5, characterized in that said at least one lock is electrically controlled. Device according to any one of claims 1 to 5, characterized in that said at least one lock is hydraulically controlled. Device according to any one of claims 1 to 7 characterized in that said at least one motor is an electric motor.

9. Device according to any one of claims 1 to 7 characterized in that said at least one motor is a hydraulic motor.

10. Method of using the device according to any one of claims 1 to 9, characterized in that, starting from a deployed position (0) of said at least one thrust reversing movable element, it comprises the steps of: commanding said at least one actuator to maneuver said at least one thrust reversing movable element in a retraction direction, until said at least one thrust reversing movable element has reached an over-retraction position, ensuring a closure of said at least one lock, and commanding said at least one actuator in a deployment direction until a part of said at least one lock carried by said at least one thrust reversing movable element is in contact with a part of said at least one lock carried by the nacelle.

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