Locking / unlocking system for a lost-motion thrust reverser actuator and actuator incorporating such a system

Abstract

The invention relates to a locking / unlocking system for a thrust reverser actuator, comprising a preload arrangement (51, 52, 53; 151, 152, 163; 263), said arrangement being mounted between the locking piece (36) and an input wheel (10) of the actuator drive mechanism, said preload arrangement holding the locking piece (36) and the input wheel (10) together in rotation when the torque between the drive mechanism and the locking piece (36) is less than the preload threshold and uncoupling the locking piece (36) and the input wheel (10) when said torque becomes greater than said preload torque, the uncoupling movement moving the locking member (30) from its locking position to its unlocking position, the drive movement then being able to be transmitted to allow the deployment of the actuator (2). Figure for the abridged version: Fig. 4

Description

Title of the invention: Locking / unlocking system for a lost motion thrust reverser actuator and actuator comprising such a system General technical field and prior art

[0001] Aircraft propulsion systems generally include a thrust reverser or TR system (Thrust Reverser) for reversing thrust during landing phases in order to improve the aircraft's braking capacity. Such a system includes a set of movable cowls or doors actuated by a set of associated actuators for temporarily obstructing the air stream and redirecting the secondary air flow outwards and towards the front of the nacelle, thereby generating counter-thrust which is added to the braking of the wheels.

[0002] These actuators conventionally incorporate locking / unlocking systems that can be controlled to engage or disengage the drive shaft to prevent or allow rotation of the drive shaft and deployment of the actuator. The system further includes a locking inhibitor for maintaining the locking device in the disengaged position until the actuator is in the retracted configuration.

[0003] These locking / unlocking systems generally incorporate return springs having a significant stiffness in order to ensure that the device does not disengage in the event of an impact (unbalance, rolling impacts, etc.). The system must also operate despite significant dynamic loads which may occur in the event of loss of a blade from the aircraft engine ("Fan Blade Out").

[0004] This is the reason why these systems usually include an electromagnet capable of generating a significant unlocking force, intended to overcome the force exerted by the return springs. An example of a locking / unlocking system in this sense is for example described in patent application FR3003605.

[0005] The invention relates more particularly to the field of lost motion actuators in which a specially designed mechanism first unlocks the cylinder, and only after unlocking does the movable rod of the cylinder itself extend. When the thrust reverser mechanism connected to the cylinder is closed, the cylinder rod retracts into the cylinder body. At a certain point, the locking mechanism comes into action again during the last revolutions of the cylinder input shaft.

[0006] Such an actuator is for example envisaged in application FR3008741. General presentation of the invention

[0007] In the systems of the state of the art, the electromagnet, as well as the control and the power supply (additional electronic components, connections, etc.) generate a significant bulk and weight for current locking / unlocking devices. This also results in a significant cost.

[0008] A general aim of the invention is to propose a solution which makes it possible to overcome the drawbacks of locking / unlocking systems.

[0009] According to one aspect in particular, the invention proposes a system for locking / unlocking a thrust reverser actuator, said actuator comprising a first element and a second element mounted to move in translation and in rotation relative to the first element, so that a rotation of the first element relative to the second element causes a translation of the second element relative to the first element, said system comprising:

[0010] - on the one hand at least one locking part integral in rotation with the first element,

[0011] - on the other hand a movable locking member between a locked position in in which said member prevents rotation of the locking part and the first element and an unlocked position in which the part allows rotation of the locking part and the first element,

[0012] characterized in that it comprises a preload arrangement, said arrangement keeping the locking part and an input wheel integral in rotation when the torque between the drive mechanism and the locking part (36) is less than a preload threshold of the preload arrangement and uncoupling the locking part (36) and said input wheel, when said torque becomes greater than said preload threshold, the arrangement comprising means for moving the locking member adapted so that the uncoupling movement moves the locking member from its locking position to its unlocking position, the drive movement then being transmitted to the first element by said arrangement in order to allow deployment of the actuator.

[0013] With this solution, the electrical opening is replaced by a mechanical opening, which makes it possible to do without the electromagnet and its electrical controls.

[0014] This results in a reduction in cost, size and weight.

[0015] It will be noted in particular that in the locking systems of the state of the art, when the deployment request is made, the control is carried out sequentially: the lock is opened electrically, then a torque is supplied to the input of the actuator to deploy it.

[0016] With the proposed solution, when the deployment request is made, there is no no sequential control, the torque is immediately supplied to the actuator input. The mechanism allows this torque to be recovered in order to open the lock; when the lock is open, the torque takes another path and allows the actuator to be deployed.

[0017] It will be noted in particular that the proposed embodiments allow unlocking despite significant external loads (unlocking under load) and have a high efficiency which allows it to operate even in the event of significant degradation of the contacts and the resulting friction coefficients.

[0018] The system is therefore robust over time.

[0019] Thus, according to various other aspects of the invention, the system is completed by the following characteristic(s) taken alone or in all their technically possible combinations:

[0020] - the means for moving the locking member comprise a carried cam by said member, said cam cooperating with a complementary means of the preload arrangement, said complementary means being adapted to tilt said cam and move the locking member during a decoupling movement;

[0021] - a complementary means which cooperates with the cam is a rotating roller mounted on an axis parallel to the axis of rotation of the locking part, said axis being integral in rotation with the input wheel;

[0022] - the preload arrangement comprises at least one spring;

[0023] - the preload arrangement comprises at least one flange integral in rotation with the input wheel, the rotary roller being mounted on an axle which extends between said flange and said input wheel;

[0024] - the preload arrangement comprises several rotating rollers mounted between said flange and the input wheel, being distributed around the periphery of said part;

[0025] - the system comprises an eccentric gear cam, mounted on an axis integral with the locking part, the gear of said cam cooperating with a gear carried by a first flange integral in rotation with the input wheel, said first flange and said cam being located in the same plane, the uncoupling of said input wheel and the locking part causing the rotation of the cam, the cam cooperating with a surface of the locking member and moving the latter under the effect of its rotation;

[0026] - the axis of the eccentric cam is mounted between the locking part and a second flange attached to it;

[0027] - the system comprises a pusher member driven in movement by the movement of uncoupling;

[0028] - the push member is mounted in a housing of the locking part, said pusher cooperating with an internally toothed wheel, said wheel being driven in rotation by at least one pinion meshing on the one hand with the internal teeth of said wheel and on the other hand with a toothing integral in rotation with the input wheel, the axes of said pinions being mounted on the locking part or a part integral with the latter, the uncoupling of said wheel and the locking part causing the translation of the pusher member cooperating with a surface of the locking member and moving the latter under the effect of its rotation.

[0029] The invention also relates to an actuating device for a thrust reverser comprising at least one actuator comprising a first element and a second element mounted to move in rotation and translation relative to the first element, so that a rotation of the first element relative to the second element causes a translation of the second element relative to the first element, characterized in that it comprises at least one proposed locking / unlocking system. Brief description of the drawings

[0030] Other characteristics and advantages of the invention will emerge from the following description, which is purely illustrative and non-limiting, and must be read in conjunction with the appended figures in which: - [Fig. 1] is a partial representation in sectional view of an actuating device; - [Fig.2a] and [Fig.2b] are partial perspective views of the actuating device, when the locking system is in the locked position ([Fig.2a]) and when said system is in the unlocked position ([Fig.2b]); - [Fig.3] and [Fig.4] are perspective and exploded perspective views of a locking system according to a possible embodiment of the invention; - [Fig.5a], [Fig.5b], [Fig.5c] and [Fig.5d] illustrate different phases of unlocking the system of figures 3 and 4; - [Fig.6] and [Fig.7] are perspective and exploded perspective views of a locking system according to a second possible embodiment of the invention; - [Fig.8a], [Fig.8b] and [Fig.8c] illustrate different phases of unlocking the system of figures 6 and 7; - [Fig. 9] and [Fig. 10] are perspective and exploded perspective views of a locking system according to another possible embodiment of the invention; - [Fig.11a], [Fig.11b], [Fig.11c] and [Fig.11d] illustrate different phases of unlocking the system in figures 9 and 10.

[0031] Description of one or more modes of implementation and embodiment

[0032] The actuating device illustrated in [Fig.l], as well as in Figures 2a and 2b comprises a general structure of the type of the device described in application FR 3,003,605 to which reference may be made and the teaching of which is incorporated here by reference. This device comprises in particular an actuator 2, a locking system 28 (figures 2a, 2b) and a locking inhibitor 40 (figures 2a, 2b). The electrical opening provided by the electromagnet is however replaced by a mechanical opening, as will emerge from the description which follows.

[0033] The actuator 2 comprises a casing 3, a screw 4 extending from the casing 3, a nut 5 and an actuator tube 6. The screw 4 is rotatably mounted relative to the casing 3 of the device around an axis of rotation X corresponding to the longitudinal axis of the body of said screw 4 and also corresponding to a deployment axis of the actuator 2.

[0034] When the motor of the actuation system is activated, a torque is introduced into the shaft 12 and the rotation of the screw 4 around the axis X concomitantly causes a translation of the nut 5 parallel to the axis X between a first extreme position (corresponding to a retracted configuration of the actuator) in which the mobile component of the thrust reverser is retracted and a second extreme position (corresponding to a deployed configuration of the actuator) in which the mobile component of the thrust reverser is deployed, thus making it possible to deflect the air flow circulating in the air stream of the fan towards the front of the nacelle.

[0035] The rotation of the screw 4 is ensured by a conical toothed wheel 10 (drive part). Said wheel 10 cooperates with a return pinion 11 which terminates a drive shaft 12. The shaft 12 is itself driven by a remote motor (not shown).

[0036] The locking device 28 is housed inside the casing 3 of the actuator 2. Its function is to block the screw 4 in rotation when the actuator 2 is in the retracted configuration and thus to prevent untimely deployment of the actuator 2, in particular during the flight phase.

[0037] The locking device 28 comprises a locking shaft 30 mounted between bearings allowing its rotation around an axis X' parallel to the axis X and having a locking portion 31. The portion 31 is a lock having a half-moon section suitable for being driven in rotation between, on the one hand, a locked position and, on the other hand, an unlocked position.

[0038] Said locking portion 31 cooperates for this purpose with a locking part 36 (wolf tooth crown for example) integral in rotation with the toothed wheel 10. In the locked position, the portion 31 blocks the rotation of the screw 4 of the actuator 2. More precisely, the half-moon section of the locking part 31 comes into engagement with a wolf tooth 37 of the locking crown 36 to prevent rotation of the screw 4 in a first direction corresponding to the direction of rotation of the screw 4 during deployment of the actuator 2.

[0039] In the unlocked position, the half-moon section of the locking portion 31 is rotated and is released from the wolf tooth 37. The portion 31 allows the screw 4 to rotate.

[0040] A return member 32 such as a torsion spring is provided to bias the locking portion 31 toward the locked position.

[0041] The locking inhibitor device 40 comprises a latch 41 which extends in a substantially radial direction relative to the axis X' and which is mounted integral with the locking shaft 30.

[0042] A mechanism blocks the latch 41 and consequently the shaft 30 so as to maintain the locking part 31 in the unlocked position as long as the actuator 2 is not completely retracted.

[0043] This prevents untimely locking of the actuator 2 which could block the actuator 2 during its deployment, particularly during the landing phase.

[0044] In a possible embodiment illustrated in Figures 3 and 4, the locking crown 36 with wolf tooth 37 is mounted interposed between two flanges 51 and 52 of a spring preloading system 50.

[0045] The locking crown 36 is rotationally integral with the screw 4.

[0046] The flanges 51 and 52 are integral with the wheel 10.

[0047] The flanges 51, 52 and the wheel 10 have a degree of freedom in rotation relative to to screw 4 and therefore of the locking crown around the X axis.

[0048] The flange 52 is connected to the wheel 10 by two axes 60 parallel to the axis X and extending between the wheel 10 and the flange 52. These two axes 60 each carry a rotating roller 61. The rollers 61 are capable of coming to bear against a cam 62 which projects relative to the portion 31 with a half-moon section.

[0049] As a further variant, it is also possible to have only one axle / roller pair.

[0050] The axles 60 and the rollers 61 may also be in a number greater than two. They are distributed around the periphery of the wheel 10 to allow the cooperation of the rollers and the cam 62.

[0051] Several springs 63 ensure the angular maintenance of the flanges 51 and 52 relative to the locking crown 36 as long as a torque threshold value is not reached between, on the one hand, the wheel 10 and, on the other hand, the locking crown 36.

[0052] Typically the preload is ensured by four helical springs 63 nested between the flanges 51 and 52. These springs 63 are distributed with axes extending in two directions perpendicular and parallel to the planes of the flanges 51 and 52. They ensure for example together a preload torque of between 10 Nm and 20 Nm, including 16 Nm

[0053] The flanges 51 and 52, as well as the springs 63 together constitute a preload arrangement.

[0054] The operation of this system is as follows.

[0055] The motor of the actuation system transmits an actuation torque to the wheel 10, via the shaft 12 and the pinion 11.

[0056] Initially, the wheel 10 begins to rotate the assembly, which is blocked by the stop of the wolf-toothed locking crown 36 against the locking portion 31 of the shaft 30 which remains in the locked position ([Fig.5a]).

[0057] If the force continues, the torque on the wheel 10 increases until it exceeds the preload torque of the springs.

[0058] The wheel 10, the flanges 51 and 52 and the rollers 61 rotate, while the locking crown 36, and the screw 4 are blocked by the stop of the wolf tooth 37 against the portion 31 ([Fig.5b]).

[0059] The roller 61 then comes to bear against the cam 62. It drives said cam 62 in its movement. The lock which constitutes the locking portion 31 is then tilted into its unlocking position where the passage of the wolf tooth 37 is released ([Fig.5c]).

[0060] The movement continues by driving the locking crown 36 and the screw 4. The actuator can then deploy ([Fig.5d]).

[0061] When the actuator begins its deployment, the inhibition system is activated and maintains the lock in the unlocked position.

[0062] In the embodiment illustrated in Figures 6 and 7, a preloading system 150 is interposed between the wheel 10 and the wolf-toothed locking crown 36. This system comprises two flanges 151 and 152 between which load springs 163 are mounted. The flange 151 is mounted so as to rotate integrally with the locking crown 36, while the flange 152 is so as to rotate integrally with the wheel 10.

[0063] The flanges 151 and 152, as well as the springs 163 together constitute a preload arrangement.

[0064] A geared cam 161 is mounted on an eccentric rotation shaft 160, which extends between the locking ring and the flange 151. Said cam 161 is in the same plane as the flange 152. The gear of said cam 161 cooperates with a complementary gear that the flange 152 has in line with said cam 161.

[0065] Said cam 161 is intended to cooperate with the half-moon section of the locking portion 31 to rotate the shaft 30.

[0066] The unlocking is illustrated in Figures 8a to 8c.

[0067] When the wheel 10 begins to be driven by the pinion 11 and the drive shaft 12, the wolf tooth 37 of the locking crown 36 comes into abutment against the half-moon section of portion 31 ([Fig.8a]).

[0068] This position is maintained until the preload torque threshold of the springs 163 is reached. Beyond this, the two flanges 151 and 152 separate, which has the effect of rotating the eccentric cam 161 on the gear of the flange 152. In fact, the flange 152 rotates with the drive wheel 10, while the flange 151 is blocked in rotation by the locking crown 36 ([Fig.8b]).

[0069] The rotation of the cam 161 on its axis then causes the tilting of the portion 31 of half-moon section with which said cam 161 cooperates ([Fig.8c]).

[0070] The shaft 30 is thus tilted, which releases the wolf tooth 37 and the crown 36. The screw 4 can then be driven.

[0071] Another solution is further illustrated in Figures 9 and 10. In this embodiment, preload springs 263 are mounted between, on the one hand, a crown 251 with internal teeth and, on the other hand, the locking crown 36.

[0072] Several pinions 254 are mounted on axes carried by the locking crown 36. These pinions 254 mesh on the one hand with said internal teeth of the crown 251 and on the other hand with teeth of a shaft secured to the input wheel 10.

[0073] Alternatively, the pinions 254 may be carried by a part integral with the locking crown 36, such as an intermediate flange.

[0074] A push member 260 is mounted on the unlocking crown 36 and is intended to engage on the half-moon section to tilt the locking portion 31 and the shaft 30 from the locking position to the unlocking position.

[0075] The operation is as follows.

[0076] When training begins, the wolf tooth 37 of the locking crown 36 comes into abutment against the half-moon section of the portion 31 ([Fig. 1 la]).

[0077] When the preload torque is reached, the input wheel 10 rotates relative to the locking crown 36. This rotation causes the rotation of the pinions 254 and therefore the rotation of the internally toothed crown 251. The rotational movement of the crown 261 moves the pusher member 260 (figures 11b and 11c).

[0078] The engagement of the latter against the portion 31 tilts the shaft 30 and releases the movement of the crown 36 and the screw 4 of the actuator ([Fig.l ld]).

Claims

Claims

1. Locking / unlocking system for a thrust reverser actuator, said actuator comprising a first element (4) and a second element (5) mounted to move in translation and in rotation relative to the first element (4), so that a rotation of the first element (4) relative to the second element (5) causes a translation of the second element (5) relative to the first element (4), said system comprising: - an input wheel (10) configured to drive the first element (4) in rotation, - on the one hand at least one locking part (36) integral in rotation with the first element (4), - on the other hand a locking member (30) movable between a locked position in which said member (30) prevents rotation of the locking part (36) and of the first element (4) and an unlocked position in which the locking member (30) allows rotation of the locking part (36) and of the first element (4), characterized in that it comprises a preload arrangement (51, 52, 63; 151, 152, 163;263), said arrangement allowing rotation of the input wheel (10) relative to the locking part (36) when the torque between the input wheel (10) and the locking part (36) is less than a preload threshold of the preload arrangement and allowing rotational driving of the locking part (36) by said input wheel (10), when said torque becomes greater than said preload threshold, the arrangement comprising means for moving (61, 62) the locking member (30) adapted so that the rotation of the input wheel (10) moves the locking member (30) from its locking position to its unlocking position, the driving movement then being transmitted to the first element (4) by said arrangement in order to allow deployment of the actuator (2).;

2. System according to claim 1, in which the means for moving the locking member (30) comprise a cam (62) carried by said member, said cam (62) cooperating with a complementary means (61) of the preload arrangement, said complementary means (61) being adapted to tilt said cam and move the locking member during an uncoupling movement.

3. System according to claim 2, in which a complementary means which cooperates with the cam (62) is a rotary roller (61) mounted on an axis (60) parallel to the axis of rotation of the locking part, said axis being integral in rotation with the input wheel.

4. System according to claim 3, in which the preload arrangement comprises at least one flange (52) integral in rotation with the input wheel (10), the rotary roller (61) being mounted on an axis (60) which extends between said flange (62) and said input wheel (10).

5. System according to claim 4, in which the preload arrangement comprises several rotating rollers (61) mounted between said flange (52) and the input wheel (10), being distributed around the periphery of said part.

6. System according to any one of the preceding claims, comprising a cam (161) with eccentric gearing, mounted on an axis integral with the locking part (36), the gearing of said cam (161) cooperating with a gearing carried by a first flange (152) integral in rotation with the input wheel (10), said first flange (152) and said cam (161) being located in the same plane, the uncoupling of said input wheel (10) and the locking part (36) causing the rotation of the cam (161), the cam (161) cooperating with a surface of the locking member and moving the latter under the effect of its rotation.

7. System according to claim 6, in which the axis of the eccentric cam (161) is mounted between the locking part (36) and a second flange (151) integral with the latter.

8. System according to any one of the preceding claims, comprising a pusher member (260) driven in movement by the uncoupling movement.

9. System according to claim 8, in which the pusher member is mounted in a housing of the locking part (36), said pusher (260) cooperating with a wheel (251) with internal teeth, said wheel (251) being driven in rotation by at least one pinion (254) meshing on the one hand with the internal teeth of said wheel (251) and on the other hand with a toothing integral in rotation with the input wheel, the axes of said pinions (254) being mounted on the locking part (36) or a part integral with the latter, the uncoupling of said wheel (251) and the locking part (36) causing the translation of the pusher member (260) cooperating with a surface of the locking member rust (30) and moving it under the effect of its rotation.

10. Actuation device for a thrust reverser comprising at least one actuator comprising a first element (4) and a second element (5) mounted to move in rotation and translation relative to the first element (4), so that a rotation of the first element (4) relative to the second element (5) causes a translation of the second element (5) relative to the first element (4), characterized in that it comprises at least one locking / unlocking system according to one of the preceding claims.

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