Actuator for maneuvering a moving assembly between two positions.

Abstract

Actuator (1, 1') comprising: a main body (10) and a secondary body (20) having respectively a first cavity (11) and a second cavity (21); a main piston (30) mounted for translational movement within the first cavity (11) between a first extreme position and a second extreme position, defining a first chamber (CH1) and a second chamber (CH2) of variable volumes; a main rod (40) extending on either side of the main piston, a section of the main rod extending into the second cavity of the secondary body; and a separating piston (80) mounted for translational movement within the second cavity (11) between a first extreme position and a second extreme position, defining a third chamber (CH3) of variable volume with a bottom of the second cavity. (Figure from the abbreviated diagram: Fig. 2A)

Description

Title of the invention: Actuator for maneuvering a moving assembly between two positions.

[0001] The present invention relates to an actuator for maneuvering a movable assembly between two positions, such as an aircraft landing gear between a deployed position and a retracted position. The invention also relates to an aircraft comprising a landing gear and such an actuator for maneuvering the landing gear between a deployed position and a retracted position.

[0002] BACKGROUND OF THE INVENTION

[0003] Aircraft landing gear is known comprising a leg mounted pivotally on an aircraft structure between a deployed position and a retracted position.

[0004] In normal mode, the deployment and retraction of the leg are generally carried out by means of a main hydraulic circuit comprising a double-acting cylinder which has a first end attached to the aircraft structure and a second end attached to the leg.

[0005] For safety reasons, a lander must be able to deploy even if the actuator fails. Many landers are therefore designed so that their deployment can be carried out under the effect of gravity and / or aerodynamic moments applied to the lander leg.

[0006] However, when the landers are deployed from rear to front relative to a principal direction of travel of the aircraft, the aerodynamic force applied in flight on the leg prevents the deployment of said landers.

[0007] It is known to equip the lander with a second, so-called "backup" cylinder which, in the event of failure of the double-acting cylinder, allows the lander to be deployed. However, integrating this second cylinder into an already highly constrained environment can prove complicated. Moreover, when the lander has several axes of articulation, there may only be one possible position for the double-acting cylinder to deploy the lander, solely via positive lever arms, so integrating a second cylinder may prove impossible.

[0008] It is also known that, in the event of a failure of the main hydraulic circuit, the double-acting cylinder can be connected to a secondary hydraulic circuit by means of a shuttle valve. However, such a solution does not compensate for a failure of the double-acting cylinder, such as, for example, a deterioration of one of its seals.

[0009] SUBJECT OF THE INVENTION

[0010] The invention therefore aims to provide an actuator that at least partially remedies the aforementioned drawbacks for maneuvering a mobile assembly between a deployed position and a retracted position. Summary of the invention

[0011] For this purpose, an actuator is provided to maneuver a moving assembly between two positions, the actuator comprising: - a main body comprising a first cavity extending along a longitudinal axis of the actuator; - a secondary body, attached to the main body and comprising a second cavity extending coaxially in line with the first cavity; - a main piston mounted to move in translation along the longitudinal axis in the first cavity between a first extreme position and a second extreme position to define a first chamber and a second chamber of variable volumes; - a main rod integral with the main piston and comprising a first section and a second section extending on either side of said main piston along the longitudinal axis, the first section extending outward from the main body opposite the secondary body and the second section extending into the second cavity of the secondary body; and - a separator piston mounted movable in translation along the longitudinal axis in the second cavity between a first extreme position and a second extreme position to define a third chamber of variable volume with a bottom of the second cavity, the main rod forming a stop to the sliding of the separator piston.

[0012] According to the invention, the main body comprises a first feed port and a second feed port opening respectively into the first chamber and the second chamber, and the secondary body comprises a third feed port opening into the third chamber.

[0013] The actuator is thus similar to a double-acting cylinder in that it is possible to control the retraction or extension of the rod by injecting, respectively via the first or second supply port, a pressurized fluid into the first cavity. In the event of piston failure, it is also possible to extend the rod by injecting a pressurized fluid into the second cavity via the third supply port.

[0014] According to a particular feature, the sliding stop of the separator piston is formed by a free end of the second section of the main rod.

[0015] According to another particular feature, a secondary rod extends axially projecting from a front face of the separator piston, the secondary rod being integral with the separator piston and sliding in the second section of the main rod.

[0016] In particular, the secondary rod defines with the second cavity of the secondary body a fourth chamber of variable volume with the secondary body, the fourth chamber being in fluidic communication with the outside of the actuator.

[0017] In particular, the fourth chamber is in fluidic communication with a bore of the secondary rod via a plurality of holes distributed equally and symmetrically on an external surface of said secondary rod to be connected to a channel through the main rod and connected to the outside of the actuator.

[0018] According to another particular characteristic, the first cavity is cylindrical.

[0019] According to another particular feature, the second cavity is cylindrical.

[0020] According to another particular feature, the first power port, the The second power port and the third power port extend in the same plane passing through the longitudinal axis.

[0021] The invention also relates to an aircraft comprising: • a movably rotating landing gear mounted on an aircraft structure around a pivot axis between a deployed and a retracted position; and • such an actuator to maneuver the lander between the deployed position and the retracted position, one free end of the first section of the rod being connected to one of the lander and the aircraft structure, and one free end of the secondary body being connected to the other of the lander and the aircraft structure.

[0022] The invention also relates to an aircraft comprising: • a movably mounted landing gear that rotates on an aircraft structure around an articulation axis between a deployed position and a retracted position; • a cargo bay designed to receive the landing gear, the cargo bay being closable by a hatch mounted movably in rotation on a structure of the aircraft between an open position and a closed position; • an actuator according to the invention for maneuvering the hatch between the open position and the closed position, one free end of the first section of the rod being connected to one of the hatch and the aircraft structure, and one free end of the secondary body being connected to the other of the hatch and the aircraft structure. Brief description of the drawings

[0023] The invention will be better understood in the light of the following description, which is purely illustrative and not limiting, and should be read in conjunction with the accompanying drawings, among which:

[0024] [Fig-1] [Fig.1] is a schematic view of an aircraft comprising a lander mobile between a deployed position and a retracted position;

[0025] [Fig.2A] [Fig.2A] is a perspective view of an actuator according to a particular embodiment of the invention for maneuvering the lander illustrated in [Fig.1], in which the actuator rod is in the retracted position and the separator piston is in its first extreme position;

[0026] [Fig.2B] [Fig.2B] is a view analogous to [Fig.2A], in which the actuator rod is in the extended position and the separator piston is in its first extreme position;

[0027] [Fig.2C] [Fig.2C] is a view analogous to [Fig.2A], in which the actuator rod is in the extended position and the separator piston is in its second extreme position;

[0028] [Fig.3A] [Fig.3A] is an axial cross-sectional view of a variant of the actuator illustrated in [Fig.2A], in which the actuator rod is in the retracted position and the separator piston is in its first extreme position;

[0029] [Fig.3B] [Fig.3B] is a view analogous to [Fig.3A], in which the actuator rod is in the extended position and the separator piston is in its first extreme position;

[0030] [Fig.3C] [Fig.3C] is a view analogous to [Fig.3A], in which the actuator rod is in the extended position and the separator piston is in its second extreme position. DETAILED DESCRIPTION OF THE INVENTION

[0031] As illustrated in [Fig. 1], the invention is described herein in relation to an aircraft A comprising a retractable landing gear L. The landing gear L comprises a leg J ​​having: - a first end articulated along an axis Y on a structure S of the aircraft A between a deployed position illustrated here and a retracted position in which the lander L is received in a bay H that can be closed by a hatch T; and - a second end, opposite the first end, carrying an axle E on which wheels R are mounted to pivot.

[0032] The lander L thus forms a mobile assembly rotating around the axis Y of articulation of the leg J.

[0033] The deployment and retraction of the damper L is carried out by means of a hydraulic actuator 1, which maneuvers the damper L between its two positions.

[0034] With reference to Figures 2A-2C, the actuator 1 comprises, according to a particular embodiment of the invention, a first tubular body or main body 10. The main body 10 defines a first cylindrical cavity 11 extending along a longitudinal axis X of said main body 10 and within which a main piston 30 slides in a sealed manner along the axis X. The main piston 30 is associated with a main rod 40 extending along the axis X and comprising a first section 40.1 and a second section 40.2 extending respectively upstream and downstream of the main piston 30. It is understood that the rod 40 is integral with the main piston 30 in that any movement of said main piston 30 along the axis X causes said rod 40 to slide along said axis X. The rod 40 is hollow and defines a channel 41 passing through the first section 40.1 and the second section 40.2 along the X-axis.

[0035] The first section 40.1 of the rod 40 includes a free end extending outside the main body 10 and into which is screwed a clevis 50 for fixing the actuator 1 to one of the structure S of the aircraft A and the leg J ​​of the landing gear L. The first section 40.1 extends through a first guide bore 12 formed in a first end of the main body 10. The first guide bore 12 includes two internal peripheral grooves in each of which a sealing gasket 13 is housed to ensure a tight seal when sliding the first section of the rod 40 in said first guide bore 12. It should be noted that the clevis 50 includes an exhaust conduit 51 connecting the channel 41 to the outside of the actuator 1'.

[0036] The second section 40.2 of the rod 40 extends through a second guide bore 61 formed in a plug 60 fitted into a second end of the main body 10. The plug 60 includes a collar 62 forming a stop for the fitting of the plug 60 into the second end of the main body 10, and an external peripheral groove in which a sealing gasket 63 is received to ensure a seal between said second end of the main body 10 and said plug 60. The second guide bore 61 includes an internal peripheral groove in which a sealing gasket 64 is received to ensure a tight seal for the rod 40 to slide within said second guide bore 61.

[0037] The main piston 30 defines in the main body 10 a first chamber CH1 or retraction chamber, and a second chamber CH2 or deployment chamber. The first chamber CH1 is delimited by a front face of the main piston 30, the walls of the first cavity 11 of the main body 10, and an external surface of the first section 40.1 of the rod 40. The second chamber CH2 is delimited by a rear face of the main piston 30, the walls of the first cavity 11 of the main body 10, a front surface of the plug 60 and an external surface of the second section 40.2 of the rod 40.

[0038] The volumes of the first and second chambers CH1, CH2 vary according to the position of the main piston 30. The main piston 30 is translationally movable along the X-axis between a first extreme position (illustrated in [Fig. 2A]) and a second extreme position (illustrated in Figures 2B and 2C) in which the rod 40 is respectively in the retracted and extended positions. The position of the rod 40 along the X-axis is controlled by the position of the main piston 30.

[0039] The main body 10 also comprises: • a first pressurized fluid supply port 14.1, which is provided at the first end of said main body 10 and which opens into the first chamber CHi to allow the main piston 30 to be moved from the second extreme position to the first extreme position and thus bring the rod 40 into the retracted position; and • a second pressurized fluid supply port 14.2, which is provided at the second end of said main body 10 and which opens into the second chamber CH2 to allow the main piston 30 to be moved from the first extreme position to the second extreme position and thus bring the rod 40 into the exit position.

[0040] The first power supply port 14.1 and the second power supply port 14.2 extending in the same plane P passing through the longitudinal X axis, the plane P corresponding here to the cutting plane of the actuator 1 of figures 2A-2C.

[0041] The first supply port 14.1 and the second supply port 14.2 are connected to a first hydraulic circuit called "main" comprising a first source of pressurized fluid.

[0042] The actuator 1 also includes a second tubular body or secondary body 20 which extends coaxially in line with the main body 10, so that the X axis is also a longitudinal axis of the secondary body 20. The secondary body 20 defines a second cylindrical cavity 21 which extends along the X axis and inside which the second section 40.2 of the rod 40 slides along said X axis.

[0043] The secondary body 20 comprises a first end fitted into the plug 60 and, opposite, a second end provided with a flange 22 for fixing the actuator 1 to the other of the structure S of the aircraft A and the leg J ​​of the landing gear L. The flange 22 comprises a ball joint tenon 23 arranged to receive a pin for fixing the actuator 1 to the other of the structure S of the aircraft A and the landing gear L.

[0044] The first end of the secondary body 20 includes a collar 23 forming a stop for the fitting of the secondary body 20 into the plug 60, and a third guide bore 24 extending coaxially in line with the second guide bore 61 of the plug 60. The third guide bore 24 includes an internal peripheral groove in which a sealing gasket 25 is received to ensure a tight sliding of the second section 40.2 of the rod 40 in said third guide bore 24.

[0045] The secondary body 20 and the plug 60 are held in position vis-à-vis the main body 10 by a retaining ring 70 screwed onto an external thread provided on the second end of the main body 10. The secondary body 20 and the plug 60 are said to be integral with the main body 10.

[0046] The actuator 1 also includes a separating piston 80 sliding in a sealed manner inside the second cylindrical cavity 21 of the secondary body 20, along the X-axis, between a first extreme position illustrated in Figures 2A-2B and a second extreme position illustrated in [Fig. 2C]. The separating piston 80 is arranged between a free end of the second section 40.2 of the rod 40 and a bottom of the second cavity 21 of the secondary body 20, such that the free end of the second section 40.2 forms a stop against the sliding of the separating piston 80 in the second cavity 21 of the secondary body 20.

[0047] The separator piston 80 defines, with the secondary body 20, a third chamber CH3 or backup chamber, and a fourth chamber CH4. The third chamber CH3 is delimited by a rear face of the separator piston 80 and the walls of the second cavity 21 of the main body 20, such that the volume of said third chamber CH3 varies according to the position of the separator piston 80. The fourth chamber CH4 is delimited by a front face of the separator piston 80, the walls of the second cavity 21 of the main body 20, and the walls of the channel 41 of the rod 40, such that the volume of said fourth chamber CH4 varies according to the position of the separator piston 80 and the position of the rod 40. The fourth chamber CH4 opens to the outside of the actuator 1 via the exhaust conduit 51 formed in the yoke 50.

[0048] The secondary body 20 also includes a third pressurized fluid supply port 26, which is provided at one end of said secondary body 20 and opens into the third chamber CH3 to move the separator piston 80 from the first extreme position to the second extreme position and thus bring the rod 40 to the extended position. The third supply port 26 of the secondary body 20 extends in the same plane P as the first and second supply ports 14.1, 14.2 of the main body 10, and is connected to a second hydraulic circuit, referred to as the "backup" hydraulic circuit. including a second pressurized fluid source independent of the first pressurized fluid source.

[0049] The operation of actuator 1 will now be detailed.

[0050] To cause the retraction of the lander L, pressurized fluid from the first pressurized fluid source is introduced into the first chamber CHi of the actuator 1 via the first supply port 14.1. The pressurized fluid exerts on the main piston 30 a thrusting force tending to move the main piston 30 from the second extreme position to the first extreme position, in other words to move the rod 40 from the extended position ([Fig.2B]) to the retracted position ([Fig.2A]).

[0051] To cause the deployment of the lander L in a so-called normal operating mode of the actuator 1, pressurized fluid from the first pressurized fluid source is introduced into the second chamber CH2 of the actuator 1 via the second supply port 14.2. The pressurized fluid exerts on the piston 30 a thrust force tending to move the piston 30 from the first extreme position to the second extreme position, in other words to move the rod 40 from the retracted position ([Fig.2A]) to the extended position ([Fig.2B]).

[0052] In the event of failure of the main hydraulic circuit or of a leak in the seal of the main piston 30 or of the plug 60 with respect to the main body 10, it is also possible, in a so-called backup operating mode of the actuator 1, to deploy the lander L by inserting pressurized fluid from the second pressurized fluid source into the third chamber CH3 of the actuator 1 via the third supply port 26. The pressurized fluid exerts on the rear face of the separator piston 80 a thrust force tending to move the separator piston 80 from its first extreme position to its second extreme position, said separator piston 80 then in turn exerting a thrust force on the free end of the second section 40.2 of the rod 40 tending to move the rod 40 from the retracted position to the extended position ([Fig.2C]).

[0053] Figures 3A-3C illustrate an actuator 1' which is none other than a variant of actuator 1.

[0054] The actuator 1' differs from the actuator 1 in that a secondary rod 90 extends axially from the front face of the separator piston 80. The secondary rod 90 is integral with the separator piston 80 and slides within the second section 40.2 of the main rod 40. It is understood that any movement of the separator piston 80 along the X-axis causes the rod 90 to slide along said X-axis, and that said secondary rod 90 guides the sliding of the separator piston 80 within the second cavity 21 of the main body 20. The rod 90 is hollow and includes a bore 91 opening into the channel 41 of the rod 40.

[0055] The separator piston 80 defines with the secondary body 20 the third chamber CH3 or relief chamber, and a fourth chamber CH4'. The fourth chamber CH4' is delimited by a front face of the separator piston 80, the free end of the second section 40.2 of the main rod 40, an external surface of the secondary rod 90, and the walls of the second cavity 21 of the secondary body 20. The volume of said fourth chamber CH4' varies according to the position of the separator piston 80 and the position of the rod 40. The fourth chamber CH4' is in fluidic communication with the second cavity 21 of the main body 20 via a plurality of holes 92 distributed equally and symmetrically on the external surface of said rod 90. The fourth chamber CH4' is thus connected to the channel 41 passing through the rod 40 and opening outside the actuator 1' via the exhaust conduit 51' formed in the yoke 50.

[0056] The operation of actuator 1' will now be detailed.

[0057] The retraction of the lander L is carried out in the same way as with the actuator 1: pressurized fluid from the first pressurized fluid source is introduced into the first chamber CHi of the actuator 1' via the first supply port 14.1. The pressurized fluid exerts a thrust force on the main piston 30 tending to move the main piston 30 from the second extreme position to the first extreme position, in other words to move the rod 40 from the extended position ([Fig.3B]) to the retracted position ([Fig.3A]).

[0058] The deployment of the lander L is carried out in the same way as with the actuator 1: pressurized fluid from the first pressurized fluid source is introduced into the second chamber CH2 of the actuator 1 via the second supply port 14.2. The pressurized fluid exerts a thrust force on the piston 30 tending to move the piston 30 equipped with the secondary rod 90 from the first extreme position to the second extreme position, in other words to move the rod 40 from the retracted position ([Fig.3A]) to the extended position ([Fig.3B]).

[0059] In the event of a failure of the main hydraulic circuit or a leak in the seal of the main piston 30 or the plug 60 vis-à-vis the main body 10, it is also possible, in a so-called backup operating mode of the actuator 1' similar to that of the actuator 1, to deploy the lander L by injecting pressurized fluid from the second pressurized fluid source into the third chamber CH3 of the actuator 1 via the third supply port 26. The pressurized fluid exerts a thrust force on the rear face of the separator piston 80, tending to move the separator piston 80 from its first extreme position to its second extreme position, said separator piston 80 then exerting at its around a pushing effort on the free end of the second section 40.2 of the rod 40 tending to move the rod 40 from the retracted position to the extended position ([Fig.3C]).

[0060] It is understood that the actuators 1,1': • incorporate a backup operating mode to deploy the L lander while limiting their size and minimizing the number of attachments to the L lander's J leg and the aircraft structure, and • allow for total segregation of the main hydraulic circuit and the backup hydraulic circuit.

[0061] 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.

[0062] Although the sliding stop of the secondary rod 90 in the main rod 40 is here achieved by the separating piston 90, it can be achieved in a different way: a ring fixed on an external periphery of the secondary rod 90, a reduction in the diameter of the channel 41 of the rod 40...

[0063] Although the actuator 1,1' is used here to perform the deployment and retraction of the lander L, it can also be used to perform the opening and closing of the hatch T.

[0064] Although the first power port 14.1, the second power port 14.2 and the third power port 26 of the actuator 1, 1' extend here in the same plane P, they can also extend in a different plane.

[0065] The retention of the secondary body 20 and the plug 60 can be ensured by any other means than the retaining ring 70, in particular by a screw ring ensuring redundancy of the retention function.

[0066] Although the first power port 14.1, the second power port 14.2 and the third power port 26 of the actuator 1, 1' extend here in the same plane P, they can also extend in a different plane.

[0067] Although the fourth chamber CH4 opens here outside the actuator 1 via the exhaust conduit 51 provided in the clevis 50, it can also open outside the actuator 1 via a leakage path provided between the secondary body 20 and the plug 60, for example via a groove provided in the plug 60 and a hole provided in the retaining ring 70.

Claims

Demands

1. Actuator (1, 1') for maneuvering a movable assembly (L, T) between two positions, the actuator comprising: - a main body (10) having a first cavity (11) extending along a longitudinal axis (X) of the actuator; - a secondary body (20), integral with the main body and having a second cavity (21) extending coaxially in the continuation of the first cavity; - a main piston (30) mounted movable in translation along the longitudinal axis in the first cavity (11) between a first extreme position and a second extreme position to define therein a first chamber (CH1) and a second chamber (CH2) of variable volumes; - a main rod (40) integral with the main piston and having a first section (40.1) and a second section (40.2) extending on either side of said main piston along the longitudinal axis, the first section extending outward from the main body opposite the secondary body and the second section extending into the second cavity of the secondary body; and - a separator piston (80) mounted movable in translation along the longitudinal axis in the second cavity (11) between a first extreme position and a second extreme position to define a third chamber (CH3) of variable volume with a bottom of the second cavity, the main rod forming a stop to the sliding of the separator piston, the main body comprising a first supply port (14.1) and a second supply port (14.2) opening respectively into the first chamber and the second chamber; and the secondary body comprising a third supply port (26) opening into the third chamber.

2. Actuator (1) according to claim 1, wherein the sliding stop of the separator piston (80) is formed by a free end of the second section (40.2) of the main rod (40).

3. Actuator (1) according to any one of the preceding claims, wherein a secondary rod (90) extends axially projecting from a front face of the separator piston (80), the secondary rod being integral with the separator piston and sliding in the second section (40.2) of the main rod (40).

4. Actuator (1') according to claim 3, wherein the secondary rod (90) defines with the second cavity (21) of the secondary body (20) a fourth chamber (CH4') of variable volume with the secondary body (20), the fourth chamber being in fluidic communication with the outside of the actuator.

5. Actuator (1') according to claim 4, wherein the fourth chamber (CH4') is in fluidic communication with a bore (91) of the secondary rod (90) via a plurality of holes (92) distributed equally and symmetrically on an external surface of said secondary rod to be connected to a channel (41) passing through the main rod (40) and connected to the outside of the actuator.

6. Actuator (1, 1') according to any one of the preceding claims, wherein the first cavity (11) is cylindrical.

7. Actuator (1, 1') according to any one of the preceding claims, wherein the second cavity (21) is cylindrical.

8. Actuator (1, 1') according to any one of the preceding claims, wherein the first feed port (14.1), the second feed port (14.2) and the third feed port (26) extend in the same plane (P) passing through the longitudinal axis (X).

9. Aircraft (A) comprising: • a landing gear (L) mounted movably in rotation on a structure (S) of the aircraft about a pivot axis (Y) between a deployed position and a retracted position; and • an actuator (1,1') according to any one of the preceding claims for maneuvering the landing gear between the deployed position and the retracted position, a free end of the first section (40.1) of the rod (40, 40') being connected to one of the landing gear and the aircraft structure, and a free end of the secondary body (20) being connected to the other of the landing gear and the aircraft structure.

10. Aircraft (A) comprising: • a movably rotating landing gear (L) mounted on a structure (S) of the aircraft around an articulation axis (Y) between a deployed position and a retracted position; • a cargo bay arranged to receive the landing gear (L), the cargo bay being closable by a hatch (T) mounted movable in rotation on a structure (S) of the aircraft between an open position and a closed position; • an actuator (1,1') according to any one of the preceding claims for maneuvering the hatch between the open position and the closed position, a free end of the first section (40.1) of the rod (40, 40') being connected to one of the hatch and the aircraft structure, and a free end of the secondary body (20) being connected to the other of the hatch and the aircraft structure.

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