Actuator for manoeuvring an assembly that is movable between two positions

Abstract

The invention relates to an actuator (1, 1'), which includes: - a main body (10) comprising a first cavity extending; - a secondary body (20), rigidly connected to the main body and comprising a second cavity extending as a continuation of the first cavity; - a piston (30) mounted so as to be translatable inside the first cavity (11) between a first end position and a second end position in order to define therein a first chamber (CH1, CH1') and a second chamber (CH2, CH2'); and - a rod (40, 40') rigidly connected to the piston and comprising a first section (40.1, 40.1') and a second section (40.2, 40.2') extending on either side of the piston, the first section projecting from the main body and the second section extending into the second cavity in order to define therein a third chamber (CH3, CH3'), the main body including a first supply port (14.1) and a second supply port (14.2) opening into the first chamber and the second chamber, respectively; and the secondary body including a third supply port (26) opening into the third chamber.

Description

[0001] Description

[0002] Title of the invention: Actuator for maneuvering a mobile assembly between two positions.

[0003] The present invention relates to an actuator for maneuvering a movable assembly between two positions, such as for example 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.

[0004] BACKGROUND OF THE INVENTION

[0005] Aircraft landing gear is known comprising a leg pivotally mounted on an aircraft structure between a deployed position and a retracted position.

[0006] In normal mode, leg deployment and retraction are generally accomplished by means of a main hydraulic circuit comprising a double-acting cylinder which has a first end coupled to the aircraft structure and a second end coupled to the leg.

[0007] For safety reasons, a landing gear must be able to deploy even if the actuator fails. Many landing gears are therefore designed so that their deployment can be carried out under the effect of gravity and / or aerodynamic moments applied to the landing gear leg.

[0008] However, when the landing gears deploy from rear to front relative to a main forward direction of the aircraft, the aerodynamic force applied in flight to the leg prevents the deployment of said landing gears.

[0009] It is known to equip the landing gear with a second so-called "emergency" cylinder which, in the event of failure of the double-acting cylinder, allows the landing gear to be deployed. However, it may prove complicated to integrate this second cylinder in an already very constrained environment. What is more, when the landing gear comprises several articulation axes, there may only be one possible position of the double-acting cylinder to deploy the landing gear solely via positive lever arms, so that the integration of a second cylinder may prove impossible.

[0010] It is also known, in the event of a failure of the main hydraulic circuit, to connect the double-acting cylinder to a secondary hydraulic circuit by means of a shuttle valve. However, such a solution does not allow for a failure of the double-acting cylinder, such as for example a deterioration of one of its seals.

[0011] SUBJECT OF THE INVENTION

[0012] The invention therefore aims to propose an actuator which at least partially overcomes the aforementioned drawbacks for maneuvering a mobile assembly between a deployed position and a retracted position.

[0013] SUMMARY OF THE INVENTION

[0014] For this purpose, an actuator is provided for maneuvering a mobile assembly between two positions, the actuator comprising:

[0015] - a main body comprising a first cavity extending along a longitudinal axis of the actuator;

[0016] - a secondary body, integral with the main body and comprising a second cavity extending coaxially in the extension of the first cavity;

[0017] - a 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; and

[0018] - a rod secured to the piston and comprising a first section and a second section extending on either side of the piston along the longitudinal axis, the first section extending in projection from the main body opposite the secondary body and the second section extending into the second cavity of the secondary body to define a third chamber of variable volume therein.

[0019] 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.

[0020] The actuator is thus similar to a double-acting cylinder in that it is possible to control a retraction or an extension of the rod by inserting, respectively via the first supply port or the 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 inserting a pressurized fluid into the second cavity via the third supply port.

[0021] According to a first embodiment of the invention, the rod comprises a bore delimiting with the second cavity the third chamber.

[0022] According to a second embodiment of the invention, the rod is telescopic and comprises a first rod element which is integral with the piston and a second rod element which fits and slides in the first rod element and in the cavity of the secondary body to define the third chamber therein, the first element or the second element comprising a stop for the fitting and sliding of the second element in the first element.

[0023] In particular, the second rod element also defines a fourth chamber of variable volume with the secondary body, the fourth chamber being in fluid communication with the exterior of the actuator. In particular, the fourth chamber is in fluid communication with a bore of the second rod element via a plurality of holes distributed equally and symmetrically on an external surface of said second element to be connected to a channel passing through the first element and opening to the exterior of the actuator.

[0024] In particular, the first cavity is cylindrical.

[0025] In particular, the second cavity is cylindrical.

[0026] In particular, the first feed port, the second feed port and the third feed port extend in the same plane passing through the longitudinal axis.

[0027] The invention also relates to an aircraft comprising:

[0028] - a landing gear mounted to rotate on a structure of the aircraft around an articulation axis between a deployed position and a retracted position; and

[0029] - an actuator according to the invention for maneuvering the landing gear between the deployed position and the retracted position, a free end of the first section of the rod being connected to one of the landing gear and the aircraft structure, and a free end of the secondary body being connected to the other of the landing gear and the aircraft structure.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The invention will be better understood in light of the following description, which is purely illustrative and not limiting, and must be read in conjunction with the appended drawings, among which:

[0032] [Fig.l] Figure 1 is a schematic view of an aircraft comprising a landing gear movable between a deployed position and a retracted position; [Fig.2A] Figure 2A is a perspective view of an actuator according to a first embodiment of the invention for maneuvering the landing gear illustrated in Figure 1;

[0033] [Fig.2B] Figure 2B is an axial sectional view of the actuator shown in Figure 2A, in which the actuator rod is in the advanced position;

[0034] [Fig.2C] Figure 2C is a view similar to Figure 2B, in which the actuator rod is in the retracted position;

[0035] [Fig.3A] Figure 3A is an axial sectional view of an actuator according to a second embodiment of the invention for maneuvering the aircraft landing gear illustrated in Figure 1, in which the rod of the actuator is in the retracted position and the separating piston is in its first extreme position;

[0036] [Fig.3B] Figure 3B is an axial sectional view of the actuator shown in Figure 3A, in which the actuator rod is in the advanced position and the separator piston is in its first extreme position;

[0037] [Fig.3C] Figure 3C is a view similar to Figure 2B, in which the actuator rod is in the advanced position and the separator piston is in its second extreme position.

[0038] DETAILED DESCRIPTION OF THE INVENTION

[0039] As illustrated in Figure 1, the invention is described here in relation to an aircraft A comprising a retractable landing gear L. The landing gear L comprises a leg J ​​having:

[0040] - 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 landing gear L is received in a hold H closable by a hatch T; and - a second end, opposite the first end, carrying an axle E on which wheels R are mounted to pivot.

[0041] The landing gear L thus forms a mobile assembly rotating around the Y axis of articulation of the leg J.

[0042] The deployment and retraction of the landing gear L is carried out by means of a hydraulic actuator 1 for maneuvering the landing gear L between its two positions.

[0043] With reference to Figures 2A-2C, the actuator 1 comprises, according to a first embodiment of the invention, a first tubular body or main body 10. The main body 10 delimits a first cylindrical cavity 11 which extends along a longitudinal axis X of said main body 10 and inside which a piston 30 slides in a sealed manner along the axis X. The piston 30 is associated with a rod 40 which extends along the axis X and which comprises a first section 40.1 and a second section 40.2 extending respectively upstream and downstream of the piston 30. It is understood that the rod 40 is integral with the piston 30 in that any movement of said piston 30 along the axis X causes said rod 40 to slide along said axis X. The rod 40 comprises a bore 41 opening onto a free end of the second section 40.2: the rod 40 is partially hollow.

[0044] The first section 40.1 of the rod 40 comprises a free end which extends outside the main body 10 and into which is screwed a yoke 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 comprises two internal peripheral grooves 13 in each of which a seal 13 is housed to ensure sealed sliding of the first section of the rod 40 in said first guide bore 12.

[0045] 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 comprises a collar 62 forming a stop for fitting the plug 60 into the second end of the main body 10, and an external peripheral groove in which a sealing joint

[0046] 63 is received to provide a seal between said second end of the main body 10 and said plug 60. The second guide bore 61 comprises an internal peripheral groove in which a seal

[0047] 64 is received to ensure a sealed sliding of the rod 40 in said second guide bore 61.

[0048] The piston 30 defines in the main body 10 a first chamber CHi or retraction chamber, and a second chamber CH2 or deployment chamber. The first chamber CHi is delimited by a front face of the piston 30, 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 piston 30, 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.

[0049] The volumes of the first and second chambers CHi, CH2 vary depending on the position of the piston 30. The piston 30 is movable in translation along the axis X, between a first extreme position (illustrated in FIG. 2B) and a second extreme position (illustrated in FIG. 2C) in which the rod 40 is respectively in the extended position and in the retracted position. The position of the rod 40 along the axis X is controlled by the position of the piston 30.

[0050] The main body 10 also comprises: - a first supply port 14.1 for pressurized fluid, which is provided at the first end of said main body 10 and which opens into the first chamber CHi to enable the piston 30 to be moved from the first extreme position to the second extreme position and thus bring the rod 40 into the retracted position; and

[0051] - a second supply port 14.2 for pressurized fluid, which is provided at the second end of said main body 10 and which opens into the second chamber CH2 to enable the piston 30 to be moved from the second extreme position to the first extreme position and thus bring the rod 40 into the extended position.

[0052] The first supply port 14.1 and the second supply port 14.2 extend in the same plane P passing through the longitudinal axis X, the plane P corresponding here to the section plane of the actuator 1 of figures 2B and 2C.

[0053] 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.

[0054] The actuator 1 also comprises a second tubular body or secondary body 20 which extends coaxially in the extension of the main body 10, so that the axis X is also a longitudinal axis of the secondary body 20. The secondary body 20 delimits a second cylindrical cavity 21 which extends along the axis X and inside which the second section 40.2 of the rod 40 slides along said axis X.

[0055] 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 23 arranged to receive an axis for fixing the actuator 1 to the other of the structure S of the aircraft A and the landing gear L.

[0056] The first end of the secondary body 20 comprises a collar 23 forming a stop for fitting the secondary body 20 into the plug 60, and a third guide bore 24 extending coaxially in the extension of the second guide bore 61 of the plug 60. The third guide bore 24 comprises an internal peripheral groove in which a sealing joint 25 is received to ensure sealed sliding of the second portion 40.2 of the rod 40 in said third guide bore 24.

[0057] The secondary body 20 and the plug 60 are held in position with respect to 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.

[0058] The rod 40 defines with the secondary body 20 a third chamber CHa or emergency chamber. The third chamber CHa is delimited by the bore 41 of the rod 40 and the walls of the second cavity 21 of the secondary body 20. The volume of the third chamber CHa varies according to the position of the rod 40, in other words according to the position of the piston 30.

[0059] The secondary body 20 also comprises a third supply port 26 for pressurized fluid which is provided at one end of said secondary body 20 and which opens into the third chamber CHa to move the piston 30 from the second extreme position to the first extreme position and thus bring the rod into 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.

[0060] The third supply port 26 is connected to a second hydraulic circuit called “emergency” comprising a second source of pressurized fluid independent of the first source of pressurized fluid.

[0061] The operation of actuator 1 will now be detailed.

[0062] 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

[0063] 14.1. The fluid inserted under pressure 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 extended position (figure 2B) to the retracted position (figure 2C).

[0064] 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

[0065] 14.2. The fluid inserted under pressure exerts on the piston 30 a thrust force tending to move the piston 30 from the second extreme position to the first extreme position, in other words to move the rod 40 from the retracted position (figure 2C) to the extended position (figure 2B).

[0066] In the event of a failure of the main hydraulic circuit or a leak in the sealing of the piston 30 or the plug 60 with respect to the main body 10, it is also possible, in a so-called emergency operating mode of the actuator 1, to deploy the landing gear L by inserting pressurized fluid from the second source of pressurized fluid into the third chamber CH3 of the actuator 1 via the third supply port 26. The fluid inserted under pressure exerts on a bottom of the bore 41 of the rod 40 a thrust force tending to move the rod 40 from the retracted position (figure 2C) to the extended position (figure 2B).

[0067] Figures 3A-3C illustrate an actuator 1', according to a second embodiment of the invention, making it possible to carry out the deployment and retraction of the landing gear L.

[0068] The actuator 1' differs from the actuator 1 in that the rod 40 is replaced by a telescopic rod 40'. The rod 40' comprises a first rod element 41' and a second rod element 42' fitting and sliding into the first element 41'.

[0069] The first rod element 41' is similar to the rod 40 and comprises a first section 41.1' and a second section 41.2' extending respectively upstream and downstream of the piston 30. Any movement of the piston 30 along the X axis between the first extreme position and the second extreme position respectively causes the first element 41' to slide along said X axis between an extended position (figures 3B and 3C) and a retracted position (figure 3A): the position of the first rod element 41' along the X axis is controlled by the position of the piston 30.

[0070] The piston 30 defines in the main body 10 a first chamber CHi' or retraction chamber, and a second chamber CH2' or deployment chamber. The first chamber CHi' is delimited by a front face of the piston 30, walls of the first cavity 11 of the main body 10 and an external surface of the first section 41.1' of the first rod element 41'. The second chamber CH2' is delimited by a rear face of the piston 30, 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 41.2' of the first rod element 41'. The first section 41.1' of the first rod element 41' comprises a free end which extends outside the main body 10 and into which the yoke 50 for fixing the actuator 1 to the structure S of the aircraft A or to the landing gear L is screwed. The first section 41.1' extends through the first guide bore 12 provided in the first end of the main body 10.

[0071] The second section 41.2' of the first rod element 41' extends through the second guide bore 61 formed in the plug 60 fitted into the second end of the main body 10.

[0072] The first rod element 41' differs from the rod 40 in that it is completely hollow and delimits a channel 41.1' passing through said first element 41' along the axis X. It will be noted that the yoke 50' comprises an exhaust duct 51' connecting the channel 41.1' to the outside of the actuator 1'.

[0073] The second rod element 42' fits and slides into the second section 41.2 of the first rod element 41': the second element 42' comprises a first end extending into the first element 41' and, opposite, a second end extending in axial projection from the first element 41', into the secondary body 20.

[0074] The second rod element 42' is partially hollow and comprises a bore 42.1' opening into the first end of said second element 42'.

[0075] The second end of the second rod element 42' comprises a collar 43' forming a stop for the fitting and sliding of the second element 42' in the first element 41'. The collar 43' comprises an external peripheral groove in which a seal 44' is received to ensure sealed sliding along the X axis of the second element 42' in the secondary body 20, between a first extreme position (illustrated in FIGS. 3A and 3B) in which the collar 43' of the second element 42' is in contact with the free end of the second section 41.2' of the first element 41' when said first element 41' is in the retracted position, and a second extreme position (illustrated in FIG. 3C) in which the collar 43' of the second element 42' is in contact with the free end of the second section 41.2' of the first element 41', said first element 41' being in the extended position.

[0076] The second element 42' defines with the secondary body 20 a third chamber CHa' or emergency chamber, and a fourth chamber CH4'. The third chamber CH3' is delimited by the second end of the second element 42' and the walls of the second cavity 21 of the secondary body 20. The volume of the third chamber CH3' varies depending on the position of the second rod element 42'. The fourth chamber CH4' is delimited by a free end of the second section 41.1' of the first rod element 41', the external surfaces of the second rod element 42' and the walls of the second cavity 21 of the secondary body 20. The volume of the fourth chamber CH4' varies depending on the position of the first rod element 41' and the second rod element 42'. The fourth chamber CH4' is in fluid communication with the bore 42.1' of the second rod element 42' via a plurality of holes 42.2' distributed equally and symmetrically on an external surface of said second element 42'. The fourth chamber CH4' is thus connected to the channel 41.1' passing through the first element 41' and opening outside the actuator 1' via the exhaust duct 51' formed in the yoke 50.

[0077] The first section 41.1' of the first rod element 41' forms a first section 40.1' of the rod 40'. The second section 41.2' of the first element 41' and the second rod element 42' together form a second section 40.2' of the rod 40'.

[0078] The first supply port 14.1 opens into the first chamber CHi' to move the piston 30 from the first extreme position to the second extreme position and thus bring the first element 41' of the rod 40' to the retracted position.

[0079] The second supply port 14.2 opens into the second chamber CH2' to move the piston 30 from the second extreme position to the first extreme position and thus bring the first element 41' of the rod 40' to the extended position.

[0080] The third supply port 26 opens into the third chamber CH3' to move the second element 42' of the rod 40' from the second extreme position to the first extreme position and thus bring, if necessary, the first element 41' of the rod 40' to the extended position.

[0081] The operation of the actuator will now be detailed.

[0082] To cause the retraction of the landing gear L, pressurized fluid from the first source of pressurized fluid is introduced into the first chamber CHi' of the actuator 1' via the first supply port 14.1. The fluid inserted under pressure 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 first rod element 41' from the extended position (figure 3B) to the retracted position (figure 3A).

[0083] To cause the deployment of the landing gear L in a so-called normal operating mode of the actuator 1', pressurized fluid from the first source of pressurized fluid is introduced into the second chamber CH2' of the actuator 1' via the second supply port 14.2. The fluid inserted under pressure exerts on the piston 30 a thrust force tending to move the piston 30 from the second extreme position to the first extreme position, in other words to move the first element 41' the rod 40' from the retracted position (figure 3A) to the extended position (figure 3B).

[0084] In the event of a failure of the main hydraulic circuit or a leak in the sealing of the piston 30 or the plug 60 with respect to the main body 10, it is also possible, in a so-called emergency operating mode of the actuator 1', to deploy the landing gear L by inserting pressurized fluid from the second source of pressurized fluid into the third chamber CHa' of the actuator 1' via the third supply port 26. The fluid inserted under pressure exerts on the second end of the second element 42' of the rod 40' a thrust force tending to move the second element 42' from its first extreme position (FIG. 3A) to its second extreme position (FIG. 3C), causing a movement of the first element 41' of the rod 40' from the retracted position to the extended position via the collar 43'.

[0085] It is understood that the actuators 1, the:

[0086] - integrate an emergency operating mode for deploying the landing gear L while limiting their size and minimizing their number of attachments with the leg J ​​of the landing gear L and the structure of the aircraft, and

[0087] - allow total segregation of the main hydraulic circuit and the emergency hydraulic circuit.

[0088] 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. Although the stop for the fitting and sliding of the second rod element 42' in the first rod element 41' is here produced by the collar 43' of said second element 42', it can be produced in a different manner: a ring fixed on an external periphery of the second element 42', a reduction in the diameter of the bore of the first element 41'...

[0089] Although the actuator 1 is here used to carry out the deployment and retraction of the landing gear L, it can also be used to carry out the opening and closing of the hatch T.

[0090] Although the rod 40 is here partially hollow to limit the weight of the actuator 1, it can also be solid.

[0091] Although the first supply port 14.1, the second supply port 14.2 and the third supply port 26 of the actuator 1, here extend in the same plane P, they can also extend in a different plane.

[0092] The secondary body 20 and the plug 60 can be held in place by any means other than the retaining ring 70, in particular by a screw crown ensuring redundancy of the holding function.

Claims

CLAIMS 1. Actuator (1, 1') for operating a mobile assembly (L) between two positions, the actuator comprising: - a main body (10) comprising a first cavity (11) extending along a longitudinal axis (X) of the actuator; - a secondary body (20), integral with the main body and comprising a second cavity (21) extending coaxially in the extension of the first cavity; - a piston (30) mounted to move 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 (CHi, CHi') and a second chamber (CH2, CH2') of variable volumes; and - a rod (40, 40') secured to the piston and comprising a first section (40.1, 40.1') and a second section (40.2, 40.2') extending on either side of the piston along the longitudinal axis, the first section extending projecting from the main body opposite the secondary body and the second section extending into the second cavity of the secondary body to define therein a third chamber (CH3, CH3') of variable volume, 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, in which the rod (40) comprises a bore (41) delimiting with the second cavity (21) the third chamber (CH3).

3. Actuator (1') according to claim 1, wherein the rod (40') is telescopic and comprises a first rod element (41') which is integral with the piston (30) and a second rod element (42') which fits and slides in the first rod element and in the cavity (21) of the secondary body to define the third chamber (CHa') therein, the first element or the second element comprising a stop for the fitting and sliding of the second element in the first element.

4. Actuator (1') according to claim 3, wherein the second rod element (42') also defines a fourth chamber (CH4') of variable volume with the secondary body (20), the fourth chamber being in fluid communication with the exterior of the actuator.

5. Actuator (1') according to claim 4, wherein the fourth chamber (CH4') is in fluid communication with a bore (42.1') ​​of the second rod element (42') via a plurality of holes (42.2') distributed equally and symmetrically on an external surface of said second element to be connected to a channel (41.1') passing through the first element (41') and opening outside the actuator.

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

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

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

9. Aircraft (A) comprising: - a landing gear (L) mounted mobile in rotation on a structure (S) of the aircraft around an axis (Y) of articulation 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, 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.

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