Aircraft landing gear comprising a braked wheel with a vibration damping ring; aircraft equipped with such a landing gear

Abstract

Aircraft landing gear (2) comprising an axle (5), a wheel (10) rotatably mounted on the axle, and a wheel braking device (20), the braking device comprising a stack of discs (21) including rotor discs (21b) rotatably fixed to the wheel and arranged alternately with stator discs (21a) carried by a torsion tube (22) which is fixed to an actuator carrier (23) threaded onto the axle and equipped with at least one actuator (24) for selectively applying a pressing force on the stack of discs, the actuator carrier being rotatably fixed to the axle by means of a stop pin (30, 30') comprising a first portion (30.1, 30.1') extending through a first bore (6.1) formed in a clevis fixed to the axle and a second portion (30.2, 30.2') extending to through a second hole (23.1) made in the actuator holder. FIGURE IN THE ABRIDGED: Fig. 2

Description

Title of the invention: Aircraft landing gear comprising a braked wheel with a vibration damping ring, aircraft comprising such a landing gear

[0001] The present invention relates to the field of braking of an aircraft wheel and more particularly to a damping ring of a stop brake.

[0002] BACKGROUND OF THE INVENTION

[0003] Aircraft landing gear is known, having at one end an axle on which a wheel is mounted for rotation, intended to cooperate with a brake. Generally, the brake comprises discs extending inside the wheel rim, including rotor discs driven in rotation by the rim and arranged alternately with stator discs carried by a torsion tube fixed to the axle. For this purpose, the torsion tube is generally attached to an actuator carrier (23) which is threaded onto the axle and equipped with a plurality of actuators to selectively apply a pressing force to the stack of discs. The rotational locking of the actuator carrier relative to the axle, and thus the absorption of the braking torque, is ensured by a locking pin passing through the actuator carrier and a yoke fixed to the axle.

[0004] The stator discs have an inner rim with peripheral notches into which extend tenons formed from the material along with the torsion tube. These tenons prevent the stator discs from rotating relative to the torsion tube. Pressure applied to all the discs via actuators brings the discs into contact with each other, generating friction and thus a braking torque that slows the rotation of the wheel.

[0005] It has been observed that the pressure applied to all the discs at low speeds or at the end of braking causes repeated impacts between the stator discs and the torsion tube. These impacts generate vibrations that travel up the aircraft structure via the landing gear and are felt by the passengers. While these vibrations do not affect the mechanical strength of the landing gear or the aircraft structure, they do create a passenger comfort problem that can even damage the image of the airline operating the aircraft.

[0006] SUBJECT OF THE INVENTION

[0007] The invention therefore aims to provide an aircraft landing gear that at least partially overcomes the aforementioned drawback. Summary of the invention

[0008] To this end, an aircraft landing gear is proposed comprising an axle, a wheel mounted for rotation on the axle, and a wheel braking device. The device The braking system comprises a stack of discs including rotor discs fixed to the wheel and arranged alternately with stator discs carried by a torsion tube attached to an actuator carrier mounted on the axle and equipped with at least one actuator for selectively applying a pressing force to the stack of discs. The actuator carrier is rotationally connected to the axle by means of a stop pin comprising a first portion extending through a first bore in a bracket fixed to the axle and a second portion extending through a second bore in the actuator carrier.

[0009] According to the invention, at least one of the first portion and of the second portion extends through a ring inserted in the first or second bore, the ring comprising an intermediate sleeve and at least one of an inner sleeve and an outer sleeve extending respectively in the intermediate sleeve and around the intermediate sleeve, the intermediate sleeve being arranged to deform elastically under the effect of tangential forces passing between the actuator carrier and the clevis via the stop shaft and to absorb vibrations due to repeated shocks between the torsion tube and the stator discs during wheel braking via the braking device.

[0010] The ring thus makes it possible to attenuate the amplitude of the vibrations generated by the repeated shocks between the tenons and the stator discs, failing to be able to cut off the excitation or the structural natural mode at the origin of the vibrations.

[0011] According to a particular feature, the first portion of the stop shaft is received for adjustment in the first hole of the clevis, and the second portion of said stop shaft is received for adjustment in the ring which is received for adjustment in the second hole of the actuator carrier.

[0012] According to another particular feature, the first portion of the stop shaft is received for fit in the ring which is received for fit in the first bore of the clevis, and the second portion of said stop shaft is received for fit in the second bore of the actuator carrier.

[0013] In particular, the intermediate sleeve extends from the inner sleeve to the outer sleeve.

[0014] In particular, the intermediate sleeve is made of elastomer.

[0015] In particular, the intermediate sleeve is made of glass wool.

[0016] In particular, the inner sleeve and / or the outer sleeve are made of metal.

[0017] The invention also relates to an aircraft comprising at least one such landing gear. Brief description of the drawings

[0018] 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:

[0019] [Fig-1] [Fig.1] is a simplified view of an aircraft including landers main ones equipped with braked wheels according to the invention;

[0020] [Fig.2] [Fig.2] is an axial cross-sectional view of one of the braked wheels of the aircraft illustrated in [Fig.1];

[0021] [Fig.3] [Fig.3] is a cross-sectional view of the damping ring of the braked wheel illustrated in [Fig.2];

[0022] [Fig.4] [Fig.4] is an axial cross-sectional view of a variant of the braked wheel illustrated in [Fig.2]. DETAILED DESCRIPTION OF THE INVENTION

[0023] With reference to [Fig. 1], the invention is described in application to an aircraft 1 comprising two main landers 2. Each of the main landers 2 has a leg 3 having a first end articulated on a structure 4 of the aircraft 1 and, opposite, a second end provided with a tubular shaft or axle 5 carrying wheels 10 rotating about a longitudinal axis X of the axle 5. The main landers 2 are here of the retractable type, but the invention is applicable to fixed landers, or even to another type of vehicle such as a land vehicle.

[0024] The following description relates to one of the wheels 10 of the aircraft, the wheels 10 being identical here but also being different.

[0025] With reference to [Fig.2], wheel 10 comprises: • an annular rim 11 on which a tire 14 is mounted; • a hub 13 received for pivoting on the axle 5 by means of bearings (not shown); and • a veil 12 connecting the rim 11 to the hub 13.

[0026] The rim 11 has free ends, each provided with a rim 11.1 annular extending radially outwards from the wheel 10 to form axial stops preventing the tire 14 from coming off the rim.

[0027] The wheel 10 is said to be "braked", that is to say, equipped with a braking device 20 intended to selectively slow down and stop the aircraft 1 when it is on the ground.

[0028] The braking device 20 comprises discs 21, including stator discs 21a and rotor discs 21b, which are stacked alternately against each other on a torsion tube 22 extending around the axle 5.

[0029] The stator discs 21a have an inner contour which includes axial peripheral notches, each receiving a section of a stator tenon extending axially projecting from an outer surface of the torsion tube to ensure rotational coupling of the stator discs 21a with the torsion tube 22 around the longitudinal X axis of the axle 5. The stator tenons each have a longitudinal axis parallel to the X axis so as to form slides allowing the stator discs 21a to slide along said X axis.

[0030] The rotor discs 21b have an outer perimeter which includes axial peripheral notches each receiving a section of a rotor tenon extending axially outward from the inner surface of the rim 11 to ensure a rotational coupling of the rotor discs 21a with the rim 11 around the X axis of rotation of the wheel 10. The rotor tenons each have a longitudinal axis parallel to the X axis so as to form slides allowing the rotor discs 21b to slide along said X axis.

[0031] The braking device 20 further includes an annular actuator carrier 23 which is threaded onto the axle 5 and on which the torsion tube 22 is attached and fixed. It is understood that the torsion tube 22 is fixed with respect to the actuator carrier 23.

[0032] The actuator carrier 23 extends coaxially to the longitudinal X-axis of the axle 5 and is equipped with a plurality of actuators 24 that selectively exert a pressing force, parallel to the X-axis, on the stack of discs 21. The pressing force generates friction between the stator discs 21a and the rotor discs 21b, resulting in the application of a braking torque on the wheel 10. The ring arrangement of the actuators 24 allows the pressing forces to be distributed evenly over the entire surface of the first stator disc 21a.

[0033] The actuator carrier 23 is fixed to the axle 5 by means of fixing means comprising axial locking means (not shown) of the actuator carrier 23 along the longitudinal axis X of the axle 5 and rotational locking means of the actuator carrier 23 around said axis X. The axial locking means ensure the absorption of the pressing force developed by the actuators 24, and the rotational locking means ensure the absorption of the braking torque.

[0034] The means for locking against rotation include a stop pin 30 extending along an axis substantially parallel to the longitudinal axis X of the axle 5. The stop pin 30 includes a first end portion 30.1, of large diameter, extending through a cylindrical bore 6.1 formed in a clevis 6 integral with the lander 2, and a second end portion 30.2, opposite to the first end portion 30.1 and of small diameter, extending through a damping ring 40 inserted in a cylindrical bore 23.1 formed in the actuator carrier 23. This is referred to as a "stop brake".

[0035] The first end portion 30.1 and the second end portion 30.2 of the stop shaft 30 are respectively received to fit in the bore 6.1 of the clevis 6 and in the damping ring 40 which is itself received to fit in the bore 23.1 of the actuator holder 23.

[0036] The damping ring 40 is cylindrical in shape and has: • a thickness e40 approximately equal to half the difference between the small diameter and the large diameter of the stop shaft 30; • a length l40 substantially equal to a length of the drilling 23.1 of the actuator holder 23; • an external diameter D40 significantly smaller than that of the hole 23.1 in the actuator holder 23; and • an internal diameter d40 substantially greater than the diameter of the second end portion 30.2 of the stop shaft 30.

[0037] With reference to [Fig.3], the ring 40 comprises the assembly of three bushings extending into one another, namely an inner bushing 41, an outer bushing 42 and an intermediate bushing 43 situated between the inner bushing 41 and the outer bushing 42.

[0038] The intermediate sleeve 43 extends inside the external sleeve 42, an external surface of said intermediate sleeve 43 cooperating with an internal surface of said external sleeve 42. Similarly, the internal sleeve 41 extends inside the intermediate sleeve 43, an external surface of said internal sleeve 41 cooperating with an internal surface of said intermediate sleeve 43.

[0039] The inner sleeve 41 and the outer sleeve 42 have a substantially identical thickness e4b e42. The intermediate sleeve 43 has a thickness e43 that is substantially equal to twice the thickness e4b e42 of the inner and outer sleeves 41, 42. The inner sleeve 41, the outer sleeve 42, and the intermediate sleeve 43 have a substantially identical length Lu, 142, 143.

[0040] The thickness e40 of the ring 40 is equal to the sum of the thicknesses e4b e42, e43 of the inner, outer and intermediate bushings 41, 42, 43. The length of the ring 40 is substantially equal to the length of the inner, outer and intermediate bushings 41, 42, 43.

[0041] The inner, outer and intermediate sleeves 41, 42, 43 thus together form the ring 40, the outer sleeve 42 comprising an outer surface defining the outer surface of the ring 40, and the inner sleeve 41 comprising an inner surface defining the inner surface of the ring 40.

[0042] The inner sleeve 41 and the outer sleeve 42 are made of metal, while the intermediate sleeve 43 is made of a damping material arranged to deform elastically under the effect of tangential forces transmitted between the actuator carrier 23 and the clevis 6 of the lander 2 via the stop pin 30 and to absorb at less partially the vibrations due to repeated shocks between the stator discs 21a and the stator tenons of the torsion tube 22 during braking of the wheel 10 carried out via the braking device 20, in particular at low speed and when the braking torque exerted on the wheel 10 is between 400 and 1500Nm (Newton meter).

[0043] The material and thickness e43 of the intermediate sleeve 43 are chosen according to the required damping and absorption capacity. The intermediate sleeve 43 is here made of elastomer or glass wool and has a thickness of approximately 1 millimeter.

[0044] It is understood that the intermediate sleeve 43 allows local modification of the stiffness of the ring 40, and therefore of the interface between the actuator carrier 23 and the clevis 6 of the landing gear 2 through which the braking torque passes, so that said intermediate sleeve 43 makes it possible to limit the transmission of vibrations from the braking device 20 into the landing gear 2 and therefore into the structure 4 of the aircraft 1.

[0045] Fig. 4 illustrates a variant of the braking device 20 in which the stop pin 30 and the damping ring 40 are replaced by a stop pin 30' and a damping ring 40'.

[0046] The stop shaft 30' comprises a first end portion 30.1', of small diameter, extending through the damping ring 40' which is inserted into the cylindrical bore 6.1 formed in the clevis 6 integral with the lander 2, and a second end portion 30.2', opposite to the first end portion 30.1' and of large diameter, extending through the cylindrical bore 23.1 formed in the actuator carrier 23.

[0047] The first end portion 30.1' and the second end portion 30.2' of the stop shaft 30' are respectively received by fit in the damping ring 40' and in the bore 23.1 of the actuator carrier 23, the ring 40' itself being received by fit in the bore 6.1 of the clevis 6.

[0048] The ring 40' is cylindrical in shape and has: • a thickness approximately equal to half the difference between the small diameter and the large diameter of the stop axis 30'; • a length l40' approximately equal to a length of the drilling 6.1 of the screed 6; • an external diameter significantly smaller than that of hole 6.1 in clevis 6; and • an internal diameter substantially greater than the diameter of the first end portion 30.1' of the stop axis 30'.

[0049] Like the ring 40, the ring 40' comprises the assembly of three sleeves extending into one another, namely an inner sleeve, an outer sleeve, and an intermediate sleeve situated between the inner and outer sleeves. The sleeve The intermediate sleeve extends inside the outer sleeve, with an outer surface of said intermediate sleeve cooperating with an inner surface of said outer sleeve. Similarly, the inner sleeve extends inside the intermediate sleeve, with an outer surface of said inner sleeve cooperating with an inner surface of said intermediate sleeve.

[0050] The inner, outer and intermediate sleeves thus together form the ring 40', the outer sleeve comprising an outer surface defining the outer surface of the ring 40', and the inner sleeve comprising an inner surface defining the inner surface of the ring 40'.

[0051] As with the ring 40, the inner and outer sleeves of the ring 40' are made of metal, while the intermediate sleeve of said ring 40' is made of a damping material designed to deform elastically under the effect of tangential forces transmitted between the actuator carrier 23 and the clevis 6 of the landing gear 2 via the stop shaft 30'. The material and thickness of the intermediate sleeve are chosen according to the required damping and absorption capacity. It is understood that the intermediate sleeve makes it possible to locally modify the stiffness of the ring 40', and therefore that of the interface between the actuator carrier 23 and the clevis 6 of the landing gear 2 through which the braking torque is transmitted, so that said intermediate sleeve makes it possible to limit the transmission of vibrations from the braking device 20 into the landing gear 2 and therefore into the structure 4 of the aircraft 1.

[0052] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0053] Although the intermediate sleeve 43 is here made of elastomer or glass wool, any other suitable material may be used.

[0054] The ring 40, 40' may only include the outer sleeve 42 and the intermediate sleeve 43, the stop pin 30, 30' acted as the inner sleeve.

[0055] The ring 40, 40' may only include the inner sleeve 41 and the intermediate sleeve 43, the hole 6.1 in the clevis 6 or the hole 23.1 in the actuator holder 23 acted as an outer sleeve.

[0056] Although the stop axes 30, 30' are here equipped with the ring 40 or the ring 40', they can also be equipped with the ring 40 and the ring 40' so as to combine the damping generated by their intermediate bushings.

Claims

Demands

1. Landing (2) of an aircraft comprising an axle (5), a wheel (10) rotatably mounted on the axle and a wheel braking device (20), the braking device comprising a stack of discs (21) including rotor discs (21b) rotatably fixed to the wheel and arranged alternately with stator discs (21a) carried by a torsion tube (22) which is attached to and fixed to an actuator carrier (23) threaded onto the axle and equipped with at least one actuator (24) for selectively applying a pressing force on the stack of discs, the actuator carrier being rotatably fixed to the axle by means of a stop pin (30, 30') comprising a first portion (30.1, 30.1') which extends through a first bore (6.1) formed in a clevis fixed to the axle and a second portion (30.2, 30.2') which extends through a second bore (23.1) provided in the actuator carrier, characterized in that at least one of the first portion and of the second portion extends through a ring (40, 40') inserted in the first or second bore, the ring comprising an intermediate sleeve (43) and at least one of an internal sleeve (41) and an external sleeve (42) extending respectively in the intermediate sleeve and around the intermediate sleeve, the intermediate sleeve being arranged to deform elastically under the effect of tangential forces passing between the actuator carrier and the clevis via the stop shaft and to absorb vibrations due to repeated shocks between the torsion tube and the stator discs during braking of the wheel via the braking device.

2. Aircraft landing gear (2) according to claim 1, wherein the first portion (30.1) of the stop pin (30) is received to fit in the first hole (6.1) of the clevis (6), and the second portion (30.2) of said stop pin is received to fit in the ring (40) which is received to fit in the second hole (23.1) of the actuator carrier (23).

3. Aircraft landing gear (2) according to claim 1, wherein the first portion (30.1') of the stop pin (30') is received by fit in the ring (40') which is received by fit in the first bore (6.1) of the clevis (6), and the second portion (30.2) of said pin stop is received to fit in the second hole (23.1) of the actuator holder (23).

4. Aircraft landing gear (2) according to any one of the preceding claims, wherein the intermediate sleeve extends from the inner sleeve (41) to the outer sleeve (42).

5. Aircraft landing gear (2) according to any one of the preceding claims, wherein the intermediate sleeve (43) is made of elastomer.

6. Aircraft landing gear (2) according to any one of claims 1 to 4, wherein the intermediate sleeve (43) is made of glass wool.

7. Aircraft landing gear (2) according to any one of the preceding claims, wherein the inner sleeve (41) and / or the outer sleeve (42) are made of metal.

8. Aircraft (1) comprising at least one landing gear (2) according to any one of the preceding claims.

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