CALIPER BRAKING SYSTEM FOR AIRCRAFT LANDING GEAR HAVING A PLURALITY OF BRAKE DISK CLAMPING ZONES

Abstract

A braking system for aircraft landing gear including a plurality of clamping zones for clamping a brake disk. The braking system comprises an actuator, a caliper, a rim rotatable about an axis of rotation, and the brake disk, which is floatingly mounted relative to the rim. The caliper comprises a stationary inner support, a movable intermediate support, and an outer support that is hinged relative to the inner support. Under action of the actuator, the movable intermediate support moves and causes the brake disk to move so that the brake disk is clamped between the intermediate support and the outer support, and then causes the outer support to tilt so that the brake disk is damped between the inner support and the outer support.

Claims

1. A braking system for wheeled aircraft landing gear, the braking system comprising: at least one actuator; at least one caliper provided with a plurality of supports, each support including at least one pad; a rim movable in rotation about an axis of rotation; and a brake disk floatingly mounted relative to the rim, the brake disk including constraining elements that co-operate with notches in the rim; wherein the at least one caliper comprises a stationary inner support, a movable intermediate support that is movable under the action of an actuator, and an outer support hinged relative to the inner support, the brake disk being arranged firstly between the intermediate support and the cuter support, and secondly between the Inner support and the outer support, at least one pad being positioned between each support and the brake disk, such that under action of the actuator, the movable intermediate support moves and begins by causing a first movement of the brake disk so that the brake disk is clamped by means of the pads between the intermediate support and the outer support, and then continues to cause a second movement of the outer support so that the brake disk is clamped by means of the pads between the inner support and the outer support.

2. The braking system according to claim 1, wherein the braking system has a single actuator and a single caliper.

3. The braking system according to claim 1, wherein the braking system has at least two actuators and at least two calipers, with each actuator co-operating with a single caliper.

4. The braking system according to claim 1, wherein the at least one caliper has an inner support provided with at least one pad, an intermediate support provided with one pad, and an outer support provided with at least two pads, the brake disk being clamped following the action of the actuator, firstly between the pad of the intermediate support and one pad of the outer support, and secondly between at least one pad of the inner support and at least one pad of the outer support.

5. The braking system according to claim 4, wherein the at least one caliper has an inner support provided with one pad, an intermediate support provided with one pad, and an outer support provided with two pads.

6. The braking system according to claim 4, wherein the at least one caliper includes an inner support having two pads, an intermediate support provided with one pad, and an outer support provided with three pads.

7. The braking system according to claim 1, wherein the outer support is hinged relative to the inner support about a pivot axis arranged perpendicularly to a plane containing the axis of rotation of the rim and a clamping direction corresponding to a movement direction of the intermediate support under action of the actuator.

8. The braking system according to claim 1, wherein the pivot axis is arranged so as to intersect the axis of rotation and is situated in a midplane of the brake disk.

9. The braking system according to claim 7, wherein the pivot axis is offset relative to the axis of rotation in a direction perpendicular to the axis of rotation and to the pivot axis.

10. The braking system according to claim 7, wherein the pivot axis is offset relative to a midplane of the brake disk in a direction parallel to the axis of rotation.

11. Wheeled landing gear, wherein the wheeled landing gear includes at least one braking system according to claim 1.

12. An aircraft including wheeled landing gear and wherein the wheeled landing gear includes at least one braking system according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The invention and its advantages appear in greater detail from the context of the following description of examples given by way of illustration and with reference to the accompanying figures, in which:

[0050] FIG. 1 is a view of aircraft landing gear having a braking system of the invention;

[0051] FIG. 2 is a view of a brake disk of such a braking system;

[0052] FIG. 3 is a view of a rim of such a braking system:

[0053] FIGS. 4 and 5 show a first embodiment of the braking system;

[0054] FIG. 6 shows a second embodiment of the braking system; and

[0055] FIG. 7 shows a third embodiment of the braking system.

DETAILED DESCRIPTION OF THE INVENTION

[0056] Elements present in more than one of the figures are given the same references in each of them.

[0057] The aircraft may in particular include wheeled landing gear 5. The wheeled landing gear 5 possesses a landing gear leg 6 carrying both a wheel axle and a braking system 10.

[0058] The braking system 10 is provided with a rim 20 that is movable in rotation about an axis of rotation AXROT1, a brake disk 40 that co-operates with the rim 20, and also an actuator 11 with a caliper 12. Thus, during a braking action, the actuator 11 acts on the caliper 12 so as to clamp the brake disk 40 by means of pads 35, 36, 37 included in the caliper 12, so as to brake rotation of the brake disk 40, and consequently rotation of the rim 20.

[0059] Conventional bearing device may be arranged between the rim 20 and the wheel axle. In addition, the rim 20 carries a tire that is not shown for convenience. FIGS. 4 to 7 show embodiments of the braking system 10 in which the rim 20 is not shown for greater clarity.

[0060] FIG. 2 shows a brake disk 40 of such a braking system 10 for an aircraft. The brake disk 40 has a hollow central portion 43 and a plurality of constraining elements 42 formed by first teeth that extend substantially radially outwards from the brake disk 40. The brake disk 40 is of constant thickness, extending front a first disk face 53 to a second disk face 56.

[0061] Furthermore, FIG. 3 shows a rim 20 of such a braking system 10. The rim 20 is provided with a rim body 21 suitable for carrying a tire and it includes notches 29 that are open towards the outside of the rim 20 and that are distributed circumferentially around the axis of rotation AXROT1 of the rim 20. Each notch 29 is defined by a wall that is substantially U-shaped.

[0062] The brake disk 40 is floatingly mounted relative to the rim 20, as shown in FIG. 1. Specifically, the brake disk 40 is movable relative to the rim 20 so as to allow it to perform movements of small amplitudes, with the constraining elements 42 of the brake disk 40 co-operating with the notches 29 of the rim 20 so that the rim 20 and the brake disk 40 are constrained to rotate together about the axis of rotation AXROT1. Consequently, the transmission of mechanical stresses between the brake disk 40 and the rim 20 is limited.

[0063] In FIGS. 4 to 7, the caliper 12 of the braking system 10 has a plurality of clamping zones for clamping the brake disk 40. A first embodiment of the braking system 1G, as shown in FIGS. 4 and 5, has two brake disk clamping zones, while second and third embodiments of the braking system 10 as shown respectively in FIGS. 6 and 7 have three brake disk clamping zones.

[0064] In a manner that is common to all of these embodiments, the caliper 12 has a stationary inner support 31, a movable intermediate support 32, and an outer support 33 that is hinged about a pivot axis AXROT2 to pivot relative to the stationary inner support 31. The brake disk 40 is arranged firstly between the intermediate support 23 and the outer support 33, and secondly between the inner support 31 and the outer support 33, as shown in FIGS. 4 to 7. Each support 31, 32, 33 has at least one pad 35, 36, 37 arranged so as to be positioned between a support 33, 32, 33 and the brake disk 40.

[0065] The actuator 11 is constrained to the stationary inner support 31. The actuator 11 is a linear actuator, such as an actuator that is electrical, electromechanical, or indeed hydraulic, and it includes a movable rod 15 suitable for moving in translation along a clamping direction DIR1. The clamping direction DIR1 is parallel to the axis of rotation AXROT1. The inner support 31 has a first passage 38 allowing the movable rod 15 of the actuator 11 to act directly on the intermediate support 32 causing it to move parallel to the clamping direction DIR1. Furthermore, the movable rod 15 and the intermediate support 32 may constitute a single part.

[0066] In addition, the braking system 10 includes at least one pivot pin 34 arranged along the pivot axis AXROT2 between the inner support 31 and the outer support 33 thus forming a pivot connection between the inner support 31 and the outer support 33. The inner support 31 and the outer support 33 are preferably connected together by a pivot pin 34 in the hollow central portion 43 of the brake disk 40, thereby advantageously limiting the overall size of the braking system 10. In addition, the inner support 31 and the outer support 33 include a second passage 39 on the axis of rotation AXROT1 serving in particular to pass the wheel axle that supports the rim 20.

[0067] The pivot axis AXROT2 is arranged substantially perpendicularly to a plane containing the clamping direction DIR1 and the axis of rotation AXROT1 of the rim 20. In addition, in the first and second embodiments of the braking system 10, the pivot axis AXROT2 is arranged so as to intersect the axis of rotation AXROT1 and lies in a midplane P1 of the brake disk 40, the midplane P1 being parallel to and equidistant from the first disk face 53 and the second disk face 56 of the brake disk 40.

[0068] In the third embodiment of the braking system 10, the pivot axis AXROT2 is arranged so as to be offset firstly from the midplane P1 of the brake disk 40 parallel to the axis of rotation AXROT1, and secondly relative to the axis of rotation AXROT1 in a direction perpendicular to the axis of rotation AXROT1 and to the pivot axis AXROT2.

[0069] Advantageously, the caliper 12 of the braking system 10 thus includes at least one zone for clamping the brake disk 40 on either side of the pivot axis AXROT2. For each clamping zone, two supports 31, 32, 33 situated on either side of the brake disk 40 carry respective pads 35, 36, 37.

[0070] In the first embodiment, the intermediate support 32 co-operates with the outer support 33 to form a first zone for clamping the brake disk 40, while the inner support 31 co-operates with the outer support 33 to form a second clamping zone. The inner support 31 and the intermediate support 32 then carry respective single pads 35, 36, while the outer support 33 carries two pads 37. These two clamping zones may be of identical dimensions, as shown in FIG. 4.

[0071] In the second and third embodiments, the intermediate support 32 co-operates with the outer support 33 in order to form a first zone for clamping the brake disk 40, whereas the inner support 31 co-operates with the outer support 33 in order to form both a second clamping zone and a third clamping zone. The inner support 31 thus has two pads 35, the intermediate support 32 thus has a single pad 36, and the outer support 33 has three pads 37. In the second embodiment, these three clamping zones are of identical dimensions, as shown in FIG. 6, thereby serving to balance clamping of the brake disk and to obtain wear that is substantially uniform. In the third embodiment, the second and third clamping zones are of smaller dimensions than the first clamping zone, as shown in FIG. 7, thus serving to compensate for the pivot axis AXROT2 being offset relative to the midplane P1 of the brake disk 40 and relative to the axis for rotation AXROT1, thereby balancing clamping of the brake disk in spite of the offset.

[0072] In these second and third embodiments, the clamping zones of the braking system 10 are angularly distributed in regular manner around the axis of rotation AXROT1. Nevertheless, the angular distribution of the clamping zones of the braking system 10 about the axis of rotation AXROT1 could be irregular, regardless of whether the clamping zones are of dimensions that are identical or different, without degrading the operation and the advantages of this braking system 10.

[0073] During a braking action of the braking system 10, the actuator 11 generates movement along the clamping direction DIR1 of the movable rod 15, thereby moving the intermediate support 32 parallel to the clamping direction DIR1. The pad 36 on the intermediate support 32 is then touching the brake disk 40. The intermediate support 32 then continues to move parallel to the clamping direction DIR1 under the action of the actuator 11, leading to a first movement and/or a first deformation of the brake-disk 40 driven by the pad 36 on the intermediate support 32. The pad 37 of the outer support 33 then touches the brake disk 40, the brake disk 40 thus being clamped between the pads 36 and 37 of the intermediate support 32 and of the outer support 33.

[0074] The intermediate support 32 continues to move parallel to the clamping direction DIR1 under the action of the actuator 11, thereby causing the first movement and/or the first deformation of the brake disk 40 and also pivoting of the outer support 33 about the pivot axis AXROT2 relative to the stationary inner support 31. At least one pad 37 of the outer support 33 then touches the brake disk 40. The intermediate support 32 continues to move parallel to the clamping direction DIR1 under the action of the actuator 11, thereby giving rise to the first movement and/or the first deformation of the brake disk 40, to pivoting of the outer support 33, and to a second movement and/or a second deformation of the brake disk 40 driven by the outer support 33. At least one pad 35 of the inner support 31 then touches the brake 40, so that the brake disk 40 is thus clamped between the pads 35, 37 of the inner support 31 and of the outer support 33.

[0075] The brake disk is thus clamped over a plurality of clamping zones by means of the pads 35, 36, 37, firstly between the intermediate support 32 and the outer support 33, and secondly between the inner support 31 and the outer support 33. The force generated by the actuator 11 can thus advantageously be multiplied in order to obtain an amplified braking force.

[0076] Preferably, the braking system 10 may include a single actuator 11 and a single caliper 12, as shown in FIGS. 4 to 7, while still delivering a braking force that Is large and sufficient.

[0077] Naturally, the present invention may be subjected to numerous variations as to its implementation. Although several embodiments are described, it will readily be understood that it is not conceivable to identify exhaustively all possible embodiments. It is naturally possible to envisage replacing any of the means described by equivalent means without going beyond the ambit of the present invention.