US-12620882-B2 - Eddy current magnetic braking device, braked vehicle wheel and aircraft landing gear equipped with such a wheel

US12620882B2US 12620882 B2US12620882 B2US 12620882B2US-12620882-B2

Abstract

A braking device includes one or more stationary elements and one movable element that is movable with respect to the one or more stationary elements, the moveable element being made of an electrically conductive material, one or the one or more stationary elements including magnets capable of generating eddy currents in the movable element, when the one or more stationary elements and the movable element are in relative movement. The magnets include first magnets and second magnets disposed alternating, the first magnets having a first magnetization vector and each of the second magnets having a second magnetization vector, and the magnets have widths such that the first magnets are spaced apart in pairs by a first distance that is less than a second distance separating the second magnets in pairs, and the length of the second magnets being around 70% of the length of the first magnets.

Inventors

Duy-Minh NGUYEN
Guillaume Durand
Graeme Klim

Assignees

SAFRAN LANDING SYSTEMS

Dates

Publication Date: 20260505
Application Date: 20220503
Priority Date: 20210503

Claims (9)

1 . An eddy current magnetic braking device comprising: at least one stationary element and one movable element that is movable with respect to the at least one stationary element in a movement direction, by having a surface opposite a surface of the at least one stationary element, the one moveable element being made of an electrically conductive material, one of the at least one stationary element comprising a plurality of magnets capable of generating eddy currents in the one movable element, when the at least one stationary element and the one movable element are in relative movement, wherein the plurality of magnets comprises first magnets and second magnets disposed alternating, the first magnets having a first magnetization vector substantially perpendicular to the opposite surfaces and each of the second magnets having a second magnetization vector substantially perpendicular to the first magnetization vectors of two first magnets, between which the second magnet is located, and wherein the plurality of magnets have widths, measured from end-to-end respectively, such that the first magnets are spaced apart in pairs by a first distance that is less than a second distance separating the second magnets in pairs, and wherein the first magnets have a length measured from end-to-end in a direction perpendicular to their width and locally parallel to the opposite surfaces which is greater than a length of the second magnets measured from end-to-end in a direction perpendicular to their width and locally parallel to the opposite surfaces, the length of the second magnets being around 70% of the length of the first magnets.
2 . The eddy current magnetic braking device according to claim 1 , wherein the width of the second magnets is around 70% of the width of the first magnets.
3 . The eddy current magnetic braking device according to claim 1 , wherein the first magnets represent around 70% of the surface of the at least one stationary element.
4 . The eddy current magnetic braking device according to claim 1 , wherein the at least one stationary element and the one movable element have a disc shape and have colinear central axes, the one movable element having a main face opposite a main face of the at least one stationary element, thus forming the opposite surfaces and the one movable element pivoting on its central axis, each first magnetization vector extending perpendicularly to the main faces, and each second magnetization vector extending parallel to the main faces and to a direction locally tangent to the at least one stationary element provided with the plurality of magnets, the width of each of the plurality of magnets being measured in a direction locally tangential to the at least one stationary element.
5 . The eddy current magnetic braking device according to claim 4 , wherein the plurality of magnets have an angular sector shape and the first magnets have a radial dimension from end-to-end greater than a radial dimension of the second magnets from end-to-end.
6 . The eddy current magnetic braking device according to claim 1 , wherein the magnets ( 11 , 12 , 13 , 14 ) are disposed according to a Halbach pattern.
7 . The eddy current magnetic braking device according to claim 1 , wherein the plurality of magnets are included in the at least one stationary element.
8 . A braked vehicle wheel comprising the the eddy current magnetic braking device according to claim 1 , wherein the braked vehicle wheel comprises a rim, a wall or a hub to which the one movable element is rotatably linked.
9 . A landing gear comprising a strut having a shaft at an end thereof, and the braked vehicle wheel according to claim 8 , wherein the braked vehicle wheel comprises the hub and the hub is mounted on the shaft, and wherein the at least one stationary element of the braked vehicle device is rotatably linked to the strut.

Description

This Application is a National Stage of International Application No. PCT/EP2022/061840 filed May 3, 2022, claiming priority based on French Patent Application No. 2104657 filed May 3, 2021 the contents of each of which being herein incorporated by reference in their entireties. The present invention relates to the field of the braking of vehicle wheels, such as aircraft wheels. BACKGROUND OF THE INVENTION An aircraft wheel generally comprises a rim connected by a wall to a hub mounted to rotate on a wheel support shaft (axle or spindle). Friction braking devices are known, comprising a brake disc stack which is housed in a space extending between the rim and the hub and which comprises alternating rotor discs rotatably linked with the wheel and stator discs, stationary with respect to the wheel support. The braking device also comprises hydraulic or electromechanical actuators mounted on an actuator carrier and arranged to apply a controlled braking force on the stack of discs, so as to block the rotation of the wheel. It has been proposed, in particular in document FR-A2953196, to equip such braked wheels with an electromagnetic auxiliary brake ensuring an energy dissipation by means other than mechanical friction. Eddy current magnetic braking devices are further known, used for the braking of vehicle wheels, and more specifically, aircraft wheels. Document WO-A-2014/029962 describes such a device comprising a rotor which is provided with one or more magnets, and which is mounted opposite an electromagnetic stator. Document US-A-20200300310 itself also describes an eddy current magnetic braking device. Generally, the performance of an eddy current magnetic braking device depends on the power of the magnets used and on their dimensions. The braking device is therefore relatively heavy and bulky when the maximum braking power required is significant. Such is the case, for example, of a use on an aeroplane, even though the mass and the bulk are severe constraints for this use. 1 Translation of the title as established ex officio. AIM OF THE INVENTION The invention aims, in particular, to propose an eddy current magnetic braking device, at least partially overcoming the abovementioned disadvantages. SUMMARY OF THE INVENTION To this end, an eddy current magnetic braking device according to the invention is provided, comprising at least one stationary element and one movable element with respect to the stationary element in a direction of movement by having a surface opposite a surface of the stationary element, one of the elements comprising a plurality of magnets capable of generating in the other of the elements, made of electrically conductive material, eddy currents, when the two elements are in relative movement. The plurality of magnets comprises first magnets that have a first magnetisation vector substantially perpendicular to the opposite surfaces and being separated in pairs by a second magnet that has a second magnetisation vector substantially perpendicular to the first magnetisation vectors of the two first magnets, between which the second magnet is located. The magnets have widths such that the first magnets are spaced apart in pairs by a first distance less than a second distance separating the second magnets in pairs. This arrangement of the magnets makes it possible to optimise and to concentrate the magnetic flow produced by the first magnets by reducing the return path of the magnetic flow which passes through the second magnets. The narrowest width of the second magnets surprisingly enables an increase of the eddy currents generated, and therefore an increase of the braking torque provided. This further has the advantage of limiting the mass and the bulk of the device. The invention also relates to a braked wheel equipped with such a device and a landing gear equipped with such a wheel. Other features and advantages of the invention will emerge upon reading the following description of particular and non-limiting embodiments of the invention. BRIEF DESCRIPTION OF THE DRAWINGS Reference will be made to the accompanying drawings, among which: FIG. 1 is a partial schematic view of an aircraft equipped with a landing gear according to the invention; FIG. 2 is a partial schematic view, as an axial cross-section, of a wheel equipped with a braking device according to a first embodiment of the invention; FIG. 3 is a partial schematic view, as an axial cross-section, of a wheel equipped with a braking device according to a second embodiment of the invention; FIG. 4 is a partial schematic view of an arrangement of magnets according to a particular embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION In reference to FIGS. 1 to 3, the braking system according to the invention is carried by an aircraft 100 comprising landing gears 101. Each landing gear 101 comprises a strut having an end provided with two coaxial shafts 102 on each of which a wheel 103 is mounted to pivot. Each wheel 1