Wheel support arm

Abstract

Arm (10) comprising a first end (11) provided with a first bore (12) extending along a first articulation axis (O12), and also comprising a second end (13) provided with a first shaft (14) extending along a second articulation axis (O14) substantially parallel to the first articulation axis (O12), the first bore (12) and the first shaft (14) are connected by a first web (30) and a second web (31) which are distinct and extend on either side of a first plane (P1) containing the first axis (O12) and the second axis (O14). Landing gear comprising such an arm. FIGURE OF THE ABSTRACT: Fig. 1

Description

Title of the invention: Wheel support arm

[0001] The present invention relates to the field of wheel support arms and more particularly to non-powered wheel support arms, in particular for landing gear.

[0002] BACKGROUND OF THE INVENTION

[0003] It is known to produce a wheel support arm using a connecting rod, the first and second ends of which are respectively provided with a first bore and a second bore extending along a first articulation axis and a second articulation axis parallel to each other.

[0004] The first bore generally accommodates mounting bearings for a first shaft secured to a vehicle chassis—here an aircraft. The second bore receives a second wheel shaft known as a “stub axle,” generally mounted in two adjustment bearings. A device for locking the rotation of the second shaft, such as a pin engaged in a radial bore of the second shaft or a stop plate cooperating with a groove in the second shaft, makes it possible to lock the rotation of the second shaft relative to the connecting rod. Devices for securing the position of the pin or the plate are also provided. The connecting rod body is conventionally made of a thick tube of large diameter.

[0005] Such a wheel support arm requires the assembly and manufacture of a large number of mechanical parts whose adjustments must be precise. Each part, and the corresponding assembly, must be calculated, controlled and verified. Finally, each mechanical part of the wheel support arm must be checked during maintenance operations.

[0006] The multiplicity of parts and assembly operations impacts the reliability and production cost of such wheel support arms. Finally, maintenance times (checking the adjustment parts and the correct tightening of the various devices) and stocks of spare parts are costly items on these critical parts.

[0007] SUBJECT OF THE INVENTION

[0008] The invention aims in particular to reduce the manufacturing and operating cost of a wheel support arm. Summary of the invention

[0009] For this purpose, an arm is provided comprising a first end provided with a first bore extending along a first articulation axis. The arm also comprises a second end provided with a first shaft extending along a second articulation axis substantially parallel to the first articulation axis. According to the invention, the first bore and the first shaft are connected by a first web and a second distinct sails extending on either side of a first plane containing the first axis and the second axis.

[0010] This results in an arm that is lighter than the arms of the prior art and which, using less material, is more economical to produce.

[0011] The dimensioning of the sails, and thus the weight of the wheel support arm, is further improved when the first and second sails are connected by a brace.

[0012] For the purposes of the present application, a brace is a reinforcing structure which connects the first web and the second web at points distinct from their ends.

[0013] The weight of the wheel support arm is further optimized when the brace and / or the first web and / or the second web are perforated.

[0014] Advantageously, the first distance measured in a second plane orthogonal to the first axis and which separates a neutral fiber of the brace from the first axis is between one third and two thirds of the distance which separates the first articulation axis from the second articulation axis and / or the second distance measured in the second plane and which separates the neutral fiber of the brace from the second axis is between one third and two thirds of the distance which separates the first articulation axis from the second articulation axis.

[0015] Advantageously, the first web has a first radius of curvature between one third and two thirds of the distance which separates the first articulation axis from the second articulation axis and / or the second web is rectilinear or has a second radius of curvature between one third and two thirds of the distance which separates the first articulation axis from the second articulation axis.

[0016] The weight of such a support arm is reduced when the first shaft is hollow.

[0017] The thermal stresses undergone by the arm and induced by the braking energy are reduced when the first shaft comprises a channel having an inlet port and an outlet port intended to be connected to a circuit for circulating a heat transfer medium. The performance and the service life of the arm and the rolling elements are thus improved.

[0018] Cooling of the part is particularly effective when the channel extends in a helix around the second articulation axis.

[0019] Advantageously, the arm incorporating the first shaft is made of a single piece. This results in a wheel support arm made of a single piece, which reduces assemblies and the risk of their failure. The management of the traceability of materials and supplies is simplified. The volume of labor to produce such an arm is also reduced. Finally, the maintenance operations of the arm according to the invention are reduced to checking the integrity of a single piece. The combination of these factors results in a wheel support arm that is more economical to operate than known wheel supports.

[0020] For the purposes of the present application, an arm is a single piece when it is made up of a single continuous part. Thus, a shaft attached to the shaft by being fitted into a bore of the shaft does not constitute a single piece for the purposes of the present application.

[0021] The invention also relates to a landing gear comprising an arm as described above.

[0022] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention. Brief description of the drawings

[0023] Reference will be made to the accompanying drawings, among which:

[0024] [Fig-1] [Fig.l] is a schematic perspective view from a first angle of the wheel support arm according to the invention;

[0025] [Fig.2] [Fig.2] is a schematic perspective view from a second angle of the support arm of [Fig.l];

[0026] [Fig.3] [Fig.3] is a schematic perspective sectional view of the support arm of [Fig.l];

[0027] [Fig.4] [Fig.4] is a partial schematic sectional view of the support arm of the [Fig.l];

[0028] [Fig.5] [Fig.5] is a schematic sectional view along a second plane P2 of the support arm of [Fig.l]. DETAILED DESCRIPTION OF THE INVENTION

[0029] With reference to [Fig.l], the landing gear of the invention, generally designated 1, comprises a wheel support arm 10. The first end 11 of the arm 10 is pivotally connected to a yoke 80 secured to an aircraft 81 using a shaft 82 (shown in dotted lines) engaged in a first bore 12 formed in the first end 11. The second end 13 of the arm 10 comprises a first shaft 14 on which a wheel 90 is rotatably mounted.

[0030] With reference to figures 1 to 3, the first bore 12 is made in a first substantially cylindrical portion 15 of the arm 10 and extends along a first articulation axis 012. The first shaft 14 extends projecting from a second cylindrical portion 16 of the arm 10 and along a second articulation axis 014 substantially parallel to the first axis 012.

[0031] As visible in figures 1, 2 and 4, a second axial bore 17 extends in the first shaft 14 along the second articulation axis 014 and also passes through the second portion 16.

[0032] The first shaft 14 also includes a channel 18 which extends helically around the second bore 17. The channel 18 has an inlet port 19 and an outlet port 20. The channel 18 here has a rectangular cross-section whose greatest width extends parallel to the second articulation axis 014. The inlet port 19 opens onto a first face 21 of the second portion 16 opposite the second face 22 of the second portion 16 from which the first shaft 14 projects. The inlet port 19 is connected to a first end of a water circulation circuit not shown. The outlet port 20 opens onto the distal end 23 of the shaft 14 and is connected to a second end of the water circulation circuit. The channel 18 is formed directly in the material of the shaft 14.

[0033] The first portion 15 and the second portion 16 are connected by a first web 30 and a second web 31 which are distinct and which extend on either side of a first plane PI containing the first articulation axis 012 and the second articulation axis 014. The first web 30 and the second web 31 are each formed by a first flat beam and a second flat beam which each have two main faces which are substantially parallel to each other: one of the main faces of the first flat beam extending opposite one of the main faces of the second beam. The first web 30 has a first radius of curvature Rc30 equal to one hundred and seventy-four millimeters and the second web 31 has a second radius of curvature Rc31 equal to three thousand millimeters.

[0034] A brace 32 connects the first web 30 and the second web 31. The first distance dl2-32 measured in a second plane P2 orthogonal to the first axis and which separates the neutral fiber 33 of the brace 32 from the first articulation axis 012 is, here, equal to one hundred and forty millimeters. The second distance dl4-32 measured in the second plane P2 and which separates the neutral fiber 33 from the second articulation axis 014 is equal to seventy millimeters.

[0035] As visible in [Fig.3], the first section S30 of the first web 30 considered according to a third plane P3 orthogonal to the first plane PI and parallel to the first articulation axis 012 is substantially rectangular.

[0036] The second section S31 of the second web 31 considered according to the third plane P3 is rectangular, just like the third section S32 of the brace 32 considered according to the third plane P3, which is also substantially rectangular.

[0037] The first web 30, the second web 31 and the brace 32 are openwork. More precisely, the first web 30 and the second web 31 are each provided with two identical openings, triangular or teardrop shaped, arranged symmetrically along the longitudinal axis of each web: the top of each opening is oriented towards the first end 11. The brace 32 is connected to the second web 31 between the two openings and to the first web 30 between the second end 13 and the adjacent opening. The brace 32 is itself provided with an opening. The main advantage of the openings is to lighten the structure of the arm.

[0038] A yoke extends projecting from the first web 31, in the vicinity of the second end 13 and opposite the second web 31 to allow the articulation of a connecting rod. The brace 32 is connected to the first web 30, directly above the end of the yoke located on the side of the openings made in the first web 30.

[0039] The arm 10 is here made of titanium by additive manufacturing so as to constitute a single-piece assembly.

[0040] 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.

[0041] In particular:

[0042] - although here the first portion and the second portion of the arm are of sen shape possibly cylindrical, the invention also applies to other shapes of first and second portion such as for example a square, triangular or any other section;

[0043] - although here the first channel is connected to a water circulation circuit, the invention also applies to other types of heat transfer medium such as glycolated water, freon;

[0044] - although here the arm is made by additive manufacturing to obtain a set monobloc titanium, the invention also applies to other manufacturing processes for obtaining a monobloc assembly such as for example casting, forging, welding or machining. The invention also applies to materials other than titanium such as for example stainless steel, bronze or aluminum;

[0045] - the openings may have a shape other than those described;

[0046] - although here the wheel support arm has been described in connection with an aircraft, the invention also applies to other types of vehicles such as land vehicles, particularly railway vehicles;

[0047] - although here the first radius of curvature is equal to one hundred and seventy-four thousand meters, the invention also applies to other values of the first radius of curvature and preferably a value between one third and two thirds of the distance which separates the first axis of articulation from the second axis of articulation;

[0048] - although here the second radius of curvature is equal to three thousand millimeters, the invention also applies to other values of the second radius of curvature and preferably a value between one third and two thirds of the distance which separates the first axis of articulation from the second axis of articulation;

[0049] - although here the first distance measured in a second plane orthogonal to the first axis and which separates the neutral fiber of the brace from the first articulation axis is equal to one hundred and forty millimeters, the invention also applies to other values of the first distance and preferably a value between one third and two thirds of the distance which separates the first axis of articulation from the second axis of articulation;

[0050] - although here the second distance measured in a second plane orthogonal to the first axis and which separates the neutral fiber of the brace from the second articulation axis is equal to seventy millimeters, the invention also applies to other values of the second distance and preferably a value between one third and two thirds of the distance which separates the first articulation axis from the second articulation axis.

Claims

Claims

1. Arm (10) comprising a first end (11) provided with a first bore (12) extending along a first articulation axis (012), the arm (10) also comprising a second end (13) provided with a first shaft (14) extending along a second articulation axis (014) substantially parallel to the first articulation axis (012),characterized in that the first bore (12) and the first shaft (14) are connected by a first web (30) and a second web (31) which are distinct and extend on either side of a first plane (PI) containing the first axis (012) and the second axis (014) and in that the first web (30) has a first radius of curvature (Rc30) of between one third and two thirds of the distance which separates the first articulation axis (012) from the second articulation axis (014) and / or in which the second web (31) is rectilinear or has a second radius of curvature (Rc31) of between one third and two thirds of the distance which separates the first articulation axis (012) from the second articulation axis (014).,

2. Arm (10) according to claim 1, wherein the first web (30) and the second web (31) are connected by a brace (32).

3. Arm (10) according to claim 2, wherein a first distance (dl2-32) measured in a second plane (P2) orthogonal to the first axis (012) and which separates a neutral fiber (33) of the brace (32) from the first axis (012) is between one third and two thirds of the distance which separates the first articulation axis (012) from the second articulation axis (014) and / or wherein the second distance (dl4-32) measured in the second plane (P2) and which separates the neutral fiber (33) of the brace (32) from the second axis (014) is between one third and two thirds of the distance which separates the first articulation axis (012) from the second articulation axis (014).

4. Arm (10) according to claim 2 or 3, in which the brace (32) is perforated.

5. Arm (10) according to any one of the preceding claims, wherein the first web (30) and / or the second web (31) is perforated.

6. An arm (10) according to any preceding claim, wherein the first shaft (14) is hollow.

7. An arm (10) according to any preceding claim, wherein the first shaft (14) comprises a channel (18) having a port inlet (19) and an outlet port (20) intended to be connected to a circulation circuit of a heat transfer medium.

8. An arm (10) according to any preceding claim, wherein the arm (10) incorporating the first shaft (14) is a single piece.

9. Landing gear (1) comprising an arm (10) according to any one of the preceding claims.

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