Mounting bracket for a braked aircraft wheel

Abstract

Aircraft braked wheel (103) comprising: a rim (104) having an inner circumference defining a space for receiving brake rotor discs (107b); at least one bar (10) fixed to the rim by means of a screw (31) to link the brake rotor discs to the rim in rotation, the screw extending in a radial direction (Y) vis-à-vis the rim in a first bore (104.2) provided in the rim and in a second bore (12) provided in the bar; and a shim (20, 20', 20'') interposed between the rim and the bar and through which the screw passes, characterized in that a portion of the shim is received by fit in a first counterbore (104.3) formed at an entrance of the first hole (104.2) of the rim and / or in a second counterbore formed at an exit of the second hole of the bar. FIGURE IN ABBREVIATION: Fig. 4B

Description

Title of the invention: Fixing wedge for a braked wheel bar on an aircraft

[0001] The present invention relates to the field of aeronautics and, more particularly, to the braking of aircraft wheels.

[0002] BACKGROUND OF THE INVENTION

[0003] Aircraft wheels mounted on landing gear and equipped with a brake are known. The brake generally comprises stator discs arranged alternately with rotor discs, which are driven in rotation by bars attached to the inner circumference of a wheel rim. The bars are received in peripheral notches of the rotor discs in a direction substantially parallel to an axis of rotation of said wheel. Controlled pressure on all the discs generates friction between the opposing discs and thus a braking torque that slows the rotation of the wheel.

[0004] With reference to [Fig. 1A], certain known bars B are attached to the wheel rim and have at one end a cylindrical shank intended to be inserted into holes made in a rim face J, and at the opposite end a hole arranged to receive a screw V of a bolt passing through a hole in the rim J. Shims C are interposed between the bars B and the rim J in order, on the one hand, to position the bars B in a direction parallel to the axis of rotation of the wheel and, on the other hand, to help to limit the heat flow between the discs and the rim J which can be detrimental to a tire mounted on said rim J.

[0005] As illustrated in [Fig.1B], the shims C generally have an upper face cooperating with a lower surface of the rim J, and a lower face, substantially flat, cooperating with an upper surface of the bar B.

[0006] During braking, the friction between the stator discs and the rotor discs generates braking forces on the bars B tending to shear the screw V fixing the bar B to the rim J. These braking forces generate a slip of the bar B on the shim C but also a slip of the shim C on the rim J, which causes the screw V to bend and may cause it to break.

[0007] SUBJECT OF THE INVENTION

[0008] The invention aims to provide a fixing wedge for a braked wheel bar on an aircraft, thereby at least partially overcoming the aforementioned drawbacks. Summary of the invention

[0009] To this end, the invention proposes a braked aircraft wheel comprising: • a rim having an inner circumference delimiting a space for receiving brake rotor discs; • at least one bar fixed to the rim by means of a screw to rotationally link the brake rotor discs to the rim, the screw extending radially from the rim through a first hole in the rim and a second hole in the bar; and • a shim placed between the rim and the bar and through which the screw passes.

[0010] According to the invention, a portion of the shim is received by adjustment in a first counterbore made at an entry of the first drilling of the rim and / or in a second counterbore made at an exit of the second drilling of the bar.

[0011] The wedge cannot therefore slide on the rim during braking, whether circumferentially or axially with respect to said rim, so that the bending of the screw is limited.

[0012] In particular, the screw is received to fit in the wedge.

[0013] In particular, the wedge is annular in shape.

[0014] According to a particular characteristic, the wedge cooperates with a bottom of the first counterbore and / or with a bottom of the second counterbore.

[0015] According to another particular feature, the wedge includes a shoulder cooperating with an edge of the first counterbore and / or with an edge of the second counterbore.

[0016] The invention also relates to a landing gear comprising at least one such braked wheel.

[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 figures, among which:

[0019] [Fig. 1 A] [Fig. 1 A] is a perspective view of a braked wheel bar aircraft, equipped with a prior art wedge;

[0020] [Fig.1B] [Fig.1B] is a cross-sectional view of the bar and wedge illustrated in [Fig.1A], along a plane perpendicular to the axis of rotation of the wheel;

[0021] [Fig.2] [Fig.2] is a side view of an aircraft including landing gear landing gear equipped with braked wheels;

[0022] [Fig.3] [Fig.3] is an axial cross-sectional view of one of the braked wheels of the aircraft illustrated in [Fig.2], the rim of which is equipped with bars and shims according to a first embodiment of the invention;

[0023] [Fig.4A] [Fig.4A] is a perspective view of the bar and wedge illustrated in [Fig.3];

[0024] [Fig.4B] [Fig.4B] is a cross-sectional view along plane AA of the bar and wedge illustrated in [Fig.4A];

[0025] [Fig.5A] [Fig.5A] is a view identical to [Fig.4A], illustrating a wedge according to a second embodiment of the invention;

[0026] [Fig.5B] [Fig.5B] is a perspective view of a first variant of the wedge illustrated in [Fig.5A];

[0027] [Fig.5C] [Fig.5C] is a perspective view of a second variant of the wedge illustrated in [Fig.5A];

[0028] [Fig.6] [Fig.6] is a view identical to [Fig.4A], illustrating a wedge according to a third embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] With reference to Figures 2 and 3, an aircraft 100 according to the invention comprises a structure provided with landing gear 101. Each landing gear 101 comprises a leg having one end articulated to the structure of the aircraft 100 and an opposite end carrying an axle 102 on which a wheel 103 is mounted to pivot about an axis X.

[0030] The wheel 103 comprises two half-wheels, each having an annular rim 104a, 104b connected by a disc 105a, 105b to a half-hub 106a, 106b pivotally received on the axle 102. An inner surface of the rim 104a extends opposite an outer surface of the hub 106a and, together with the latter, defines a space for receiving a stack of brake discs. The stack comprises stator discs 107a fixed in rotation relative to the landing gear leg and rotor discs 107b having peripheral notches receiving bars, generally designated as 10, fixed to the inner surface of the rim 104a. The rotor discs 107b are thus driven in rotation by the rim 104a via the bars 10.

[0031] With reference to figures 4A-4B, each bar 10 comprises a body 11 extending along an axis Xi i substantially parallel to the axis X of rotation of the wheel 103. The body 11 comprises a first end 1 la, in the form of a cylindrical tail, which is received in an orifice of the rim 104a extending parallel to the axis X of rotation of the wheel 103, and a second end 11b having a bore 12 which extends in a radial direction Y with respect to the rim 104a and which is traversed by a screw 31 for fixing the bar 10 to an axial extension 104.1 of the rim 104a. The screw 31 comprises a head 31.1 bearing against an internal surface of the body 11 and, opposite it, a threaded end portion 31.2 extending through a bore 104.2 provided in the rim extension 104.1 in the radial direction Y. The threaded end portion 31.2 of the screw 31 extends outward from an external surface of the rim extension 104.1 and receives a nut 32 bearing against the external surface of said extension 104.1 via a washer 33. The screw 31, the nut 32 and the washer 33 form a bolt 30 for fixing the bar 10 to the rim 104a.

[0032] The body 11 of the bar 10 also includes two lateral bearing faces 13 extending parallel to the longitudinal axis Xi i of said body 11. The bearing faces 13 are intended to cooperate with riders 108 arranged in the peripheral notches of the brake rotor discs 107b. The two bearing faces 13 here form a non-zero angle α so that, in operation, they extend radially with respect to the rim 104a.

[0033] A shim 20 is interposed between the bar 10 and the rim extension 104.1 to both maintain the bar 10 in a position substantially parallel to the X axis of rotation of the wheel 103, form a mechanical interface between the bar 10 and the rim 104a, and form a thermal barrier to the conduction of heat from the bar 10 to the rim 104a. All of this is well known and is mentioned only for information purposes.

[0034] According to a first embodiment of the invention, the wedge 20 is generally annular in shape and has in its center a cylindrical hole 21 which extends along the radial direction Y and which receives substantially by adjustment the screw 31 for fixing the bar 10 to the rim extension 104.1.

[0035] The shim 20 externally comprises a shoulder 22 defining an upper portion 20a and a lower portion 20b of the shim 20. The upper portion 20a comprises a free end delimiting a first bearing face 20.1, annular and flat, cooperating with an external, flat surface of the body 11 of the bar 10. The lower portion 20b comprises an external circumference received for fitting in a counterbore 104.3 provided at an entrance of the bore 104.2 of the rim extension 104.1, and has a free end delimiting a second bearing face 20.2, annular and flat, cooperating with a bottom of the counterbore 104.3.

[0036] It is understood that the outer perimeter of the upper portion 20b of the wedge 20 cooperates with a lateral face of the counterbore 104.3, which prevents any movement of the wedge 20 in a plane perpendicular to the radial direction Y.

[0037] It is also understood that the upper portion 20b of the wedge 20 has a height greater than a height of the counterbore 104.3, so that the clamping forces of the bolt 30 pass through the bottom of the counterbore 104.3.

[0038] It will be noted that the lower portion 20a and the upper portion 20b of the wedge 20 include respectively a first recess 23.1 and a second recess 23.2 into which the hole 21 for the passage of the screw 31 opens in order to limit the weight of the wedge 20.

[0039] It should also be noted that the annular shape of the shim 20 allows it to be manufactured entirely by turning. Its manufacturing cost is thus controlled and limited compared to a prior art shim manufactured by milling. This annular shape, known as a shape of revolution, also eliminates the need for positioning the shim 20 with a keying mechanism, resulting in time savings during assembly.

[0040] During the braking of the wheel 103, the riders 108 arranged in the peripheral notches of the rotor discs 107b exert on the bars 10 braking forces substantially perpendicular to the radial direction Y tending to shear the screw 31 of fixing the bar 10 to the rim 104a.

[0041] By receiving the screw 31 in the hole 21, the shim 20 absorbs the shear forces to which said screw 31 is subjected and transmits them to the rim extension 104.1 via the side wall of the counterbore 104.3 while remaining stationary relative to said rim extension 104.1. The bending of the screw 31 is thus limited, which makes it possible to exploit the shear strength of the screw 31 and to prevent any breakage of said screw 31 during braking of the wheel 103.

[0042] Figure 5A illustrates a shim 20' according to a second embodiment of the invention. Similar to the shim 20, the shim 20' externally comprises a shoulder 22' defining a lower portion 20a' and an upper portion 20b' of the shim 20'. The shim 20' differs from the shim 20 in that the height of the upper portion 20b' of the shim 20' is less than the height of the counterbore 104.3 and in that the shoulder 22' forms a bearing surface cooperating with an inner surface of the rim extension 104.1 that extends around the counterbore 104.3. We understand that the 20' wedge is no longer supported against the bottom of the counterbore 104.3 but against an edge of the counterbore 104.3: the tightening forces of the bolt 30 pass through the said edge of the counterbore 104.3 and not the said bottom of the counterbore 104.3.

[0043] It will be noted that the shoulder 22' of the shim 20' has a greater height than that of the shoulder 22 of the shim 20 so that the bearing surface formed by said shoulder 22' cooperates sufficiently with the inner surface of the rim extension 104.1 to properly transmit the clamping forces of the bolt 30.

[0044] The spacer 20', like the spacer 20, absorbs the shear forces to which the screw 31 is subjected and transmits them to the rim extension 104.1 via the lateral wall of the counterbore 104.3 while remaining stationary relative to the rim extension 104.1. The bending of the screw 31 is thus limited, which makes it possible to utilize the shear strength of the screw 31 and to prevent any breakage of the screw 31 during braking of the wheel 103.

[0045] Figures 5B and 5C each illustrate a variant of the 20' wedge illustrated in [Fig.5A].

[0046] The wedge 20' illustrated in Figure 5B differs from that illustrated in [Fig.5A] in that it includes a flat 24' machined at the level of the first bearing face 20.1' with the body 11 of the bar 10.

[0047] The wedge 20' illustrated in Figure 5C differs from that illustrated in [Fig.5A] in that it comprises two bevels 25' extending symmetrically on either side of the first bearing face 20.1 with the body 11 of the bar 10.

[0048] The flat 24' and the bevels 25' are arranged to allow the shim 20' to be mounted, respectively in one direction and in two directions, between the rim extension 104.1 and the bar 10 in the presence of keying reliefs 14 extending outward from the outer surface of the body 11 of the bar 10 for prior art shims (figures IA, 4A).

[0049] Figure 6 illustrates a 20" spacer according to a third embodiment of the invention. The 20" spacer differs from the 20" spacer in that it lacks an external shoulder 22 and has a median plane of symmetry orthogonal to the radial direction Y, so that the 20" spacer can be mounted between the rim extension 104.1 and the bar 10 in either direction.

[0050] The shim 20”, like the shim 20, absorbs the shear forces to which said screw 31 is subjected and transmits them to the rim extension 104.1 via the lateral wall of the counterbore 104.3 while remaining stationary relative to said rim extension 104.1. The bending of the screw 31 is thus limited, which makes it possible to exploit the shear strength of the screw 31 and to prevent any breakage of said screw 31 during braking of the wheel 103.

[0051] 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.

[0052] Although the upper portion 20b, 20b' of the shim 20, 20' is here received by fit in the counterbore 104.3 made at the entrance of the bore 104.2 of the rim 104a, its lower portion 20a, 20a' can also be received by fit in a counterbore made at an exit of the bore 12 of the bar 10.

[0053] Although the shim is here annular in shape, it can adopt any other shape (oval, square, rectangular, triangular...) which, combined with an appropriate counterbore shape in the rim extension 104.1, prevents any slippage of the shim 20, 20', 20" on the inner surface of the rim 104a during braking.

[0054] Although the bar 10 is here fixed to the rim extension 104.1 by bolting using the bolt 30, it can also be fixed by screwing using a screw received in a tapped hole of the rim extension 104.1.

[0055] Although the bearing faces 13 of the bar 10 here form a non-zero angle α, they can also be parallel.

Claims

Demands

1. Aircraft braked wheel (103) comprising: - a rim (104a) having an inner circumference defining a space for receiving brake rotor discs (107b); - at least one bar (10) fixed to the rim by means of a screw (31) for rotationally linking the brake rotor discs to the rim, the screw extending in a radial direction (Y) vis-à-vis the rim in a first bore (104.2) provided in the rim and in a second bore (12) provided in the bar; and - a shim (20, 20', 20") interposed between the rim and the bar and through which the screw passes, characterized in that a portion of the shim is received by adjustment in a first counterbore (104.3) made at an entry of the first hole (104.2) of the rim and / or in a second counterbore made at an exit of the second hole of the bar.

2. Wheel (103) braked according to claim 1, in which the screw (31) is received to fit in the shim (20, 20', 20").

3. Wheel (103) braked according to any one of the preceding claims, wherein the wedge (20, 20', 20") is annular in shape.

4. Wheel (103) braked according to any one of the preceding claims, wherein the wedge (20, 20”) cooperates with a bottom of the first counterbore (104.3) and / or with a bottom of the second counterbore.

5. Wheel (103) braked according to any one of claims 1 to 3, wherein the wedge (20') comprises a shoulder (22') cooperating with an edge of the first counterbore (104.3) and / or with an edge of the second counterbore.

6. Landing gear (101) comprising at least one wheel (103) braked according to any one of the preceding claims.

7. Aircraft (100) comprising at least one landing gear (101) according to claim 6.

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