Aircraft wheel braking device
By designing a minimum clearance structure between the final stator disc and the torque tube in the aircraft wheel brake system, the problem of strut creep caused by frictional heat is solved, ensuring that the piston can continue to apply pressure during emergency braking, reducing the frequency of disc replacement and operating costs.
Patent Information
- Application Number
- CN202480011510.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2023-02-08
- Filing Date
- 2024-02-05
- Publication Date
- 2025-09-16
AI Technical Summary
In existing aircraft wheel brake devices, the heat release generated by friction causes axial creep of the struts, resulting in wheel disc displacement. The piston stroke is insufficient to continue to apply pressure, especially when the wheel disc is worn, and the frequency of wheel disc replacement is increased, resulting in high operating costs.
The shapes of the last stator wheel and the torque tube are designed to define a minimum gap, and the piston stroke is sufficient to continue to apply pressure when the strut creeps. Pressure transmission is ensured by providing a boss between the last stator wheel and the torque tube or a boss at the end of the torque tube to form a gasket.
It effectively avoids wheel disc displacement caused by strut creep, ensures that the piston can continue to apply pressure during emergency braking, reduces the frequency of wheel disc replacement, and reduces operating costs.
Smart Images
Figure CN120659742A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of aircraft wheel brakes. Background Art
[0002] Aircraft wheels are typically rotatably mounted on axles carried by the lower ends of the landing gear legs. Aircraft wheels may be equipped with brakes to slow down and stop the aircraft when it is on the ground.
[0003] The brake system typically includes a stack of discs, including stator discs and rotor discs, alternately stacked on a torque tube secured to the wheel axle. The stator discs are rotatably fixed relative to the wheel axle and include a rotor disc and further stator discs extending between a first stator disc and a last stator disc. The rotor discs are rotatably connected to the wheel.
[0004] The braking device also includes:
[0005] a hydraulic ring fixed to the first end of the torque tube and comprising an actuator provided with a piston arranged opposite the first stator disc for selectively applying pressure to the stack of discs; and
[0006] A stud arranged between the second end of the torque tube and the last stator disc in order to absorb the pressure and transmit it to the torque tube.
[0007] The heat release due to friction between the discs can be considerable (particularly during landing of the aircraft, when the energy to be dissipated is at its maximum due to the weight and high speed of the aircraft), which can cause axial creep of the struts, resulting in displacement of the stacked discs, with the final stator disc bearing against the torque tube. The piston travel may be insufficient to continue to exert pressure on the stacked discs, especially as the discs become worn.
[0008] Some have considered using actuators with longer strokes, but this approach is heavier, more cumbersome, and difficult to implement in an already defined and highly constrained environment.
[0009] Some have considered reducing the maximum allowable wear of the wheel discs, but this would lead to more frequent wheel disc replacements, which would incur significant costs for aircraft operators. Summary of the Invention
[0010] Therefore, the present invention aims to propose an aircraft wheel brake device that is able to at least partially avoid the above-mentioned problems.
[0011] To achieve this object, the present invention provides a braking device for an aircraft wheel, comprising:
[0012] - a torque tube extending along the longitudinal axis;
[0013] - the stacked brake discs include stator discs and rotor discs alternately stacked on the torque tube, the stator discs including a first stator disc and a last stator disc, and intermediate stator discs and rotor discs alternately arranged between the first stator disc and the last stator disc;
[0014] at least one actuator fixed to the first end of the torque tube and comprising a piston mounted to be movable in translation along an axis parallel to the longitudinal axis between a first end position and a second end position, in the first end position the piston being spaced apart from the stack of discs so as to apply pressure to the first stator disc; and
[0015] - at least one strut arranged between the second end of the torque tube and the last stator disc in order to absorb the pressure and transmit it to the torque tube.
[0016] According to the invention, the shape of the final stator wheel and the torque tube is designed to define a minimum gap between them along the longitudinal axis, which minimum gap is smaller than the distance separating the piston from its second end position when said piston applies pressure, for a given maximum amount of wear of the wheel.
[0017] Thus, even in the event of creep of the strut, which tends to cause the rearmost stator disc to bear against the second end of the torque tube (particularly during emergency braking), the piston travel is sufficient to allow the piston to continue to apply pressure. It should be noted that this adaptation of the rearmost stator disc and / or the torque tube does not affect other components of the braking system. The second end of the rearmost stator disc or the torque tube comprises at least one boss which, together with the torque tube or the rearmost stator disc, defines a minimum clearance.
[0018] According to a particular feature, the boss of the last stator disc comprises a main face extending in a plane orthogonal to the longitudinal axis, this main face defining, together with the torque tube, a minimum clearance.
[0019] Specifically, the braking device comprises a plurality of pillars evenly distributed around the longitudinal axis, and finally the stator wheel comprises a plurality of bosses, each boss extending between two adjacent pillars.
[0020] Specifically, the boss is in the shape of an arc and is inscribed in a circle whose center is the longitudinal axis.
[0021] The invention also relates to an aircraft wheel provided with such a braking device.
[0022] The invention also relates to an aircraft landing gear comprising at least one such wheel.
[0023] The invention also relates to an aircraft comprising at least one such landing gear. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The invention will be better understood from the following description, which is purely illustrative and not restrictive and should be read with reference to the accompanying drawings, in which:
[0025] [ Figure 1 ] Figure 1 is a simplified illustration of an aircraft comprising a wheel equipped with a braking device according to a first embodiment of the invention;
[0026] [ Figure 2 ] Figure 2 yes Figure 1 An axial cross-sectional view of one of the brake wheels of the aircraft is shown;
[0027] [ Figure 3A ] Figure 3A Is equipped with Figure 2 A perspective view of the last stator disc of the wheel brake device shown in FIG;
[0028] [ Figure 3B ] Figure 3B yes Figure 3A An axial cross-sectional view of the final stator wheel and torque tube is shown in FIG;
[0029] [ Figure 3C ] Figure 3C yes Figure 3A A perspective view of a variant of the final stator wheel disc shown in FIG;
[0030] [ Figure 4A ] Figure 4A is an axial cross-sectional view of a torque tube and a final stator disc of a brake device according to a second embodiment of the present invention;
[0031] [ Figure 4B ] Figure 4B yes Figure 4A An axial cross-sectional view of a first variant of the final stator wheel disc is shown in FIG;
[0032] [ Figure 4C ] Figure 4C yes Figure 4A An axial cross-sectional view of a second variant of the final stator wheel disc is shown in FIG;
[0033] [ Figure 5 ] Figure 5 FIG. 4 is an axial cross-sectional view of a torque tube and a final stator disc of a brake device according to a third embodiment of the present invention. DETAILED DESCRIPTION
[0034] like Figure 1As shown in the figure, the aircraft A comprises two main landing gears P, each comprising a leg J, the first end of which is articulated to the structure S of the aircraft A and the second end at the opposite end carrying a wheel 1 rotating on a tubular axle E around an axis X. The leg J is movable between a stowed position (not shown) and a deployed position (not shown).
[0035] The wheels 1 are called "braked", ie equipped with braking means 10 intended for selectively slowing down and stopping the aircraft A when it is on the ground. The following description refers to one of the braked wheels 1 , which in this example are identical but may also be different for the aircraft A.
[0036] refer to Figure 2 The wheel 1 comprises two wheel halves 1a, 1b, each comprising an annular rim 2a, 2b connected by means of webs 3a, 3b to half-hubs 4a, 4b, which are pivotally received on an axle E by means of bearings 5a, 5b. The wheel half 1a comprises a housing formed on the edge of the rim 2a and in which a sealing gasket 6 is arranged so that it is elastically compressed between the wheel halves 1a, 1b once they are assembled.
[0037] The wheel halves 1a, 1b move towards each other in a direction parallel to the axis of rotation X of the wheel 1 and include centering surfaces to ensure the correct relative positioning of the two wheel halves 1a, 1b. The wheel halves 1a, 1b are fixed in place by assembly bolts 7, which are arranged in holes drilled opposite each other in the webs 3a, 3b.
[0038] After the tire (not shown) has been mounted between the sidewalls of the rims 2a, 2b, the wheel halves 1a, 1b are assembled by tightening the bolts 7. In this position, the sealing gasket 6 is elastically compressed between the wheel halves 1a, 1b, thus preventing the gas contained in the volume defined by the tire and the wheel halves 1a, 1b from escaping to the outside of the wheel 1.
[0039] The brake device 10 comprises, in a manner known per se, a carbon brake disc 11 comprising stator discs 11.1, 11.2, 11.3, 11.4, 11.5 and rotor discs 12.1, 12.2, 12.3, 12.4, which are stacked alternately against one another on a torque tube 13 fixed to a hand E1 of the wheel axle E. The torque tube 13 and the stack of discs 11 extend inside the wheel half 1 a in an annular space defined by the inner surface of the rim 2 a, the web 3 a and the outer surface of the half hub 4 a, the outer surface of the half hub 4 a extending opposite the inner surface of the rim 2 a.
[0040] The stator wheels 11.1, 11.2, 11.3, 11.4, and 11.5 specifically include a first stator wheel 11.1 and a last stator wheel 11.5, and the rotor wheels 12.1, 12.2, 12.3, 12.4 and other stator wheels 11.2, 11.3, and 11.4 extend between the first stator wheel 11.1 and the last stator wheel 11.5 (hereinafter referred to as "intermediate stator wheels").
[0041] The first stator wheel 11.1 and the intermediate stator wheels 11.2, 11.3, 11.4 comprise axial peripheral notches, each receiving a tenon (not shown) fixed to the outer surface of the torque tube 13. The tenon extends along an axis parallel to the axis of rotation X of the wheel 1 and ensures that the first stator wheel 11.1 and the intermediate stator wheels 11.2, 11.3, 11.4 are coupled in rotation with the torque tube 13 about said axis X.
[0042] Finally, the stator disk 11.5 comprises a friction front face 11a facing the rotor disk 12.4 and a rear face 11b opposite the front face 11a, the rear face 11b facing the first end of the torque tube 13 near the web 3a. The front face 11a and the rear face 11b each extend in a plane substantially orthogonal to the axis X and define the thickness e of the stator disk 11.5.
[0043] refer to Figure 3A The rear face 11b of the final stator wheel 11.5 includes a plurality of cylindrical recesses 11c, evenly distributed about the axis X, which receive therein posts 14 (also called "pucks") integral with the first end of the torque tube 13. The final stator wheel 11.5 also includes holes 11d extending therethrough, each hole 11d including a tapered shoulder and opening into one of the recesses 11c of the rear face 11b. A rivet 15 extending into each hole 11d enables each post 14 to be secured to the final stator wheel 11.5.
[0044] The struts 14 are identical and include a tubular end 14 a extending along an axis parallel to the axis X and projecting from the rear face 11 b of the last stator disk 11 . 5 . The end 14 a of each strut 14 is received in a hole 13 a formed in the first end of the torque tube 13 , thereby ensuring that the last stator disk 11 . 5 is coupled in rotation with the torque tube 13 about the axis X. Furthermore, the end 14 a of the strut 14 includes a shoulder 14 b that bears against the periphery of the hole in order to absorb and, as will be seen later, transmit to the torque tube 13 the pressure exerted on the stack of disks 11 .
[0045] The rotor disks 12.1, 12.2, 12.3, 12.4 comprise axial peripheral recesses, each of which receives a portion of a rod (not shown) fixed to the inner surface of the rim 2a. The rod 14 extends along an axis parallel to the axis of rotation X of the wheel 1 and ensures that the rotor disks 12.1, 12.2, 12.3, 12.4 are coupled in rotation with the rim 2a about said axis X.
[0046] The braking device 10 also comprises a hydraulic ring 16 fixed to the second end of the torque tube 13 by means of screws 17. The ring 16 comprises a plurality of cavities 16a evenly distributed about the axis of rotation X of the wheel 1 and connected together by channels 16b. Each cavity 16a houses an actuator 18 which selectively applies pressure to the stack of wheel discs 11 along an axis parallel to the axis X, via a pressurized hydraulic fluid circulating inside the ring 16 through the channels 16b.
[0047] Each actuator 18 comprises a substantially cylindrical sleeve 18.1 received in a sealed manner in the cavity 16a of the ring 16, and a piston 18.2 mounted in the sleeve 18.1 so as to be movable along an axis parallel to the axis of rotation X of the wheel 1 in a first end position (e.g. Figure 2 1. The piston 18.2 slides between an initial position (shown), in which the piston 18.2 is retracted into the sleeve 18.1, and a second position (not shown), in which the piston 18.2 is extended from the sleeve 18.1. The first and second end positions define the stroke of the piston 18.2. One end of the piston 18.2 receives a washer 18.3 to push against the first stator disk 11a of the stack of disks 11. The uniform distribution of the actuators 18 about the axis X enables the pressure exerted by the piston 18.2 on the first stator disk 11.1 (via the washer 18.3) to be evenly distributed.
[0048] The pressure applied to the first stator disk 11.1 forces all the disks 11 to rub against each other, dissipating part of the kinetic energy of the aircraft A as heat. The friction of the disks 11 causes wear of the friction surfaces of the stator disks 11.1, 11.2, 11.3, 11.4, 11.5 and the rotor disks 12.1, 12.2, 12.3, 12.4, resulting in a reduction in their thickness.
[0049] According to the first embodiment of the brake device 10, the last stator wheel 11.5 comprises a boss 11e between each recess 11c, the boss being in the shape of a circular arc and protruding from the rear face 11b of the last stator wheel 11.5 ( Figure 3A and 3B). The boss 11e extends from a recess 11c to an adjacent recess 11c and is inscribed therein in a circle whose center substantially belongs to the axis X. Each boss 11e comprises a main face 11f extending in a plane parallel to the rear face 11b and arranged to bear against the end face 13b of the torque tube 13 in the event of axial creep of the strut 14, in particular during emergency braking applied by the actuator 18. The boss 11e thus forms a gasket capable of absorbing and transmitting the pressure to the torque tube 13 in the event of a failure of the strut 14.
[0050] The main face 11f of the boss 11e and the end face 13b of the torque tube 13 are arranged to define a minimum gap J between the last stator disk 11.5 and the torque tube 13 along the axis X. For a given maximum wear of the disks 11, the minimum gap J is less than the distance between the piston 18.2 of the actuator 18 and their second end position when the piston 18.2 is applying pressure to the first stator disk 11.1. Thus, even in the event of axial creep of the strut 14, which tends to move the stack of disks and bring the last stator disk 11.5 into bearing against the end of the torque tube 13, the piston 18.2 can continue to apply pressure to the stack of disks 11.
[0051] Figure 3C Shown Figure 3A A variant of the last stator wheel 11 . 5 in which the projections 11 e each extend between two adjacent recesses 11 c and have semicircular ends.
[0052] In the second embodiment of the brake device 10, the last stator disc 11.5 is Figure 4A The final stator disc 11.5' shown in FIG is replaced with the final stator disc 11.5'. Final stator disc 11.5' differs from final stator disc 11.5 in that its rear face 11b' lacks a boss. Rear face 11b' and front face 11a define a thickness e' of final stator disc 11.5', which is greater than the thickness e of final stator disc 11.5. Rear face 11b' is arranged to define a minimum gap J together with torque tube 13.
[0053] Figure 4B and 4C The corresponding Figure 4A5 '. The final stator discs 11.5' and 11.5'' are variations of the final stator disc 11.5' shown in FIG. The final stator discs 11.5' and 11.5'' differ from the final stator disc 11.5' in that they comprise rear faces 11b' and 11b'' which together with the front face 11a define a thickness e' and e'' of the final stator discs 11.5' and 11.5'', the thickness e' and e'' being different from the thickness e' of the final stator disc 11.5'. The thickness e' and e'' of the final stator discs 11.5' and 11.5'' are greater than the thickness e of the final stator disc 11.5, and the rear faces 11b' and 11b'' are arranged to define a minimum gap J together with the torque tube 13.
[0054] According to a third embodiment of the braking device 10, the last stator disc 11.5 consists of Figure 5 The last stator wheel disc 11.5" shown in the figure is replaced, and the torque tube 13 is replaced by a torque tube 13'. The last stator wheel disc 11.5"" differs from the last stator wheel disc 11.5 in that its rear face 11b"" does not have a boss. The rear face 11b"" and the front face 11a define the thickness of the last stator wheel disc 11.5", which is equal to the thickness e of the last stator wheel disc 11.5. The torque tube 13' differs from the torque tube 13 in that a boss 13e' is provided at the first end of the torque tube 13', which extends relative to the rear surface 11b"" of the last stator wheel disc 11.5". Each boss 13e' extends between two adjacent pillars 14 and includes a main surface 13f', which extends in a plane parallel to the rear surface 11b"" of the last stator wheel disc 11.5"" and bears against the rear face 11b"" in the event of axial creep of the pillar 14. Thus, boss 13e' forms a gasket capable of withstanding and transmitting the pressure to torque tube 13' in the event of a failure of strut 14. Main surface 13f' of boss 13e' is arranged to define a minimum gap J together with rear face 11b"" of rearmost stator disc 11.5".
[0055] Of course, the invention is not limited to the embodiments described but covers any variant coming within the ambit of the invention such as defined by the claims.
[0056] The rim can be made up of one or more parts.
[0057] The number of stator disks and the number of rotor disks may differ from that shown.
[0058] The number, shape and location of the struts 14 may vary from that shown.
[0059] The number of actuators 18 may be equal to or different from the number of struts 14 .
[0060] The number, shape, and position of the bosses 11e may be different from those shown in the figure.
[0061] Although the actuator in this example is hydraulic, it could also be electric.
[0062] Although the bosses 11 e , 13 e ′ are in this example made in one piece with the last stator wheel 11 . 5 , 11 . 5 ″″ and the torque tube 13 , 13 ′, they can also be added.
[0063] While the brake disc in this example is made of carbon, the bosses 11e, 13e' may be made of other materials such as steel, titanium, nickel / chromium / iron alloys such as Inconel brand alloys, polymers such as polyetheretherketone (PEEK), ceramics, etc.
Claims
1. A braking device (10) for an aircraft wheel (1), comprising: - a torque tube (13, 13') extending along the longitudinal axis; - a stacked brake disc (11), comprising stator discs (11.1, 11.2, 11.3, 11.4, 11.5, 11.5', 11.5", 11.5"', 11.5") and rotor discs (12.1, 12.2, 12.3, 12.4) stacked alternately on the torque tube, the stator discs comprising a first stator disc (11.1) and a last stator disc (11.5, 11.5', 11.5", 11.5"', 11.5"), intermediate stator discs (11.2, 11.3, 11.4) being arranged alternately with the rotor discs between the first stator disc (11.1) and the last stator disc (11.5, 11.5', 11.5", 11.5"', 11.5"); at least one actuator (18) fixed to a first end of the torque tube and comprising a piston mounted to be translationally movable along an axis parallel to the longitudinal axis between a first end position and a second end position, in which the piston is spaced apart from the stack of discs so as to apply pressure to the first stator disc; as well as - at least one strut (14) arranged between the second end of the torque tube and the last stator disc in order to receive and transmit pressure to the torque tube; It is characterized in that the shape of the last stator wheel and the torque tube is designed to define a minimum gap between them along the longitudinal axis, and for a given maximum wear of the wheel, the minimum gap is less than the distance that separates the piston from its second end position when the piston applies pressure.
2. The braking device (10) according to claim 1, characterized in that The last stator wheel disc (11.5) additionally comprises a boss (11e) protruding from a rear face (11b) of the last stator wheel disc (11.5), the boss defining the minimum gap (J) together with the torque tube (13).
3. The braking device (10) according to claim 2, characterized in that The boss (11e) includes a main face (11f) extending in a plane orthogonal to the longitudinal axis, the main face defining the minimum gap (J) together with the torque tube (13).
4. The braking device (10) according to claim 2 or 3, characterized in that The stator wheel disc (11.5) comprises a plurality of pillars (14) uniformly distributed around the longitudinal axis, and the last stator wheel disc (11.5) comprises a plurality of bosses (11e), each of which extends between two adjacent pillars.
5. The braking device (10) according to claim 4, characterized in that The boss (11e) is in the shape of an arc and is inscribed in a circle whose center is located on the longitudinal axis.
6. The braking device (10) according to claim 1, characterized in that The last stator wheel (11.5', 11.5", 11.5'", 11.5") comprises a rear face (11.b', 11.b", 11.b'", 11.b") which together with the torque tube (13, 13') defines the minimum gap (J).
7. The braking device (10) according to claim 1, characterized in that The second end of the torque tube (13') comprises at least one boss (13e'), which defines the minimum gap (J) together with the last stator wheel (11.5").
8. An aircraft wheel (1) provided with a braking device (1) according to any one of the preceding claims.
9. Aircraft landing gear (P) comprising at least one wheel (1) according to claim 8.
10. Aircraft (A) comprising at least one landing gear (P) according to claim 9.