A static disc assembly for aircraft wheel brake

Abstract

A static disc assembly for aircraft wheel brakes has a protective sheet embedded and fixed in the convex key surface of the friction disc, and the concave arc surface of each protective sheet fits with the convex arc surface of the bottom of the protective sheet installation groove, and the convex arc surface of each protective sheet fits with the concave arc surface of the bottom of the protective sheet installation groove; the groove on each protective sheet corresponds to the concave keyway of the static disc. The present invention changes the force form of the static disc assembly, avoids the static disc concave keyway being stressed, increases the service life and safety of the static disc assembly, and can share the radial torque of the brake housing convex key through the coordinated use of the protective sheet groove, avoids the static disc groove being stressed and damaging the static disc, and increases the service life of the static disc.

Description

Technical Field

[0001] The invention relates to the field of aircraft brakes, in particular to a static disc assembly structure for aircraft wheel brakes. Background Art

[0002] The aircraft brake wheel includes a wheel assembly and a brake device. The wheel assembly and the brake device are installed together on the main landing gear shaft of the aircraft. The wheel assembly is mainly used to bear the weight of the aircraft and support the aircraft; the brake device is mainly used for braking the aircraft. The brake device is mainly composed of a cylinder seat, a piston assembly, a brake housing, a pressure plate assembly, a dynamic plate assembly, a static plate, a pressure plate, a steel pressure plate, etc. The static plate cooperates with the convex key of the brake housing through a keyway and is fixed to the aircraft landing gear. When the aircraft brakes, the brake hydraulic oil enters the cylinder seat under the action of the brake pressure, pushing the piston to move axially, and the pressure plate presses the static plate, the pressure plate and the dynamic plate that rotates with the wheel, generating a friction torque to brake the wheel.

[0003] The types of brake discs in existing brake devices include: steel brake disc assembly: the friction part of the brake disc is made of powder metallurgy material, and the skeleton is made of steel material; carbon-carbon brake disc assembly: the brake disc is formed by deposition of carbon-carbon composite material, and the brake disc is an integral part; carbon-ceramic brake disc assembly, the brake disc is formed by deposition of carbon-ceramic composite material, and the brake disc is an integral part.

[0004] Since the concave keyway of the static disc of the carbon-carbon composite material or carbon-ceramic composite material needs to cooperate with the convex key of the brake housing made of steel or titanium alloy, but the strength of the carbon-carbon composite material or carbon-ceramic composite material is relatively low compared to steel and titanium alloy materials, when the static disc keyway and the convex key of the brake housing are directly matched and subjected to force, the surface of the static disc keyway is easily damaged or deformed after being subjected to force for a long time, affecting the service life and safety of the carbon brake disc. When the aircraft brakes, the friction of the brake disc will generate high temperature. The keyway will be subjected to load at high temperature for a long time, which will accelerate the damage and deformation of the surface of the static disc keyway. In the case of aircraft overload, the keyway is more likely to collapse when it is subjected to excessive torque.

[0005] By searching keywords: static disc, static disc assembly, brake pad, brake disc, carbon brake disc, carbon ceramic brake disc, carbon-carbon composite material, carbon ceramic composite material, aircraft, wheel, brake device, brake, Xi'an Aviation Technology Brake, Zhang Wanshun, Deng Qian, Lou Jintao, Xia Mengcong, Li Shuo. The relevant invention patents are as follows:

[0006] In the invention with patent number 201611200855.4, an aircraft carbon / ceramic brake device is proposed. In the invention with patent number 201721276237.8, an aircraft brake device is proposed. In the invention with patent number 201721255769.3, an aircraft main wheel brake device assembly is proposed. In the invention with patent number 201620685578.X, an aircraft main wheel brake device is proposed. In the invention with patent number 201520069451.0, a main wheel brake device is proposed. The brake stator in the above brake devices is supported by carbon-carbon or carbon-ceramic materials and is an integral structure. There is no protective structure at the keyway of the brake stator, and it is in direct contact with the brake housing.

[0007] In the invention with application number 201610037039.X, a U-shaped key force transmission device for aircraft carbon / carbon brake disc is proposed. The brake disc body and the brake disc body of the invention are provided with concave grooves, and a metal key clamp is connected to the outer edge of the brake disc body between two adjacent concave grooves by rivets, which is characterized in that: a protective coating is coated on the inner surface of the concave groove and a U-shaped key is installed, the metal key clamp is in a fixed state, the U-shaped key is limited in the concave groove between the two metal key clamps, and the U-shaped key can move along the outer circumferential direction of the brake disc body within the interval locked by the two adjacent metal key clamps, the U-shaped key is immovable along the radial direction of the brake disc body, and when the end face of the brake disc body is used as the reference face, the force-bearing surface of the assembled U-shaped key is higher than the end face of the metal key, which can ensure

[0008] When the brake disc body and the metal force transmission key work, the metal key clamp is not subjected to force.

[0009] The surface is protected, and the external dimensions of the grooves and cams are required to be high, so it is not suitable for static disks with smaller inner diameters.

[0010] In the invention with application number 201810426331.X, an aircraft carbon brake disc steel clip is proposed. The invention includes a first steel clip, a second steel clip and a rivet, which solves the problem that the inner diameter of the brake disc is small and cannot meet the size and space requirements for installing a general single steel clip. It can protect the convex key on the inner ring of the brake disc, reduce the impact on the keyway, and extend the life of the brake disc. This technology is to make a protective structure on the outside of the brake disc, while the present invention is to embed a reinforced protective structure inside the brake disc. The purpose is similar, but the structure is not similar. Summary of the invention

[0011] In order to overcome the shortcomings of the prior art that there is no protective structure at the keyway of the static disc, and that the keyway becomes widened and crushed due to long-term direct contact with the brake housing; and the defect that the inner diameter of the static disc is small and insufficient to install a single protective device on each keyway, the present invention proposes a static disc assembly for aircraft wheel brakes.

[0012] The present invention comprises a static plate and three protective plates; the static plate comprises a friction plate and a plurality of convex keys evenly distributed on the inner circumferential surface of the friction plate; the protective plates are arc-shaped strips, embedded and fixed in the protective plate mounting grooves on the inner arc surfaces of the convex keys.

[0013] The protection sheet installation groove is opened on the inner arc surface of each convex key and extends in a circular ring shape along the circumference of the convex key. The center line of the installation groove in the width direction is located on the symmetric plane of the axial length of the convex key. The width of the protection sheet installation groove is 3 to 5 mm.

[0014] The bottom surface of each protection sheet installation groove is a concave arc surface and a convex arc surface that are smoothly connected to form a circle, and the vertices of the concave arc surface correspond to the center line of the width of the static plate key slot, and the vertices of the convex arc surface correspond to the center line of the width of the static plate convex key. The radius of the concave arc surface is the same as that of the convex arc surface.

[0015] The outer circumferential surface of the protection sheet is a convex arc surface and a concave arc surface that match the bottom surface of the protection sheet installation groove, so that the concave arc surface of each protection sheet fits with the convex arc surface of the bottom of the protection sheet installation groove, and the convex arc surface of each protection sheet fits with the concave arc surface of the bottom of the protection sheet installation groove; grooves are evenly distributed on the inner circumferential surface of each protection sheet, and each groove is located at each convex arc surface of the protection sheet, so that the center line of each groove in the width direction corresponds to the vertex of each convex arc surface. The width of the groove is 1 to 3 mm smaller than the width of the keyway on the static plate.

[0016] The width of the protection sheet installation groove is 3-5 mm; the radius of the concave arc surface and the convex arc surface is 22-28 mm.

[0017] The inner radius of the protection plate is the same as the inner radius of the static disk.

[0018] Rivet holes are distributed on both sides of the groove, and each rivet hole corresponds to a rivet hole on the static disk one by one.

[0019] The surface of the convex key is evenly distributed with two through rivet holes.

[0020] The present invention can optimize the existing stator disk assembly structure, change the stress form of the stator disk assembly, avoid stress on the stator disk concave keyway, and increase the service life and safety of the stator disk assembly.

[0021] To facilitate the installation of the protective sheet in the protective sheet installation groove, the present invention has three protective sheets, which are arc-shaped strips that divide the circumference into three equal parts. The protective sheet is embedded in the protective sheet installation groove. To avoid stress on the wall of the static plate groove, the width of the groove is 1 to 3 mm smaller than the width of the keyway on the static plate. Rivet holes are distributed on both sides of the groove, and each rivet hole corresponds to the rivet hole on the static plate.

[0022] When the static disc assembly of the new structure is matched with the brake housing, the concave keyway of the static disc made of carbon-carbon composite material or carbon-ceramic composite material and the concave keyway of the protective plate are matched with the convex key of the brake housing made of steel or titanium alloy. The coordinated use of the groove of the protective plate can protect the low-strength static disc groove, share the radial torque of the convex key of the brake housing during use, and avoid static

[0023] The disc groove is stressed to damage the static disc, thus increasing the service life of the static disc.

[0024] Compared with the prior art, the aircraft wheel brake static disc assembly proposed by the present invention has the following characteristics:

[0025] The present invention includes a brake stator, a protective sheet and rivets. The stator assembly with a new structure can effectively reduce the failure of the stator caused by excessive deformation and damage of the keyway, improve the stability and safety of the stator assembly, and extend the service life of the stator brake disc by 60%.

[0026] The static disc assembly adds a steel protective plate part with a keyway width slightly smaller than the static disc keyway width. When cooperating with the brake housing cam, the protective plate keyway replaces the static disc keyway to bear the force. Since the strength of steel material is greater than that of carbon-carbon and carbon-ceramic materials, deformation of the static disc keyway can be avoided during use.

[0027] The static disc assembly adds a steel protective plate with a concave arc surface and a convex arc surface tangently connected in a circle. The protective plate is designed with this structure to increase the contact area between the protective plate and the static disc, increase the radial force area by 22% to 100%, disperse and bear part of the radial force transmitted by the brake housing, reduce the pressure on a single side of the static disc keyway, and improve the stress condition of the static disc assembly.

[0028] The present invention embeds a reinforced protection structure inside the brake disc, and the size of the protection sheet can be adjusted according to the inner diameter of the static disc, and has no similarity with the existing structure. The existing static discs are mostly integrally formed, using carbon-carbon or carbon-ceramic materials, and there is no protection structure at the keyway, and they are directly in contact with the brake housing. The static disc assembly with a protection structure at the keyway is a protection structure outside the brake disc, which has high requirements on the inner diameter of the static disc and is not suitable for small inner diameters.

[0029] The brake device was assembled with the original structure static disc without protection and the static disc assembly of the present invention, and the braking performance comparison test was carried out according to the dynamic torque spectrum requirements of GJB1184A-2010 "General Specification for Aircraft Wheels and Braking Devices". 100 dynamic braking tests were carried out in the initial stage of brake disc wear, the median stage of wear, and the limit stage of wear. After the test, it was found through decomposition and inspection that the keyway of the original structure static disc without protection had different degrees of widening, and the widening size was 0.8-1.4mm; while the static disc assembly of the present invention, because the protective sheet bears and disperses the force, the size of the keyway does not change. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the static disk assembly;

[0031] Figure 2 It is an axonometric view of the static disk;

[0032] Figure 3 3a is a cross-sectional view of the static disk, wherein 3a is a front view and 3b is a side view;

[0033] Figure 4 It is an axonometric view of the protective sheet;

[0034] Figure 5 is a front view of the protective sheet;

[0035] Figure 6 This is a schematic diagram of the installation of the static disk assembly.

[0036] In the figure: 1. static plate; 2. protective plate; 3. rivet; 4. key; 5. keyway. DETAILED DESCRIPTION

[0037] This embodiment is a static disc assembly for a certain type of brake device. Figure 1 As shown, it comprises a stator 1, three protection sheets 2 and 24 rivets 3. The three protection sheets 2 are evenly distributed on the inner circumference of the stator 1, embedded between the convex keys on the inner circumference of the stator, and fixed by the rivets 3.

[0038] The static disc 1 is of prior art, made of carbon-carbon composite material, with a total weight of 3.5kg; the protective plate is made of 1Cr18Ni9Ti, and the surface treatment is passivation. It includes a friction disc and 9 to 15 cams. Each of the cams is evenly distributed on the inner circumferential surface of the friction disc, and a keyway is formed by the spacing between adjacent cams. The width of the keyway is 13 to 18 mm, and the depth is 12 to 16 mm. In this embodiment, the outer diameter of the static disc is 412 mm, the inner diameter is 280 mm, and the total thickness of the disc body is 22 mm; there are 12 cams; the width of the keyway is 16 mm, and the depth is 14.5 mm.

[0039] In order to install the protection sheet 2 on the inner circumferential surface of the static disk, the inner arc surface of each of the convex keys is processed with

[0040] Circumferential protection sheet installation grooves; the width of each protection sheet installation groove is 3-5 mm. The center line of each protection sheet installation groove in the width direction is located on the symmetric plane of the axial length of the convex key.

[0041] The bottom surface of each protective sheet installation groove is a concave arc surface and a convex arc surface that are tangentially connected in one circle, so that the bottom surface of the groove is wavy, and the vertices of the concave arc surface correspond to the center line of the width of the static disk keyway, and the vertices of the convex arc surface correspond to the center line of the width of the static disk convex key. The radius of the concave arc surface and the convex arc surface are the same, both of which are 25mm. The centers of the concave arc surface and the convex arc surface are on a pitch circle with a diameter of φ325, and the pitch circle is concentric with the center of the static disk. In this embodiment, the width of the protective sheet installation groove is 3 to 5mm; the radius of the concave arc surface and the convex arc surface is 22 to 28mm.

[0042] The surface of the convex key is provided with two through rivet holes with a hole diameter of φ6mm, a distance of 32mm between the two holes, and evenly distributed on a dividing circle with a circumferential diameter of φ270mm.

[0043] There are three protective sheets 2, all of which are arc-shaped strips. The radius of the inner arc surface of the protective sheet is the same as the radius of the static disk, and the outer arc edge of each protective sheet is also a continuous concave arc surface and a convex arc surface, forming a wavy shape that fits with the wavy bottom of the protective sheet installation groove, and the concave arc surface of each protective sheet fits with the convex arc surface of the bottom of the protective sheet installation groove, and the convex arc surface of each protective sheet fits with the concave arc surface of the bottom of the protective sheet installation groove.

[0044] Grooves are evenly distributed on the inner arc surface of the protective sheet, and each groove is located at each convex arc surface of the protective sheet, so that the center line of each groove in the width direction corresponds to the vertex of each convex arc surface. The width of the groove is 1 to 3 mm smaller than the width of the keyway on the static disk. Rivet holes are distributed on both sides of the groove, and each rivet hole corresponds to the rivet hole on the static disk one by one. In this embodiment, the width of the groove is 1 mm smaller than the width of the keyway on the static disk.

[0045] During installation, each of the protective sheets is respectively embedded in the protective sheet installation groove on the inner arc surface of the stator convex key, and the continuous concave arc surface and convex arc surface on the outer arc surface of each protective sheet are matched with the convex arc surface and concave arc surface at the bottom of the protective sheet installation groove. The protective sheet is fixed to the stator by rivets 3. The spacing between the ends of two adjacent protective sheets is 16 to 25 mm. In this embodiment, the spacing between the ends of two adjacent protective sheets is 20 mm.

[0046] The width of the groove on the protection sheet is 1-3 mm smaller than the width of the keyway on the static plate, so as to prevent the wall of the keyway on the static plate from being stressed.

Claims

1. A static disc assembly for aircraft wheel brakes, comprising a static disc; the static disc comprises a friction disc, and a plurality of convex keys are uniformly distributed on the inner circumferential surface of the friction disc; characterized in that: It also includes three protective sheets; the protective sheets are arc-shaped strips, embedded in the protective sheet installation grooves on the inner arc surface of each of the convex keys; the protective sheet installation grooves are opened on the inner arc surface of each convex key, and extend in a circular ring shape along the circumference of the convex key; the center line of the protective sheet installation groove in the width direction is located on the symmetric plane of the axial length of the convex key; the width of the protective sheet installation groove is 3 to 5 mm; The bottom surface of each of the protective sheet installation grooves is a concave arc surface and a convex arc surface that are smoothly connected to form a circle, and the vertices of the concave arc surface correspond to the center line of the width of the static disk key slot, and the vertices of the convex arc surface correspond to the center line of the width of the static disk convex key; the radius of the concave arc surface is the same as that of the convex arc surface; The outer circumferential surface of the protection sheet is a convex arc surface and a concave arc surface that match the bottom surface of the protection sheet installation groove, so that the concave arc surface of each protection sheet fits with the convex arc surface of the bottom of the protection sheet installation groove, and the convex arc surface of each protection sheet fits with the concave arc surface of the bottom of the protection sheet installation groove; grooves are evenly distributed on the inner circumferential surface of each protection sheet, and each groove is located at the convex arc surface of the protection sheet, so that the center line of each groove in the width direction corresponds to the vertex of each convex arc surface; the width of the groove is 1 to 3 mm smaller than the width of the keyway on the static disk.

2. The aircraft wheel brake static disc assembly according to claim 1, characterized in that: The width of the protection sheet installation groove is 3-5 mm; the radius of the concave arc surface and the convex arc surface is 22-28 mm.

3. The aircraft wheel brake static disc assembly according to claim 1, characterized in that: The inner radius of the protection plate is the same as the inner radius of the static disk.

4. The aircraft wheel brake static disc assembly according to claim 1, characterized in that: Rivet holes are distributed on both sides of the groove, and each rivet hole corresponds to a rivet hole on the static disk one by one.

Images