A repair method for replacing bearings on aircraft wheels

Abstract

This invention relates to the field of wheel hub bearing repair technology, specifically to a repair method for replacing bearings on aircraft wheels, comprising: disassembling the bearing outer ring; repairing the bearing housing of the wheel hub; machining the bearing bushing; installing the bearing bushing; further machining the bearing bushing; and installing a new bearing outer ring. This invention solves the problem that after a bearing failure and removal, the bearing housing of the wheel hub becomes larger and more elliptical, failing to meet the fit requirements between the bearing housing and the bearing. This significantly reduces the scrap rate of wheel hubs requiring repair and lowers maintenance costs throughout the product's lifespan.

Description

Technical Field

[0001] This invention relates to the field of aircraft wheel hub repair technology, specifically to a repair method for replacing bearings on aircraft wheels. Background Technology

[0002] Aircraft wheels typically consist of a hub, seals, and tapered roller bearings. The tapered roller bearings are divided into an outer ring and an inner ring. The outer ring is interference-fitted with the bearing housing on the hub, and the two are assembled together using a press-fit process. The inner ring is fitted onto the landing gear shaft. After the wheel is mounted on the landing gear shaft, the outer ring on the hub and the inner ring on the landing gear shaft mate to bear the dynamic and static loads of the aircraft, serving the functions of takeoff, landing, taxiing, and ground parking. All dynamic and static loads must be transmitted to the landing gear shaft through the bearings. The bearings experience complex stress conditions and operate in harsh environments. Over long-term use, the outer ring raceways are prone to wear, scratches, pitting, indentations, blueing, corrosion, rust, and peeling, requiring timely replacement of the bearings.

[0003] The bearing housing and outer ring of the wheel hub are interference fit. After the bearing is removed, the inner bore size of the bearing housing of the wheel hub will inevitably increase. In addition, as the load on aircraft wheels increases, the inner bore of the bearing housing of the wheel hub will become larger and more elliptical after being subjected to dynamic and static loads for a long time. Since the bearing is a standard component, when replacing the bearing, it is impossible to guarantee the interference fit between the inner bore of the bearing housing of the wheel hub and the outer ring of the new bearing. Long-term use may cause the outer ring of the bearing to loosen, which may lead to aircraft wheel vibration, cracking and other failures, affecting the safety of aircraft takeoff and landing.

[0004] Existing technologies, such as CN 116292647 A, disclose a bearing fixing structure and assembly method for an aircraft wheel speed sensor. This method eliminates direct contact between the bearing and bushing, solving the problem of axial jamming during prolonged bearing operation affecting bushing lifespan. In this structure, the bearing and bearing housing have no direct contact, and the load conditions on both are simple and small, making it suitable only for aircraft wheel speed sensors, as the force principle is completely different from that of aircraft wheel bearings. For example, CN113068432 B discloses a method for replacing brake wheel bearings in Soviet-made aircraft. Using domestically produced tapered roller bearings with the same inner and outer diameters, and following thermal decomposition, hot assembly, and cold assembly processes, it achieves the replacement of domestic and Russian bearings. This solves the replacement problem caused by the inconsistency in inner ring dimensions between domestic and Russian bearings after the Russian bearings fail and become unusable. However, after the bearing housing of the wheel hub is press-fitted with the outer ring of the bearing, the inner diameter of the bearing housing will change. Moreover, after long-term use and bearing the dynamic and static loads of the aircraft, the inner diameter will inevitably become larger and the roundness cannot be guaranteed. This replacement method is extremely strict on the inner diameter of the bearing housing of the wheel hub. Wheel hubs that have undergone press-fitting and have been used basically cannot meet this requirement, making it practically impossible to implement.

[0005] Therefore, existing technology cannot solve the problem of bearing failure. After removing the outer ring of the bearing, the bearing chamber of the wheel hub becomes larger and elliptical. Replacing the outer ring of the bearing cannot meet the interference fit issue, which leads to the wheel hub bearing being unrepairable and resulting in a high scrap rate of the wheel hub.

[0006] Therefore, a repair method for replacing bearings on aircraft wheels is needed to solve the above problems. Summary of the Invention

[0007] This invention provides a repair method for replacing bearings on aircraft wheels, which solves the problem that existing technologies cannot address when bearings fail, the bearing housing size of the wheel hub becomes larger and elliptical after the outer ring of the bearing is removed, and the interference fit between the two cannot be met after replacing the outer ring of the bearing, thus making the wheel hub bearing unrepairable and resulting in a high scrap rate of the wheel hub.

[0008] The present invention provides a repair method for replacing bearings on aircraft wheels, which adopts the following technical solution, including:

[0009] Disassemble the bearing outer ring;

[0010] Repairing the bearing housing of a wheel hub: removing plastic deformation areas, damaged areas, or corroded areas from the bearing housing of the wheel hub;

[0011] Machining bearing bushings: The bearing bushing is a cylinder with one end open. The bottom of the bearing bushing has a through hole coaxial with the bearing bushing. The hardness of the bearing bushing is higher than that of the wheel hub.

[0012] Install bearing bushing: Heat the repaired wheel hub in a preset first temperature environment, and cool the bearing bushing in a preset second temperature environment. The heating time and cooling time are both preset heating times. Then press the bearing bushing into the bearing chamber of the wheel hub.

[0013] Additional machining of bearing bushings: Based on the dimensions of the repaired bearing housing, additional machining is performed on the inner ring of the bearing bushing to ensure that the inner diameter, cylindricity, coaxiality, and surface roughness of the bearing bushing meet the dimensional requirements of the repaired bearing housing.

[0014] Installing a new bearing outer ring: Heat the wheel hub where the bearing bushing is installed in a preset first temperature environment, and cool the new bearing outer ring in a preset second temperature environment. The heating time and cooling time are both preset heating times. Then, press the new bearing outer ring into the bearing bushing.

[0015] The preferred steps for disassembling the bearing outer ring are as follows:

[0016] The wheel hub before repair is heated at a preset first temperature and for a preset heating time, and then the outer ring of the bearing is removed.

[0017] Preferably, the preset first temperature is 120℃; the preset second temperature is above -70℃ to -90℃; and the preset heating time is not less than 30 minutes.

[0018] Preferably, the conductivity and hardness of the bearing housing of the wheel hub after removing the outer ring of the bearing are measured. If the conductivity and hardness results meet the requirements, the outer ring of the bearing is removed. If the conductivity or hardness results do not meet the requirements, the wheel hub is scrapped.

[0019] Preferably, the step of removing the plastic deformation area, damaged area, or corroded area of ​​the bearing housing of the wheel hub is as follows:

[0020] The wheel hub is machined, and 2mm is removed from both the axial and radial sides of the bearing chamber bore. The surface roughness of the machined area is Ra1.6.

[0021] Preferably, in the step of repairing the bearing housing of the wheel hub: the bearing housing of the machined wheel hub is subjected to fluorescent flaw detection. If no cracks are found, the inner bore of the bearing housing of the wheel hub is shot-peened with a shot peening intensity of 0.25mmA to 0.35mmA. If cracks are found, the bearing housing of the wheel hub is repaired according to the requirements for bearing bushing repair, with a repair depth of 1mm. The bearing housing of the repaired wheel hub is subjected to fluorescent flaw detection again. If no cracks are found, the inner bore of the bearing housing of the wheel hub is shot-peened with a shot peening intensity of 0.25mmA to 0.35mmA. If cracks are still found, the wheel hub is scrapped.

[0022] Preferably, in the step of repairing the bearing chamber of the wheel hub: an oxidant is applied to the inner bore surface of the bearing chamber of the shot-peened wheel hub to form an oxide film.

[0023] Preferably, the steps for machining the bearing bushing are as follows:

[0024] The wall thickness of the bearing bushing is 3mm;

[0025] The inner diameter of the through hole of the bearing bushing is 3mm smaller than the inner diameter of the bearing housing shoulder of the wheel hub;

[0026] The outer ring of the bearing bushing is interference-fitted with the bearing housing bore of the hub, with an interference amount of 0.18mm to 0.22mm.

[0027] Preferably, in the bearing bushing installation step: after the installed bearing bushing has returned to normal temperature, use a feeler gauge to check the gap between the bearing bushing and the shoulder of the bearing housing of the hub. If the gap meets the requirements, then proceed with the subsequent bearing bushing rework; if the gap does not meet the requirements, then remove the bearing bushing and reinstall it using the bearing bushing installation steps until the gap meets the requirements.

[0028] Preferably, in the step of installing a new bearing outer ring, after the installed new bearing outer ring has returned to normal temperature, a feeler gauge is used to check the gap between the side of the new bearing outer ring and the bearing bushing. If the gap meets the requirements, the bearing repair is completed; if the gap does not meet the requirements, the bearing bushing is removed, and the steps of installing a new bearing outer ring are performed to reinstall the new bearing outer ring until the gap meets the requirements.

[0029] The beneficial effects of this invention are:

[0030] By adding a bearing bushing between the bearing housing and the outer ring of the bearing in the wheel hub, the bearing housing of the deformed wheel hub can be repaired. This solves the problem that the bearing housing of the wheel hub becomes larger and more elliptical after the bearing fails and is removed, which cannot meet the requirements for the fit between the bearing housing and the bearing. This greatly reduces the scrap rate of wheel hubs requiring repair and lowers the maintenance cost throughout the product's life cycle. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 A flowchart illustrating a repair method for replacing bearings on an aircraft wheel according to the present invention;

[0033] Figure 2 This is a schematic diagram of the wheel hub before repair in this embodiment;

[0034] Figure 3 This is a schematic diagram of the repaired wheel hub in this embodiment;

[0035] Figure 4 This is a schematic diagram of the bearing bushing structure in this embodiment;

[0036] Figure 5 This is a dimensional diagram of the repaired wheel hub in this embodiment.

[0037] In the diagram: 1. Hub; 1a. Bearing housing; 1b. Shoulder; 2. Bearing outer ring; 3. Bearing bushing. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] This invention provides an embodiment of a repair method for replacing bearings on aircraft wheels. This embodiment uses the repair of a certain type of aircraft wheel aluminum alloy hub bearing as an example. The specific repair steps are as follows: Figure 1 As shown, it includes:

[0040] S1. Disassemble the outer ring of the bearing;

[0041] Before repair, the wheel hub is heated at 120°C for 30 minutes. Then, the outer bearing ring is removed. After heating, the outer bearing ring 2 is removed from the press table using a special tool. The removed outer bearing ring 2 is scrapped. In this embodiment, a 2A14 aluminum alloy wheel hub 1 is used as an example. First, the conductivity and hardness of the bearing chamber 1a of the 2A14 aluminum alloy wheel hub 1 are measured. The conductivity must meet 19Ms / m~23Ms / m, and the hardness must meet HBS≥110. If the conductivity or hardness results do not meet the requirements, the wheel hub 1 is scrapped. If both conductivity and hardness meet the requirements, the wheel hub 1 is placed in a high-temperature chamber and heated at 120°C for 30 minutes. After heating, the outer bearing ring 2 is removed from the press table using a special tool. The removed outer bearing ring 2 is scrapped.

[0042] S2: Repair the bearing housing of the wheel hub;

[0043] After the hub 1 returns to normal temperature, the bearing chamber bore of the hub 1 is machined to remove the plastic deformation area, damaged area or corroded area. The axial and radial machining dimensions of the bearing chamber bore are both 2mm, and the surface roughness of the bearing chamber bore is required to be Ra1.6.

[0044] Fluorescent flaw detection is performed on the bearing chamber 1a of the processed wheel hub 1. If no cracks are found, the inner hole of the bearing chamber 1a is strengthened by ceramic shot peening with a shot peening intensity of 0.25 mmA to 0.35 mmA (0.3 mmA in this embodiment). If cracks are found, the bearing chamber 1a of the wheel hub is repaired according to the requirements for bearing bushing repair, with a repair depth of 1 mm. The repaired bearing chamber 1a of the wheel hub is subjected to fluorescent flaw detection again. If no cracks are found, the inner hole of the bearing chamber of the wheel hub 1 is strengthened by shot peening with a shot peening intensity of 0.25 mmA to 0.35 mmA (0.3 mmA in this embodiment). If cracks are found, the wheel hub 1 is scrapped. After shot peening, the aluminum alloy surface of the inner hole of the bearing chamber is oxidized with ALODINE1200 to form an oxide film to improve corrosion resistance.

[0045] S3: Machining bearing bushings;

[0046] Processing such as Figure 4The bearing bushing 3 shown has the following requirements: a wall thickness of 3mm; an inner diameter of the bearing bushing's through hole that is 3mm smaller than the inner diameter of the bearing housing shoulder of the hub; an interference fit between the outer ring of the bearing bushing and the inner bore of the hub's bearing housing, with an interference amount of 0.18mm to 0.22mm; and a material of 30CrMoA with a hardness of HRC25-30. Specifically, the outer diameter of the bearing bushing is determined based on the measured outer diameter of the bearing housing bore after repair in step S2 and the interference fit of (0.18 to 0.22)mm, i.e., the outer diameter is φA. ++0 0.. 3 4 6 4mm; the inner diameter of the bearing housing shoulder is φ129mm, and the inner diameter of the bearing bushing through hole is 3mm smaller than the inner diameter of the bearing housing shoulder, that is, the inner diameter of the bearing bushing through hole is φ126mm; the wall thickness of the bearing bushing is 4mm; the inner hole depth of the bearing bushing is the same as the outer ring width of the bearing, that is, when the outer ring width of the bearing is 24mm, the through hole depth of the bearing bushing is 24mm.

[0047] S4: Install bearing bushing;

[0048] After repairing the wheel hub 1, heat it to 120°C in a high-temperature chamber and cool it to -70°C in a low-temperature chamber. The heating and cooling times are both 30 minutes. Using a special tool, press the bearing bushing 3 into the bearing chamber 1a of the wheel hub 1 on the press table. After returning to normal temperature, use a 0.05mm feeler gauge to check the gap between the bearing bushing 3 and the shoulder 1b of the bearing chamber 1a of the wheel hub 1. If the gap does not meet the requirements, the bearing bushing 3 should be removed according to step 1 and reinstalled according to step S4.

[0049] S5: Repair machining of bearing bushings;

[0050] Based on the dimensions of the repaired bearing housing, i.e. Figure 5 The dimensions shown indicate that the inner ring of bearing bushing 3 requires additional machining. The inner diameter is determined based on the outer diameter of the bearing outer ring and the interference fit of (0.18~0.22) mm. The machining is then performed to φ145- -0 0.. 2 2 1 5mm; all other dimensions, positional accuracy, and surface roughness must meet the dimensional requirements of the bearing chamber 1a of the hub 1 part.

[0051] S6: Install the new bearing outer ring;

[0052] The hub 1 with the bearing bushing 3 installed is placed in a high-temperature chamber and heated to 120°C. The new bearing outer ring is then placed in a low-temperature chamber and cooled to -70°C. Both heating and cooling times are 30 minutes each. Using a special tooling on the press table, the new bearing outer ring is pressed into the bearing bushing 3. After returning to room temperature, the gap between the side of the new bearing outer ring and the bearing bushing 3 is checked with a 0.05mm feeler gauge. If the gap does not meet the requirements, the new bearing outer ring must be removed according to step S1, and then the new bearing outer ring must be reinstalled according to step S6.

[0053] It should be noted that the wheel hub 1 before repair was as follows: Figure 2 As shown, it does not include the bearing bushing; the repaired hub 1 is as follows. Figure 3 As shown, it has been fitted with a bearing bushing.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method of repairing an aircraft wheel replacement bearing, characterized by, include: Disassemble the bearing outer ring; Repairing the bearing housing of a wheel hub: removing plastic deformation areas, damaged areas, or corroded areas from the bearing housing of the wheel hub; Machining bearing bushings: The bearing bushing is a cylinder with one end open. The bottom of the bearing bushing has a through hole coaxial with the bearing bushing. The hardness of the bearing bushing is higher than that of the wheel hub. Install bearing bushing: Heat the repaired wheel hub in a preset first temperature environment, and cool the bearing bushing in a preset second temperature environment, with both heating and cooling times being preset heating times. Then press the bearing bushing into the bearing chamber of the wheel hub. Additional machining of bearing bushings: Based on the dimensions of the repaired bearing housing, additional machining is performed on the inner ring of the bearing bushing to ensure that the inner diameter, cylindricity, coaxiality, and surface roughness of the bearing bushing meet the dimensional requirements of the repaired bearing housing. Installing a new bearing outer ring: Heat the wheel hub where the bearing bushing is installed in a preset first temperature environment, and cool the new bearing outer ring in a preset second temperature environment. The heating time and cooling time are both preset heating times. Then, press the new bearing outer ring into the bearing bushing.

2. A method of repairing an aircraft wheel bearing replacement bearing according to claim 1, characterized in that The steps for disassembling the bearing outer ring are as follows: The wheel hub before repair is heated at a preset first temperature and for a preset heating time, and then the outer ring of the bearing is removed.

3. A method of repairing an aircraft wheel bearing replacement bearing according to claim 2, wherein, The preset first temperature is 110℃~120℃; the preset second temperature is -70℃~-90℃; and the preset heating time is 30min~40min.

4. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, Conduct electrical conductivity and hardness measurements are performed on the bearing housing of the wheel hub after removing the outer bearing ring. If both electrical conductivity and hardness results meet the requirements, the outer bearing ring removal step is performed. If the electrical conductivity or hardness results do not meet the requirements, the wheel hub is scrapped.

5. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, The steps for removing the plastically deformed, damaged, or corroded areas from the bearing housing of the wheel hub are as follows: The wheel hub is machined, and 2mm is removed from both the axial and radial sides of the bearing chamber bore. The surface roughness of the machined area is Ra1.

6.

6. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, In the repair process of the bearing housing of a wheel hub: The bearing housing of the machined wheel hub is subjected to fluorescent flaw detection. If no cracks are found, the inner bore of the bearing housing is shot-peened with an intensity of 0.25mmA to 0.35mmA. If cracks are found, the bearing housing is repaired according to the requirements for bearing bushing repair, with a repair depth of 1mm. The repaired bearing housing is then subjected to fluorescent flaw detection again. If no cracks are found, the inner bore of the bearing housing is shot-peened with an intensity of 0.25mmA to 0.35mmA. If cracks still exist, the wheel hub is scrapped.

7. A method of repairing an aircraft wheel bearing replacement bearing according to claim 6, wherein, In the process of repairing the bearing housing of a wheel hub: an oxidant is applied to the inner bore surface of the bearing housing after shot peening to form an oxide film.

8. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, The steps for machining bearing bushings are as follows: The wall thickness of the bearing bushing is at least 3 mm; The inner diameter of the through hole of the bearing bushing is 2mm to 4mm smaller than the inner diameter of the bearing housing shoulder of the hub; The outer ring of the bearing bushing is interference-fitted with the bearing housing bore of the hub, with an interference amount of 0.18mm to 0.22mm.

9. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, During the bearing bushing installation process: After the installed bearing bushing has returned to normal temperature, use a feeler gauge to check the clearance between the bearing bushing and the shoulder of the bearing housing of the hub. If the clearance meets the requirements, proceed with the subsequent bearing bushing rework; if the clearance does not meet the requirements, remove the bearing bushing and reinstall it using the bearing bushing installation process until the clearance meets the requirements.

10. The method of repairing an aircraft wheel bearing replacement bearing of claim 1, wherein, During the installation of a new bearing outer ring, after the new bearing outer ring has returned to normal temperature, use a feeler gauge to check the clearance between the side of the new bearing outer ring and the bearing bushing. If the clearance meets the requirements, the bearing repair is complete; if the clearance does not meet the requirements, remove the bearing bushing and repeat the steps for installing a new bearing outer ring until the clearance meets the requirements.

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