A method of replacing an aeroengine forward pivot point graphite seal assembly in situ

Abstract

The application relates to a method for replacing an aero-engine front fulcrum graphite sealing assembly in situ, and solves the problems that the current method has high labor intensity, a complicated process, and that the engine needs to be returned to the factory for repair and has a long delivery cycle. The method comprises the following steps: step one, supporting a low-pressure compressor first-stage rotor below the low-pressure compressor first-stage rotor by using an aluminum gasket; step two, disassembling an engine fairing; step three, disassembling a support of an oil return pump with a front fulcrum; step four, disassembling an oil nozzle; step five, disassembling a fixed cup sleeve; step six, removing a bearing seat of a front fulcrum bearing; step seven, removing a front fulcrum graphite sealing assembly; and step eight, installing a front fulcrum graphite sealing assembly with good factory sealing test to the front fulcrum bearing seat. The application realizes replacement of the front fulcrum graphite sealing assembly in situ on the airplane, avoids returning the engine to the factory, reduces the engine maintenance cost, saves troubleshooting time, and improves troubleshooting efficiency.

Description

Technical Field

[0001] This invention relates to a method for troubleshooting oil leakage at the front pivot of an aero-engine, specifically a method for replacing the graphite sealing assembly at the front pivot of an aero-engine in situ. Background Technology

[0002] During the field use of aircraft engines, after the engine has been running for a period of time, the performance of various parts of the graphite sealing assembly will decline, such as the spring force and wear of graphite parts, resulting in poor lubricating oil sealing effect. When the engine stops working, there is no pressure difference between the inside and outside of the graphite parts in the stationary state, the sealing effect is greatly reduced, and lubricating oil leakage is likely to occur.

[0003] The previous process for replacing the front pivot graphite seal assembly was as follows: Engine returned to factory → Engine assembly disassembly → Engine transmission disassembly → Imported diffuser disassembly → Front support graphite seal assembly repair and sealing test → Imported diffuser assembly → Engine transmission assembly → Engine assembly → Engine test passed and shipped.

[0004] The normal disassembly and repair process involves nine steps. The entire process is time-consuming, labor-intensive, and complicated. In addition, the engine needs to be returned to the factory for repair, resulting in a long delivery cycle and affecting its use in the field. Summary of the Invention

[0005] This invention provides a method for in-situ replacement of the front pivot graphite sealing assembly on an aircraft during field use, which solves the problems of high labor intensity, cumbersome process, and long delivery cycle of the current method, which requires the engine to be returned to the factory for repair.

[0006] This invention is achieved through the following technical solution: 1. Understand the structure of graphite sealing components and study the replacement methods for graphite sealing components; 2. Research how to ensure that the low-pressure compressor rotor blades do not fall onto the low-pressure casing during the removal of the front support graphite sealing assembly, thus preventing damage to the compressor rotor blades and casing coating; 3. Ensure that the replaced graphite sealing components have a good sealing effect.

[0007] The method for replacing the graphite seal assembly at the front support point of an aircraft engine in situ includes the following steps: 1. Step 1: Use aluminum shims to support the first-stage rotor of the low-pressure compressor below it. 2. Step Two: Remove the engine cowling 4; 3. Step 3: Remove bracket 5 of the lubricating oil return pump 8 with front pivot point; 4. Step Four: Remove the sliding oil nozzle 9; 5. Step five: Remove the retaining cup sleeve 10; 6. Step Six: Remove the bearing housing of the front pivot bearing 7; 7. Step Seven: Remove the front fulcrum graphite sealing assembly 11; 8. Step 8: Install the front support graphite sealing assembly, which has passed the factory sealing test, onto the front support bearing housing.

[0008] This invention enables in-situ replacement of the front pivot graphite seal assembly on the aircraft, avoiding engine return to the factory, reducing engine maintenance costs, saving troubleshooting time, and improving troubleshooting efficiency.

[0009] The present invention has the following advantages: 1. When replacing the front support graphite sealing assembly, the inlet guide does not need to be removed; the front support graphite sealing assembly is replaced only in its original position, saving manpower and resources. 2. This invention enables rapid replacement of the front pivot graphite seal assembly in the field, ensuring the operation of the engine in the field; Attached Figure Description

[0010] Figure 1 This is a structural diagram of the front support point of the low-pressure compressor in an aero-engine. In the diagram, 1-bolt, 2-mesh, 3-washer, 4-fairing, 5-bracket, 6-screw, 7-front pivot bearing, 8-front pivot return oil pump, 9-nozzle, 10-fixed cup sleeve, 11-front pivot graphite sealing assembly, 12-lubricating oil chamber housing. Detailed Implementation

[0011] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings, but the scope of protection of the present invention is not limited to the following description.

[0012] like Figure 1 As shown, the specific embodiments of the present invention are as follows: 1. The low-pressure rotor of a certain type of aero-engine adopts a 1-2-1 support configuration. The low-pressure compressor and the low-pressure turbine are each supported by two bearings. The front support bearing of the low-pressure compressor is a roller bearing. Aluminum shims are used to support the first-stage low-pressure rotor to prevent the front journal of the low-pressure compressor from falling off after the front support bearing housing is removed, and to avoid the low-pressure compressor rotor blades falling onto the low-pressure casing and damaging the coating. 2. Prepare an oil collection tray and place it below fairing 4; 3. Loosen the safety lock on bolt 1 that secures fairing 4, use a wrench to disassemble and remove bolt 1 that secures fairing 4, and remove washer 3 and mesh 2; 4. Remove fairing 4 and remove the sealing ring from fairing 4; 5. Remove the gasket 3 and the sealing ring from the outer shell 12 of the lubricating oil chamber at the front pivot point; 6. Loosen the locking plate on the screw 6 that secures the outer shell 12 of the lubricating oil chamber at the front pivot point; 7. Remove the screws 6 that fix the front pivot lubricating cavity housing 12 and remove the locking plate; 8. Remove the front pivot lubricating chamber housing 12 from the intake guide housing, and remove the sealing ring from the housing; 9. Loosen the safety lock on the nut of the mounting bracket 5 for the front fulcrum return oil pump 8, remove the nut of the mounting bracket, remove the nut, locking plate and bolt, and remove the bracket 5 with the front fulcrum return oil pump 8. 10. Place the bracket 5 of the disassembled front support return oil pump 8 into a clean packaging bag for protection. 11. Loosen the safety screw on the fixed front pivot lubricating nozzle 9, remove the screw fixing the nozzle, remove the nozzle and the sealing ring.

[0013] 12. Place the disassembled nozzles into a clean packaging bag for protection.

[0014] 13. Loosen the safety bolts on the fixed cup sleeve 10, remove the fixed cup sleeve bolts, remove the screws and locking plates, remove the cup sleeve, and remove the sealing ring.

[0015] 14. Disassemble the front support bearing housing.

[0016] 15. The graphite sealing assembly at the lower support point is 11.

[0017] 16. Reassemble the front pivot bearing, nozzle, and fairing in reverse order.

[0018] The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for in-situ replacement of a graphite seal assembly at the front support point of an aircraft engine, characterized in that: it includes... The following steps: Step 1: Use aluminum shims to support the first-stage rotor of the low-pressure compressor below it; Step 2: Remove the engine cowling; Step 3: Remove the bracket with the front pivot lubricating oil return pump; Step 4: Remove the oil nozzle; Step 5: Remove the cup sleeve; Step 6: Remove the bearing housing of the front pivot bearing; Step 7: Remove the front pivot graphite sealing assembly; Step 8: Install the front support graphite sealing assembly, which has passed the sealing test, onto the front support bearing housing in reverse order; Step two includes the following process: 1) Prepare an oil collection tray and place it under the fairing; 2) Loosen the safety catches on the bolts securing the fairing, use a wrench to disassemble and remove the bolts securing the fairing, and remove the washers and mesh; 3) Remove the fairing and the sealing ring from the fairing; Step three includes the following process: 1) Remove the gasket and sealing ring from the outer shell of the front pivot lubricating oil chamber; 2) Loosen the locking tab on the screw that secures the outer shell of the lubricating oil chamber at the front pivot point; 3) Remove the screws securing the front pivot lubricating oil chamber housing and remove the locking plate; 4) Remove the front pivot lubricating chamber housing from the intake guide housing, and remove the sealing ring from the housing; 5) Loosen the safety lock on the nut of the fixed front support return oil pump mounting bracket, remove the nut of the fixed bracket, remove the nut, locking plate and bolt, and remove the bracket with the front support return oil pump. 6) Place the disassembled front pivot return pump bracket into a clean packaging bag for protection.

2. The method for in-situ replacement of the graphite seal assembly at the front support point of an aero-engine according to claim 1, characterized in that: Step Four The process includes the following: 1) Loosen the safety screw on the screw that fixes the front pivot lubricating nozzle, remove the screw that fixes the nozzle, remove the nozzle and remove the sealing ring; 2) Place the disassembled nozzles into a clean packaging bag for protection.

3. The method for in-situ replacement of the graphite seal assembly at the front support point of an aero-engine according to claim 1, characterized in that: Step 5 The process includes the following steps: loosening the safety bolts securing the cup sleeve, removing the bolts securing the cup sleeve, removing the screws and locking plates, removing the cup sleeve, and removing the sealing ring.

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