Method and tooling for assembling and inspecting a load cell

Abstract

This invention discloses a method and tooling for assembling and inspecting a load-bearing casing, applicable to an aero-engine. The aero-engine includes a gas turbine rotor, an inner casing, a load-bearing casing, and cylindrical roller bearings. The assembly and inspection method includes: vertical positioning of the engine and mandrel installation; installing the gas turbine rotor with the inner ring of the cylindrical roller bearings onto the inner casing; installing a mandrel on the gas turbine rotor; color marking; color marking on the surface of the fuse on the connector seat outside the load-bearing casing and on the surface of the rollers of the outer ring of the cylindrical roller bearings assembled on the load-bearing casing; the marking medium having contactable transfer properties; hoisting the load-bearing casing onto the inner casing for assembly; simulating working condition tensioning; simulating the rearward displacement state of the gas turbine rotor under axial thrust during engine operation; horizontal rotation inspection; disassembly; and determining fuse interference, bearing axial overlap, and bearing radial eccentricity based on the color mark transfer.

Description

Technical Field

[0001] This invention relates to the field of aero-engine assembly technology, and in particular, to a method for assembling and inspecting a load-bearing engine casing. Furthermore, this invention also relates to a tooling incorporating the aforementioned method for assembling and inspecting a load-bearing engine casing. Background Technology

[0002] The aero-engine load-bearing casing is a crucial load-bearing component that supports the gas turbine rotor and provides lubrication chambers for the bearings on the gas turbine rotor. The load-bearing casing assembly has six evenly distributed support plates in the center, connecting the inner and outer walls of the casing, and is a vital load-bearing component of the turbine assembly. Its inner mounting edge connects to the gas turbine bearing housing assembly and the elastic support. The force borne by the engine's No. 4 bearing is transmitted from the inner mounting edge through the six support plates. Six connecting pipe seats pass through the six support plate cavities, respectively used for oil supply, oil return, bleed air, and ventilation of the bearing cavity. The outer surface of each of the six connecting pipe seats has a safety hole; after assembly, a 0.8mm safety wire is used to secure the connecting pipe seats and the nuts above them to prevent them from loosening in the engine vibration environment.

[0003] The front mounting edge of the load-bearing casing assembly is connected and fixed to the inner casing mounting edge of the combustion chamber using bolts and self-locking nuts. After assembly, the front half of the load-bearing casing extends into the inner casing and is completely invisible from the outside. At this time, the gap between the fuses on the outer circumference of the six connectors of the load-bearing casing and the flow channel surface of the inner casing is extremely small, making contact interference likely. If interference occurs and goes undetected, excessive vibration or even bearing failure may occur during engine testing after assembly, resulting in huge repair costs and time delays. If interference occurs, the fuses will be squeezed between the load-bearing casing and the inner casing, which will partially lift the load-bearing casing, causing the rear mounting edge of the load-bearing casing to not fit tightly with the outer casing mounting edge of the combustion chamber. This will cause the outer ring of bearing No. 4 on the load-bearing casing to become misaligned. In this misaligned state, the bearing rollers and inner ring will be radially misaligned, causing the gas turbine rotor supported by this bearing to become eccentric, resulting in abnormal vibration of the engine during operation.

[0004] Furthermore, bearing No. 4 is an outer ring raceway cylindrical roller bearing. The outer ring is fixed inside the front end of the bearing housing, and the inner ring is mounted on the gas turbine rotor journal. After the bearing housing is installed from top to bottom, the overlap between the inner and outer rings is completely enclosed inside the component and cannot be directly observed. If axial or radial misalignment occurs between the rollers and the inner ring, the following serious consequences will occur: reduced load-bearing capacity. In the design of cylindrical roller bearings, the contact area between the rollers and the inner ring is precisely calculated. When misalignment occurs, the effective contact length decreases, the load per unit area increases sharply, and the overall load-bearing capacity of the bearing decreases significantly, failing to meet the requirements of the bearing. The load requirements of the motor under design conditions; abnormal heating; in the misaligned state, the relative motion between the roller and the inner ring is no longer pure rolling, but accompanied by sliding friction. The heat generated by sliding friction is much greater than that of rolling friction, causing local temperature rise in the bearing, destroying the lubricating oil film, and further aggravating friction; accelerated wear; the combined effect of friction and heat accelerates the wear of the raceway and rollers. After the wear debris enters the lubricating oil, it can also cause secondary damage to other precision components; risk of bearing disintegration; in extreme cases, severe misalignment and wear may lead to cage breakage, roller detachment, bearing disintegration, and subsequently catastrophic failures such as rotor seizure or breakage. For the overlap quality of the inner and outer rings of the bearing, traditional methods rely on the operator's experience and feel, lacking objective and quantitative judgment criteria. The judgment results of different operators may differ, and quality control is unstable. When poor overlap occurs, traditional methods are also difficult to provide specific adjustment directions and amounts, often requiring repeated disassembly and reassembly and repeated trial and error, which is extremely inefficient.

[0005] These problems often only surface during engine testing, by which time substantial damage has already occurred, resulting in high repair costs, long lead times, and potential impacts on the engine's overall lifespan. In the field of aero-engine maintenance, the cost of testing an overhauled engine is high. If testing fails due to assembly quality issues, it not only causes direct economic losses but also delays delivery schedules.

[0006] In existing technologies, the inspection of the internal condition of blind cavities mainly relies on endoscopy. Endoscopes can be inserted into confined spaces for visual inspection. However, in this application, the gap between the fuse and the inner casing flow channel surface is extremely small (on the millimeter scale), and the interference point is in a blind spot, making it difficult for the endoscope to accurately determine whether contact has occurred. Furthermore, the overlap area between the inner and outer rings of the bearing is obscured by the rollers, preventing the endoscope from directly observing the integrity of the contact surface between the rollers and the inner ring, and making it impossible to determine whether the overlap is uniform. In addition, endoscopic inspection requires specialized operators, and the results are greatly influenced by the operator's experience, making it impossible to quantify the inspection conclusions. Summary of the Invention

[0007] This invention provides a method and tooling for assembling and inspecting load-bearing casings, in order to solve the technical problems in the prior art, such as the inability to directly inspect the interference between the load-bearing casing pipe joint fuse and the inner casing, the inability to directly inspect the overlap of the inner and outer rings of cylindrical roller bearings, the inability to simulate working conditions for pre-inspection, and the lack of quantitative interpretation standards.

[0008] According to one aspect of the present invention, a method for inspecting the assembly of a load-bearing casing is provided, applicable to an aero-engine. The aero-engine includes a gas turbine rotor, an inner casing, a load-bearing casing, and cylindrical roller bearings. The method for inspecting the assembly of the load-bearing casing includes: S1. Vertical positioning of the engine and installation of the mandrel: Install the gas turbine rotor with cylindrical roller bearing inner ring into the inner casing, and install the mandrel on the gas turbine rotor; S2. Color marking: Color marking is applied to the surface of the fuse in the connector seat outside the load-bearing housing, and to the surface of the rollers on the outer ring of the cylindrical roller bearing mounted on the load-bearing housing. The marking medium has the property of being contactable and transferable. S3. Hoist the load-bearing casing onto the inner casing for assembly; S4. Simulate working condition tensioning, simulating the rearward displacement state of the gas turbine rotor under axial thrust during engine operation; S5. Horizontal rotation check; S6. Decomposition; S7. Determine fuse interference, bearing axial overlap, and bearing radial eccentricity based on the color mark transfer situation.

[0009] As a further improvement to the above technical solution, step S2 includes: S21. Apply ink evenly to the fuse surface of each connector on the outside of the load-bearing casing, and control the coating thickness; S22. Apply printing ink evenly to the surface of each roller of bearing No. 4 inside the load-bearing housing. Rotate the outer ring during application to ensure that the entire circumference of each roller is covered. S23. After coating, rotate the outer ring to check if the coloring of the roller is uniform.

[0010] As a further improvement to the above technical solution, a tooling fixture is also included. The tooling fixture includes a support plate, a lifting lug, and a mounting pin. The support plate is used for axial positioning and limiting with the first end face of the mounting edge of the load-bearing casing and for radial positioning and regulating with the inner wall of the load-bearing casing. A bushing that mates with a mandrel is provided in the middle of the support plate, and the inner diameter of the bushing and the outer diameter of the mandrel guide section are designed for clearance fit. The lifting lug is used for axial positioning and regulating with the second end face of the mounting edge of the load-bearing casing and for radial positioning and regulating with the outer ring surface of the mounting plate. The lifting lug and the support plate are respectively provided with mounting holes that match the bolt hole positions of the mounting edge of the load-bearing casing. The mounting pin is used to be inserted into the mounting hole to make the lifting lug and the support plate radially positioned and regulated. Step S3 includes: S31. Install a support plate on the mounting edge of the load-bearing casing with the inner circle as the reference; S32. Install a lifting lug at the mating point between the support plate and the mounting edge of the load-bearing casing, and pass the mounting pin through the mounting hole of the support plate, the bolt hole of the mounting edge of the load-bearing casing, and the mounting hole of the lifting lug in sequence; S33. Lift the load-bearing casing above the inner casing; S34. Make the upper end of the mandrel pass through the internal cavity of the load-bearing housing and align with the bushing at the center of the support plate; S35. Guided by the clearance fit between the spindle and the bushing, slowly lower the load-bearing casing until the mounting edge of the load-bearing casing is fully engaged with the mounting edge of the casing inside the combustion chamber.

[0011] As a further improvement to the above technical solution, the tooling fixture further includes a push rod and a pressure block. The pressure block is used to abut against the mounting edge of the load-bearing casing. The push rod includes a connecting section and a pressure-applying section. A central hole for the connecting section is opened in the middle of the pressure block. The end of the mandrel is provided with an external thread for engaging with the internal thread of the end of the gas turbine rotor. Step S4 includes: S41. Install a pressure block on the mounting side of the load-bearing casing, pass the connecting section of the push rod through the center hole of the pressure block, and screw the connecting section of the push rod into the internal thread hole at the upper end of the spindle; S42. Tighten the push rod to press the pressure block against the load-bearing casing to the inner casing. The reaction force of the push rod will pull the mandrel backward, thereby pulling the gas turbine rotor backward.

[0012] As a further improvement to the above technical solution, step S5 includes: S51. Slowly rotate the engine from a vertical position until the rotor axis is horizontal, and let it stand for 10 to 30 seconds; S52. Rotate the gas turbine rotor to determine whether the gas turbine rotor has good free spin and whether there is any abnormal noise; if the rotor has good free spin and no abnormal friction noise, then the rotor support is normal and there is no scraping.

[0013] As a further improvement to the above technical solution, step S6 includes: S61. Return the engine from a horizontal position to a vertical position with the turbine end facing upwards; S62. Use a crane to lift the load-bearing casing vertically upwards and separate it from the casing inside the combustion chamber.

[0014] As a further improvement to the above technical solution, step S7 includes: Inspect the flow channel surface of the combustion chamber casing, and check the circumferential position corresponding to the load-bearing casing connector and the protruding parts of the flow channel surface. If there are colored markings on the flow channel surface, the fuse of the load-bearing casing external connector is in contact with the flow channel surface of the inner casing and is interfering with the contact. Adjust the direction of the fuse or change the position of the fuse hole and re-lock it. Repeat steps S2-S6 until there is no interference. If there are no colored markings on the flow channel surface, it is determined that the fuse is not interfering with the inner casing and is qualified.

[0015] As a further improvement to the above technical solution, step S7 includes: Visually inspect the distribution of colored markings on the outer cylindrical surface of the inner ring of the cylindrical roller bearing on the gas turbine rotor journal: If the colored markings are evenly distributed around the outer cylindrical surface of the inner ring of the bearing, and the width of the colored markings covers the entire effective working width of the inner ring, then the axial overlap between the inner and outer rings of the bearing is deemed to be qualified and no adjustment is required. If the color markings are only distributed in the front half of the inner ring, it is determined that the outer ring of the bearing installed on the load-bearing casing has moved forward relative to the inner ring, that is, the stator component is too far forward relative to the rotor; add an adjusting shim between the mounting edge of the combustion chamber casing and the load-bearing casing, adjust the stator component backward, and restore the inner and outer rings of the bearing to the correct axial overlap position. If the color markings are only distributed on the rear half of the inner ring, it is determined that the outer ring of the bearing mounted on the load-bearing casing has shifted backward relative to the inner ring, that is, the stator component is too far back relative to the rotor; reduce the adjusting shims between the combustion chamber casing and the load-bearing casing mounting edge, adjust the stator component forward, and restore the bearing inner and outer rings to the correct axial overlap position.

[0016] As a further improvement to the above technical solution, step S7 also includes: If the colored markings are continuous and unbroken in the entire 360° direction, it is determined that the inner and outer rings of the bearing are well radially aligned, the rotor and stator are concentric, and there is no eccentricity. If the colored markings show a break in the circumferential direction, it is determined that the roller corresponding to the break area is not in contact with the inner ring, the bearing is radially misaligned, and the rotor is eccentric relative to the stator. Based on the fuse interference inspection results, comprehensive adjustments are made, including reinstalling the fuse, checking the mating surfaces of the load-bearing casing and the combustion chamber casing, re-inspecting the perpendicularity of the spindle guide, or re-assembling the entire process.

[0017] According to another aspect of the present invention, a tooling is also provided, which includes the above-described load-bearing housing assembly inspection method, the tooling including a mandrel, a support plate, a lifting lug, a mounting pin, a pressure block, and a push rod.

[0018] The present invention has the following beneficial effects: This inspection method uses a mandrel-guided assembly of the load-bearing housing to ensure precise maintenance of the relative position of the outer and inner bearing rings during the housing's descent. Two critical quality control points—fuse interference and bearing overlap—that are not directly observable during blind assembly of the load-bearing housing are transformed into observable markers using transferable colored markings. Operators can intuitively judge assembly quality without relying on expensive endoscopes or complex sensors, significantly reducing the difficulty and cost of quality control. Furthermore, by simulating the actual rearward operation of the gas rotor during engine operation, inspections under these simulated conditions can detect defects that static inspections cannot reveal. This method addresses the dynamic fit issues of exposed components, fundamentally shifting the focus from fault detection during post-testing to fault prevention during assembly, overcoming the limitations of traditional static assembly inspections. This inspection method simultaneously performs multiple checks—including fuse interference and bearing lap misalignment—through a single coloring, hoisting, and inspection process, resulting in high efficiency and low cost. Applying this method to pre-inspection and adjustment during assembly ensures that the rollers and inner ring of cylindrical roller bearings are always in the correct axial and radial fit positions, fundamentally eliminating the risks of bearing misalignment, abnormal wear, overheating, and disintegration caused by assembly, significantly extending engine overhaul intervals and service life.

[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the assembly of a cylindrical roller bearing using existing technology; Figure 2 This is a schematic diagram of an existing engine with the turbine facing upwards, stored vertically. Figure 3This is a top view of the tooling according to a preferred embodiment of the present invention; Figure 4 This is a front view of the tooling according to a preferred embodiment of the present invention; Figure 5 yes Figure 4 Sectional view along direction A.

[0021] Legend: 100, Load-bearing casing; 101, Connecting pipe seat; 200, Combustion chamber; 201, Inner casing; 202, Gas turbine rotor; 300, Cylindrical roller bearing; 301, Outer ring; 302, Inner ring; 400, Push rod; 500, Pressure block; 600, Support plate; 700, Lifting lug; 800, Mandrel; 900, Mounting pin. Detailed Implementation

[0022] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0023] Figure 3 This is a top view of the tooling according to a preferred embodiment of the present invention; Figure 4 This is a front view of the tooling according to a preferred embodiment of the present invention; Figure 5 yes Figure 4 Sectional view along direction A.

[0024] like Figures 3 to 5 As shown, the assembly and inspection method for the load-bearing casing 100 in this embodiment is applied to an aero-engine. The aero-engine includes a gas turbine rotor 202, an inner casing 201, a load-bearing casing 100, and cylindrical roller bearings 300. The assembly and inspection method for the load-bearing casing 100 includes: S1. The engine is vertically positioned and the spindle 800 is installed. The gas turbine rotor 202 with the inner ring 302 of the cylindrical roller bearing 300 is installed into the inner casing 201, and the spindle 800 is installed on the gas turbine rotor 202. S2. Color marking: Color marking is applied to the surface of the fuse of the connector 101 outside the load-bearing housing 100, and to the surface of the rollers of the outer ring 301 of the cylindrical roller bearing 300 mounted on the load-bearing housing 100. The marking medium has the property of being contactable and transferable. S3. Hoist the load-bearing casing 100 onto the inner casing 201 for assembly; S4. Simulate working condition tensioning, simulating the rearward displacement state of the gas turbine rotor 202 under axial thrust during engine operation; S5. Horizontal rotation check; S6. Decomposition; S7. Determine fuse interference, bearing axial overlap, and bearing radial eccentricity based on the color mark transfer situation.

[0025] The upper end of the mandrel 800 is a guide section, the outer diameter of which is the same as the outer diameter of the inner ring 302 of the cylindrical roller bearing 300. The mandrel 800 is preferably made of hard aluminum (such as LD5 or 2A12, etc.), and one end is provided with an external thread for screwing into the rotor journal. The outer diameter of the guide section is the same as the outer diameter of the inner ring 302 of the cylindrical roller bearing 300. The guiding function of the mandrel 800 is to ensure that the outer ring 301 and the inner ring 302 of the bearing remain aligned during the vertical descent of the load-bearing casing 100, preventing misalignment and collision. Understandably, this inspection method uses the mandrel 800 to guide the assembly of the load-bearing housing 100, ensuring the precise maintenance of the relative position of the outer ring 301 and inner ring 302 of the bearing during the descent of the load-bearing housing 100. By using transferable colored markings, two critical quality control points that cannot be directly observed during the blind assembly of the load-bearing housing 100—fuse interference and bearing overlap—are transformed into observable markers. Operators can intuitively judge the assembly quality without relying on expensive endoscopes or complex sensors, significantly reducing the difficulty and cost of quality control. Furthermore, by simulating the actual backward-facing working condition of the gas rotor during engine operation, inspections can be conducted under these simulated conditions. This method can detect dynamic fit problems that static inspections cannot reveal, achieving a fundamental shift from fault detection during post-testing to fault prevention during assembly, thus overcoming the limitations of traditional static assembly inspections. This inspection method simultaneously completes multiple inspection items, including fuse interference checks and bearing lap misalignment checks, through a single coloring, hoisting, and inspection process, resulting in high efficiency and low cost. Applying this method to pre-inspection and adjustment during assembly ensures that the rollers of the cylindrical roller bearing 300 and the inner ring 302 are always in the correct axial and radial fit positions, fundamentally eliminating the risks of bearing misalignment, abnormal wear, overheating, and disintegration caused by assembly, significantly extending the engine's overhaul intervals and service life.

[0026] In some preferred embodiments, step S2 includes: S21. Apply ink evenly to the fuse surface of each connector 101 outside the load-bearing casing 100, and control the coating thickness. The coloring mark can be made of ink such as red ink, which has good adhesion and color development and can be clearly transferred after contact. The red ink is evenly coated with a brush on the fuse surface of the six connecting pipe seats 101 on the outside of the load-bearing housing 100. The coating thickness is controlled between 0.05mm and 0.15mm, so that it just covers the surface and does not drip. S22. Apply printing ink evenly to the surface of each roller of bearing No. 4 inside the load-bearing housing 100. When applying, rotate the outer ring 301 to ensure that the entire circumference of each roller is covered. S23. After coating, rotate the outer ring 301 2-3 times to check if the coloring of the roller is uniform and avoid missed coating.

[0027] In some preferred embodiments, a tooling fixture is also included, comprising a support plate 600, a lifting lug 700, and a mounting pin 900. The support plate 600 is used for axial positioning and limiting with the first end face of the mounting edge of the load-bearing housing 100 and for radial positioning and regulating with the inner wall of the load-bearing housing 100. A bushing that mates with the spindle 800 is provided in the middle of the support plate 600, and the inner diameter of the bushing is designed to be clearance-fitted with the outer diameter of the guide section of the spindle 800. The lifting lug 700 is used for axial positioning and regulating with the second end face of the mounting edge of the load-bearing housing 100 and for radial positioning and regulating with the outer annular surface of the mounting plate. The lifting lug 700 and the support plate 600 are respectively provided with mounting holes that match the bolt hole positions of the mounting edge of the load-bearing housing 100. The mounting pin 900 is used to be inserted into the mounting hole to make the lifting lug 700 and the support plate 600 radially positioned and regulated. Step S3 includes: S31. Mount the support plate 600 on the mounting edge of the load-bearing casing 100 with the inner circle as the reference; S32. Install a lifting lug 700 at the mating point between the support plate 600 and the mounting edge of the load-bearing casing 100. Pass a mounting pin 900 sequentially through the mounting holes of the support plate 600, the bolt holes of the mounting edge of the load-bearing casing 100, and the mounting hole of the lifting lug 700. The lifting lug 700 has an arc-shaped opening structure, and its shape, opening depth, and bolt hole position are consistent with those of the mounting edge of the load-bearing casing 100 and the support plate 600. The mounting pin 900 has an R-shaped pull ring, allowing for a quick and secure connection between the support plate 600, the lifting lug 700, and the load-bearing casing 100 by passing the mounting pin 900 sequentially through the mounting holes of the support plate 600, the bolt holes of the mounting edge of the load-bearing casing 100, and the mounting hole of the lifting lug 700. S33. Lift the load-bearing casing 100 above the inner casing 201; use a crane to lift the load-bearing casing 100 above the inner casing 201 of the combustion chamber 200; S34. The upper end of the spindle 800 passes through the internal cavity of the load-bearing housing 100 and aligns with the bushing at the center of the support plate 600; S35. Guided by the clearance fit between the spindle 800 and the bushing, the load-bearing housing 100 is slowly lowered until the mounting edge of the load-bearing housing 100 is fully engaged with the mounting edge of the inner housing 201 in the combustion chamber 200. A clearance fit of 0.15mm to 0.25mm is designed between the inner diameter of the bushing at the center of the support plate 600 and the outer diameter of the guide section of the spindle 800 to achieve precise guidance. Guided by the clearance fit between the guide section and the bushing, the load-bearing housing 100 is slowly lowered until the front mounting edge of the load-bearing housing 100 is fully engaged with the mounting edge of the inner housing 201 in the combustion chamber 200. During this process, the spindle 800 guides and ensures the relative alignment of the outer ring 301 and the inner ring 302 of the bearing, preventing misalignment and impact.

[0028] In some preferred embodiments, the tooling fixture further includes a push rod 400 and a pressure block 500. The pressure block 500 is used to abut against the mounting edge of the load-bearing casing 100. The push rod 400 includes a connecting section and a pressure-applying section. A central hole for the connecting section is opened in the middle of the pressure block 500. The end of the spindle 800 is provided with an external thread for engaging with the internal thread of the end of the gas turbine rotor 202. Step S4 includes: S41. Install the pressure block 500 on the mounting side of the load-bearing casing 100, pass the connecting section of the push rod 400 through the center hole of the pressure block 500, and screw the connecting section of the push rod 400 into the internal thread hole at the upper end of the spindle 800. S42. Tighten the push rod 400 to press the pressure block 500 against the load-bearing housing 100 to the inner housing 201. The reaction force of the push rod 400 pulls the spindle 800 backward, thereby pulling the gas turbine rotor 202 backward. This state simulates the backward displacement state of the gas turbine rotor 202 under axial thrust during engine operation. By simulating the actual backward working condition of the gas rotor under engine operation through the push rod 400 and pressure block 500 during assembly, inspection under this simulated working condition can discover dynamic fit problems that cannot be exposed by static inspection, realizing a fundamental shift from discovering faults after post-testing to preventing faults during assembly.

[0029] In some preferred embodiments, step S5 includes: S51. Slowly rotate the engine from a vertical position to a horizontal rotor axis and let it stand for 10 to 30 seconds; this step allows the lubricating oil and coloring ink to be stably distributed under the action of gravity. S52. Rotate the gas turbine rotor 202 to determine whether the gas turbine rotor 202 has good residual rotation and whether there is any abnormal noise; if the rotor has good residual rotation and no abnormal friction noise, then the rotor support is normal and there is no scraping.

[0030] In some preferred embodiments, step S6 includes: S61. Return the engine from a horizontal position to a vertical position with the turbine end facing upwards; loosen the push rod 400, remove the pressure block 500, press each handle of the R-type pull ring handle quick-release pin to retract its locking mechanism, and pull out all the mounting pins 900 in sequence. S62. Use a crane to lift the load-bearing casing 100 vertically upwards and separate it from the casing 201 inside the combustion chamber 200; the operation is convenient and quick.

[0031] In some preferred embodiments, step S7 includes: Inspect the flow channel surface of the inner casing 201 of the combustion chamber 200, and check the circumferential position corresponding to the connecting pipe seat 101 of the load-bearing casing 100 and the protruding parts of the flow channel surface; if there are colored markings on the flow channel surface, the fuse of the outer connecting pipe seat 101 of the load-bearing casing 100 is in contact with the flow channel surface of the inner casing 201 and interferes. Adjust the direction of the fuse or change the position of the fuse hole and re-lock it. Repeat steps S2-S6 until there is no interference; if there are no colored markings on the flow channel surface, it is determined that there is no interference between the fuse and the inner casing 201, and it is deemed qualified.

[0032] In some preferred embodiments, step S7 includes: Visually inspect the distribution of colored markings on the outer cylindrical surface of the inner ring 302 of the cylindrical roller bearing 300 on the journal of the gas turbine rotor 202: If the colored markings are evenly distributed around the outer cylindrical surface of the inner ring 302 of the bearing, and the width of the colored markings covers the entire effective working width of the inner ring 302, then the axial overlap of the inner and outer rings 301 of the bearing is deemed to be qualified and no adjustment is required. If the color markings are only distributed on the front half of the inner ring 302, it is determined that the outer ring 301 of the bearing installed on the load-bearing casing 100 has moved forward relative to the inner ring 302, that is, the stator component is too far forward relative to the rotor; add an adjusting shim between the casing 201 and the mounting edge of the load-bearing casing 100 in the combustion chamber 200, adjust the stator component backward, and restore the inner and outer rings 301 of the bearing to the correct axial overlap position; If the color markings are only distributed on the rear half of the inner ring 302, it is determined that the outer ring 301 of the bearing installed on the load-bearing casing 100 has shifted backward relative to the inner ring 302, that is, the stator component is too far back relative to the rotor; reduce the adjusting shim between the inner casing 201 of the combustion chamber 200 and the mounting edge of the load-bearing casing 100, adjust the stator component forward, and restore the inner and outer rings 301 of the bearing to the correct axial overlap position.

[0033] In some preferred embodiments, step S7 further includes: If the colored markings are continuous and unbroken in the 360° direction, it is determined that the inner and outer rings 301 of the bearing are well radially aligned, the rotor and stator are concentric, and there is no eccentricity. If the colored marking shows a break in the circumferential direction, it is determined that the roller corresponding to the broken area is not in contact with the inner ring 302, the bearing has radial misalignment, and the rotor is eccentric relative to the stator. Based on the fuse interference inspection results, comprehensive adjustments are made, including reinstalling the fuse, checking the mating surfaces of the load-bearing casing 100 and the inner casing 201 of the combustion chamber 200, re-inspecting the perpendicularity of the mandrel 800 guide, or reassembling the entire process. This method not only provides an inspection method but also forms a complete quantitative judgment standard and corresponding adjustment measures from the logic of phenomenon observation, conclusion judgment, adjustment measures, and re-verification. Through one hoisting, one coloring, and one inspection, multiple inspection items, including fuse interference inspection and bearing lap misalignment, are completed simultaneously, resulting in high efficiency and low cost. The coloring marking allows two application scenarios to share the same operating procedure. Based on this method, pre-inspection and adjustment during the assembly process are achieved, ensuring that the bearing roller and inner ring 302 are always in the correct axial and radial mating positions, fundamentally eliminating the risks of bearing misalignment, abnormal wear, overheating, and disintegration caused by assembly, significantly extending the engine's overhaul interval and service life.

[0034] This method uses red ink to color two key quality control points that cannot be directly observed during the blind assembly of the load-bearing housing 100, namely fuse interference and bearing overlap, which are visible to the naked eye. Operators can intuitively judge the assembly quality without relying on expensive endoscopes or complex sensors, which greatly reduces the difficulty and cost of quality control. On the other hand, a preferred embodiment of the present invention also provides a tooling that applies the above-mentioned assembly and inspection method for the load-bearing casing 100. The tooling includes a mandrel 800, a support plate 600, a lifting lug 700, a mounting pin 900, a pressure block 500, and a push rod 400. Specifically, the mandrel 800 is made of hard aluminum (LD5 or 2A12) and has a stepped shaft structure. Its lower end is provided with an external thread for connection with the internal threaded hole in the center of the gas turbine rotor 202. The middle section of the mandrel 800 is a guide section, and its outer diameter is consistent with the outer diameter of the inner ring 302 of the cylindrical roller bearing 300. The tolerance is controlled at the same precision level as the outer diameter of the inner ring 302 of the bearing. The upper end of the mandrel 800 is provided with an internal threaded hole for connection with the push rod 400. The top of the mandrel 800 is provided with a hexagonal head or a slotted groove for easy tightening with tools. The support plate 600 is a disc-shaped, portal-shaped, or arch-shaped component. Its outer edge matches the inner circle of the rear mounting edge of the load-bearing casing 100, and is used for positioning with the inner circle as a reference. A bushing is provided at the center of the support plate 600, and the inner diameter of the bushing forms a clearance fit of 0.15mm to 0.25mm with the outer diameter of the guide section of the spindle 800. Multiple bolt holes are evenly distributed on the support plate 600, and their positions correspond one-to-one with the bolt holes on the rear mounting edge of the load-bearing casing 100. The lifting lug 700 has an arc-shaped opening structure. Its shape and opening depth match the outer arc of the mounting edge of the load-bearing casing 100. The upper and lower end faces of the lifting lug 700 are provided with bolt holes. The bolt holes on the upper and lower end faces are arranged coaxially. The lifting lug 700 is quickly and securely connected to the support plate 600 and the load-bearing casing 100 by mounting pins 900. The mounting pin 900 consists of a pin body, an R-shaped pull ring handle, and a spring locking mechanism. The outer diameter of the pin body matches the bolt hole diameter of the lifting lug 700, support plate 600, and load-bearing housing 100. When inserting, pressing the R-shaped pull ring handle retracts the locking mechanism; after insertion, releasing the handle automatically ejects the locking mechanism for quick locking. To remove, simply press the handle again. The pressure block 500 has a gate-shaped or bridge-shaped structure, with two support legs and a crossbeam. The two support legs are respectively pressed into the two bolt holes on the mounting side of the load-bearing casing 100. The center of the crossbeam has a through hole for inserting the top rod 400. The push rod 400 is a long rod-shaped component with an external thread at its lower end that matches the internal thread hole at the upper end of the spindle 800. The upper end of the push rod 400 is equipped with a hexagonal head or handle for easy rotation. The middle section of the push rod 400 passes through the central through hole of the crossbeam of the pressure block 500. By rotating the push rod 400, the clamping force of the pressure block 500 on the load-bearing housing 100 can be adjusted.

[0035] In the description of this invention, it should be noted that the terms "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for assembling and inspecting a load-bearing casing, applied to an aero-engine, the aero-engine including a gas turbine rotor (202), an inner casing (201), a load-bearing casing (100), and cylindrical roller bearings (300), characterized in that, The assembly inspection method for the load-bearing casing includes: S1. The engine is vertically positioned and the spindle (800) is installed. The gas turbine rotor (202) with the inner ring (302) of the cylindrical roller bearing (300) is installed into the inner casing (201), and the spindle (800) is installed on the gas turbine rotor (202); S2. Color marking, color marking is applied to the surface of the fuse of the connecting pipe seat (101) outside the load-bearing housing (100), and color marking is applied to the roller surface of the outer ring (301) of the cylindrical roller bearing (300) mounted on the load-bearing housing (100), the marking medium having the property of being contactable and transferable; S3. Hoist the load-bearing casing (100) onto the inner casing (201) for assembly; S4. Simulate working condition tensioning, simulating the rearward displacement state of the gas turbine rotor (202) under axial thrust during engine operation; S5. Horizontal rotation check; S6. Decomposition; S7. Determine fuse interference, bearing axial overlap, and bearing radial eccentricity based on the color mark transfer situation.

2. The method for inspecting the assembly of a load-bearing casing according to claim 1, characterized in that, Step S2 includes: S21. Apply ink evenly to the fuse surface of each connector (101) outside the load-bearing casing (100) and control the coating thickness; S22. Apply printing ink evenly to the surface of each roller of bearing No. 4 inside the load-bearing housing (100). When applying the ink, rotate the outer ring (301) to ensure that the entire circumference of each roller is covered. S23. After coating, rotate the outer ring (301) to check whether the coloring of the roller is uniform.

3. The method for inspecting the assembly of a load-bearing casing according to claim 1, characterized in that, It also includes tooling fixtures, which include a support plate (600), a lifting lug (700), and a mounting pin (900). The support plate (600) is used for axial positioning and limiting with the first end face of the mounting edge of the load-bearing housing (100) and for radial positioning with the inner wall of the load-bearing housing (100). A bushing that mates with the mandrel (800) is provided in the middle of the support plate (600), and the inner diameter of the bushing and the outer diameter of the guide section of the mandrel (800) are designed for clearance fit. The lifting lug (700) is used for axial positioning engagement with the second end face of the mounting edge of the load-bearing housing (100) and radial positioning engagement with the outer annular surface of the mounting plate. The lifting lug (700) and the support plate (600) are respectively provided with mounting holes that match the bolt hole positions of the mounting edge of the load-bearing housing (100). The mounting pin (900) is used to be inserted into the mounting hole to make the lifting lug (700) and the support plate (600) radially positioned. Step S3 includes: S31. A support plate (600) is installed on the mounting edge of the load-bearing casing (100) with the inner circle as the reference; S32. Install a lifting lug (700) at the mating point of the support plate (600) and the mounting edge of the load-bearing casing (100), and insert the mounting pin (900) through the mounting hole of the support plate (600), the bolt hole of the mounting edge of the load-bearing casing (100), and the mounting hole of the lifting lug (700) in sequence. S33. Lift the load-bearing casing (100) above the inner casing (201); S34. Make the upper end of the spindle (800) pass through the internal cavity of the load-bearing housing (100) and align with the bushing at the center of the support plate (600); S35. Guided by the clearance fit between the spindle (800) and the bushing, slowly lower the load-bearing casing (100) until the mounting edge of the load-bearing casing (100) is fully engaged with the mounting edge of the casing (201) inside the combustion chamber (200).

4. The method for assembling and inspecting a load-bearing casing according to claim 3, characterized in that, The tooling fixture further includes a push rod (400) and a pressure block (500). The pressure block (500) is used to abut against the mounting edge of the load-bearing casing (100). The push rod (400) includes a connecting section and a pressure-applying section. A central hole for the connecting section is opened in the middle of the pressure block (500). The end of the mandrel (800) is provided with an external thread for engaging with the internal thread of the end of the gas turbine rotor (202). Step S4 includes: S41. Install a pressure block (500) on the mounting side of the load-bearing casing (100), pass the connecting section of the push rod (400) through the center hole of the pressure block (500), and screw the connecting section of the push rod (400) into the internal thread hole at the upper end of the spindle (800); S42. Tighten the push rod (400) so that the pressure block (500) presses the load-bearing casing (100) against the inner casing (201), and the reaction force of the push rod (400) pulls the spindle (800) backward, thereby pulling the gas turbine rotor (202) backward.

5. The method for inspecting the assembly of a load-bearing casing according to claim 1, characterized in that, Step S5 includes: S51. Slowly rotate the engine from a vertical position until the rotor axis is horizontal, and let it stand for 10 to 30 seconds; S52. Rotate the gas turbine rotor (202) by turning it to determine whether the gas turbine rotor (202) has good residual rotation and whether there is any abnormal noise; if the rotor has good residual rotation and no abnormal friction noise, then the rotor support is normal and there is no scraping.

6. The method for inspecting the assembly of a load-bearing casing according to claim 1, characterized in that, Step S6 includes: S61. Return the engine from a horizontal position to a vertical position with the turbine end facing upwards; S62. Use a crane to lift the load-bearing casing (100) vertically upwards and separate it from the casing (201) inside the combustion chamber (200).

7. The method for inspecting the assembly of a load-bearing casing according to claim 1, characterized in that, Step S7 includes: Inspect the flow channel surface of the inner casing (201) of the combustion chamber (200), and check the circumferential position corresponding to the connecting pipe seat (101) of the load-bearing casing (100) and the protruding parts of the flow channel surface; if there are colored marking marks on the flow channel surface, the fuse of the connecting pipe seat (101) of the load-bearing casing (100) has contacted and interfered with the flow channel surface of the inner casing (201). Adjust the direction of the fuse or change the position of the fuse hole to re-lock it, and repeat steps S2-S6 until there is no interference; if there are no colored marking marks on the flow channel surface, it is determined that the fuse does not interfere with the inner casing (201), and it is deemed qualified.

8. The method for inspecting the assembly of a load-bearing casing according to claim 7, characterized in that, Step S7 includes: Visually inspect the distribution of colored markings on the outer cylindrical surface of the inner ring (302) of the cylindrical roller bearing (300) on the journal of the gas turbine rotor (202): If the colored markings are evenly distributed around the outer cylindrical surface of the inner ring (302) of the bearing, and the width of the colored markings covers the entire effective working width of the inner ring (302), then the axial overlap of the inner and outer rings (301) of the bearing is deemed to be qualified and no adjustment is required. If the color markings are only distributed on the front half of the inner ring (302), it is determined that the outer ring (301) of the bearing installed on the load-bearing housing (100) has moved forward relative to the inner ring (302), that is, the stator component is too far forward relative to the rotor; add an adjusting shim between the mounting edge of the housing (201) and the load-bearing housing (100) in the combustion chamber (200) and adjust the stator component backward so that the inner and outer rings (301) of the bearing are restored to the correct axial overlap position; If the color markings are only distributed on the rear half of the inner ring (302), it is determined that the outer ring (301) of the bearing mounted on the load-bearing housing (100) has shifted backward relative to the inner ring (302), that is, the stator component is too far back relative to the rotor; reduce the adjusting shim between the housing (201) and the mounting edge of the load-bearing housing (100) in the combustion chamber (200), adjust the stator component forward, and restore the inner and outer rings (301) of the bearing to the correct axial overlap position.

9. The method for assembling and inspecting a load-bearing casing according to claim 8, characterized in that, Step S7 also includes: If the colored markings are continuous and unbroken in the 360° direction, it is determined that the inner and outer rings (301) of the bearing are well radially aligned, the rotor and stator are concentric, and there is no eccentricity. If the colored marking has a broken band in the circumferential direction, it is determined that the roller corresponding to the broken band area is not in contact with the inner ring (302), the bearing has radial misalignment, and the rotor is eccentric relative to the stator; based on the fuse interference inspection results, comprehensive adjustments are made, including reinstalling the fuse, checking the mating surfaces of the load-bearing casing (100) and the inner casing (201) of the combustion chamber (200), re-inspecting the perpendicularity of the mandrel (800) guide, or re-assembling the entire process.

10. A tooling, characterized in that, The load-bearing housing assembly inspection method according to any one of claims 1-9 is used, wherein the tooling includes a mandrel, a support plate, a lifting lug, a mounting pin, a pressure block, and a push rod.

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