Method for adjusting coaxiality of bearing mounting hole on aero-engine casing

Abstract

The application discloses a method for adjusting coaxiality of bearing mounting holes on an aero-engine casing, comprising the following steps: S1: measuring coaxiality of front bearing mounting holes and rear bearing mounting holes on an inner casing relative to an outer casing, and establishing a polar coordinate system on the outer casing to mark phases of the front bearing mounting holes and the rear bearing mounting holes in the polar coordinate system respectively; S2: calculating corresponding adjusting amounts of tension bolts according to the coaxiality of the bearing mounting holes relative to the outer casing and the phases of the bearing mounting holes in the polar coordinate system; S3: converting the adjusting amounts of the tension bolts into torsion angles to twist the tension bolts, thereby adjusting the coaxiality of the bearing mounting holes and ensuring that tightening torques are within a set range; and S4: measuring again the coaxiality of the front bearing mounting holes and the rear bearing mounting holes on the inner casing relative to the outer casing, and judging whether the coaxiality of the front bearing mounting holes and the rear bearing mounting holes relative to the outer casing meets set requirements according to a coaxiality judging condition.

Description

Technical Field

[0001] This invention relates to the field of engine casing assembly technology, and in particular, to a method for adjusting the coaxiality of bearing mounting holes on an aero-engine casing. Background Technology

[0002] In aero engines, the coaxiality of bearing supports is critical to ensure that the rotor can withstand additional forces and operate stably during high-speed rotation.

[0003] In aero engines, the bearing housing is mainly divided into two parts: an inner and an outer housing. The inner housing has circumferentially distributed ribs with threaded holes. Each rib is connected to the outer housing by a tension bolt. To ensure bearing coaxiality, the runout of the bearing mounting hole to the outer housing stop needs to be checked after assembly. However, because the inner housing has multiple detachable parts, and these parts are all large interference fits, there are one or more high and low points with different radii between the outer diameter of the inner housing and the inner diameter of the outer housing. The high point of the outer diameter of the inner housing is easily aligned with the high point of the inner diameter of the outer housing. The high points of the inner and outer diameters will squeeze each other, causing the housing to shift. The runout test results often exceed the tolerance by several times, and the coaxiality of the bearing mounting hole and the outer housing cannot be controlled. Summary of the Invention

[0004] This invention provides a method for adjusting the coaxiality of bearing mounting holes on an aero-engine casing, in order to solve the technical problem of poor coaxiality between bearing mounting holes and the outer casing in existing aero-engines.

[0005] According to one aspect of the present invention, a method for adjusting the coaxiality of bearing mounting holes on an aircraft engine casing is provided, comprising the following steps: S1: measuring the coaxiality of the front bearing mounting holes and the rear bearing mounting holes on the inner casing relative to the outer casing, and establishing a polar coordinate system on the outer casing to mark the phases of the front bearing mounting holes and the rear bearing mounting holes in the polar coordinate system, as well as the distribution of a plurality of circumferentially distributed tension bolts in the polar coordinate system; S2: calculating the corresponding tension bolts based on the coaxiality of the bearing mounting holes relative to the outer casing and the phases of the bearing mounting holes in the polar coordinate system. S3: Convert the bolt tightening adjustment amount into a torsion angle, tighten the bolt by turning the torque, and then adjust the coaxiality of the bearing mounting hole, and ensure that the tightening torque is within the set range; S4: Measure the coaxiality of the front bearing mounting hole and the rear bearing mounting hole on the inner casing relative to the outer casing again, and judge whether the coaxiality of the front bearing mounting hole and the rear bearing mounting hole relative to the outer casing meets the set requirements according to the coaxiality judgment conditions. If the set requirements are met, the adjustment ends. If the set requirements are not met, repeat steps S2-S4 until the set requirements are met.

[0006] As a further improvement to the above technical solution:

[0007] Further, in step S2, when the phase of the bearing mounting hole in the polar coordinate system is α, and two adjacent tension bolts β, which are 180° out of phase with α, are selected for adjustment in the polar coordinate system, the following calculation formula is obtained:

[0008]

[0009] Where A is the eccentricity of the bearing mounting hole in the polar coordinate system, A1 is the adjustment amount of the first tension bolt, A2 is the adjustment amount of the second tension bolt, i is the phase of the first tension bolt in the polar coordinate system, and n is the number of tension bolts evenly distributed circumferentially.

[0010] Furthermore, in step S2, the formula for calculating the adjustment amount of the tension bolt is:

[0011] ΔA = k·A·cosα;

[0012] Where ΔA is the adjustment amount of the tension bolt, k is the proportional coefficient, A is the eccentricity of the bearing mounting hole in the polar coordinate system, and α is the phase of the bearing mounting hole in the polar coordinate system.

[0013] Furthermore, in step S3, the conversion formula between the tension bolt adjustment amount and the torsion angle is:

[0014] ΔA / P = γ / 2π;

[0015] Where P is the pitch of the tension bolt and γ is the torsion angle.

[0016] Furthermore, k is 0.5, 0.284, or 0.797.

[0017] Furthermore, the specific steps for establishing a polar coordinate system on the outer casing are as follows:

[0018] Choose the rear end face of the outer casing as the X-plane, the line connecting the axis of the locating pin on the rear end face of the outer casing and the axis of the outer casing as the Y-plane, the intersection of the X-plane and the axis of the outer casing as the origin of the polar coordinates, and the intersection of the X-plane and the Y-plane as the starting position of the angle, thus establishing a polar coordinate system.

[0019] Furthermore, in step S4, the condition for the coaxiality to meet the set requirements is:

[0020] A F ≤0.01, A B ≤0.01;

[0021] Among them, A F For the coaxiality of the front bearing mounting hole relative to the outer casing, A B This refers to the coaxiality of the rear bearing mounting hole relative to the outer casing.

[0022] Furthermore, when measuring coaxiality, there should be no fewer than three coaxiality measurement sections, and the axial deviation of the measurement position should not exceed 2 mm when the measurement is repeated.

[0023] Furthermore, before step S1, there is also the following step: during the assembly of the outer casing and the inner casing, all the circumferentially distributed tension bolts are tightened in a star-shaped sequence with gradually increasing tightening torque, and the upper limit of the tightening torque is the middle value of the set torque range.

[0024] Furthermore, before step S1, there is also the step of mounting the housing on a turntable or a coordinate measuring machine.

[0025] The present invention has the following beneficial effects:

[0026] The present invention discloses a method for adjusting the coaxiality of bearing mounting holes on an aero-engine casing. This method involves measuring the coaxiality of the front and rear bearing mounting holes on the inner casing relative to the outer casing, establishing a polar coordinate system on the outer casing, marking the phases of the front and rear bearing mounting holes in the polar coordinate system, and the distribution of circumferentially distributed tension bolts in the polar coordinate system. This establishes a correlation between the bearing mounting holes and the tension bolts in the polar coordinate system. The adjustment amount of the tension bolts is calculated based on the coaxiality of the bearing mounting holes relative to the outer casing and their phases in the polar coordinate system. The coaxiality of the bearing mounting holes relative to the outer casing can then be adjusted by tightening the tension bolts. By converting the tension bolt adjustment amount into a torsion angle, the coaxiality of the bearing mounting holes is adjusted by tightening the bolts. The torsion angle and tightening torque of the tension bolts are linearly related, allowing the tightening torque to be obtained based on changes in the torsion angle. To ensure the tightening torque is within the set range, it is crucial to avoid both insufficient tightening torque (leading to loosening) and excessive tightening torque (causing damage from excessive pressure). The coaxiality of the front and rear bearing mounting holes on the inner casing relative to the outer casing is measured again. Based on the coaxiality judgment criteria, it is determined whether the coaxiality of the front and rear bearing mounting holes relative to the outer casing meets the set requirements. If the requirements are met, the adjustment ends; otherwise, the above steps are repeated until the requirements are met, achieving precise control of the coaxiality of the bearing mounting holes and the outer casing. Compared to existing technologies, this solution establishes a polar coordinate system to correlate the coaxiality of the bearing mounting holes with the adjustment amount of the tightening bolts. This allows for effective control of the coaxiality of the bearing mounting holes relative to the outer casing simply by tightening the tightening bolts, ensuring that the coaxiality of the bearing mounting holes relative to the outer casing meets design requirements, avoiding deviations in the inspection results, and demonstrating strong practicality and suitability for widespread promotion and application.

[0027] 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

[0028] 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:

[0029] Figure 1 This is a flowchart of a preferred embodiment of the present invention, showing a method for adjusting the coaxiality of bearing mounting holes on an aero-engine casing.

[0030] Figure 2 This is a schematic diagram of the structure of the outer casing in the method for adjusting the coaxiality of the bearing mounting holes on the aircraft engine casing according to a preferred embodiment of the present invention;

[0031] Figure 3 This is a schematic diagram of the layout of the tension bolts in the polar coordinate system in the method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to a preferred embodiment of the present invention. Detailed Implementation

[0032] 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.

[0033] like Figures 1-3 As shown, the method for adjusting the coaxiality of bearing mounting holes on the aircraft engine casing in this embodiment includes the following steps: S1: Measuring the coaxiality of the front bearing mounting holes and rear bearing mounting holes on the inner casing relative to the outer casing, and establishing a polar coordinate system on the outer casing to mark the phases of the front bearing mounting holes and rear bearing mounting holes in the polar coordinate system, as well as the distribution of multiple circumferentially distributed tension bolts in the polar coordinate system; S2: Calculating the corresponding tension bolt adjustment based on the coaxiality of the bearing mounting holes relative to the outer casing and the phases of the bearing mounting holes in the polar coordinate system. S3: Convert the adjustment amount of the tension bolt into a torsion angle, tighten the bolt by turning the torque, and then adjust the coaxiality of the bearing mounting hole, and ensure that the tightening torque is within the set range; S4: Measure the coaxiality of the front bearing mounting hole and the rear bearing mounting hole on the inner casing relative to the outer casing again, and judge whether the coaxiality of the front bearing mounting hole and the rear bearing mounting hole relative to the outer casing meets the set requirements according to the coaxiality judgment conditions. If the set requirements are met, the adjustment ends. If the set requirements are not met, repeat steps S2-S4 until the set requirements are met.

[0034] like Figures 1-3As shown, specifically, the method for adjusting the coaxiality of bearing mounting holes on the aircraft engine casing of the present invention involves measuring the coaxiality of the front and rear bearing mounting holes on the inner casing relative to the outer casing, and establishing a polar coordinate system on the outer casing to mark the phases of the front and rear bearing mounting holes in the polar coordinate system, as well as the distribution of the circumferentially distributed tension bolts in the polar coordinate system, thereby associating the bearing mounting holes and tension bolts in the polar coordinate system. The adjustment amount of the tension bolts is calculated based on the coaxiality of the bearing mounting holes relative to the outer casing and the phases of the bearing mounting holes in the polar coordinate system. The coaxiality of the bearing mounting holes relative to the outer casing can then be adjusted by tightening the tension bolts. By converting the adjustment amount of the tension bolts into a torsion angle, the coaxiality of the bearing mounting holes is adjusted by tightening the tension bolts. The torsion angle and tightening torque of the tension bolts are linearly related, allowing the tightening force of the tension bolts to be obtained based on changes in the torsion angle. The tightening torque is adjusted to ensure it is within the set range, preventing loosening due to insufficient torque and damage due to excessive torque. The coaxiality of the front and rear bearing mounting holes on the inner casing relative to the outer casing is measured again. Based on the coaxiality judgment criteria, it is determined whether the coaxiality of the front and rear bearing mounting holes relative to the outer casing meets the set requirements. If it does, the adjustment ends; if not, the above steps are repeated until the requirements are met, achieving precise control of the coaxiality of the bearing mounting holes and the outer casing. Compared to existing technologies, this solution establishes a polar coordinate system to correlate the coaxiality of the bearing mounting holes with the adjustment amount of the tension bolts. This allows for effective control of the coaxiality of the bearing mounting holes relative to the outer casing simply by tightening the tension bolts, ensuring that the coaxiality of the bearing mounting holes relative to the outer casing meets design requirements, avoiding runout checks, and demonstrating strong practicality and suitability for widespread promotion and application.

[0035] It should be understood that the casing includes an outer casing and an inner casing.

[0036] It should be understood that bearing mounting holes include front bearing mounting holes and rear bearing mounting holes.

[0037] It should be understood that the outer casing and the inner casing are connected by a plurality of circumferentially distributed tension bolts.

[0038] like Figure 3 As shown, in one embodiment, seven tension bolts are evenly distributed along the circumference.

[0039] like Figure 3 As shown, in this embodiment, in step S2, when the phase of the bearing mounting hole in the polar coordinate system is α, and two adjacent tension bolts β, which are 180° out of phase with α, are selected for adjustment in the polar coordinate system, the following calculation formula is obtained:

[0040]

[0041] Where A is the coaxiality of the bearing mounting hole relative to the outer casing, A1 is the adjustment amount of the first tension bolt, A2 is the adjustment amount of the second tension bolt, i is the phase of the first tension bolt in the polar coordinate system, and n is the number of tension bolts evenly distributed circumferentially.

[0042] Specifically, the coaxiality of the bearing mounting hole relative to the casing is the eccentricity of the bearing mounting hole in the polar coordinate system. This can be obtained by converting trigonometric functions to the above calculation formula. Then, the adjustment amount of the two tension bolts arranged opposite to the bearing mounting hole can be calculated using the above calculation formula. By increasing the tightening torque of these two tension bolts, the axis of the bearing mounting hole can be brought closer to the axis of the outer casing, thereby effectively controlling the coaxiality of the bearing mounting hole relative to the outer casing.

[0043] In this embodiment, the formula for calculating the adjustment amount of the tension bolt in step S2 is as follows:

[0044] ΔA = k·A·cosα;

[0045] Where ΔA is the adjustment amount of the tension bolt, k is the proportional coefficient, A is the coaxiality of the bearing mounting hole relative to the outer casing, and α is the phase of the bearing mounting hole in the polar coordinate system.

[0046] Specifically, the above formula is a simplified formula, and the proportional coefficient is an empirical coefficient, which helps to save calculations, quickly obtain the calculation structure of the tension bolt adjustment amount, and thus improve the efficiency of coaxiality adjustment.

[0047] In this embodiment, the conversion formula between the tension bolt adjustment amount and the torsion angle in step S3 is as follows:

[0048] ΔA / P = γ / 2π;

[0049] Where P is the pitch of the tension bolt and γ is the torsion angle.

[0050] Specifically, the adjustment amount of the tension bolt can be converted into the torsion angle using the above formula. The tightening torque can then be calculated based on the torsion angle to ensure that it is within the set range, thus guaranteeing that the tightening torque of the tension bolt meets the set requirements.

[0051] In this embodiment, k is 0.5, 0.284, or 0.797. Specifically, when the center of the bearing mounting hole is on the X-axis of the polar coordinate system, and the coaxiality of the bearing mounting hole relative to the outer casing is e, it is only necessary to move the center of the bearing mounting hole in the -X direction by e. By adjusting the corresponding tension bolt, the resultant movement direction is in the -X direction, and the distance is e. In one embodiment, the proportional coefficient k of the corresponding tension bolt is 0.5. When the center of the bearing mounting hole is on the Y-axis of the polar coordinate system, and the coaxiality of the bearing mounting hole relative to the outer casing is e, it is only necessary to move the center of the bearing mounting hole in the -Y direction by e. By adjusting the corresponding tension bolt, the resultant movement direction is in the -Y direction, and the distance is e. In this case, in one embodiment, the proportional coefficient k of the first tension bolt is 0.284, and the proportional coefficient k of the second tension bolt is 0.797.

[0052] It should be understood that the proportional coefficient is an empirical coefficient. In the initial adjustment process, the adjustment amount of the tension bolt is usually calculated first using the conversion formula, and then the proportional coefficient is obtained using the simplified formula. This is to gradually accumulate the coaxiality of the bearing mounting hole relative to the outer casing under different conditions. When encountering the same situation later, the adjustment amount of the tension bolt can be directly obtained using the simplified formula, thereby saving calculation and improving adjustment efficiency.

[0053] like Figure 2 As shown, in this embodiment, the specific steps for establishing a polar coordinate system on the outer casing are as follows: The rear end face of the outer casing is selected as the X-plane; the line connecting the axis of the positioning pin on the rear end face of the outer casing and the axis of the outer casing is selected as the Y-plane; the intersection of the X-plane and the axis of the outer casing is selected as the origin of the polar coordinate system; and the intersection of the X-plane and the Y-plane is selected as the starting position of the angle, thereby establishing the polar coordinate system. Specifically, through the above-mentioned polar coordinate system, the coaxiality of the bearing mounting hole relative to the outer casing can be correlated with the adjustment amount of the tension bolt, so that the coaxiality of the bearing mounting hole relative to the outer casing can be effectively controlled by tightening the tension bolt.

[0054] In this embodiment, in step S4, the condition for the coaxiality to meet the set requirements is:

[0055] A F ≤0.01, A B ≤0.01;

[0056] Among them, A F For the coaxiality of the front bearing mounting hole relative to the outer casing, A B This refers to the coaxiality of the rear bearing mounting hole relative to the outer casing.

[0057] In this embodiment, during coaxiality measurement, there are no fewer than three coaxiality measurement sections, and the axial deviation of the measurement position is guaranteed to be no more than 2 mm during repeated measurements. Specifically, the accuracy of coaxiality measurement is ensured by guaranteeing the number of coaxiality measurement sections and the axial deviation of the measurement position during repeated measurements, thereby effectively controlling the coaxiality of the bearing mounting hole relative to the outer casing.

[0058] In this embodiment, before step S1, the following step is included: during the assembly of the outer casing and the inner casing, all circumferentially distributed tension bolts are tightened in a star-shaped sequence with gradually increasing tightening torque, the upper limit of which is the midpoint of a set torque range. Specifically, by tightening all circumferentially distributed tension bolts in a star-shaped sequence with gradually increasing tightening torque, it is ensured that the initial torque of all tension bolts is the same and in a relatively stable state; and by setting the upper limit of the tightening torque to the midpoint of a set torque range, after coaxiality adjustment, the tightening torque of the tension bolts is kept within the set torque range as much as possible to meet the design requirements.

[0059] In this embodiment, before step S1, the following step is included: mounting the housing on the turntable. Specifically, after the housing is mounted on the turntable, the coaxiality of the bearing mounting hole relative to the outer housing is quickly determined using a dial indicator in conjunction with a rotary scale; by mounting the housing on a coordinate measuring machine, the coaxiality of the bearing mounting hole relative to the outer housing can be quickly determined using the coordinate measuring machine method.

[0060] 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.

[0061] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0062] This document uses specific examples to illustrate the principles and implementation methods of this application. The examples are merely for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, and the existence of an infinite number of specific structures, those skilled in the art can make various improvements, modifications, or variations without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, variations, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered as protected by this application.

Claims

1. A method for adjusting the coaxiality of bearing mounting holes on an aero-engine casing, characterized in that, Includes the following steps: S1: Determine the coaxiality of the front bearing mounting holes and rear bearing mounting holes on the inner casing relative to the outer casing, and establish a polar coordinate system on the outer casing to mark the phase of the front bearing mounting holes and rear bearing mounting holes in the polar coordinate system, as well as the distribution of multiple circumferentially distributed tension bolts in the polar coordinate system. S2: Calculate the corresponding tension bolt adjustment amount based on the coaxiality of the bearing mounting hole relative to the outer casing and the phase of the bearing mounting hole in the polar coordinate system; S3: Convert the adjustment amount of the tension bolt into a torsion angle, tighten the bolt by turning the torque, thereby adjusting the coaxiality of the bearing mounting hole and ensuring that the tightening torque is within the set range; S4: Measure the coaxiality of the front bearing mounting hole and the rear bearing mounting hole on the inner casing relative to the outer casing again. Determine whether the coaxiality of the front bearing mounting hole and the rear bearing mounting hole relative to the outer casing meets the set requirements according to the coaxiality judgment conditions. If the set requirements are met, the adjustment ends. If the set requirements are not met, repeat steps S2-S4 until the set requirements are met. In step S2, the formula for calculating the adjustment amount of the tension bolt is: ； Where ΔA is the adjustment amount of the tension bolt, k is the proportional coefficient, A is the eccentricity of the bearing mounting hole in the polar coordinate system, and α is the phase of the bearing mounting hole in the polar coordinate system. In step S3, the conversion formula between the tension bolt adjustment amount and the torsion angle is: ΔA / P = γ / 2π; Where P is the pitch of the tension bolt and γ is the torsion angle.

2. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to claim 1, characterized in that, In step S2, when the phase of the bearing mounting hole in the polar coordinate system is α, and two adjacent tension bolts β, which are 180° out of phase with α, are selected for adjustment in the polar coordinate system, the following calculation formula is obtained: ； Where A is the eccentricity of the bearing mounting hole in the polar coordinate system, A1 is the adjustment amount of the first tension bolt, A2 is the adjustment amount of the second tension bolt, i is the phase of the first tension bolt in the polar coordinate system, and n is the number of tension bolts evenly distributed circumferentially.

3. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to claim 1, characterized in that, k is 0.5, 0.284, or 0.

797.

4. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to any one of claims 1-3, characterized in that, The specific steps for establishing a polar coordinate system on the outer casing are as follows: Choose the rear end face of the outer casing as the X-plane, the line connecting the axis of the locating pin on the rear end face of the outer casing and the axis of the outer casing as the Y-plane, the intersection of the X-plane and the axis of the outer casing as the origin of the polar coordinates, and the intersection of the X-plane and the Y-plane as the starting position of the angle, thus establishing a polar coordinate system.

5. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to any one of claims 1-3, characterized in that, In step S4, the condition for the coaxiality to meet the set requirements is: A F ≤0.01,A B ≤0.01; Among them, A F For the coaxiality of the front bearing mounting hole relative to the outer casing, A B This refers to the coaxiality of the rear bearing mounting hole relative to the outer casing.

6. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to any one of claims 1-2, characterized in that, When measuring coaxiality, there should be no less than 3 measurement sections, and the axial deviation of the measurement position should not exceed 2mm when the measurement is repeated.

7. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to any one of claims 1-2, characterized in that, Step S1 is preceded by the following steps: During the assembly of the outer and inner casings, all circumferentially distributed tension bolts are tightened in a star-shaped sequence with gradually increasing tightening torque. The upper limit of the tightening torque is the midpoint of the set torque range.

8. The method for adjusting the coaxiality of the bearing mounting holes on the aero-engine casing according to any one of claims 1-2, characterized in that, Step S1 is preceded by the following steps: Mount the housing on a turntable or coordinate measuring machine.

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