Method for assembling axial flow rotor

Abstract

The invention discloses an axial flow rotor assembly method, and belongs to the technical field of aero-engine rotor assembly, and the method comprises the following steps: S1, measuring the radial run-out and end face run-out of a spigot of each stage of disc in an axial flow rotor, and obtaining the high-point amplitude and phase of the run-out of each spigot; s2, based on the measurement data in the step S1, executing a rotor assembly algorithm, calculating and determining an optimal assembly phase combination of the front and rear discs, and enabling the theoretical unbalance to be minimum; s3, regulating and controlling the matching state of each stage of disc through a temperature difference method, and assembling a plurality of discs on the middle stage of disc at the same time by adopting a one-step assembling method to form a rotor assembly; s4, after the seam allowance is assembled, axial loading force is applied to the position adjacent to the seam allowance, and it is ensured that the stress of the seam allowance is uniform and the end faces are attached; and S5, the connecting bolt set is tightened in a staged mode for multiple times in an evenly-distributed mode, so that the overall pre-tightening force is balanced. According to the closed-loop control system from error measurement, structure matching and force field control to feedback adjustment, the initial assembly balance degree of the rotor is remarkably improved, the unbalance risk caused by error coupling is reduced, and dual optimization of assembly quality and efficiency is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of aero-engine rotor assembly, and specifically to an axial-flow rotor assembly method. Background Art

[0002] As one of the core components of an aero-engine, the assembly quality of an axial-flow rotor directly affects the running balance and service life of the whole engine. To meet the design requirements of high rotational speed and high thrust-to-weight ratio of the engine, the axial-flow rotor usually consists of multiple blade disks, connecting sections and other components, and forms an integral structure through mating surfaces, interference fits and bolt groups. Due to the large diameter and multi-stage levels of the rotor, problems such as the accumulation of geometric errors, form and position errors between components, and uneven tightening loads during the assembly process are likely to cause the deviation of the rotor axis and the out-of-tolerance of the initial unbalance.

[0003] Traditional assembly methods mostly adopt the misaligned arrangement of the light and heavy points of the disk parts to reduce the unbalance, but this method does not fully consider the combined effect of the radial runout and end face runout of the mating surface on the deviation of the rotor axis, nor does it include the uniformity of the bolt pre-tightening force in the overall assembly accuracy control range. Therefore, it often fails to achieve the expected balance effect, and even requires multiple disassembly and assembly adjustments, seriously affecting the production efficiency and product consistency. Therefore, there is an urgent need for an axial-flow rotor assembly method that combines mating surface measurement, assembly phase optimization, assembly sequence planning and connection force control to improve the one-time success rate of assembly and reduce the initial unbalance. Summary of the Invention

[0004] The present invention provides an axial-flow rotor assembly method to solve the technical problem of difficult control of the unbalance in the axial-flow rotor assembly.

[0005] According to one aspect of the present invention, an axial-flow rotor assembly method is provided, including the following steps: S1, measuring the radial runout and end face runout of the mating surfaces of each stage of disks in the axial-flow rotor to obtain the high point amplitude and phase of the runout of each mating surface; S2, based on the measurement data in step S1, executing a rotor assembly algorithm to calculate and determine the optimal assembly phase combination of the front and rear disks to minimize the theoretical unbalance; S3, regulating the mating state of each stage of disks by the temperature difference method, and using the one-step assembly method to assemble multiple disks onto the intermediate-stage disk simultaneously to form a rotor assembly; S4, after the mating surface assembly is completed, applying an axial loading force at a position adjacent to the mating surface to ensure uniform mating surface stress and end face fitting; S5, tightening the connecting bolt group in multiple stages with uniform distribution to achieve balanced overall pre-tightening force.

[0006] Optionally, it further includes the following step: S6, measuring the tensile amount of each bolt, and if the measurement result exceeds the preset range, adjusting the tightening torque of the corresponding bolt until the measurement result reaches the preset range.

[0007] Optionally, the following steps are further included: S7, measuring the radial runout and end face runout of the exposed end diameter of the assembled rotor. If the measurement result exceeds the preset range, disassemble the rotor and return to step S3.

[0008] Optionally, in step S7, the judgment method for the end face runout detection result is as follows:

[0009] If k - m - n ≤ ±0.02 is satisfied, it indicates that the end face runout of the assembled rotor is within the preset range;

[0010] m is the distance from the second-stage disk stop to the first-stage disk stop; n is the thickness of the third-stage disk; k is the distance from the rear end face of the third-stage disk to the first-stage disk stop.

[0011] Optionally, in step S5, the steps of tightening in stages are as follows: According to the triangular tightening or diagonal cross-tightening method, gradually increase the torque to perform uniform pre-tightening on the bolt group no less than three times.

[0012] Optionally, in step S2, the rotor assembly algorithm adopts the following formula:

[0013]

[0014] U = ∑M i (a Ri +a Xi );

[0015] In the formula, V Ri is the radial runout of the current mating stop diameter, V Xi is the axial runout of the current mating stop, α i is the included angle of the radial high points of the front and rear disks at the current mating stop, β i is the included angle of the end face high points of the front and rear disks at the current mating stop, M i is the weight of each stage of the disk, U is the theoretical unbalance, a Ri is the influence of the radial runout at each stage of the stop, a Xi is the influence of the end face runout at each stage of the stop. The rotor assembly algorithm traverses the combinations of β i and α i to make U minimum, so as to determine the optimal assembly phase combination of the front and rear disks.

[0016] Optionally, the following steps are further included: S8, performing the final unbalance and runout detection. If the measurement result exceeds the preset range, disassemble the rotor and return to step S2.

[0017] Optionally, in step S3, the one-step assembly method includes the following steps: heating the second-stage disk, and simultaneously cooling the first-stage disk and the third-stage disk or not performing a cooling operation; when the first-stage disk, the second-stage disk, and the third-stage disk reach the expected temperature, assembling the first-stage disk and the third-stage disk onto the second-stage disk simultaneously to form a preliminary rotor assembly.

[0018] Optionally, in step S4, a multi-point pressing device is used to uniformly apply an axial loading force at multiple positions in the circumferential direction of the rotor stop, and the magnitude of the axial loading force is automatically adjusted according to the interference of the stop, and the pressure is maintained until the subsequent connecting parts are completely fastened in place and then withdrawn.

[0019] Optionally, in step S6, an ultrasonic detection technique is used to measure the tensile amount of each bolt.

[0020] In summary, the present application includes at least one of the following beneficial technical effects:

[0021] In step S1, by accurately measuring the radial and end face runout of the stops of each stage of the disk, the key error sources are identified; in S2, an assembly algorithm is used to combinatorially optimize the runout phase and amplitude of the stop, and accurately calculate the relative assembly phase of the front and rear disks, fundamentally reducing the axis skew caused by the accumulation of form and position errors; in S3, a one-step assembly method is combined with thermal difference fitting to complete the multi-disk assembly in one assembly process, effectively reducing the stop fitting disturbance caused by multiple assemblies; in S4, multi-point pressing is used to achieve uniform axial loading of the stop, improving the end face fitting quality and reducing the local eccentricity induced by uneven contact; in S5, through a bolt tightening strategy in multiple and staggered ways, combined with hierarchical control of the loading force, the balance of the connection force field is ensured, and additional deformation caused by uneven bolt pre-tightening is avoided. Overall, this method establishes a closed-loop control system from error measurement, structure matching, force field control to feedback adjustment, significantly improving the initial assembly balance of the rotor, reducing the imbalance risk caused by error coupling, and achieving double optimization of assembly quality and efficiency.

[0022] In addition to the purposes, features, and advantages described above, the present invention has other purposes, features, and advantages. The present invention will be further described in detail below with reference to the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0024] Figure 1 is a flowchart of the axial flow rotor assembly method of the present invention;

[0025] Figure 2 is a schematic diagram for measuring the high point of the stop runout;

[0026] Figure 3 Schematic diagram of the influence of the end face runout of the mating surface

[0027] Figure 4 Schematic diagram of the influence of the end face runout of the mating surface

[0028] Figure 5 Schematic diagram of the triangular tightening sequence of bolts

[0029] Figure 6 Schematic diagram of the four - point cross - tightening sequence of bolts Specific implementation mode

[0030] The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings. However, the present invention can be implemented in many different ways defined and covered by the following.

[0031] The following will be further described in detail with reference to the attached Figures 1-6 This application will be further described in detail.

[0032] The embodiment of this application discloses an axial - flow rotor assembly method.

[0033] The axial - flow rotor assembly method provided by the present invention is applicable to multi - stage rotor structures with mating surface structures, interference fits, and bolt - group connection features, and is particularly applicable to high - precision assembly scenarios of aero - engine compressors or turbines. This method requires high - precision mating surface measuring instruments, numerical - control heating and cooling equipment, hydraulic axial loading devices, ultrasonic bolt pre - tightening force detection equipment, and turntable systems capable of runout and dynamic balance detection.

[0034] Refer to Figure 1 , the axial - flow rotor assembly method includes the following steps:

[0035] S1. Measure the radial runout and end - face runout of the mating surfaces of each stage of disks in the axial - flow rotor to obtain the high - point amplitudes and phases of the runout of each mating surface;

[0036] S2. Based on the measurement data in step S1, execute the rotor assembly algorithm to calculate and determine the optimal assembly phase combination of the front and rear disks to minimize the theoretical unbalance;

[0037] S3. Regulate the mating state of each stage of disks by the temperature - difference method, and use the one - step assembly method to assemble multiple disks onto the intermediate - stage disk simultaneously to form a rotor assembly;

[0038] S4. After the mating surface assembly is completed, apply an axial loading force at a position adjacent to the mating surface to ensure uniform mating surface stress and end - face fitting;

[0039] S5. Tighten the connecting bolt group multiple times in a uniformly distributed and staged manner to achieve balanced overall pre - tightening force.

[0040] S6. Measure the elongation of each bolt. If the measurement result exceeds the preset range, adjust the tightening torque of the corresponding bolt until the measurement result reaches the preset range.

[0041] S7. Measure the radial runout and end face runout of the exposed stop diameter of the assembled rotor. If the measurement result exceeds the preset range, disassemble the rotor and return to step S3.

[0042] S8. Conduct the final unbalance and runout detection. If the measurement result exceeds the preset range, disassemble the rotor and return to step S2.

[0043] Refer to Figure 2 , what significantly affects the assembly effect is the height fluctuations of the radial and end faces of the stop diameters at all levels. Measure the circular runout size and phase of the arc surface relative to the reference and the high point size and phase of the end face flatness as algorithm inputs. There may be more than one high point position of the stop diameter runout, and all need to be measured and marked.

[0044] In step S1, aiming at the significant influence of the stop form and position error on the assembly quality and unbalance during the axial flow rotor assembly process, high-precision measurement means are used to comprehensively evaluate the form and position states of the stop cylindrical surfaces and end faces of all levels of disks. The specific operation is as follows: Install each disk to be measured into a special measurement tooling or turntable fixture respectively, make it rotate with the stop center as the reference, and conduct a full-circle scan of the stop cylindrical surface through a coordinate measuring machine or a laser interferometer to obtain its radial runout data. At the same time, use a contact or non-contact flatness probe to measure the local height fluctuations of the stop end face, and record the maximum runout value at each place and its corresponding circumferential phase angle. After the obtained data is processed by software, output the peak value and position of the stop radial runout, and the high point position and amplitude of the end face runout of each disk, and mark them in the form of an angle relative to a reference datum, such as the keyway or the installation hole position. The key to this step is that not only the radial eccentricity information affecting the rotor coaxiality is obtained, but also the non-ideal fitting state of the stop end face caused by machining or thermal deformation is captured, so that it can be used for subsequent assembly algorithms to optimize and match the relative installation phases of the front and rear disks.

[0045] Refer to Figure 3 and Figure 4 , the end face runout and radial runout of the stop cause the rotor axis to shift and twist. The influence of the end face runout on the radial skew is related to the distance of each level of disk from the rotor center of gravity. When the axial dimension is larger, the center of gravity offset is larger and the unbalance is also larger.

[0046] In step S2, the phase combination optimization is the key link to achieve the low unbalance target in the entire axial flow rotor assembly method. Its core is to use the stop runout data of all levels of disks measured in step S1, combined with the disk mass information, and conduct an exhaustive calculation of all possible assembly phase combinations through a mathematical model and a calculation program to identify the combination relationship with the minimum theoretical unbalance U.

[0047] Specifically, the rotor assembly algorithm uses the following formula:

[0048]

[0049] U = ∑M i (a Ri + a Xi )

[0050] In the formula, V Ri is the radial runout of the current mating stop bore, V Xi is the axial runout of the current mating stop bore, α i is the included angle of the radial high points of the front and rear discs at the current mating stop bore, β i is the included angle of the end face high points of the front and rear discs at the current mating stop bore, M i is the weight of each stage disc, U is the theoretical unbalance, a Ri is the influence of the radial runout at each stage stop bore, a Xi is the influence of the end face runout at each stage stop bore. The rotor assembly algorithm traverses the combinations of β i and α i to minimize U, thereby determining the optimal assembly phase combination of the front and rear discs.

[0051] The radial runout and end face runout data of the stop cylinder surface of each stage disc are input into the optimization algorithm in the form of amplitude and corresponding phase, and combined with the mass values and installation position parameters of each disc to construct a rotor axis offset and torque synthesis model, calculate the rotor center offset vector caused by each set of front and rear disc phase combinations, and then calculate the theoretical unbalance U according to the standard unbalance formula by this offset; this algorithm traverses and combines all possible installation phases of the disc parts, and outputs the best matching scheme with the minimum U, including the angles by which each disc part should be rotated and installed. This process depends on programming implementation, and has the advantages of comprehensive operation, stability, repeatability, etc. Its results are significantly better than the traditional empirical method of misaligning the light and heavy points. In multi-stage rotors, due to the extremely large number of phase space combinations, it is impossible to exhaust them manually, and there are often serious deviations between the unbalance and the theoretical expectation, and even multiple disassembly and assembly trials are required to correct the errors. The present invention converts the form and position error parameters of the disc parts into the basis for optimal assembly decisions in a data-driven manner, so that the optimal phase relationship can be determined before assembly, maximizing the cancellation of the distortion and eccentricity trend of the overall axis caused by the stop bore error, thereby significantly reducing the initial assembly unbalance, improving the first inspection pass rate of the assembly, and enhancing the predictability and engineering control force of the entire rotor assembly process.

[0052] In step S3, the temperature difference assembly is an efficient assembly strategy for realizing the simultaneous mating of multi-stage disc parts during the assembly process. Its core principle is to utilize the dimensional changes caused by the temperature difference between the disc parts, that is, thermal expansion and contraction, to form a controllable assembly gap between the mating parts, thereby avoiding stop bore abrasion or assembly stress concentration caused by mechanical forced assembly.

[0053] The one-step assembly method includes the following steps: heating the second-stage disk, and simultaneously cooling or not cooling the first-stage disk and the third-stage disk; after the first-stage disk, the second-stage disk, and the third-stage disk reach the expected temperature, assembling the first-stage and third-stage disks onto the second-stage disk simultaneously to form a preliminary rotor assembly.

[0054] The assembly operation of the temperature difference method is divided into "one-step method" and "two-step method". Taking the assembly of three-stage disks as an example, the "one-step method" is a method of heating the second-stage disk, simultaneously cooling or not cooling the first-stage and third-stage disks, and assembling the first-stage and third-stage disks onto the second-stage disk simultaneously after reaching the expected temperature. The "two-step method" is to heat the second-stage disk, install the first-stage disk, and after waiting for the assembly formed by the first-stage and second-stage disks to return to normal temperature, install the cooled third-stage disk onto the second-stage disk. Due to the influence of interference, the extrusion of the stop makes the outer surface of the stop of the second-stage disk expand outward, changing from a cylindrical surface to a conical surface. The contact pressure makes the first-stage and third-stage disks tend to deviate from the second-stage disk, and the position farther away from the stop shows an obvious "opening" trend more significantly, affecting the bolt pre-tightening force. Therefore, the one-step method is adopted in this embodiment to facilitate maintaining a stable axial load during the subsequent tightening process of the connecting piece.

[0055] During the specific implementation process, place the second disk in the assembly structure in an inductive heating device or a constant temperature furnace and heat it to a set temperature, such as 250°C - 350°C, so that its inner stop expands thermally to reach a predetermined size. At the same time, keep the first-stage disk and the third-stage disk at normal temperature or perform a short-time cooling treatment according to the material conditions to slightly contract their outer stops, creating a radial installation gap of about 0.01 - 0.03 mm. After the middle disk is heated to the target temperature, immediately align the front and rear disks to the corresponding positions simultaneously, use a special guiding tool or positioning block to ensure the coaxial accuracy of the axis, and quickly assemble the two outer disks onto the stop structure of the middle disk under the thermal expansion and contraction fit to complete the "one-step insertion" process. The key advantage of this method is that multiple stop mating surfaces achieve contact and positioning in a single thermal expansion state, which can greatly reduce problems such as stop deformation, stop scratch, or angular misalignment caused by multiple insertions and extractions during the assembly process. Moreover, the middle disk is inserted as a whole under a stable heating state, avoiding the problem of asynchronous thermal deformation caused by inconsistent assembly times. The one-step method is completed through temperature difference control and synchronous assembly actions, which not only saves assembly time, reduces processes, but also makes it easier to achieve symmetry and balance in the assembly state, improves the balance of the overall axial rotor assembly in the initial assembly state, provides a good foundation for subsequent dynamic balance correction, and effectively improves the stability, controllability, and quality consistency of the entire assembly process.

[0056] In step S5, multi-point axial loading is a key assembly control measure taken after the hot fitting of the spigot is completed to ensure the tightness of the mating end faces of each disk part and the uniform stress distribution in the spigot area. The specific implementation method is as follows: After the spigot mating of the middle disk with the front and rear disks is completed, a special multi-point hydraulic loading device is immediately used to apply an axial loading force to the area adjacent to the spigot. This device usually consists of 4, 6 or more symmetrically arranged hydraulic cylinders, which are equally spaced around the rotor axis, so that the loading directions are evenly distributed over the entire assembly circumference. The loading action adjusts the pressure according to the preset interference amount of the interference fit. For example, by programming, each hydraulic cylinder outputs the corresponding pressure level at different interference fit values to ensure that, without causing further plastic deformation of the spigot, sufficient end face tightening force is provided to effectively compact the local gaps or warping generated during the assembly process. The loading process is continuous until all connection bolts are finally pre-tightened and it is confirmed that the connecting parts are in a stable locked state, and then the hydraulic device unloads synchronously, which maximally ensures that the axis position during the rotor assembly process is not disturbed and the spigot contact surface is not intermittently released. Compared with the traditional method of achieving preliminary compaction by using a shrink ring or a process bolt, these traditional means often only apply force to a certain local area axially, making it difficult to form a continuous axial compaction force field, and often require multiple disassembly, trial tightening, and correction during the tightening or adjustment process, which not only increases the assembly time and labor intensity, but also is more likely to cause poor end face fitting or axis distortion due to uneven force, thus affecting the overall dynamic balance performance. The multi-point axial loading scheme provided by the present invention realizes the full coverage, equal strength, and continuous action of the spigot pressing through a symmetric, multi-source, and automatic feedback control loading mechanism, which is superior to the existing methods in terms of structural accuracy, assembly stability, and operation efficiency, laying a foundation for the rotor assembly to form an initial installation state with high fitting degree and high coaxiality, and effectively supporting the subsequent assembly quality and long-term service performance.

[0057] In step S5, a loading strategy of multi-stage tightening of the connection bolt group in multiple and evenly distributed stages is adopted. The steps of multi-stage tightening are to perform uniform pre-tightening on the bolt group not less than three times by gradually increasing the torque according to the triangular tightening or diagonal cross-tightening method. The purpose is to achieve the uniform distribution of the pre-tightening force of the bolts at the connection part and the flat fitting of the flange connection surface, which is specifically implemented by the triangular tightening or four-point cross-tightening method, so as to effectively avoid the accumulation of pre-tightening force deviation and flange warping caused by the traditional clockwise tightening in the same circle. The tightening sequence of triangular tightening is as Figure 5 , and the tightening sequence of four-point cross-tightening is as Figure 6 .

[0058] The specific implementation method is as follows: First, perform the first round of initial tightening. Tighten in sequence according to the bolt numbers using a low torque (such as 30% of the rated pre-tightening torque) to initially eliminate the assembly gap between the connection surfaces. Then, perform the second round of intermediate tightening. Increase the torque to 60%-70% and further compress the contact surface in sequence according to the bolt numbers to control the overall fit of the flange surface and the local deformation trend. Finally, perform the third round of final tightening. Use the target pre-tightening torque and maintain the tightening sequence. After all bolts reach the set load, cycle through again to confirm that there is no loosening or torque regression. If necessary, perform re-tightening to correct the minor fluctuations in the stress state of the bolts. The core advantage of this method is that the torque increase and sequence arrangement in each round of tightening are planned based on the symmetry and balance principles of the force field distribution between bolts, so that the entire flange connection part is always in an environment of a small stress gradient during the entire pre-tightening process, effectively suppressing assembly defects such as end face warping, bolt sliding, or secondary interference deformation of the spigot caused by local concentrated loading. Compared with the traditional methods of tightening in a circle or single torque loading, the latter often has problems such as some bolts being over-tightened, some bolts being loosely tightened, the end face not fitting, and even local stress abnormally concentrated, which affect the overall assembly strength and operation reliability. However, the multi-round cross-tightening strategy in stages adopted in the present invention not only significantly improves the structural integrity and long-term force consistency of the connecting parts, but also provides a more stable initial loading state for the subsequent ultrasonic stretching amount verification, ensuring the bolt connection of the entire axial flow rotor assembly structure is safe, durable, symmetrical, and precise.

[0059] In step S6, ultrasonic measurement and torque correction are important links in realizing the balanced control of bolt pre-tightening force. Its operating principle is based on the correlation between the propagation speed of ultrasonic waves in metal bolts and tensile deformation. By comparing the ultrasonic flight time difference of the bolt before and after tightening, the axial tensile length of the bolt is indirectly calculated, so as to infer its actual stress state. Specifically, during implementation, first set up an ultrasonic coupling interface at the head or tail of the bolt, record the ultrasonic propagation time T0 of the bolt in the initial free state as the reference value, and perform ultrasonic scanning on each bolt again after the pre-tightening process is completed, and record the propagation time T1 in the current state. The difference ΔT between the two can be converted into the actual tensile amount ΔL, and the current actual pre-tightening force value of the bolt can be further calculated according to the material elastic modulus and cross-sectional area. After all bolts are detected, compare the pre-tightening force of each bolt with the theoretical target value, and set an allowable deviation range (such as ±10%). If the detected value falls within this range, the pre-tightening force is determined to be qualified; if the pre-tightening force of an individual bolt exceeds this deviation, tighten or loosen it again until the tensile amount enters the control range. The advantage of this method is that compared with the traditional method of directly determining that the torque meets the standard as qualified after tightening with a torque wrench, the traditional method highly depends on the stability of the friction factor and the repeatability of the installation environment, and it is extremely easy to cause large differences in the actual tensile force due to the surface state of the thread, the type of lubricant, and the experience of the operator, and it cannot accurately reflect the connection strength. The ultrasonic detection method bypasses the friction factor and directly measures based on physical deformation, with the characteristics of non-contact, high precision, and strong repeatability. It can effectively identify the hidden danger bolts of "qualified torque but insufficient tensile force" or "excessive tightening causing material yield", so as to realize a more rigorous and real quality control of the rotor assembly connection structure, keep the overall bolt group in a symmetric force field and stable structure after assembly, and provide strong guarantee for the long-term reliability in the high-speed rotation environment of the rotor.

[0060] In step S7, assembly dimension and runout detection is a key step in the accuracy confirmation and assembly quality control of the axial-flow rotor after assembly. It aims to ensure that the assembly state of each disk component meets the requirements of dimensional consistency and rotational accuracy. Its specific implementation method includes two aspects: first, quantitative verification of the axial positioning dimensions of the overall rotor structure, and second, re-measurement of the runout of the exposed stop and end face. In terms of dimensional verification, the actual distance from the positioning end face of the intermediate disk to the stop of the front and rear disks is measured and substituted into the judgment formula of kmn≤±0.02, where m is the distance from the stop of the second-stage disk to the stop of the first-stage disk; n is the thickness of the third-stage disk; and k is the distance from the rear end face of the third-stage disk to the stop of the first-stage disk. This formula expresses the maximum allowable difference between the cumulative error of each stage of assembly and the theoretical design value, and uses ±0.02mm as the allowable deviation limit. In terms of runout detection, the assembled rotor is placed on a high-precision inspection turntable, and a micrometer is used to perform contact detection along the radial direction and end surface of the stopper at low speed (the number of points depends on the diameter of the rotor). The maximum runout value of each circle is recorded to determine whether it meets the axial compressor assembly tolerance standards (such as radial runout <0.04mm, end runout <0.03mm, etc.). Compared with the traditional empirical method of judging whether the product is qualified or not only by visual inspection of the end face clearance or single-point caliper, this step has significant advantages: first, it transforms structural tolerance control from subjective judgment into objective quantifiable data, thereby improving the consistency and reliability of detection; second, the formulated dimension verification method can realize the prediction and rapid tracing of assembly errors. If a deviation occurs, it can be traced back to the specific disk assembly deviation; third, the runout detection covers multiple key areas such as the stop, end face, and positioning section, providing a more comprehensive rotation quality assessment; finally, through the feedback of the S7 test results, if runout or dimensional deviation is found, it can be directly guided back to the S3 or S2 link, triggering the optimization of the assembly phase or adjustment of the assembly sequence, forming an assembly control closed-loop mechanism with detection data as the core, thereby significantly improving the first inspection pass rate of the assembly, reducing repeated disassembly and assembly due to human misjudgment, and improving the engineering stability of the overall rotor assembly and the factory execution efficiency.

[0061] In step S8, the final unbalance and runout detection is the final inspection link in the entire axial-flow rotor assembly process. Its core purpose is to evaluate the dynamic and static accuracy of the assembled rotor, verify the actual assembly effects of the previous assembly strategies, such as phase combination optimization, temperature difference fitting, and staged pre-tightening, and determine whether the rotational balance standard required for engineering operation is met. The specific implementation method is as follows: First, install the assembled rotor on the dynamic balance measurement platform or turntable system, ensure that the support points are consistent with the working bearings or the simulated working conditions are symmetric, start the low-speed rotation mode, and use highly sensitive dynamic balance sensors, such as eddy current sensors, laser displacement meters, etc., to monitor the radial vibration amplitude and phase of the rotor on each cylindrical surface and end face in real time; by collecting and analyzing the vibration signals at multiple speed segments, calculate the unbalance value U of the current rotor on each measurement segment, and determine whether it is within the allowable range in combination with the engineering standard. At the same time, repeatedly detect the exposed mating surface and end face runout values to evaluate whether there is an accumulation of secondary assembly errors caused by the release of assembly stress, deformation of the mating surface, or sliding of the connecting parts during the assembly process; if the detection data shows that the unbalance exceeds the standard limit value, or the runout value exceeds the tolerance set in S8 again, disassemble the current rotor and return to step S2, re-perform the analysis of the runout phase of the mating surface and the calculation of the optimal combination, and then perform secondary optimized assembly through the assembly process from S3 to S8. The greatest advantage of this step is to construct a closed-loop control mechanism of "data-driven - assembly optimization - feedback adjustment", making the rotor assembly process no longer a passive process of single trial assembly plus verification, but a dynamic optimization system with logical self-adjustment ability, thus greatly improving the one-time assembly success rate, reducing the risk of rework and component damage caused by unqualified dynamic balance adjustment, and at the same time enhancing the engineering response ability to complex error coupling in the multi-stage rotor system, and finally achieving the assembly goal of high-speed, high-precision, and high-stability axial-flow rotor products.

[0062] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An axial flow rotor assembly method, characterized in that, It includes the following steps: S1. Measure the radial runout and axial runout of the stop surfaces of each stage disk in the axial-flow rotor to obtain the high-point amplitude and phase of the runout of each stop surface; S2. Based on the measurement data in step S1, execute the rotor assembly algorithm to calculate and determine the optimal assembly phase combination of the front and rear disks to minimize the theoretical unbalance; S3. Regulate the mating state of each stage disk by the temperature difference method, and use the one-step assembly method to assemble multiple disks onto the intermediate-stage disk simultaneously to form a rotor assembly; S4. After the stop surface assembly is completed, apply an axial loading force at a position adjacent to the stop surface to ensure uniform stop surface stress and end-face fitting; S5. Tighten the connecting bolt group in multiple stages with uniform distribution to achieve balanced overall pre-tightening force.

2. The axial flow rotor assembly method according to claim 1, wherein It also includes the following steps: S6. Measure the elongation of each bolt. If the measurement result exceeds the preset range, adjust the tightening torque of the corresponding bolt until the measurement result reaches the preset range.

3. The axial flow rotor assembly method according to claim 1, characterized in that, It also includes the following steps: S7. Measure the radial runout and axial runout of the exposed stop surface of the assembled rotor. If the measurement result exceeds the preset range, disassemble the rotor and return to step S3.

4. The axial-flow rotor assembly method according to claim 3, wherein: In step S7, the judgment method for the axial runout detection result is as follows: If k - m - n ≤ ±0.02 is satisfied, it indicates that the axial runout of the assembled rotor is within the preset range; m is the distance from the stop surface of the second-stage disk to the stop surface of the first-stage disk; n is the thickness of the third-stage disk; k is the distance from the rear end face of the third-stage disk to the stop surface of the first-stage disk.

5. The axial-flow rotor assembly method according to claim 4, wherein: In step S5, the steps of tightening in stages are: Gradually increase the torque to uniformly tighten the bolt group not less than three times in the triangular tightening or diagonal cross-tightening manner.

6. The axial-flow rotor assembly method according to claim 1, wherein: In step S2, the rotor assembly algorithm uses the following formula: U = ∑M i (a Ri + a Xi ); Wherein, V Ri is the radial runout of the current mating stop bore, V Xi is the axial runout of the current mating stop bore, α i is the included angle of the radial high points of the front and rear discs at the current mating stop bore, β i is the included angle of the end face high points of the front and rear discs at the current mating stop bore, M i is the weight of each stage disc, U is the theoretical unbalance, a Ri is the influence of the radial runout at each stage stop bore, a Xi is the influence of the end face runout at each stage stop bore. The rotor assembly algorithm traverses the combinations of β i and α i to minimize U, thereby determining the optimal assembly phase combination of the front and rear discs.

7. The axial flow rotor assembly method according to claim 6, characterized in that, It also includes the following steps: S8. Perform final unbalance and runout detection. If the measurement result exceeds the preset range, disassemble the rotor and return to step S2.

8. The axial-flow rotor assembly method according to claim 7, wherein: In step S3, the one-step assembly method includes the following steps: Heat the second-stage disk, and cool the first-stage disk and the third-stage disk simultaneously or do not perform the cooling operation; When the first-stage disk, the second-stage disk, and the third-stage disk reach the expected temperature, assemble the first-stage and third-stage disks onto the second-stage disk simultaneously to form a preliminary rotor assembly.

9. The axial-flow rotor assembly method according to claim 8, wherein: In step S4, use a multi-point pressing device to uniformly apply an axial loading force at multiple positions in the circumferential direction of the rotor stop surface, and the magnitude of the axial loading force is automatically adjusted according to the interference of the stop surface, and maintain the pressure until the subsequent connecting parts are completely tightened and then cancel it.

10. The axial-flow rotor assembly method according to claim 2, wherein: In step S6, use ultrasonic detection technology to measure the elongation of each bolt.

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