Engine rotor online assembly optimization method considering clearance-interference composite fit

Abstract

The invention provides an engine rotor online assembly optimization method considering clearance-interference composite fit, and the method comprises the steps: 1, collecting the geometrical morphology data of multiple sections of an engine clearance rotor, and carrying out the preprocessing of the measurement data; 2, geometrical morphology data of multiple sections of the interference rotor of the engine are collected, and the measurement data are preprocessed; 3, fitting by adopting a least square method to obtain a geometric form and position error parameter; step 4, establishing a clearance-interference rotor error transfer model; 5, determining the maximum possible position of the gap rotor; step 6, establishing an assembly optimization model; 7, optimizing the assembly angle of each stage of rotor; and 8, checking the clearance allowance of each stage of clearance rotor under the assembly angle obtained by optimization, and if the clearance allowance is smaller than a required threshold value, returning to the step 7 until the coaxiality and the clearance allowance of the clearance rotor meet the requirements at the same time. The method can solve the problem that the gap rotor can not be correctly installed in a traditional assembly optimization method.

Description

Technical Field

[0001] The invention belongs to the technical field of engine rotor assembly, and in particular relates to an engine rotor online assembly optimization method considering clearance-interference composite fit. Background Art

[0002] Small turbine engines are the power system of long-duration, high-speed unmanned aerial vehicles. Due to the flight speed requirements of high-speed unmanned aerial vehicles, small turbine engines usually have a higher operating speed. Therefore, small turbine engines place higher requirements on the processing and assembly quality of their own rotors. The coaxiality and other assembly index deviations caused by the processing and assembly process will cause the engine vibration to exceed the limit, directly affecting the assembly reliability of small turbine engines. The rotor system of a small turbine engine is assembled by a gap rotor and an interference rotor, and its assembly quality is affected by the gap, the interference rotor matching characteristics, and the gap rotor clearance allowance. During the assembly optimization process, the gap rotor clearance allowance may cause interference between the gap rotor and the interference rotor, resulting in the optimization effect failing to achieve the expected result. If not discovered in time, it may even have a negative impact on the engine.

[0003] Therefore, in the process of small turbine engine assembly optimization, it is necessary to consider the matching characteristics of clearance and interference rotors, analyze the error transmission process of clearance-interference composite matching rotors, and establish a small turbine engine rotor system assembly optimization model. At the same time, the constraints of clearance rotor clearance allowance on assembly optimization cannot be ignored, and the clearance constraints brought by the clearance rotor need to be considered in the engine clearance-interference rotor assembly optimization model. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] The present invention provides an online assembly optimization method for an engine rotor considering clearance-interference compound fit, the method comprising:

[0006] Step 1, collecting geometric morphology data of multiple cross sections of the engine clearance rotor and preprocessing the measurement data;

[0007] Step 2, collecting geometric morphology data of multiple sections of the engine interference rotor and preprocessing the measurement data;

[0008] Step 3, based on the pre-processed axial and radial measurement data of the clearance rotor and the interference rotor, the least squares method is used to fit and obtain the geometric shape and position error parameters;

[0009] Step 4: using the geometric shape and position error parameters of each level of rotors to establish a clearance-interference rotor error transmission model;

[0010] Step 5, determining the maximum possible position of the clearance rotor;

[0011] Step 6, establishing an assembly optimization model with the rotor assembly angles at each level as variables and the coaxiality of the rotor assembly as the optimization target;

[0012] Step seven, optimizing the assembly angles of the rotors at all levels;

[0013] Step eight, check the clearance allowances of the clearance rotors at each level under the assembly angles obtained by optimization. If the allowances meet the required threshold, confirm that this group of assembly angles is the optimized assembly angle; if the clearance allowances are less than the required threshold, return to step seven and re-optimize until the coaxiality and the clearance allowances of the clearance rotors meet the requirements at the same time.

[0014] By applying the technical solution of the present invention, an online assembly optimization method for engine rotors considering clearance-interference compound fit is provided. The method collects and preprocesses the geometric morphology data of multiple sections of the engine clearance rotor and the interference rotor, obtains geometric shape and position error parameters, and uses the geometric shape and position error parameters of each level of rotors to establish a clearance-interference rotor error transmission model; establishes an engine clearance-interference rotor assembly optimization model and introduces clearance constraints into the assembly optimization model, and finally obtains the optimized assembly phase. The present invention provides a more complete assembly optimization model for engine rotor assembly, meeting the actual assembly requirements of clearance-interference compound fit rotors. Compared with the prior art, the technical solution of the present invention can solve the problem that the clearance rotor may not be correctly installed in the traditional assembly optimization method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The included drawings are used to provide a further understanding of the embodiments of the present invention, which constitute a part of the specification, are used to illustrate the embodiments of the present invention, and together with the text description, explain the principles of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 A schematic flow chart of an online assembly optimization method for an engine rotor considering clearance-interference compound fit according to a specific embodiment of the present invention is shown;

[0017] Figure 2 A schematic diagram of a multi-stage rotor assembly optimization coordinate system provided according to a specific embodiment of the present invention is shown;

[0018] Figure 3 A schematic diagram of an incorrect assembly of a gap rotor is shown.

[0019] The above drawings include the following reference numerals:

[0020] 10. Clearance rotor; 20. Interference rotor; 30. Spindle. DETAILED DESCRIPTION

[0021] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0023] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0024] like Figure 1 As shown, according to a specific embodiment of the present invention, an engine rotor online assembly optimization method considering clearance-interference compound fit is provided, and the method comprises:

[0025] Step 1, collecting geometric morphology data of multiple cross sections of the engine clearance rotor and preprocessing the measurement data;

[0026] Step 2, collecting geometric morphology data of multiple sections of the engine interference rotor and preprocessing the measurement data;

[0027] Step 3, based on the pre-processed axial and radial measurement data of the clearance rotor and the interference rotor, the least squares method is used to fit and obtain the geometric shape and position error parameters;

[0028] Step 4: using the geometric shape and position error parameters of each level of rotors to establish a clearance-interference rotor error transmission model;

[0029] Step 5, determining the maximum possible position of the clearance rotor;

[0030] Step 6, establishing an assembly optimization model with the rotor assembly angles at each level as variables and the coaxiality of the rotor assembly as the optimization target;

[0031] Step seven, optimizing the assembly angles of the rotors at all levels;

[0032] Step eight, check the clearance allowances of the clearance rotors at each level under the assembly angles obtained by optimization. If the allowances meet the required threshold, confirm that this group of assembly angles is the optimized assembly angle; if the clearance allowances are less than the required threshold, return to step seven and re-optimize until the coaxiality and the clearance allowances of the clearance rotors meet the requirements at the same time.

[0033] By applying this configuration, an online assembly optimization method for engine rotors considering clearance-interference compound fit is provided. The method collects and preprocesses the geometric morphology data of multiple sections of the engine clearance rotor and the interference rotor, obtains geometric shape and position error parameters, and uses the geometric shape and position error parameters of each level of rotors to establish a clearance-interference rotor error transmission model; establishes an engine clearance-interference rotor assembly optimization model and introduces clearance constraints into the assembly optimization model, and finally obtains the optimized assembly phase. The present invention provides a more complete assembly optimization model for engine rotor assembly, meeting the actual assembly requirements of clearance-interference compound fit rotors. Compared with the prior art, the present invention can solve the problem that the clearance rotor may not be correctly installed in the traditional assembly optimization method.

[0034] First, in the present invention, step one is performed to collect geometric morphology data of multiple cross sections of the engine clearance rotor, and pre-process the measurement data.

[0035] As a specific embodiment of the present invention, an inductive displacement sensor can be used to collect geometric morphology data of multiple cross sections of the engine gap rotor 10. The collected geometric morphology data of multiple cross sections of the gap rotor include radial and axial measurement data points of the front assembly surface of each level of gap rotors, and radial and axial measurement data points of the rear assembly surface of each level of gap rotors.

[0036] As another specific embodiment of the present invention, filtering and error separation methods may be used for preprocessing.

[0037] Furthermore, step 2 is performed to collect geometric morphology data of multiple cross sections of the engine interference rotor and pre-process the measurement data.

[0038] As a specific embodiment of the present invention, the inductive displacement sensor can also be used to collect geometric morphology data of multiple cross sections of the engine interference rotor 20. The collected geometric morphology data of multiple cross sections of the interference rotor include radial and axial measurement data points of the front assembly surface of each level of interference rotor, and radial and axial measurement data points of the rear assembly surface of each level of interference rotor.

[0039] As another specific embodiment of the present invention, filtering and error separation methods may be used for preprocessing.

[0040] In the present invention, the collected geometric morphology data of multiple cross sections of the engine clearance rotor and the interference rotor can be represented as a data point set Among them, Rf i Rr is the radial and axial measurement data points of the front assembly surface of the i-th stage rotor, i are the radial and axial measurement data points of the rear assembly surface of the i-th rotor, i = 1, 2, ... N, N is the total number of rotors.

[0041] After preprocessing by filtering and error separation methods, the obtained data point set can be expressed as R i ′ is the radial and axial measurement data points of the front assembly surface of the i-th stage rotor after preprocessing, Rr i ′ is the radial and axial measurement data points of the rear assembly surface of the i-th stage rotor after preprocessing.

[0042] Further, step three is performed to obtain geometric shape and position error parameters by using the least squares fitting method based on the pre-processed axial and radial measurement data of the clearance rotor and the interference rotor.

[0043] As a specific embodiment of the present invention, the geometric shape error parameters that can be obtained include: eccentricity, eccentricity angle, verticality and verticality angle, etc.

[0044] Furthermore, step 4 is performed to establish a clearance-interference rotor error transmission model using geometric shape and position error parameters of each level of rotors.

[0045] As a specific embodiment of the present invention, the coordinate system for multi-stage rotor assembly optimization is established as follows: Figure 2 As shown, the X and Y axes are established with the plane where the lower end surface of the main shaft 30 is located, and the straight line perpendicular to the lower end surface and passing through the centroid is the Z axis.

[0046] according to The gap-interference rotor error transmission model is established, where E is the error transmission matrix; E ri The phase control matrix for the rotor installation is the rotation matrix around the Z axis; E i is the eccentricity expression matrix of the i-th rotor; E ci is the translation transformation matrix of the i-th rotor reference surface clearance, Ezi is the eccentricity expression matrix caused by machining error; E oi is the matrix that transforms the rotor coordinate system to the assembly surface coordinate system.

[0047] Further, step five is executed to determine the maximum possible position of the clearance rotor; step six is ​​to establish an assembly optimization model with the assembly angles of the rotors at various levels as variables and the coaxiality of the rotor assembly as the optimization target.

[0048] As a specific embodiment of the present invention, the coordinates of the upper end surface centroid of the i-th stage rotor can be obtained from the error transfer matrix as (x i ,y i ,z i ), then the eccentricity of the rotor of this stage after assembly is Among them, ecci is the eccentricity of the i-th stage rotor.

[0049] Finally, after the N-level clearance-interference fit rotor is assembled, the coaxiality t of the rotor assembly at the assembly angle θ is θ Represented as t θ =2max{ecc i ,i=1,2,…,N}.

[0050] According to t m =min{t θ},θ∈[]1°,360°] to establish an assembly optimization model, where t m Optimize the model for assembly.

[0051] Further, execute step seven to optimize the assembly angles of the rotors at each level; in step eight, check the clearance margins of the gap rotors at each level under the assembly angles obtained by optimization. If the margins meet the required threshold, confirm that this group of assembly angles is the optimized assembly angle; if the clearance margins are less than the required threshold, return to step seven and optimize again until the coaxiality and the clearance margins of the gap rotors meet the requirements at the same time.

[0052] As a specific embodiment of the present invention, a genetic algorithm may be used to optimize the assembly angles of the rotors at each level.

[0053] The structure of the clearance-interference compound fit rotor of a small turbine engine is different from the multi-stage rotor structure of a traditional aircraft engine core. The existence of the clearance rotor and the main shaft constrains the optimization process. When the front-stage rotor is affected by its own processing error and the assembled rotor, the clearance rotor may not be installed correctly due to the limitation of the main shaft, resulting in friction with the main shaft and the front and rear stage rotors. Figure 3 Therefore, clearance constraints need to be introduced in the assembly optimization process to ensure the correct installation of the clearance rotor.

[0054] The error transfer matrix can be used to calculate the inclination angle of the lower end surface of the i-th level gap rotor relative to the horizontal plane, and the position coordinates of its upper end surface in space (x i ,y i ,z i ). Calculate the minimum clearance value l between the upper end surface of the i-th level clearance rotor and the main shaft based on the spatial geometric relationship i There are two situations:

[0055]

[0056] In the actual assembly process, the minimum assembly clearance of the clearance rotor has corresponding requirements. Assuming that the minimum clearance threshold is m, the coaxiality optimization model of the N-level clearance-interference fit rotor assembly subject to clearance constraints is expressed as: min =min{t θ},l i (θ)≥m,θ∈[1°,360°],t min The coaxiality optimization model of the N-level clearance-interference fit rotor after assembly is proposed to meet the clearance allowance constraint.

[0057] The present invention proposes an online assembly optimization method for engine rotors that takes into account clearance-interference compound fit, which can provide more reasonable assembly suggestions for engine clearance-interference compound fit rotor assembly, and solve the problem that clearance rotors may not be correctly installed in traditional assembly optimization methods. The present invention incorporates the clearance constraints introduced by the clearance rotors into the assembly optimization model to provide more accurate assembly phases for each level of rotors, so as to meet the actual assembly requirements of clearance-interference compound fit rotors.

[0058] In order to further understand the present invention, the following Figures 1 to 3 The engine rotor online assembly optimization method considering clearance-interference composite fit of the present invention is described in detail.

[0059] like Figures 1 to 3 As shown, according to a specific embodiment of the present invention, an engine rotor online assembly optimization method considering clearance-interference compound fit is provided.

[0060] Step 1: Based on the double-column ultra-precision assembly measuring instrument, the geometric morphology data of the five sections of each engine gap rotor 10 are collected using an inductive displacement sensor, 1024 measurement points are collected for each section, and the measurement data are pre-processed by filtering and error separation methods;

[0061] Step 2: Also use the inductive displacement sensor to collect geometric morphology data of five sections of the engine interference rotor 20, collect 1024 measurement points for each section, and pre-process the measurement data by filtering and error separation methods;

[0062] Step 3: Based on the pre-processed axial and radial measurement data of the clearance rotor and the interference rotor, the least squares method is used to fit the geometric error parameters such as eccentricity, eccentricity angle, verticality, and verticality angle;

[0063] Step 4: Use the geometric shape and position error parameters of each level of rotor to establish the gap-interference rotor error transmission model as follows:

[0064]

[0065] Step 5, determine the maximum possible position of the clearance rotor;

[0066] Step 6: Establish an assembly optimization model with the rotor assembly angles at each level as variables and the coaxiality of the rotor assembly as the optimization target as follows:

[0067] t θ =2max{ecc i ,i=1,2,...,N}

[0068] t m =min{t θ},θ∈[1°,360°];

[0069] Step 7: Optimize the assembly angles of the rotors at all levels using a genetic algorithm;

[0070] Step 8: Check the clearance margins of the clearance rotors at all levels under the assembly angles obtained by optimization. If the margins meet the required threshold, confirm that the assembly angle group is the optimized assembly angle; if the clearance margin is less than the required threshold, return to step 7 and optimize again until the coaxiality and the clearance margin of the clearance rotor meet the requirements at the same time. i (θ)≥m,i=1,2,...,N. At this time, the corresponding rotor assembly angles of each stage are the found optimal assembly phases.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An online assembly optimization method for engine rotors considering clearance-interference compound fit, characterized in that: The engine rotor online assembly optimization method considering clearance-interference composite fit includes: Step 1, collecting geometric morphology data of multiple cross sections of the engine clearance rotor and preprocessing the measurement data; Step 2, collecting geometric morphology data of multiple sections of the engine interference rotor and preprocessing the measurement data; Step 3, based on the pre-processed axial and radial measurement data of the clearance rotor and the interference rotor, the least squares method is used to fit and obtain the geometric shape and position error parameters; Step 4: using the geometric shape and position error parameters of each level of rotors to establish a clearance-interference rotor error transmission model; Step 5, determining the maximum possible position of the clearance rotor; Step 6, establishing an assembly optimization model with the rotor assembly angles at each level as variables and the coaxiality of the rotor assembly as the optimization target; Step seven, optimizing the assembly angles of the rotors at all levels; Step eight, check the clearance allowances of the clearance rotors at each level under the assembly angles obtained by optimization. If the allowances meet the required threshold, confirm that this group of assembly angles is the optimized assembly angle; if the clearance allowances are less than the required threshold, return to step seven and re-optimize until the coaxiality and the clearance allowances of the clearance rotors meet the requirements at the same time.

2. The engine rotor online assembly optimization method considering clearance-interference composite fit according to claim 1 is characterized in that: Inductive displacement sensors are used to collect geometric morphology data of multiple cross sections of engine clearance rotors and interference rotors.

3. The engine rotor online assembly optimization method considering clearance-interference compound fit according to claim 1 is characterized in that: The collected geometric morphology data of multiple cross sections of the gap rotor and the interference rotor include radial and axial measurement data points of the front assembly surfaces of the gap rotor and the interference rotor at each level, and radial and axial measurement data points of the rear assembly surfaces of the gap rotor and the interference rotor at each level.

4. The engine rotor online assembly optimization method considering clearance-interference compound fit according to claim 1 is characterized in that: Filtering and error separation methods are used for preprocessing.

5. The engine rotor online assembly optimization method considering clearance-interference compound fit according to claim 1 is characterized in that: The geometric shape error parameters include eccentricity, eccentricity angle, verticality and verticality angle.

6. The engine rotor online assembly optimization method considering clearance-interference compound fit according to any one of claims 1 to 5, characterized in that: In step 4, according to The gap-interference rotor error transmission model is established, where E is the error transmission matrix; E ri The phase control matrix for the rotor installation is the rotation matrix around the Z axis; E i is the eccentricity expression matrix of the i-th rotor; E ci is the translation transformation matrix of the i-th rotor reference surface clearance, E zi E is the eccentricity expression matrix caused by machining error; oi is the matrix for transforming the rotor coordinate system to the assembly surface coordinate system, i=1,2,…N, where N is the total number of rotors.

7. The engine rotor online assembly optimization method considering clearance-interference compound fit according to any one of claims 1 to 6, characterized in that: In step 6, according to t m =min{t θ },θ∈[1°,360°] to establish an assembly optimization model, where t m Optimize the model for assembly; θ After the N-level clearance-interference fit rotor is assembled, the coaxiality of the rotor assembly at the assembly angle θ, t θ =2max{ecc i ,i=1,2,…,N};ecc i is the eccentricity of the i-th stage rotor, x i and i are the coordinates of the centroid of the upper end surface of the i-th rotor on the X and Y axes.

8. The engine rotor online assembly optimization method considering clearance-interference compound fit according to claim 1 is characterized in that: In step seven, a genetic algorithm is used to optimize the assembly angles of the rotors at each level.

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