Four-degree-of-freedom automatic aligning, inclination adjusting and decoupling method for large rotary equipment
By calculating the coupling amount δ between the spherical center height difference and the axis distance, the precise adjustment of the four-degree of freedom automatic center-adjustment and tilt adjustment device of large-scale rotary equipment is achieved, solving the problem of low accuracy and efficiency in the eccentricity and tilt adjustment process, and improving the adjustment efficiency and accuracy.
Patent Information
- Application Number
- CN202510529759.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-08-05
AI Technical Summary
When using the four-degree of freedom automatic center-adjustment device for eccentricity and inclination adjustment, the two affect each other, resulting in a decrease in adjustment accuracy and efficiency, which requires repeated operation, affecting work efficiency and accuracy.
By calculating the height difference h between the height section of the spherical center during center alignment and the position of the spherical center of the spherical guide member when the center is aligned, combining the distance d between the workpiece axis and the spherical guide member after tilt adjustment, the coupling amount δ is calculated, and one-time precise adjustment is performed to reduce repeated operations.
The eccentricity and inclination adjustment accuracy and efficiency of the four-degree of freedom automatic center-alignment adjustment device of large-scale rotary equipment has been improved, the repeated operation steps have been reduced, and the adjustment accuracy and efficiency of the workpiece has been improved.
Smart Images
Figure CN120426933A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a four-degree-of-freedom automatic centering and tilting decoupling method for large-scale rotary equipment, and belongs to the technical field of ultra-precision geometric control. Background Art
[0002] As a national strategic high-tech industry, the aerospace manufacturing industry holds a leading position in the advanced equipment manufacturing sector. It is also a key indicator of a country's scientific, technological, and economic development levels internationally. It plays a crucial role in enhancing my country's comprehensive strength and promoting the modernization of its national defense. As the integration of cutting-edge technologies within the aerospace manufacturing sector, aircraft engines are the "heart" of aircraft and are hailed as the "crown jewel of the aviation industry." The measurement and assembly accuracy of engines directly impacts the reliability, stability, and overall performance of the entire aircraft. Engine failures are primarily caused by vibration and rubbing, which are primarily caused by misalignment and excessive imbalances among various components after assembly. For example, the F119 turbofan engine equipped with the US military's fifth-generation F22 fighter jet. The core engine is the most complex component in the engine assembly, and its assembly accuracy has a crucial impact on engine performance and lifespan. Reports indicate that within two years, cracks in the turbine seal rings caused by rubbing in the US Air Force's aircraft engines led to the crash of four F16 fighter jets and the direct or indirect grounding of 339 aircraft engines.
[0003] Engine assembly is the final step in the aircraft engine production process. The level of assembly technology significantly impacts the engine's overall performance, reliability, and lifespan, crucial to the stable operation and safety of aviation systems. The aircraft engine core is the heart of the entire engine, and its assembly quality, such as concentricity and coaxiality, directly impacts its performance. The aircraft engine core consists of the combustion chamber, high-pressure compressor, and high-pressure turbine, constructed from stacked multi-stage rotors. During the assembly process, coaxiality, as a critical geometric parameter, is crucial for verifying assembly quality.
[0004] In order to ensure the measurement accuracy of the circular contours and related geometric parameters of various rotating parts in aircraft engines, the axis of the rotating part to be measured is required to coincide with the rotary axis of the turntable as much as possible during measurement. Therefore, the eccentricity and tilt of the workpiece relative to the turntable axis need to be adjusted before each measurement. However, when the four-degree-of-freedom automatic centering and tilting device is actually applied, due to its structural influence, the eccentricity adjustment and tilt adjustment will be coupled to the axis of large rotating equipment. During the eccentricity and tilt adjustment process, the two will affect each other, thereby reducing the eccentricity and tilt adjustment accuracy, convergence efficiency, etc. At the same time, it is necessary to repeatedly adjust the centering and tilt until the target verticality or eccentricity value is reached. The control work is cumbersome, affecting work efficiency, and the accuracy of the workpiece eccentricity and tilt control is low. Summary of the Invention
[0005] The present invention aims to solve the problem that when a four-degree-of-freedom automatic centering and tilting device is used for centering and tilting, due to the coupling effect, the two affect each other during the adjustment process of eccentricity and tilt, and it is necessary to repeatedly adjust the centering and tilt, thereby reducing the eccentricity and tilt adjustment accuracy and convergence efficiency. A four-degree-of-freedom automatic centering and tilting decoupling method for large-scale rotary equipment is proposed.
[0006] The technical solution adopted by the present invention to solve the above problems is: the present invention comprises the following steps:
[0007] Step 1: Adjust the eccentricity of the workpiece relative to the turntable axis based on the measuring section;
[0008] Step 2: Adjust the inclination of the workpiece to be measured relative to the axis of the turntable;
[0009] Step 3: Measure the angle θ between the axis of the workpiece after tilting and the axis of the workpiece before tilting, the height difference h between the workpiece measurement section used during centering and the section where the center of the spherical guide component of the actual four-degree-of-freedom automatic centering and tilting device is located, and the distance d between the axis of the workpiece after centering and the axis of the spherical guide component. Calculate the displacement δ of the geometric center of the workpiece caused by the tilting, and re-center the workpiece based on the displacement δ to complete the centering and tilting of the workpiece.
[0010] Furthermore, the four-degree-of-freedom centering and tilting device in step 1 includes a centering and tilting table and an air-floating turntable. The centering and tilting table is arranged on the air-floating turntable, and the centering and tilting table is driven to rotate by the air-floating turntable. The centering and tilting table is provided with annularly evenly distributed dense beads and spherical guide components. The dense beads are fixed by a retaining frame. The spherical guide component is a ball bowl type and is fixedly connected to the bottom of the working table of the centering and tilting table. It is coaxial with the worktable. The spherical guide component is placed on the retaining frame and contacts with each dense bead. The spherical guide component is driven to rotate by the rolling of the dense beads.
[0011] Furthermore, the measurement section is determined based on the section where the center of the spherical guide component is located, and the height difference between the section where the center of the spherical guide component is located and the actual center is h.
[0012] Furthermore, the calculation formula for the displacement δ of the geometric center of the workpiece caused by tilting is:
[0013]
[0014] In formula (1), d is the distance between the axis of the workpiece after centering and the axis of the spherical guide component, θ is the angle between the axis of the workpiece after tilting and the axis of the workpiece before tilting, and h is the height difference between the center height section used during centering and the actual center position of the spherical guide component.
[0015] The beneficial effects of the present invention are:
[0016] The present invention only needs to calculate the height difference h between the spherical center height section used during centering and the actual spherical center spherical guide component center position, so as to obtain the coupling amount δ that needs to be adjusted during centering. Therefore, after a single centering and tilting adjustment, precise adjustment of the workpiece to be measured can be achieved without the need to repeatedly perform the centering and tilting process, thereby improving the accuracy, convergence effect and adjustment efficiency of the eccentricity and tilt adjustment of the four-degree-of-freedom automatic centering and tilting device of large-scale rotary equipment in actual application. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 This is the centering and tilting coupling analysis diagram provided by the present invention;
[0018] Figure 2 A schematic diagram of the relative relationship of the actual central axes of the workpiece centering provided by the present invention;
[0019] Figure 3 The coupling amount variation curve of different spherical center section height measurement deviations h provided by the present invention. DETAILED DESCRIPTION
[0020] The steps of the four-degree-of-freedom automatic centering and tilting decoupling method for large-scale rotary equipment described in this embodiment include:
[0021] Step 1: Use the four-degree-of-freedom automatic centering and tilting device to align the workpiece to be tested;
[0022] like Figure 2 As shown, the four-degree-of-freedom automatic centering and tilting device adopted in this embodiment is composed of a centering and tilting table and an ultra-precision air-floating turntable. The four-degree-of-freedom centering and tilting device includes a centering and tilting table and an air-floating turntable. The centering and tilting table is arranged on the air-floating turntable, and the centering and tilting table is driven to rotate by the air-floating turntable. The centering and tilting table is provided with an annularly evenly distributed dense beads and a spherical guide component. The spherical guide component is a ball bowl type and is fixedly connected to the bottom of the working table of the centering and tilting table. The spherical guide component is rotated by the rolling of the dense beads.
[0023] When aligning the center, it is impossible to obtain the exact height of the section where the center of the guide sphere is located. Therefore, this embodiment uses the section corresponding to the spherical guide component and the bottom of the workpiece as the measuring center section (center height section), and aligns the workpiece on this section. The height difference between this section and the actual center of the spherical guide component is h.
[0024] The relative relationship of the actual center axis of the workpiece centering is as follows Figure 2As shown in the figure, the axis of the spherical guide component of the actual centering and tilting table cannot be completely coincident with the axis of the turntable. The deviation is set to d1. After the section at the center height of the ball is accurately aligned, the center of the circle at the section at the center height of the ball coincides with the axis of rotation of the turntable. Under ideal circumstances, there is a deviation d1 between the axis of the workpiece at the center height of the ball and the axis of the spherical guide component during precise centering. However, under actual circumstances, completely precise centering cannot be performed, and there is a certain deviation d2 between the axis of the workpiece at the center height of the ball and the axis of the turntable. After actual centering, there will be a distance d between the axis of the workpiece and the axis of the spherical guide component. If d1 and d1 are in the same direction, then d=d1+d2. If d1 and d1 are not in the same direction, then d<d1+d2.
[0025] Step 2: Use the four-degree-of-freedom automatic centering and tilting device to tilt the workpiece after centering;
[0026] For the large-load four-degree-of-freedom centering and tilting device, during the tilt adjustment process, the workpiece rotates around the center of the guide sphere together with the adjustment device table. Therefore, during the tilt adjustment process, the eccentricity of the section at the center height changes the least. In the actual tilt adjustment process, after completing the eccentricity measurement of the section at the center height, only the other section with a larger eccentricity affected by the coupling is repeatedly measured, thereby calculating the axis tilt size and direction and performing the tilt adjustment. This embodiment is achieved by Figure 1 Analyze the factors that affect the coupling between centering and tilting. Figure 1 It includes the actual workpiece axis after centering (workpiece axis 1), the actual working axis after centering and tilting (workpiece axis 2), the axis of the spherical guide component, the worktable surface after centering (worktable surface 2) and the worktable surface after centering and tilting (worktable surface 1). Since the accurate height of the section where the center of the guide sphere is located cannot be obtained in the actual experiment, the distance between the workpiece measurement section and the actual workpiece measurement section measured in this embodiment is h, and the plane where the point O with a distance d between the axis of the spherical guide component and the actual working axis after centering is located is used as the actual workpiece measurement section. At this time, the inclination angle of the workpiece axis is θ. Then, on the workpiece section undergoing eccentricity adjustment, the geometric center of the workpiece moves from point O1 to point O2 due to the change in the size of the workpiece inclination angle. The coupling amount between the eccentricity and tilt adjustment generated in the process is recorded as δ.
[0027] Step 3: Calculate the angle θ between the axis of the workpiece after tilting (it can also be the axis of the turntable after tilting or the axis of the spherical guide component) and the axis of the workpiece before tilting, the height difference h between the spherical center height section used during centering and the actual spherical center of the spherical guide component, and the distance d between the axis of the workpiece after centering and the axis of the spherical guide component to calculate the coupling amount δ, and re-center the workpiece according to the coupling amount δ to complete the centering and tilting of the workpiece.
[0028] according to Figure 1The corresponding geometric relationship in the calculation of the coupling amount δ is calculated. The calculation formula of the coupling amount δ is:
[0029]
[0030] In formula (1), d is the distance between the axis of the workpiece after centering and the axis of the spherical guide component, θ is the angle between the axis of the workpiece after tilting and the axis of the workpiece before tilting, and h is the height difference between the center height section used during centering and the actual center position of the spherical guide component.
[0031] After the calculation of the coupling amount δ is completed, the centering and tilting can be adjusted once. The distance h between the center section height and the actual center section height is calculated and substituted into formula (1) to obtain the coupling amount δ. The workpiece can be re-centered according to the coupling amount δ, which reduces the repeated measurement steps of the traditional centering and tilting method and improves the efficiency of the workpiece precision adjustment.
[0032] This embodiment specifically analyzes the relationship between the coupling amount δ and the distance d between the workpiece axis and the spherical guide component axis, and the inclination angle θ, as follows:
[0033] Due to the influence of the measurement error of the center height of the spherical guide component on the coupling between the tilt adjustment and the eccentricity adjustment, the range of the distance d between the workpiece axis and the spherical guide component axis is within the range of the eccentricity adjustment device of ±0.5mm, and the tilt angle θ is within the range of the tilt angle adjustment device of ±0.5°. When the distance between the measured center section height and the actual center section height is 500μm, 100μm, 50μm, 20μm, 10μm, and 5μm respectively, the above-mentioned geometric relationship is used to draw the change curve of the coupling amount δ when the axis distance d and the tilt angle θ are different. Figure 3 shown.
[0034] Depend on Figure 3 It can be seen that as the workpiece tilt angle θ increases, the change in eccentricity caused by coupling increases approximately linearly. Therefore, if the workpiece tilt can be accurately adjusted to minimize θ before adjusting the eccentricity, the coupling between the centering and tilting processes will be greatly reduced. However, when h = 500 μm, the influence of the tilt angle θ is negligible, and the influence of d is far smaller than that caused by h, indicating that the coupling is primarily caused by the center section measurement deviation h. As the cross-sectional measurement deviation h increases, the coupling between the two increases significantly. Specifically, the farther the measurement section is from the section at the spherical guide component's center height, the greater the coupling. Therefore, it can be seen that at the section at the ideal center height of the spherical guide component, the change in cross-sectional eccentricity caused by tilt adjustment is minimal.
[0035] In order to verify the effectiveness of the decoupling method for automatic centering and tilting of large-scale rotary equipment with four degrees of freedom proposed in the present invention, this embodiment is tested using an aircraft engine rotor. When the tilt adjustment is performed, the eccentricity of the cross-section at the center height of the ball will also change accordingly due to the coupling between the tilt adjustment of the workbench and the eccentricity adjustment. The eccentricity measurement results are shown in Table 1. It can be seen that the eccentricity of the cross-section at the center height of the spherical guide component changes by only tens of nanometers, indicating that the decoupling method for automatic centering and tilting of large-scale rotary equipment with four degrees of freedom proposed in the present invention is effective.
[0036] Table 1
[0037]
[0038] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any technician familiar with the present profession can make some changes or modifications to equivalent embodiments of equivalent changes using the technical content disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement of the above embodiments made according to the technical essence of the present invention, within the spirit and principles of the present invention, without departing from the content of the technical solution of the present invention, shall still fall within the scope of protection of the technical solution of the present invention.
Claims
1. A method for automatic centering and tilting decoupling of large-scale rotary equipment with four degrees of freedom, characterized in that: The eccentricity and tilt of the workpiece to be measured relative to the axis of the turntable are adjusted using a four-degree-of-freedom automatic centering and tilting device, including the following steps: Step 1: Adjust the eccentricity of the workpiece relative to the turntable axis based on the measuring section; Step 2: Adjust the inclination of the workpiece to be measured relative to the axis of the turntable; Step 3: Measure the angle θ between the axis of the workpiece after tilting and the axis of the workpiece before tilting, the height difference h between the workpiece measurement section used during centering and the section where the center of the spherical guide component of the actual four-degree-of-freedom automatic centering and tilting device is located, and the distance d between the axis of the workpiece after centering and the axis of the spherical guide component. Calculate the displacement δ of the geometric center of the workpiece caused by the tilting, and re-center the workpiece based on the displacement δ to complete the centering and tilting of the workpiece.
2. A method for automatic centering and tilting decoupling of large-scale rotary equipment with four degrees of freedom according to claim 1, characterized in that: The four-degree-of-freedom centering and tilting device described in step 1 includes a centering and tilting table and an air-floating turntable. The centering and tilting table is arranged on the air-floating turntable, and the centering and tilting table is driven to rotate by the air-floating turntable. The centering and tilting table is provided with annularly evenly distributed dense beads and spherical guide components. The dense beads are fixed by a retaining frame. The spherical guide component is a ball bowl type and is fixedly connected to the bottom of the working table of the centering and tilting table. It is coaxial with the workbench. The spherical guide component is placed on the retaining frame and contacts each dense bead. The spherical guide component is driven to rotate by the rolling of the dense beads.
3. The method for automatic centering and tilting decoupling of large-scale rotary equipment with four degrees of freedom according to claim 1 is characterized in that: The measurement section is determined based on the section where the center of the spherical guide component is located, and the height difference between the section where the center of the spherical guide component is located and the actual center of the spherical guide component is located is h.
4. The method for automatic centering and tilting decoupling of large-scale rotary equipment with four degrees of freedom according to claim 1 is characterized in that: The calculation formula for the displacement δ of the geometric center of the workpiece caused by the tilt adjustment is: In formula (1), d is the distance between the axis of the workpiece after centering and the axis of the spherical guide component, θ is the angle between the axis of the workpiece after tilting and the axis of the workpiece before tilting, and h is the height difference between the center height section used during centering and the actual center position of the spherical guide component.