Water turbine stator and rotor assembly clearance control method based on dynamic tracking measurement

Abstract

The invention discloses a dynamic tracking measurement-based water turbine stator and rotor assembly clearance control method. The method comprises the following steps of S1, creating three-dimensional assembly characteristics of a water turbine stator and a rotor; s2, creating an assembly coordinate system of three-dimensional assembly characteristics of the stator and the rotor; s3, assembling the three-dimensional assembling characteristics of the stator and the rotor of the water turbine, and extracting a gap value of the stator and the rotor in an assembling coordinate system state; s4, constructing a constraint condition, optimizing the gap value, and obtaining a transformation matrix under the assembly coordinate system; s5, planning a rotor hoisting path; s6, creating an actual stator assembly coordinate system; s7, creating an actual rotor assembly coordinate system; and S8, dynamically measuring and positioning the actual rotor through at least three laser trackers, and obtaining the adjustment amount in real time to guide assembly. According to the method, through virtual assembly, hoisting path planning and guided assembly, the scientificity and accuracy of assembly are improved.

Description

Technical Field

[0001] The invention relates to the technical field of water turbine stator and rotor assembly, in particular to a water turbine stator and rotor assembly clearance control method based on dynamic tracking measurement. Background Art

[0002] Large component assembly technology is a key link in the assembly of turbine stators and rotors, involving complex assembly relationships and precise assembly. With the development of measurement technology, new measurement technologies and methods are constantly emerging in this field to meet the high requirements for precise measurement and assembly of large turbine stators and rotors. At present, the assembly of large turbine components is mainly carried out by manual measurement and adjustment, which is inefficient, has large measurement errors, cannot form digital assets, and cannot iteratively optimize the assembly process.

[0003] For example, Chinese patent document CN113339178A, published (announcement) date: 2021.09.03, discloses an installation method for a shaft-extended cross-flow hydro-turbine generator set, which discloses the installation of the stator and rotor. Specifically, the stator is hoisted to the installation room and placed on the stator and rotor assembly station to ensure that the rotor can be inserted normally. The rotor is lifted with the main hook of a double-beam bridge crane. When lifting the rotor, the rotor lifting tool is used to lift it to prevent the wire rope from damaging the magnetic pole when lifting the rotor; the generator shaft of the rotor is slowly inserted into the stator, so that the rotor is as close to the stator as possible, and the gap between the stator and the rotor is roughly adjusted, and then it falls on the pre-placed steel bracket, and the generator shaft pad is firmly fixed and then the hook is released; the stator is lifted with the main hook and inserted into the rotor, and 8 self-made 1200*20*3 insulating plates are evenly arranged between the stator and the rotor, and the air gap between the stator and the rotor is checked to avoid collision between the stator core and the rotor magnetic poles. After the rotor is successfully inserted into the stator, the stator and rotor are hoisted as a whole, and the front and rear ends of the generator shaft are adjusted to fall on the lower half of the rotor bearing seat; the front and rear positions of the rotor are fine-tuned, and the air gap of the generator is checked and adjusted. After meeting the design requirements, the guide bearings and combined bearings and other accessories of the stator and rotor are installed, and the gaps and air gaps of the guide bearings and thrust bearings should meet the design requirements. In this process, the assembly of the rotor and stator adopts a relatively rough positioning, and the installation accuracy is low. Summary of the invention

[0004] In order to solve the current technical problems, the main purpose of the present invention is to provide a method for controlling the gap between the stator and rotor of a turbine based on dynamic tracking measurement. The method improves the scientificity and accuracy of assembly through virtual assembly, hoisting path planning and guided assembly.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for controlling the stator and rotor assembly clearance of a hydraulic turbine based on dynamic tracking measurement, comprising the following steps: S1. Create 3D assembly features of the turbine stator and rotor; S2, creating an assembly coordinate system for the three-dimensional assembly features of the stator and rotor; S3, assembling the three-dimensional assembly features of the stator and rotor of the turbine, and extracting the clearance value between the stator and the rotor in the assembly coordinate system state; S4, constructing constraint conditions, optimizing the clearance value, and obtaining the transformation matrix in the assembly coordinate system; S5. planning the rotor hoisting path; S6. Create an actual stator assembly coordinate system; S7, creating an actual rotor assembly coordinate system; S8. Use at least three laser trackers to dynamically measure and locate the actual rotor, and obtain the adjustment amount in real time to guide assembly.

[0006] In S1, the point cloud data of the assembly features in the actual rotor and the actual stator are extracted, including the base flange, spindle axis and mounting holes of the actual stator and the actual rotor, and the point cloud is filtered and denoised to eliminate the noise in the point cloud data. Among them, the point cloud data is fitted with cylinder, plane and hole features.

[0007] In S2, the stator assembly coordinate system Dxyz and the rotor assembly coordinate system Zxyz are created respectively, with the cylinder axis as the Z axis, the intersection of the cylinder axis and the plane as the coordinate system origin O, and the line connecting the origin O and the hole center on the plane as the X axis.

[0008] In S3, the three-dimensional assembly features of the stator and the rotor are assembled, the gap value between the outer circumference of the rotor and the inner circumference of the stator is measured, and the rotor is adjusted by translation or rotation.

[0009] Anchor the guide line on the gap plane between the stator and the rotor, create 2D sections perpendicular to the guide line and with equal spacing based on the guide line, adjust the range of the 2D section so that the 2D section includes the stator and rotor planes and the gap surface, and extract the gap value of each 2D section position in the assembly coordinate system state.

[0010] In S4, the gap value is optimized with the cylindrical axis and plane of the stator as constraints to make the gap value uniform, and the transformation matrix from the rotor assembly coordinate system to the optimized coordinate system is recorded.

[0011] In S5, planning the rotor lifting path includes the following steps: S51, calculating the spatial displacement vector of the rotor from the initial position to the target assembly position based on the stator assembly coordinate system and the optimized rotor coordinate system; S52. Considering the space limitations, equipment layout and safety factors of the assembly site, multiple key path points are set to form a preliminary lifting path; S53. Set the position and posture parameters for each key path point and generate a detailed lifting instruction sequence.

[0012] In S6, the methods for creating the actual stator assembly coordinate system include: S61, arranging a plurality of first positioning marks on the circumference of the actual stator, and evenly arranging at least three laser trackers around the stator; S62, each laser tracker measures the first positioning mark point in the field of view respectively to obtain the point coordinates in the coordinate system of each laser tracker; S63, unify the measurement coordinate systems of three laser trackers and complete the system networking; S64. Measure the base flange, main shaft and mounting holes of the actual stator, and simulate the features to create the actual stator assembly coordinate system.

[0013] In S7, the methods for creating the actual rotor assembly coordinate system include: A plurality of second positioning marks are arranged on the circumference of the actual rotor, the base flange, main shaft and mounting holes of the actual rotor are measured, and a rotor assembly coordinate system is created.

[0014] In S8, the method of dynamically measuring and positioning the actual rotor by at least three laser trackers and obtaining the adjustment amount in real time includes: At least three laser trackers are used to track and measure the second positioning mark on the actual rotor in real time, so as to obtain the transformation relationship between the actual rotor assembly coordinate system and the actual stator assembly coordinate system. By comparing the transformation matrix before and after optimization with the virtual stator and rotor assembly coordinate systems, the adjustment amount at this time is obtained to guide the assembly.

[0015] The present invention has the following beneficial effects: The present invention relies on point cloud data of large components of stator and rotor, to virtual assembly of data, to optimization of assembly relationship to determine final assembly state, to planning of lifting path, and finally to guiding specific installation and debugging on site according to virtual assembly results. The whole process combines virtual and real, and tracks dynamically, which improves assembly efficiency and reduces labor costs for the assembly of large components. The whole process is digitized, which can pre-judge unknown problems, optimize assembly process, etc., store assembly process data, provide a data basis for process improvement and optimization, and improve the scientificity and accuracy of assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation or the prior art description are briefly introduced below. Obviously, the drawings in the following description are some implementations of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work: Figure 1 is a flow chart of the method of the present invention; Figure 2 This is the actual site diagram of the turbine stator; Figure 3 This is the actual site diagram of the turbine rotor; Figure 4 Create stator and assembly coordinate system for extracting assembly features from measured point clouds; Figure 5 Create rotor and assembly coordinate system for extracting assembly features from measured point clouds; Figure 6 Extract the clearance value of 2D section for creating surface guide line; Figure 7 is the pose parameter after optimizing the gap value under the constraint conditions; Figure 8 This is a schematic diagram of the rotor lifting path planning; Fig. 9 Create a stator assembly coordinate system for networking multiple laser tracker measurement systems; Fig.10 Assemble the coordinate system and position the rotor points; Fig.11 To achieve on-site guided assembly through real-time tracking measurement. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0018] See also Figure 1-11 As shown, a method for controlling the gap between the stator and rotor of a hydraulic turbine based on dynamic tracking measurement comprises the following steps: S1. Create 3D assembly features of the turbine stator and rotor; S2, creating an assembly coordinate system for the three-dimensional assembly features of the stator and rotor; S3, assembling the three-dimensional assembly features of the stator and rotor of the turbine, and extracting the clearance value between the stator and the rotor in the assembly coordinate system state; S4, constructing constraint conditions, optimizing the clearance value, and obtaining the transformation matrix in the assembly coordinate system; S5. planning the rotor hoisting path; S6. Create an actual stator assembly coordinate system; S7, creating an actual rotor assembly coordinate system; S8. Use at least three laser trackers to dynamically measure and locate the actual rotor, and obtain the adjustment amount in real time to guide assembly.

[0019] The present invention relies on point cloud data of large components of stator and rotor, to virtual assembly of data, to optimization of assembly relationship to determine final assembly state, to planning of lifting path, and finally to guiding specific installation and debugging on site according to virtual assembly results. The whole process combines virtual and real, and tracks dynamically, which improves assembly efficiency and reduces labor costs for the assembly of large components. The whole process is digitized, which can pre-judge unknown problems, optimize assembly process, etc., store assembly process data, provide a data basis for process improvement and optimization, and improve the scientificity and accuracy of assembly.

[0020] For details, see Figure 2 , 3 , 4, 5. In S1, the point cloud data of the assembly features in the actual rotor and the actual stator are extracted, including the base flange, the main shaft axis and the mounting holes of the actual stator and the actual rotor, and the point cloud is filtered and denoised to eliminate the noise in the point cloud data, wherein the point cloud data is fitted with the cylindrical, plane and hole features.

[0021] Figure 4 for Figure 2 Point cloud data of the actual turbine stator, Figure 5 for Figure 3 Point cloud data of the actual turbine rotor.

[0022] In S2, continue to see Figure 4 , 5 , with the cylinder axis as the Z axis, the intersection of the cylinder axis and the plane as the coordinate system origin O, and the line connecting the origin O and the hole center on the plane as the X axis, create the stator assembly coordinate system Dxyz and the rotor assembly coordinate system Zxyz respectively.

[0023] In S3, see Figure 6 , virtually assemble the three-dimensional assembly features of the stator and rotor, measure the gap value between the outer circumference of the rotor and the inner circumference of the stator, and adjust the rotor by translation or rotation.

[0024] Further, see Figure 6 In this embodiment, a 2D section guide line is anchored on the gap plane of the stator and the rotor, and multiple 2D sections perpendicular to the guide line and equally spaced are created according to the guide line. The size of the 2D section is adjusted so that the 2D section includes the stator and rotor planes and the gap surface. After cutting along the plane, the two-dimensional shape of the stator and rotor cylindrical surface is obtained, and the gap value of each 2D section position in the assembly coordinate system state is extracted. In this way, by setting the 2D section, the gap between the stator and the rotor can be accurately extracted, which facilitates the optimization of the gap value through rotation or translation constraints.

[0025] In S4, see Figure 7, lock the point cloud data of the stator, optimize the gap value according to the assembly process, take the cylindrical axis and plane of the stator as constraints, make the 2D cross-sectional gap value of each position uniform, and record the transformation matrix T from the rotor assembly coordinate system to the optimized coordinate system Zxyz .exist Figure 7 In FIG. 1 , it is shown that the rotor is adjusted by translation or rotation so that the 2D cross-sectional gap value at each position reaches a uniform state.

[0026] In S5, see Figure 8 , planning the rotor lifting path includes the following steps: S51, calculating the spatial displacement vector of the rotor from the initial position to the target assembly position based on the stator assembly coordinate system and the optimized rotor coordinate system; S52. Considering the space limitations, equipment layout and safety factors of the assembly site, multiple key path points are set to form a preliminary lifting path; S53. Set the position and posture parameters for each key path point and generate a detailed lifting instruction sequence.

[0027] In S6, see Fig. 9 , the methods for creating the actual stator assembly coordinate system include: S61, eight first positioning marks are arranged on the circumference of the actual stator, and three laser trackers are evenly arranged around the stator. The first positioning marks use magnetic laser tracker target balls; S62, each laser tracker measures the first positioning mark point in the field of view respectively to obtain the point coordinates in the coordinate system of each laser tracker; S63. Use the "common point conversion" method to unify the measurement coordinate systems of the three laser trackers and complete the system networking; S64. Measure the base flange, main shaft and mounting holes of the actual stator, and simulate the features to create the actual stator assembly coordinate system.

[0028] In S7, see Fig.10 , the methods for creating the actual rotor assembly coordinate system include: Three second positioning marks are arranged on the circumference of the actual rotor, and the base flange, main shaft and mounting holes of the actual rotor are measured to create a rotor assembly coordinate system. The second positioning mark uses a magnetic laser tracker target ball.

[0029] In S8, see Fig.11 , the actual rotor is dynamically measured and positioned by three laser trackers, and the method of obtaining the adjustment amount in real time includes: The second positioning mark on the actual rotor is tracked and measured in real time by three laser trackers. The position and posture of the rotor assembly coordinate system in this state can be obtained according to the second positioning mark, and the transformation relationship between the rotor assembly coordinate system and the stator assembly coordinate system is solved. The transformation matrix T before and after is optimized with the virtual stator and rotor assembly coordinate systems. Zxyz By comparison, the adjustment amount at this time can be obtained to provide guidance for assembly.

[0030] This method not only ensures high-precision measurement of the geometric characteristics of large-size turbine rotors, but also establishes a complete accuracy assurance system, which solves the problems of uncontrollable accuracy transfer and imperfect verification mechanism in traditional measurement methods, and can significantly improve the efficiency and reliability of turbine rotor measurement.

Claims

1. A method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement, characterized in that: The following steps are involved: S1. Create 3D assembly features of the turbine stator and rotor; S2, creating an assembly coordinate system for the three-dimensional assembly features of the stator and rotor; S3, assembling the three-dimensional assembly features of the stator and rotor of the turbine, and extracting the clearance value between the stator and the rotor in the assembly coordinate system state; S4, constructing constraint conditions, optimizing the clearance value, and obtaining the transformation matrix in the assembly coordinate system; S5. planning the rotor hoisting path; S6. Create an actual stator assembly coordinate system; S7, creating an actual rotor assembly coordinate system; S8. Use at least three laser trackers to dynamically measure and locate the actual rotor, and obtain the adjustment amount in real time to guide assembly.

2. A method for controlling the assembly gap of a hydraulic turbine stator and rotor based on dynamic tracking measurement according to claim 1, characterized in that: In S1, the point cloud data of the assembly features in the actual rotor and the actual stator are extracted, including the base flange, spindle axis and mounting holes of the actual stator and the actual rotor, and the point cloud is filtered and denoised to eliminate the noise in the point cloud data. Among them, the point cloud data is fitted with cylinder, plane and hole features.

3. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S2, the stator assembly coordinate system Dxyz and the rotor assembly coordinate system Zxyz are created respectively, with the cylinder axis as the Z axis, the intersection of the cylinder axis and the plane as the coordinate system origin O, and the line connecting the origin O and the hole center on the plane as the X axis.

4. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S3, the three-dimensional assembly features of the stator and the rotor are assembled, the gap value between the outer circumference of the rotor and the inner circumference of the stator is measured, and the rotor is adjusted by translation or rotation.

5. A method for controlling the assembly gap of a hydraulic turbine stator and rotor based on dynamic tracking measurement according to claim 4, characterized in that: Anchor the guide line on the gap plane between the stator and the rotor, create 2D sections perpendicular to the guide line and with equal spacing based on the guide line, adjust the range of the 2D section so that the 2D section includes the stator and rotor planes and the gap surface, and extract the gap value of each 2D section position in the assembly coordinate system state.

6. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S4, the gap value is optimized with the cylindrical axis and plane of the stator as constraints to make the gap value uniform, and the transformation matrix from the rotor assembly coordinate system to the optimized coordinate system is recorded.

7. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S5, planning the rotor lifting path includes the following steps: S51, calculating the spatial displacement vector of the rotor from the initial position to the target assembly position based on the stator assembly coordinate system and the optimized rotor coordinate system; S52. Considering the space limitations, equipment layout and safety factors of the assembly site, multiple key path points are set to form a preliminary lifting path; S53. Set the position and posture parameters for each key path point and generate a detailed lifting instruction sequence.

8. The method for controlling the assembly clearance of a hydraulic turbine stator and rotor based on dynamic tracking measurement according to claim 1, characterized in that: In S6, the methods for creating the actual stator assembly coordinate system include: S61, arranging a plurality of first positioning marks on the circumference of the actual stator, and evenly arranging at least three laser trackers around the stator; S62, each laser tracker measures the first positioning mark point in the field of view respectively to obtain the point coordinates in the coordinate system of each laser tracker; S63, unify the measurement coordinate systems of three laser trackers and complete the system networking; S64. Measure the base flange, main shaft and mounting holes of the actual stator, and simulate the features to create the actual stator assembly coordinate system.

9. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S7, the methods for creating the actual rotor assembly coordinate system include: A plurality of second positioning marks are arranged on the circumference of the actual rotor, the base flange, main shaft and mounting holes of the actual rotor are measured, and a rotor assembly coordinate system is created.

10. The method for controlling the gap between stator and rotor of a hydraulic turbine based on dynamic tracking measurement according to claim 1, characterized in that: In S8, the method of dynamically measuring and positioning the actual rotor by at least three laser trackers and obtaining the adjustment amount in real time includes: At least three laser trackers are used to track and measure the second positioning mark on the actual rotor in real time, so as to obtain the transformation relationship between the actual rotor assembly coordinate system and the actual stator assembly coordinate system. By comparing the transformation matrix before and after optimization with the virtual stator and rotor assembly coordinate systems, the adjustment amount at this time is obtained to guide the assembly.

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