Axial flow turbine rotor assembly and coordinate measurement device and use method

Abstract

The present invention discloses an axial-flow turbine rotor assembly and coordinate measurement device and its use method. The device comprises a base, a first support frame, a second support frame, a third support frame, and a fourth support frame sequentially arranged on the base, wherein the first, second, and fourth support frames are capable of sliding relative to the base via a guide rail pair; two rotor positioning members respectively arranged on the first and third support frames; a rotor pressing member arranged on the first support frame; a vertical linear module arranged on the second and fourth support frames, wherein the vertical linear module is provided with a sensor positioning clamping platform and a coaxial displacement gauge fixture; the sensor positioning clamping platform is used to set the displacement sensor; the coaxial displacement gauge fixture is used to set the coaxial displacement gauge; and the vertical linear module and indexing rotation are used to align the displacement sensor with the front and back reflective targets on the blades to complete distance calibration and coordinate measurement. The present invention has high testing accuracy, high assembly efficiency, and strong versatility.

Description

Technical Field

[0001] The present invention belongs to the field of turbine assembly, and in particular to an axial flow turbine rotor assembly and coordinate measurement device and a use method thereof. Background Art

[0002] To improve the efficiency and quality of turbine rotor assembly, it is necessary to measure the coordinates of the turbine blade surface in real time and calculate assembly errors. This allows for timely adjustments to the fit and tightness of parts, dynamic balancing, and weighting to complete assembly. Current assembly and coordinate measurement systems are often specialized devices with low generalization, often only meeting the needs of turbine rotor assembly for specific specifications. Therefore, a highly generalizable assembly and measurement device is needed. For test parts with free-form surfaces or complex shapes, non-contact measurement offers advantages such as no blind spots and high measurement efficiency. Therefore, it is necessary to develop turbine rotor assembly and coordinate measurement devices using non-contact sensors. Summary of the Invention

[0003] For the real-time assembly and measurement of small aircraft engine rotors, a desktop non-contact rotor blade coordinate measurement system with strong versatility and simple and convenient operation is provided. It is convenient to calculate the errors caused by the assembly of the connection between the blade and the rotor shaft through mathematical models, and adjust the assembly quality in time, so as to assemble the optimal structure while saving time and cost, and improve work efficiency.

[0004] The technical solutions for achieving the purpose of the present invention are:

[0005] An axial-flow turbine rotor assembly and coordinate measurement device, comprising:

[0006] base,

[0007] A first support frame, a second support frame, a third support frame, and a fourth support frame are sequentially arranged on the base, wherein the first support frame, the second support frame, and the fourth support frame can slide relative to the base via a guide rail pair, and the sliding direction is parallel to the axial direction of the turbine;

[0008] Two rotor positioning members are respectively provided on the first support frame and the third support frame, and are used to rotatably support the turbine;

[0009] A rotor pressing member provided on the first support frame, for rotating and pressing the turbine;

[0010] The reflective targets include a front reflective target set at the tangent point between the lower left corner of the blade and the edge line, and a back reflective target set at the tangent point between the upper right corner of the blade and the edge line;

[0011] Two vertical linear modules are respectively arranged on the second support frame and the fourth support frame, and the vertical linear modules are provided with a sensor positioning clamping platform and a coaxial displacement meter fixture; the sensor positioning clamping platform is used to set the displacement sensor, and the two displacement sensors are respectively used to measure the distance between the front reflection target and the back reflection target on the blade, corresponding to the axial coordinate value; the coaxial displacement meter fixture is used to set the coaxial displacement meter, and the two coaxial displacement meters are respectively used to measure the positions of the two sensor positioning clamping platforms, corresponding to the vertical diameter coordinate value; the vertical linear module can drive the sensor positioning clamping platform to slide up and down, so that the two displacement sensors are respectively aligned with the front reflection target and the back reflection target on the blade, completing the distance calibration of the displacement sensor and the coaxial displacement meter relative to the turbine.

[0012] A method for using an axial-flow turbine rotor assembly and coordinate measurement device, comprising:

[0013] Complete the turbine rotor assembly, install the turbine on the first and third support frames, and complete the calibration of the straightness of the guide rail pair of the coordinate measuring device;

[0014] Paste a reflective target on the surface of the blade, measure and record the tilt angle of the blade and the reflective target;

[0015] Adjust the height of the sensor positioning clamping platform and control the height of the laser displacement sensors so that the two laser displacement sensors are aligned with the front reflective target and the back reflective target respectively. Record the calibrated distances between the laser displacement sensors and the coaxial displacement meter relative to the turbine: axial distance y0 and vertical diameter distance z0.

[0016] Perform dynamic balancing, rotate the turbine at intervals, measure the coordinates of the reflective targets on the blades one by one, and record the measurement time t i , axial displacement Δy' of each measuring point i and vertical diameter displacement Δz i ;

[0017] Perform blade surface inclination compensation of the measuring point in the measurement coordinate system to obtain the compensated axial displacement, three-dimensional reconstruction of the measuring point to obtain the measuring point coordinates, and guide rail straightness compensation; perform coordinate transformation of the measuring point from the measurement coordinate system to the theoretical coordinate system to obtain the theoretical coordinates of the measuring point;

[0018] By comparing with the three-dimensional ideal assembly coordinates, the axial, radial and swing assembly errors are calculated; when the assembly errors meet the requirements, the turbine rotor is tightened.

[0019] Compared with the prior art, the present invention has the following significant advantages:

[0020] (1) High test accuracy: According to the proposed method of use, the invented device can eliminate the errors of curved surface inclination and guide rail straightness, maximize the test accuracy of the carried sensor, and provide blade installation errors in real time.

[0021] (2) High assembly and measurement efficiency: The invented non-contact rotor blade assembly and coordinate measurement system makes the pre-assembly and final error adjustment of the turbine rotor convenient and fast, with high assembly efficiency.

[0022] (3) The equipment has strong versatility: the first support frame can move on the base along the linear guide rail to realize the positioning and clamping of the turbine rotor of similar specifications by the rotor positioning mechanism. The device is suitable for the assembly and testing of turbine rotors of similar specifications and has good versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the axial-flow turbine rotor assembly and coordinate measurement device of the present invention.

[0024] Figure 2 Schematic diagram of the turbine assembly mechanism.

[0025] Figure 3 This is a schematic diagram of the rotor positioning and clamping mechanism structure.

[0026] Figure 4 Schematic diagram of the positions of the front and back reflective targets.

[0027] Figure 5 It is a schematic diagram of the vertical motion and clamping mechanism structure.

[0028] Figure 6 Flowchart for coordinate measurement of turbine rotor. DETAILED DESCRIPTION

[0029] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0030] Combine Figure 1The present invention provides an axial-flow turbine rotor assembly and coordinate measuring device, comprising a movable base, a rotor positioning clamping mechanism, and a sensor positioning mechanism, wherein: the movable base is composed of a base 16, a linear guide 1, a slide (including a first slide 2-1, a second slide 2-2, a third slide 2-3, and a fourth slide 2-4), a support frame (including a first support frame 3-1, a second support frame 3-2, a third support frame 3-3, and a fourth support frame 3-4); the rotor positioning clamping mechanism is composed of a rotor positioning member (including a first rotor positioning member 4-1 and a second rotor positioning member 4-2), and a rotor pressing member 5; the sensor positioning mechanism is composed of a guide rail back plate (including a first guide rail back plate 6- 1, the second guide rail back plate 6-2), a coaxial displacement gauge fixture (including a first coaxial displacement gauge fixture 10-1, a second coaxial displacement gauge fixture 10-2), a stepper motor (including a first stepper motor 11-1 and a first stepper motor 11-2), a vertical linear module (including a first vertical linear module 12-1, a second vertical linear module 12-2), a sensor positioning clamping platform (including a first sensor positioning clamping platform 13-1, a second sensor positioning clamping platform 13-2), a positioning frame (including a first positioning frame 14-1, a second positioning frame 14-2), a positioning plate (including a first positioning plate 15-1, a second positioning plate 15-2), etc.

[0031] The left and right sides of the first support frame 3-1 are respectively installed on the first slide 2-1 and the second slide 2-2, the left and right sides of the second support frame 3-2 are respectively installed on the third slide 2-3 and the fourth slide 2-4, the third support frame 3-3 is fixed on the base 16, and the fourth support frame 3-4 is installed on the fifth slide 2-5 and the sixth slide 2-6. The first slide 2-1, the second slide 2-2, the third slide 2-3 and the fourth slide 2-4 can slide on the linear guide rail 1 fixed on the base 16; the first rotor positioning member 4-1 and The rotor clamping member 5 is installed on the first support frame 3-1. The first rotor positioning member 4-1 is the same as the second rotor positioning member 4-2. Both are two tangent discs rotatably connected to the first support frame 3-1. The middle of the two discs is used to rotatably support the turbine. The rotor clamping member 5 is slidably connected to the upper end of the first support frame 3-1 horizontally, and can slide vertically relative to the first support frame 3-1 through a sliding rod, and can be locked in position by a bolt. The bottom of the sliding rod of the rotor clamping member 5 is rotatably connected to a disc for clamping the turbine, and the turbine can still rotate. The disc of the first rotor positioning member 4-1 is the positioning surface, and the movement of the bolt presses the disc of the rotor clamping member 5 onto the turbine; the second rotor positioning member 4-2 is installed on the third support frame 3-3, and is pressed by the gravity of the turbine; the first positioning frame 14-1 is installed on the second support frame 3-2 through the first positioning plate 15-1, and the second positioning frame 14-2 is installed on the fourth support frame 3-4 through the second positioning plate 15-2; the first positioning frame 14-1 is provided with a first vertical linear module 12-1 (the first vertical linear module 12-1 is fixed to the first positioning frame 14-1 through the first guide rail back plate 6-1), the first vertical linear module 12-1 is provided with a seventh slide 2-7, the seventh slide 2-7 is connected to the first sensor positioning clamping platform 13-1, and the first sensor positioning clamping platform 13-1 is provided with a first displacement sensor 8-1; the second The positioning frame 14-2 is provided with a second vertical linear module 12-2, and the second vertical linear module 12-2 is fixed on the second positioning frame 14-2 through the second guide rail back plate 6-2. The second vertical linear module 12-2 is provided with an eighth slide 2-8, and the eighth slide 2-8 is connected to the second sensor positioning and clamping platform 13-2. The second sensor positioning and clamping platform 13-2 is provided with a second displacement sensor 8-2; the first displacement sensor 8-1 is used in conjunction with the front reflective target 7-1 on the reflective target 7; the second displacement sensor 8-2 is used in conjunction with the back reflective target 7-2 on the reflective target 7; the first coaxial displacement meter 9-1 is fixed on the first vertical linear module 12-1 through the first coaxial displacement meter clamp 10-1; the second coaxial displacement meter 9-2 is fixed on the second vertical linear module 12-2 through the second coaxial displacement meter clamp 10-2. The first stepper motor 11 - 1 and the first stepper motor 11 - 2 drive the seventh slide 2 - 7 and the eighth slide 2 - 8 to slide vertically along the first vertical linear module 12 - 1 and the second vertical linear module 12 - 2 respectively.

[0032] like Figure 2 As shown, the first support frame 3-1, the second support frame 3-2 and the fourth support frame 3-3 can move on the base along the linear guide rail to realize the positioning and clamping of turbine rotors of similar specifications by the rotor positioning mechanism, which is suitable for the assembly and testing of turbine rotors of similar specifications.

[0033] like Figure 3 As shown, the disc-extending shafts of the first rotor positioning member 4-1 and the second rotor positioning member 4-2 are interference fit with the bearings in the grooves installed on the first support frame 3-1 or the third support frame 3-3 to achieve axial limitation of the rotor; the rotor clamping member 5 uses a rotating body to clamp the turbine shaft to prevent the rotor from swinging and jumping.

[0034] like Figure 4 As shown, there are two installation positions of the reflective target 7. The front reflective target 7-1 is attached to the tangent point of the lower left corner of the blade and the edge line, and the back reflective target 7-2 is attached to the tangent point of the upper right corner of the blade and the edge line, which is convenient for positioning and measurement of the sensor.

[0035] like Figure 5 As shown, the first coaxial displacement meter 9-1 and the second coaxial displacement meter 9-2 respectively measure the positions of the first sensor positioning clamping platform 13-1 and the second sensor positioning clamping platform 13-2 on the seventh slide 2-7 and the eighth slide 2-8, corresponding to the radial coordinate values; the first displacement sensor 8-1 and the second displacement sensor 8-2 respectively measure the positions of the front reflection target 7-1 and the back reflection target 7-2, corresponding to the axial coordinate values.

[0036] like Figure 6 As shown, the method of using the device is as follows:

[0037] ① Install a laser displacement sensor and a coaxial displacement meter to calibrate the straightness of the linear guide 1 and measure the straightness error (δx, 0, δz) of the linear guide 1, where δx and δz represent the coordinate changes of the linear guide 1 placed in the Y direction (axial direction) in the X direction (horizontal radial direction) and the Z direction (vertical diameter direction), respectively;

[0038] ②Attach a reflective target to the measuring point on the blade surface, and measure and record the inclination angles β1 and β2 of the measuring points on the front and back sides of the blade using computer-aided design software. The blade surface inclination angle is the angle between the normal of the curved surface at the reflective target position and the laser direction. It is generally measured using a theoretical model, but can also be obtained using sensor ranging on the actual object.

[0039] ③ Install a turbine shaft and n turbine blades, perform initial positioning in the direction of rotation, use a stepper motor to drive the seventh and eighth slides, adjust the height of the sensor positioning clamping platform, and control the height of the laser displacement sensor so that the two laser displacement sensors are aligned with the front and back reflective targets, respectively. Record the calibrated distances between the laser displacement sensor and the coaxial displacement meter relative to the turbine. The distance in the Y-axis (axial) direction is y0, and the distance in the Z-axis (vertical diameter) direction is z0.

[0040] ④ Perform dynamic balancing, rotate the turbine at intervals, measure the coordinates of the reflective targets on the blades one by one, and record the measurement time t i , axial displacement Δy' of each measuring point i and vertical diameter displacement Δz i , where i represents the measurement point number, i ranges from 1 to n and represents the number of the front reflective target, i ranges from n+1 to 2n and represents the number of the back reflective target, and n represents the total number of blades;

[0041] ⑤Axial displacement Δy' i The measurement adopts the laser triangulation method. The tilt of the measured surface will cause the measurement result deviation. According to the radius R of the receiving lens of the laser displacement sensor, the calibration distance y0 between the sensor and the blade, the angle ω between the measuring direction and the lens axis, and the tilt angle β of the blade surface j , according to formula 1, the axial displacement Δy' i The inclination compensation is used to obtain the axial displacement Δy after compensation. i ;

[0042]

[0043] Where i ranges from 1 to the total number of measurement points 2n, j represents the front or back reflective target, and takes the value 1 (front) or 2 (back) to distinguish;

[0044] ⑥ For the calibration distances y0 and z0, add the corresponding axial displacement Δy after compensation i , radial displacement Δz i , get the axial coordinate y of the measuring point i With radial coordinate z i ;

[0045] ⑦ According to the total number of blades n and the measuring time t i , axial coordinate y i With radial coordinate z i According to formula 2, in the measurement coordinate system, fill in the x-axis coordinate to complete the three-dimensional reconstruction of the measurement point and obtain the measurement point coordinate (x i ,y i ,z i ,);

[0046]

[0047] ⑧According to formula 3, eliminate the guide rail straightness error (δx,0,δz,) and measure the point coordinates (x i ,y i ,z i ,) Coordinate transformation from the measurement coordinate system to the theoretical coordinate system to obtain the theoretical coordinates of the measuring point (X i ,Y i ,Z i );

[0048]

[0049] Wherein, l1, m1, n1, l2, m2, n2, l3, m3, and n3 are the trigonometric functions of the theoretical coordinate system X, Y, and Z axes rotating around the measurement coordinate system x, y, and z axes by angles α, β, and γ, respectively, satisfying Equation 4. a2, b2, and c2 are the three coordinates of the origin of the measurement coordinate system in the theoretical coordinate system, and a1, b1, and c1 are the three coordinates of the sensor in the measurement coordinate system.

[0050]

[0051] ⑨ Compare with the coordinates of the three-dimensional ideal assembly to calculate the axial, radial and swing errors of the turbine blades relative to the turbine shaft. When the assembly error meets the requirements, the turbine rotor is tightened.

[0052] In a measurement, taking the front measuring point as an example, the number of blades is 20, the guide rail straightness error is (0.1mm, 0, 0.1mm), the angle ω between the displacement sensor measurement direction and the lens axis is 0°, the coordinate transformation coefficient matrix from the measurement coordinate system to the theoretical coordinate system satisfies Equation 5, the three coordinates of the sensor in the measurement coordinate system are (22mm, 220mm, 2mm), the three coordinates of the origin of the measurement coordinate system in the theoretical coordinate system are (250mm, 464mm, 825mm), and the average axial error of the 20 blades tested is 17.52μm, the average radial error is 30.29μm, and the average swing error is 20.00μm.

[0053]

[0054] The present invention: The test accuracy of the sensor carried is high, the linearity of the displacement sensor is ±0.02% FS, and the linearity of the coaxial displacement meter reaches ±2μm and ±0.72μm respectively. After calibration, the invented device can eliminate the errors of curved surface inclination and guide rail straightness, and the test device has high accuracy.

Claims

1. An axial flow turbine rotor assembly and coordinate measuring device, characterized in that: include: base, A first support frame, a second support frame, a third support frame, and a fourth support frame are sequentially arranged on the base, wherein the first support frame, the second support frame, and the fourth support frame can slide relative to the base via a guide rail pair, and the sliding direction is parallel to the axial direction of the turbine; Two rotor positioning members are respectively provided on the first support frame and the third support frame, and are used to rotatably support the turbine; A rotor pressing member provided on the first support frame, for rotating and pressing the turbine; The reflective targets include a front reflective target set at the tangent point between the lower left corner of the blade and the edge line, and a back reflective target set at the tangent point between the upper right corner of the blade and the edge line; Two vertical linear modules are respectively arranged on the second support frame and the fourth support frame, and the vertical linear modules are provided with a sensor positioning clamping platform and a coaxial displacement meter fixture; the sensor positioning clamping platform is used to set the displacement sensor, and the two displacement sensors are respectively used to measure the distance between the front reflection target and the back reflection target on the blade, corresponding to the axial coordinate value; the coaxial displacement meter fixture is used to set the coaxial displacement meter, and the two coaxial displacement meters are respectively used to measure the positions of the two sensor positioning clamping platforms, corresponding to the vertical diameter coordinate value; the vertical linear module can drive the sensor positioning clamping platform to slide up and down, so that the two displacement sensors are respectively aligned with the front reflection target and the back reflection target on the blade, completing the distance calibration of the displacement sensor and the coaxial displacement meter relative to the turbine.

2. The axial flow turbine rotor assembly and coordinate measuring device according to claim 1, characterized in that: The rotor positioning member is two tangent discs rotatably connected to the first support frame or the third support frame, and the middle of the two discs is used to rotatably support the turbine; the rotor clamping member can slide and be fixed vertically relative to the first support frame, and a disc is rotatably connected to the bottom for clamping the turbine.

3. The axial flow turbine rotor assembly and coordinate measuring device according to claim 1, characterized in that: The vertical linear module is fixed on the second support frame and the fourth support frame through a positioning frame.

4. The axial flow turbine rotor assembly and coordinate measuring device according to claim 1, characterized in that: The first support frame, the second support frame and the fourth support frame are slidably matched with the linear guide rail on the fixed base through a slide.

5. The method for using the axial-flow turbine rotor assembly and coordinate measurement device according to any one of claims 1 to 4, characterized in that: include: Complete the turbine rotor assembly, install the turbine on the first and third support frames, and complete the calibration of the straightness of the guide rail pair of the coordinate measuring device; Paste a reflective target on the surface of the blade, measure and record the tilt angle of the blade and the reflective target; Adjust the height of the sensor positioning clamping platform and control the height of the laser displacement sensors so that the two laser displacement sensors are aligned with the front reflective target and the back reflective target respectively. Record the calibrated distances between the laser displacement sensors and the coaxial displacement meter relative to the turbine: axial distance y0 and vertical diameter distance z0. Perform dynamic balancing and measure the coordinates of the reflective targets on the blades one by one, and record the measurement time t i , axial displacement Δy' of each measuring point i and vertical diameter displacement Δz i ; Perform blade surface inclination compensation of the measuring point in the measurement coordinate system to obtain the compensated axial displacement, three-dimensional reconstruction of the measuring point to obtain the measuring point coordinates, and guide rail straightness compensation; perform coordinate transformation of the measuring point from the measurement coordinate system to the theoretical coordinate system to obtain the theoretical coordinates of the measuring point; By comparing with the three-dimensional ideal assembly coordinates, the axial, radial and swing assembly errors are calculated; when the assembly errors meet the requirements, the turbine rotor is tightened.

6. The method of use according to claim 5, characterized in that: Axial displacement Δy after compensation i ; Where i represents the measurement point number, i ranges from 1 to n and represents the number of the front reflective target, i ranges from n+1 to 2n and represents the number of the back reflective target, and n represents the total number of blades; R is the radius of the displacement sensor receiving lens, y0 is the calibration distance between the sensor and the blade, ω is the angle between the measurement direction and the lens axis, β j is the blade surface inclination angle, and j represents the front or back reflective target.

7. The method of use according to claim 5, characterized in that: The 3D reconstruction structure of the measuring points includes: The calibrated distances y0 and z0, plus the corresponding compensated axial displacement Δy i , radial displacement Δz i , get the axial coordinate y of the measuring point i With radial coordinate z i ; According to the total number of blades n, the measuring time t i , axial coordinate y i With radial coordinate z i , in the measurement coordinate system, fill in the x-axis coordinates: Complete the three-dimensional reconstruction of the measuring point and obtain the measuring point coordinates (x i ,y i ,z i ,).

8. The method of use according to claim 5, characterized in that: Theoretical coordinates of the measuring point (X i ,Y i ,Z i )for: Where (x i ,y i ,z i ,) are the coordinates of the measuring point, a1, b1, c1 are the three coordinates of the sensor in the measurement coordinate system; l1, m1, n1, l2, m2, n2, l3, m3, n3 are the trigonometric functions of the theoretical coordinate system X, Y, and Z axes rotating around the measurement coordinate system x, y, and z axes by angles α, β, and γ, respectively, satisfying: a1, b1, and c1 are the three coordinates of the sensor in the measurement coordinate system.

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