Automatic stator core measuring arm based on laser measurement and measurement compensation method

Abstract

The invention belongs to the field of hydropower engineering electromechanical equipment installation, and particularly relates to an automatic stator core measuring arm based on laser measurement and a measurement compensation method.The automatic stator core measuring arm comprises a cantilever and a servo motor driving the cantilever to rotate, and pull rods hinged to the root of the cantilever are arranged on the top side and the two sides of the end and the middle of the cantilever; the pull rod is connected with the cantilever through a damping rod, the cantilever is provided with a laser displacement sensor, the outer side wall of the center body is sleeved with a driven gear, an output shaft of the servo motor is connected with an input shaft of a speed reducer, and a driving gear meshed with the driven gear is arranged on an output shaft of the speed reducer. The actual radius of a measurement point is obtained through the cosine theorem by performing least square fitting on a measurement value of the laser displacement sensor and compensating a measurement angle. The measuring arm utilizes the laser displacement sensor to realize non-contact measurement of the stator core lamination, the measuring arm continuously rotates to improve the measuring efficiency, the damping rod and the pull rod are used to realize rapid suppression of start-stop vibration of the measuring arm, and the deflection is reduced.

Description

Technical Field

[0001] The invention belongs to the field of hydropower engineering electromechanical equipment installation, and in particular relates to an automatic stator core measuring arm based on laser measurement and a measurement compensation method. Background Art

[0002] As an efficient, clean and stable power supply mode, hydropower has always played an important role in the domestic power industry. In recent years, the installation technology of hydropower engineering electromechanical equipment has developed rapidly, but some basic measurement methods still have problems such as traditional methods and low effectiveness.

[0003] According to the investigation, the stator assembly of large and medium-sized hydropower stations in China mostly adopts the method of stacking iron cores on the construction site, circumferentially distributing the stator cores on the inner wall of the generator housing, and then continuously stacking the stator cores arranged in the circumferential direction. During the construction process, the installation data of each stator core is generally measured by using an internal diameter micrometer combined with a circular measuring frame to control the installation quality and ensure that the installation position of each stator core is correct. This measurement method currently has the following problems:

[0004] 1. The number of control points for stacked stator core measurement is large and the measurement frequency is high. It is necessary to manually lift and rotate the measuring frame, and then move the inner diameter micrometer to each measuring point to complete the reading of all measuring points (the measuring points correspond to the number of stator cores). The single measurement time is long and the efficiency is low;

[0005] 2. Limited by the size and structure of the measuring circle frame, the measuring circle frame itself has certain disturbance and elasticity. Every time you align a point, you need to wait for it to stabilize before reading, which affects the measurement efficiency;

[0006] 3. The measurement process is all manual operation, which is greatly affected by human factors, and the measurement accuracy and precision are unstable;

[0007] 4. The existing measurement method cannot achieve eccentricity compensation for the stator core measuring arm. In the existing measurement method, the center of the central body of the stator measuring arm does not coincide with the center of the circle where the stator core is located, resulting in eccentricity, which leads to inaccurate measurement. The only way is to manually adjust the center of the central body of the stator measuring arm and the center of the stator core to be measured to a certain tolerance range as much as possible before measurement. The adjustment process is time-consuming and laborious.

[0008] In summary, the current stator core stacking measurement tools are relatively backward, with a low degree of automation, are greatly affected by measurement equipment and human factors, and have unstable measurement accuracy and precision.

[0009] The present invention proposes a fully automatic stator core stacking measuring arm for hydropower station stator assembly and a stator measuring arm measurement eccentricity compensation method based on laser measurement technology. The main purpose is to control the stator core stacking measurement control accuracy, shorten the stator core stacking timing, and improve the installation efficiency. Moreover, through the laser continuous measurement data, the eccentricity compensation of the stator measuring arm can be realized. The measuring arm of the present invention can be used for direct measurement, eliminating the concentricity adjustment process and improving the measurement efficiency. Summary of the invention

[0010] In order to solve the above technical problems, the present invention provides an automatic stator core measuring arm and a measurement compensation method based on laser measurement.

[0011] The purpose of the present invention is to be achieved by adopting the following technical solutions. According to the present invention, an automatic stator core measuring arm based on laser measurement includes a cantilever vertically arranged on the outer wall of the central body, a servo motor driving the cantilever to rotate, the end of the cantilever, the top side of the middle part, and both sides are obliquely arranged with a pull rod hinged to the root of the cantilever, the pull rod hinged to the top side of the cantilever end is connected to the middle part of the cantilever through a vertical damping rod, a laser displacement sensor is arranged at the end of the cantilever, a passive gear is sleeved on the outer wall of the central body, the output shaft of the servo motor is connected to the input shaft of the reducer, and a driving gear meshing with the passive gear is arranged on the output shaft of the reducer.

[0012] Furthermore, the cantilever includes a first cantilever connected to the laser displacement sensor and a second cantilever connected to the central body, and connecting plates are provided on the top side and both sides of the connection position between the first cantilever and the second cantilever.

[0013] Furthermore, the connection plates are all obliquely provided with pull rods hinged to the cantilever roots, and the damping rods are vertically provided on the connection plates on the top side.

[0014] Furthermore, a guide rail is detachably provided at the end of the cantilever, and a laser displacement sensor is provided at the end of the guide rail.

[0015] Furthermore, a central body base is arranged at the bottom of the central body, a support arm is arranged on one side of the central body base, a bottom plate is arranged in the middle of the support arm, the top of the bottom plate is connected to the top of the central body through a sleeve, and the pull rod is hinged at the top of the bottom plate or the two ends of the support arm.

[0016] Furthermore, a motor mounting plate is arranged above the central body, a reducer is arranged on the upper side of the motor mounting plate, an input shaft of the reducer is connected to the servo motor, and an output shaft passes through the motor mounting plate and is connected to the driving gear.

[0017] Furthermore, the driving gear is installed on the output shaft of the reducer through a tension sleeve, and the passive gear is installed on the central body through screws. Both the driving gear and the passive gear are helical gears.

[0018] A method for measuring and compensating an automatic stator core measuring arm based on laser measurement comprises the following steps:

[0019] After the laser displacement sensor rotates one circle, the angle θ of the measuring point corresponding to each stator core and the measuring distance r corresponding to the angle θ are obtained, where the angle θ is the angle that the laser displacement sensor rotates from the starting measuring point, and the measuring distance r is the distance between the measuring point and the rotation center when the angle θ is rotated;

[0020] The least squares circle fitting is performed on the measurement data of each measurement point to obtain the fitting circle center O'(Δx, Δy) and the eccentric distance e, where the eccentric distance e is the distance between the fitting circle center O' and the ideal circle center O;

[0021] A rectangular coordinate system is established with the ideal center O, and the angle α between the line connecting the fitting center 0' and the ideal center 0 (0, 0) and the horizontal line is obtained using the formula α = 90°-arcsin(Δx / e), where the horizontal line is the X-axis of the rectangular coordinate system;

[0022] Add α to the angle θ in the measurement data corresponding to each measurement point to obtain the corrected angle β;

[0023] The cosine value of the angle between the two sides is obtained by using cosγ=cos(180°-β), where the two sides are the measurement distance r and the eccentric distance e corresponding to the corresponding measurement point.

[0024] Using the cosine theorem, the actual radius R of the measurement point is √(r^2+e^2-2recosY).

[0025] Compared with the prior art, the present invention is beneficial in that:

[0026] (1) The measuring arm adopts a lightweight design with low mass and does not require a balance arm. Its mechanical interface can directly match the existing stator circle measuring frame to achieve the connection between the measuring arm center body, the circle measuring frame and the lifting device;

[0027] (2) The measuring arm can be automatically rotated by a servo reduction motor with an absolute encoder through a helical gear transmission, eliminating the need for manual rotation and improving work efficiency;

[0028] (3) The non-contact measurement of the stator core laminations is achieved by using a high-precision laser displacement sensor, which allows the measuring arm to rotate continuously and measure the stator core laminations simultaneously during the rotation process, thus improving the measurement efficiency;

[0029] (4) Since the measuring arm adopts a lightweight design, has a large deflection and is prone to vibration, during the rotation process, the damping rod and the pull rod are used to quickly suppress the start-stop vibration of the measuring arm and reduce the deflection;

[0030] (5) By processing the measurement data of the laser displacement sensor, the torsion value of the stator assembly process can be measured at one time;

[0031] (6) Through the measurement compensation method, the measured value can be compensated to reduce the error. Therefore, the measurement arm can be used directly for measurement without the need for concentric adjustment, thereby improving the measurement efficiency.

[0032] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 A three-dimensional diagram of an embodiment of an automatic stator core measuring arm based on laser measurement of the present invention;

[0034] Figure 2 for Figure 1 Side view of

[0035] Figure 3 for Figure 1 Schematic diagram of the location of the laser displacement sensor;

[0036] Figure 4 for Figure 1 Schematic diagram of the location of the middle connecting plate;

[0037] Figure 5 for Figure 1 Schematic diagram of the location of the centrosome;

[0038] Figure 6 for Figure 2 Schematic diagram of the location of the laser displacement sensor;

[0039] Figure 7 for Figure 2 Schematic diagram of the location of the middle connecting plate;

[0040] Figure 8 for Figure 2 Schematic diagram of the location of the centrosome;

[0041] Fig. 9 It is a schematic diagram of an embodiment of an automatic stator core measuring arm measurement compensation method based on laser measurement of the present invention.

[0042] [Reference Signs]

[0043] 1. Laser displacement sensor; 2. First long pull rod; 3. Second long pull rod; 4. Third long pull rod; 5. First cantilever; 6. Damping rod; 7. First connecting plate; 8. First short pull rod; 9. Second short pull rod; 10. Second connecting plate; 11. Third short pull rod; 12. Second cantilever; 13. Bottom plate; 14. Support arm; 15. Center body base; 16. Center body; 17. Sleeve; 18. Motor mounting plate; 19. Reducer; 20. Servo motor; 21. Driving gear; 22. Passive gear; 23. Third connecting plate; 24. Guide rail. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. Based on the embodiments of 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.

[0045] An embodiment of an automatic stator core measuring arm based on laser measurement of the present invention is as follows: Figures 1 to 8 As shown. The measuring arm includes a motor mounting plate 18 arranged on the circle measuring frame, a reducer 19 is arranged on the upper side of the motor mounting plate 15, and the input shaft of the reducer 19 is connected to the output shaft of the servo motor 20. The output shaft of the reducer 19 is connected to the driving gear 21 rotatably arranged on the lower side of the motor mounting plate 18, and the central body 16 is rotatably arranged on the circle measuring frame. The central body 16 is a sleeve structure, and a passive gear 22 meshing with the driving gear 21 is arranged on the outer circumference of the top of the central body 16. Under the drive of the servo motor 20, the central body 16 can rotate around the center of the circle measuring frame. The servo motor 20 is connected to an absolute encoder for accurately controlling the rotation of the central body 16. The lifting device on the circle measuring frame can drive the central body 16 and the motor mounting plate 15 to rise and fall along the circle measuring frame. In this embodiment, the driving gear 21 is installed on the output shaft of the reducer 19 through a tension sleeve, and the passive gear 22 is installed on the central body 16 through a screw. The driving gear 21 and the passive gear 22 both use helical gears with more stable operation.

[0046] A central body base 15 is provided at the bottom of the central body 16, and a support arm 14 is horizontally provided on one side of the central body base 15. A sleeve 17 is provided on one side of the top end of the central body 16, and the sleeve 17 and the support arm 14 are located on the same side of the central body 16. A bottom plate 13 is provided in the middle of the support arm 14, and the top of the bottom plate 13 is connected to the sleeve 17, so that the bottom plate 13 is fixed to the central body 16. In this embodiment, the support arm 14 is made of a profile with a model number of 4080.

[0047] The second cantilever 12 is vertically arranged at the bottom of the bottom plate 13, and the first cantilever 5 for extending the measuring arm is arranged at the end of the second cantilever 12. The first connecting plate 7, the second connecting plate 10, and the third connecting plate 23 are respectively arranged at the top and both sides of the connecting portion between the second cantilever 12 and the first cantilever 5 to connect the second cantilever 12 and the first cantilever 5. The first cantilever 5 adopts a profile with a specification of 4080, and the second cantilever 12 adopts a profile with a specification of 8080, so as to realize a lightweight design.

[0048] A guide rail 24 is provided at the end of the first cantilever 5, and the extension direction of the guide rail 24 is parallel to the extension direction of the first cantilever 5. A laser displacement sensor 1 is provided at the end of the guide rail 24. The guide rail 24 is fixed to the first cantilever 5 by a nut, and the position of the laser displacement sensor 1 on the extension line of the measuring arm is changed by changing the fixed position of the guide rail 24 on the first cantilever 5, and the position of the laser displacement sensor 1 is adjusted according to actual conditions.

[0049] Since the measuring arm adopts a lightweight design, when the measuring arm rotates, it is affected by gravity and start-stop acceleration, and the measuring arm is prone to vibration and elastic deformation, which has an adverse effect on the measurement results. Therefore, a pull rod is used to increase the stiffness and vibration resistance of the measuring arm. The top side and both sides of the end of the first cantilever 5 are respectively hinged to the second long pull rod 3, the first long pull rod 2, and the third long pull rod 4. The other end of the second long pull rod 3 is hinged to the top of the bottom plate 23, and the other ends of the first long pull rod 2 and the third long pull rod 4 are respectively hinged to the two ends of the support arm 14. The second short pull rod 9 is hinged on the first connecting plate 7, the third short pull rod 11 is hinged on the second connecting plate 10, and the first short pull rod 8 is hinged on the third connecting plate 23. The other end of the second short pull rod 9 is hinged to the top of the bottom plate 23, and the other ends of the third short pull rod 11 and the first short pull rod 8 are respectively hinged to the two ends of the support arm 14. By obliquely arranging tie rods between the end of the first cantilever 5 and the base plate 23 and the support arm 14, and between the connection between the second cantilever 12 and the first cantilever 5 and the base plate 23 and the support arm 14, the rigidity of the measuring arm can be ensured while achieving a lightweight design, thereby avoiding the influence of gravity and acceleration when the measuring arm is started and stopped on the deflection and vibration of the measuring arm, thereby avoiding affecting the accuracy and stability of the measurement.

[0050] A damping rod 6 is vertically arranged on the top of the first connecting plate 7, and the top of the damping rod 6 is connected to the second long pull rod 3. In this embodiment, two damping rods 6 are vertically arranged on the top of the first connecting rod 7, and the tops of the two damping rods 6 are respectively located on both sides of the second long pull rod 3 and connected to the second long pull rod 3. During the rotation of the measuring arm, the damping rod 6 can further absorb vibration to avoid inaccurate measurement of the laser displacement sensor 1 caused by vibration of the measuring arm.

[0051] The measuring arm is set on the circle measuring frame, and the position of the laser displacement sensor 1 is adjusted so that it is close to the stator core but not in contact. The servo motor 20 is controlled to rotate at a certain speed through the absolute encoder. The servo motor 20 drives the large gear 22 to rotate through the reducer 19 and the small gear 21. The rotation of the large gear 22 drives the central body 16 to rotate, and then drives the first cantilever 5 and the second cantilever 12 to rotate; the laser displacement sensor 1 passes through each stator core in turn to achieve non-contact measurement of the stator core laminations. The servo motor 20 rotates continuously. During the rotation process, the stator core laminations are measured without stopping to measure each stator core, thereby improving the measurement efficiency. The laser displacement sensor 1 transmits the measured data to the computer, and the measured data is analyzed and processed by the analysis software on the computer, which can realize the measurement of the torsional deviation value of the stator assembly process at one time, thereby improving the measurement efficiency.

[0052] In other embodiments of the present invention, the first cantilever 5 and the second cantilever 12 may be combined into one cantilever, and a pull rod is hinged at the end and the middle of the cantilever.

[0053] In other embodiments of the present invention, the base plate 23 may be replaced by a support arm, and a plurality of support arms are fixed on the central body to form the root of the cantilever.

[0054] An embodiment of an automatic stator core measuring arm measurement compensation method based on laser measurement of the present invention comprises the following steps:

[0055] After the laser displacement sensor is adjusted to a certain height and the laser displacement sensor 1 rotates one circle, the angle θ of the measuring point corresponding to each stator core and the measuring distance r corresponding to the angle θ are obtained, wherein the angle θ is the angle that the laser displacement sensor 1 rotates from the starting measuring point, and the measuring distance r is the distance between the measuring point and the rotation center when the angle θ is rotated;

[0056] The least squares circle fitting is performed on the measurement data of each measurement point to obtain the fitting circle center O'(Δx, Δy) and the eccentric distance e, where the eccentric distance e is the distance between the fitting circle center O' and the ideal circle center O;

[0057] A rectangular coordinate system is established with the ideal center O, and the angle α between the line connecting the fitting center 0' and the ideal center O(0,0) and the horizontal line is obtained using the formula α=90°-arcsin(Δx / e), where the horizontal line is the X-axis of the rectangular coordinate system;

[0058] Add α to the angle θ in the measurement data corresponding to each measurement point to obtain the corrected angle β;

[0059] The cosine value of the angle between the two sides is obtained by using cosγ=cos(180°-β), where the two sides are the measurement distance r and the eccentric distance e corresponding to the corresponding measurement point.

[0060] Using the cosine theorem, the actual radius R of the measurement point is √(r^2+e^2-2recosY).

[0061] The above method is used to calculate the actual radius R of each measuring point at the same height and compare it with the design radius. The stator core is adjusted according to the comparison deviation to achieve auxiliary installation. The measuring arm is raised to a certain height, and the above method can be used to continue to measure the actual radius of each measuring point at the height.

[0062] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. An automatic stator core measuring arm based on laser measurement, comprising a cantilever vertically arranged on the outer side wall of a central body (16), and a servo motor (20) driving the cantilever to rotate, characterized in that: The end, the top side and both sides of the cantilever are obliquely provided with pull rods hinged to the root of the cantilever; the pull rod hinged to the top side of the end of the cantilever is connected to the middle of the cantilever via a vertical damping rod (6); a laser displacement sensor (1) is provided at the end of the cantilever; a passive gear (22) is sleeved on the outer wall of the central body (16); the output shaft of the servo motor (20) is connected to the input shaft of the reducer (19); and a driving gear (21) meshing with the passive gear (22) is provided on the output shaft of the reducer (19).

2. The automatic stator core measuring arm based on laser measurement according to claim 1, characterized in that: The cantilever comprises a first cantilever (5) connected to the laser displacement sensor and a second cantilever (12) connected to the central body, and connecting plates are provided on the top side and both sides of the connection position between the first cantilever (5) and the second cantilever (12).

3. The automatic stator core measuring arm based on laser measurement according to claim 2, characterized in that: The connection plates are all obliquely provided with pull rods hinged to the cantilever roots, and the damping rod (6) is vertically provided on the connection plates at the top side.

4. The automatic stator core measuring arm based on laser measurement according to claim 1, characterized in that: A guide rail (24) is detachably provided at the end of the cantilever, and a laser displacement sensor (1) is provided at the end of the guide rail (24).

5. The automatic stator core measuring arm based on laser measurement according to claim 1, characterized in that: A central body base (15) is arranged at the bottom of the central body (16), a support arm (14) is arranged on one side of the central body base (15), a bottom plate (13) is arranged in the middle of the support arm (14), the top of the bottom plate (13) is connected to the top of the central body (16) through a sleeve (17), and a pull rod is hinged at the top of the bottom plate (13) or at both ends of the support arm (14).

6. The automatic stator core measuring arm based on laser measurement according to claim 1, characterized in that: A motor mounting plate (18) is arranged above the central body (16), a reducer (19) is arranged on the upper side of the motor mounting plate (16), an input shaft of the reducer is connected to a servo motor (20), and an output shaft passes through the motor mounting plate (18) and is connected to a driving gear (21).

7. The automatic stator core measuring arm based on laser measurement according to claim 1, characterized in that: The driving gear (21) is mounted on the output shaft of the reducer (19) via a tension sleeve, and the driven gear (22) is mounted on the central body (16) via screws. Both the driving gear (21) and the driven gear (22) are helical gears.

8. A method for measuring and compensating an automatic stator core measuring arm based on laser measurement, characterized in that: The following steps are involved: After the laser displacement sensor (1) rotates one circle, the angle θ of the measuring point corresponding to each stator core and the measuring distance r corresponding to the angle θ are obtained, wherein the angle θ is the angle that the laser displacement sensor (1) rotates from the starting measuring point, and the measuring distance r is the distance between the measuring point and the center of rotation when the angle θ is rotated; The least squares circle fitting is performed on the measurement data of each measurement point to obtain the fitting circle center O'(Δx, Δy) and the eccentric distance e, where the eccentric distance e is the distance between the fitting circle center O' and the ideal circle center O; Establish a rectangular coordinate system with the ideal center O, and use the formula Obtain the angle α between the line connecting the fitting circle center 0' and the ideal circle center 0(0,0) and the horizontal line, where the horizontal line is the X-axis of the rectangular coordinate system; Add α to the angle θ in the measurement data corresponding to each measurement point to obtain the corrected angle β; The cosine value of the angle between the two sides is obtained by using cosγ=cos(180°-β), where the two sides are the measurement distance r and the eccentric distance e corresponding to the corresponding measurement point. Using the cosine theorem, the actual radius R of the measurement point is √

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