A high-precision six-component force measuring device for a water turbine main shaft of a water turbine scale model and a measuring method

Abstract

This invention proposes a high-precision six-component force measuring device and method for the main shaft of a scaled-down model of a hydraulic turbine, belonging to the field of hydraulic machinery model testing technology. The aim is to solve the problem in existing technologies where differences in structure and mass distribution between the model and the actual turbine easily generate various inertial force interferences, making it impossible to accurately deduct inertial forces, separate hydraulic loads, and achieve sufficient measurement accuracy. The invention houses a main shaft and a motor assembly within an outer casing. The motor assembly is connected to the end of the main shaft. An angular contact bearing is located on the front side between the main shaft and the outer casing, and an encoder is located in the middle of the main shaft. A six-dimensional force sensor is installed at the front end of the main shaft, with one end connected to the blade assembly and the other end in contact with a three-axis accelerometer mounted on the main shaft. This invention can realistically simulate the actual rotational operation of a hydraulic turbine, solving the problem of insufficient measurement accuracy caused by various inertial force interferences arising from differences in structure and mass distribution between the model and the actual turbine, making it impossible to accurately deduct inertial forces, separate hydraulic loads, and achieve sufficient measurement accuracy.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic machinery model testing technology, and in particular relates to a high-precision six-component force measuring device and measurement method for the main shaft of a water turbine suitable for scaled-down models of water turbines. Background Technology

[0002] Large and medium-sized hydro turbines require scaled-down model tests during engineering design and bidding certification processes. The performance of the actual turbine is predicted by converting parameters such as model efficiency, thrust, and radial force. Scaled-down hydro turbine models are characterized by small size, high rotational speed, and flow rate and head scaled according to similarity criteria. This results in significantly higher accuracy, dynamic response, and structural stiffness for force measurement systems compared to monitoring the actual turbine.

[0003] Existing force measurement structures have the following obvious defects:

[0004] 1. The model and the actual machine have different structures and mass distributions, and the inertial force components such as centrifugal force, Coriolis force, and moment of inertia are significant, which are directly superimposed on the hydraulic load and cause the measurement results to be distorted.

[0005] 2. Traditional structures cannot achieve accurate deduction of inertial forces and separation of hydraulic loads.

[0006] In summary, there is an urgent need to design a high-precision six-component force measuring device and method for the main shaft of a turbine suitable for scaled-down models. This would solve the problem in existing technologies where various inertial forces easily arise due to differences in structure and mass distribution between the model and the actual turbine, making it impossible to accurately deduct inertial forces, separate hydraulic loads, and achieve sufficient measurement accuracy. Summary of the Invention

[0007] A brief overview of the invention is given below to provide a basic understanding of certain aspects of it. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0008] In view of this, in order to solve the problem that the differences in structure and mass distribution between the model and the real machine can easily generate various inertial force interferences, making it impossible to accurately deduct inertial forces and separate hydraulic loads, resulting in insufficient measurement accuracy, the present invention provides a high-precision six-component force measuring device and measurement method for the main shaft of a turbine suitable for scaled-down models of turbines.

[0009] Option 1: A high-precision six-component force measuring device for the main shaft of a water turbine suitable for a scaled-down model of a water turbine, comprising a blade assembly, a six-dimensional force sensor, a three-axis accelerometer, an angular contact bearing, a main shaft, an encoder, a motor assembly, and an outer casing;

[0010] The outer casing houses a main shaft and a motor assembly. The motor assembly is connected to the end of the main shaft. An angular contact bearing is provided on the front side between the main shaft and the outer casing. An encoder is provided in the middle of the main shaft.

[0011] The six-dimensional force sensor is installed at the front end of the main shaft. One end of the six-dimensional force sensor is connected to the blade assembly, and the other end is attached to the three-axis accelerometer installed on the main shaft.

[0012] Furthermore, a rotating glyph is installed at the foremost end between the outer cover and the main shaft.

[0013] Furthermore, the three axes of the triaxial accelerometer are parallel to the three axes of the six-dimensional force sensor.

[0014] Furthermore, a coupling is installed between the motor assembly and the main shaft.

[0015] Option 2: A method for high-precision six-component force measurement of the main shaft of a hydro-turbine suitable for a scaled-down model, which is based on the high-precision six-component force measurement device for the main shaft of a hydro-turbine suitable for a scaled-down model described in Option 1, and specifically includes the following steps:

[0016] S1. Place the scaled-down model of the turbine in the test environment and record the initial parameters of the scaled-down model: the initial parameters include the initial load values ​​of the six-dimensional force sensor X0, Y0, Z0, Mx0, My0, M... z0 Triaxial accelerometer zero point U 加X0 U 加Y0 U 加Z0 The weight m of the propeller assembly and the horizontal distance Lz from the center of gravity of the six-dimensional force sensor calibration center;

[0017] Where: X0 is the initial load value of the six-dimensional force sensor in the X direction;

[0018] Y0 is the initial load value of the six-dimensional force sensor in the Y direction;

[0019] Z0 is the initial load value of the six-dimensional force sensor in the Z direction;

[0020] Mx0 is the initial load value of the six-dimensional force sensor in the torsional direction;

[0021] My0 is the initial load value of the six-dimensional force sensor in the yaw direction;

[0022] M z0 This represents the initial load value of the six-dimensional force sensor in the pitch direction.

[0023] U 加X0 The accelerometer's X-axis is the zero point;

[0024] U 加Y0 The accelerometer's Y-axis is the zero point;

[0025] U 加Z0 The accelerometer's Z-axis is the zero point;

[0026] S2. Start the test equipment and record the parameters of the scaled-down turbine model under the test conditions. The parameters include the real-time values ​​of each component of the six-dimensional force sensor, recorded as X1, Y1, Z1, Mx1, My1, and Mz1, and the real-time zero-point value of the three-axis accelerometer, recorded as U. 加X1 U 加Y1 U 加Z1 The encoder measures the spindle rotation angle θ in real time.

[0027] S3. Calculate inertial forces:

[0028] X 惯 =m(U 加X1 -U 加X0 )K 加X ;

[0029] Y 惯 =m(U 加Y1 -U 加Y0 )K 加Y ;

[0030] Z 惯 =m(U 加Z1 -U 加Z0 )K 加z ;

[0031] My 惯 =-F 惯Z ×Lz;

[0032] Mz 惯 =-F 惯Z ×Lz;

[0033] Where K 加X K 加Y K 加z These are the inertia correction factors for the X, Y, and Z axes of the triaxial accelerometer, respectively.

[0034] S4. Calculate the six-dimensional force loads after correcting for the effects of inertial forces and gravity:

[0035] X 修正 =X1-X0-X 惯 ;

[0036] Y 修正 =Y1-Y0-Y 惯 ;

[0037] Z 修正 =Z1-Z0-Z 惯 ;

[0038] Mx修正 =Mx1-Mx0;

[0039] My 修正 =My1-My0-My 惯 ;

[0040] Mz 修正 =Mz1-Mz0-Mz 惯 ;

[0041] S5. Correct to the turbine body coordinate system:

[0042] Y=Y 修正 ×sin(θ+90°)+Z 修正 ×sinθ;

[0043] Z=Y 修正 ×cos(θ+90°)+Z 修正 ×cosθ;

[0044] M Z =M y修正 ×cos(θ+90°)+M Z修正 ×cosθ;

[0045] M Y =My 修正 ×sin(θ+90°)+M Z修正 ×sinθ;

[0046] M X =M X修正 ;

[0047] X=X 修正 .

[0048] The present invention has the following advantages over the prior art:

[0049] 1. This invention can realistically simulate the actual rotating operation of a water turbine, perfectly meeting the similarity criteria requirements of scaled-down model tests, and the test simulation effect closely matches the actual operating conditions of the real machine;

[0050] 2. The device of this invention is equipped with a six-dimensional force sensor and an accelerometer, which can effectively counteract various inertial force interferences generated during the test, and successfully achieve precise elimination of inertial forces and effective separation of pure water force loads;

[0051] 3. This invention can stably and accurately complete the comprehensive detection of six components of load, including axial force, radial force, and torque of the main shaft, completely solving the problem of data distortion in traditional equipment and significantly improving the overall testing accuracy of turbine model tests. Attached Figure Description

[0052] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0053] Figure 1 This is a schematic diagram of a high-precision six-component force measuring device for the main shaft of a water turbine, suitable for scaled-down models of water turbines.

[0054] In the diagram: 1-blade assembly, 2-six-dimensional force sensor, 3-triaxial accelerometer, 4-rotating Glyd ring, 5-angular contact bearing, 6-spindle, 7-encoder, 8-coupling, 9-motor assembly, 10-outer casing. Detailed Implementation

[0055] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0056] Example 1, Reference Figure 1 This embodiment describes a high-precision six-component force measuring device for the main shaft of a water turbine, suitable for scaled-down models of water turbines. The device includes a blade assembly 1, a six-dimensional force sensor 2, a triaxial accelerometer 3, an angular contact bearing 5, a main shaft 6, an encoder 7, a motor assembly 9, and an outer casing 10.

[0057] The outer casing 10 contains a main shaft 6 and a motor assembly 9. The motor assembly 9 is connected to the end of the main shaft 6. An angular contact bearing 5 is provided on the front side between the main shaft 6 and the outer casing 10. An encoder 7 is provided in the middle of the main shaft 6. The encoder 7 can record the rotation angle of the main shaft 6 in real time.

[0058] The six-dimensional force sensor 2 is installed at the front end of the main shaft 6. One end of the six-dimensional force sensor 2 is connected to the blade assembly 1, and the other end is attached to the triaxial accelerometer 3 installed on the main shaft 6.

[0059] Furthermore, a rotating glyph 4 is installed at the front end between the outer cover 10 and the main shaft 6 to provide a dynamic sealing effect.

[0060] Furthermore, the three axes of the triaxial accelerometer 3 are parallel to the three axes of the six-dimensional force sensor 2.

[0061] Furthermore, a coupling 8 is installed between the motor assembly 9 and the main shaft 6.

[0062] Furthermore, the triaxial accelerometer 3 can also be installed inside the six-dimensional force sensor 2.

[0063] Example 2, Reference Figure 1 This embodiment describes a method for high-precision six-component force measurement of the main shaft of a hydro-turbine suitable for a scaled-down model. It is based on the high-precision six-component force measurement device for the main shaft of a hydro-turbine suitable for a scaled-down model described in Embodiment 1, and specifically includes the following steps:

[0064] S1. Place the scaled-down model of the turbine in the test environment and record the initial parameters of the scaled-down model: the initial parameters include the initial load values ​​of the six-dimensional force sensor 2: X0, Y0, Z0, Mx0, My0, M... z0 Triaxial accelerometer 3 zero point U 加X0 U 加Y0 U 加Z0 The weight m of the blade assembly 1 and the horizontal distance Lz from the center of gravity of the six-dimensional force sensor 2;

[0065] Where: X0 is the initial load value of the six-dimensional force sensor 2 in the X direction;

[0066] Y0 is the initial load value of the six-dimensional force sensor 2 in the Y direction;

[0067] Z0 is the initial load value of the six-dimensional force sensor 2 in the Z direction;

[0068] Mx0 is the initial load value of the six-dimensional force sensor in the torsional direction;

[0069] My0 is the initial load value of the six-dimensional force sensor in the yaw direction;

[0070] M z0 This represents the initial load value of the six-dimensional force sensor in the pitch direction.

[0071] U 加X0 The accelerometer's X-axis is the zero point;

[0072] U 加Y0 The accelerometer's Y-axis is the zero point;

[0073] U 加Z0 The accelerometer's Z-axis is the zero point;

[0074] S2. Start the test equipment and record the parameters of the scaled-down turbine model under the test conditions. The parameters include the real-time values ​​of each component of the six-dimensional force sensor 2, recorded as X1, Y1, Z1, Mx1, My1, and Mz1, and the real-time zero-point value of the triaxial accelerometer 3, recorded as U. 加X1 U 加Y1 U 加Z1 The encoder 7 measures the spindle rotation angle θ in real time.

[0075] S3. Calculate inertial forces:

[0076] X 惯 =m(U 加X1 -U 加X0 )K 加X ;

[0077] Y 惯 =m(U 加Y1 -U 加Y0 )K 加Y ;

[0078] Z 惯 =m(U 加Z1 -U 加Z0 )K 加z ;

[0079] My 惯 =-F 惯Z ×Lz;

[0080] Mz 惯 =-F 惯Z ×Lz;

[0081] Where K 加X K 加Y K 加z These are the inertia correction factors for the X, Y, and Z axes of the triaxial accelerometer 3, respectively.

[0082] S4. Calculate the six-dimensional force loads after correcting for the effects of inertial forces and gravity:

[0083] X 修正 =X1-X0-X 惯 ;

[0084] Y 修正 =Y1-Y0-Y 惯 ;

[0085] Z 修正 =Z1-Z0-Z 惯 ;

[0086] Mx 修正 =Mx1-Mx0;

[0087] My 修正 =My1-My0-My 惯 ;

[0088] Mz 修正 =Mz1-Mz0-Mz 惯 ;

[0089] S5. Correct to the turbine body coordinate system:

[0090] Y=Y 修正 ×sin(θ+90°)+Z 修正 ×sinθ;

[0091] Z=Y 修正 ×cos(θ+90°)+Z 修正 ×cosθ;

[0092] M Z =M y修正 ×cos(θ+90°)+M Z修正 ×cosθ;

[0093] M Y =My 修正 ×sin(θ+90°)+M Z修正 ×sinθ;

[0094] M X =M X修正 ;

[0095] X=X 修正 .

[0096] This invention can realistically simulate the actual rotating operation of a water turbine, perfectly meeting the similarity criteria requirements of scaled-down model tests. The test simulation effect closely matches the actual operating conditions of the real machine. At the same time, it is equipped with a six-dimensional force sensor and accelerometer, which can effectively counteract various inertial force interferences generated during the test, and successfully achieve precise elimination of inertial forces and effective separation of pure hydraulic loads.

[0097] This invention can stably and accurately complete the comprehensive detection of six components of load, including axial force, radial force, and torque of the main shaft, completely solving the problem of data distortion in traditional equipment and significantly improving the overall testing accuracy of turbine model tests.

[0098] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

1. A high-precision six-component force measuring device for the main shaft of a hydro-turbine suitable for scaled-down models, characterized in that, It includes a blade assembly (1), a six-dimensional force sensor (2), a three-axis accelerometer (3), an angular contact bearing (5), a main shaft (6), an encoder (7), a motor assembly (9), and a housing (10); The outer casing (10) contains a main shaft (6) and a motor assembly (9). The motor assembly (9) is connected to the end of the main shaft (6). An angular contact bearing (5) is provided on the front side between the main shaft (6) and the outer casing (10). An encoder (7) is provided in the middle of the main shaft (6). The six-dimensional force sensor (2) is installed at the front end of the main shaft (6). One end of the six-dimensional force sensor (2) is connected to the blade assembly (1), and the other end is attached to the three-axis accelerometer (3) installed on the main shaft (6).

2. The high-precision six-component force measuring device for the main shaft of a hydro-turbine suitable for a scaled-down model of a hydro-turbine, as described in claim 1, is characterized in that... A rotating glyph (4) is also installed at the front end between the outer cover (10) and the main shaft (6).

3. The high-precision six-component force measuring device for the main shaft of a hydro-turbine suitable for a scaled-down model of a hydro-turbine, as described in claim 1, is characterized in that... The three axes of the triaxial accelerometer (3) are parallel to the three axes of the six-dimensional force sensor (2).

4. The high-precision six-component force measuring device for the main shaft of a hydro-turbine suitable for a scaled-down model of a hydro-turbine, as described in claim 1, is characterized in that... A coupling (8) is installed between the motor assembly (9) and the main shaft (6).

5. A method for high-precision six-component force measurement of the main shaft of a hydro-turbine suitable for a scaled-down model of a hydro-turbine, which is based on the high-precision six-component force measurement device for the main shaft of a hydro-turbine suitable for a scaled-down model of a hydro-turbine as described in claim 1, characterized in that, Specifically, the following steps are included: S1. Place the scaled-down model of the turbine in the test environment and record the initial parameters of the scaled-down model of the turbine: The initial parameters include the initial load values ​​of the six-dimensional force sensor (2): X0, Y0, Z0, Mx0, My0, M z0 Triaxial accelerometer (3) zero point U 加X0 U 加Y0 U 加Z0 The weight m of the blade assembly (1) and the horizontal distance Lz from the center of gravity of the six-dimensional force sensor (2) are the centering points. Where: X0 is the initial load value of the six-dimensional force sensor (2) in the X direction; Y0 is the initial load value of the six-dimensional force sensor (2) in the Y direction; Z0 is the initial load value of the six-dimensional force sensor (2) in the Z direction; Mx0 is the initial load value of the six-dimensional force sensor (2) in the torsional direction; My0 is the initial load value of the six-dimensional force sensor (2) in the yaw direction; M z0 The initial load value of the six-dimensional force sensor (2) in the pitch direction; U 加X0 The accelerometer's X-axis is the zero point; U 加Y0 The accelerometer's Y-axis is the zero point; U 加Z0 The accelerometer's Z-axis is the zero point; S2. Start the test equipment and record the parameters of the scaled-down model of the turbine under the test conditions. The parameters include the real-time values ​​of each component of the six-dimensional force sensor (2) as X1, Y1, Z1, Mx1, My1, and Mz1, and the real-time value of the zero point of the triaxial accelerometer (3) as U. 加X1 U 加Y1 U 加Z1 The encoder (7) measures the spindle rotation angle θ in real time; S3. Calculate inertial forces: X 惯 =m(U 加X1 -U 加X0 )K 加X ; Y 惯 =m(U 加Y1 -U 加Y0 )K 加Y ; Z 惯 =m(U 加Z1 -U 加Z0 )K 加z ; My 惯 =-F 惯Z ×Lz; Mz 惯 =-F 惯Z ×Lz; Where K 加X K 加Y K 加z These are the inertia correction coefficients for the X, Y, and Z axes of the triaxial accelerometer (3), respectively; S4. Calculate the six-dimensional force loads after correcting for the effects of inertial forces and gravity: X 修正 =X1−X0−X 惯 4 Y 修正 =Y1-Y0-Y 惯 ; WITH 修正 =Z1-Z0-Z 惯 ; Mx 修正 =Mx1-Mx0; My 修正 =My1-My0-My 惯 ; Mr. 修正 =Mz1-Mz0-Mz 惯 ; S5. Correct to the turbine body coordinate system: Y=Y 修正 ×sin(θ+90°)+Z 修正 ×sinθ; Z=Y 修正 ×cos(θ+90°)+Z 修正 ×cosθ; M Z =M y修正 ×cos(θ+90°)+M Z修正 ×cosθ; M Y =My 修正 ×sin(θ+90°)+M Z修正 ×sinθ; M X =M X修正 ; X=X 修正 。

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