RU2530428C1 - Method of hydraulic turbine rotor wheel balancing - Google Patents

Abstract

FIELD: measuring instrumentation.

SUBSTANCE: method involves wheel centring with reference points for location of coordinates of dynamometers positioned on surface of platforms used for rotor wheel suspension. Load is applied to the centre of each platform by force application unit for each weight range of rotor wheel. Then characteristic points corresponding to projections of weight measuring platforms are selected on the wheel surface by superposition method, and the wheel is rotated clockwise at a defined angle against these platforms. After each wheel turn, weight is measured on each platform with one selected like characteristic point, with further arithmetic averaging of measurement results for all platforms in each like characteristic point. Then unbalance is determined in a certain way by calculation using measurement system and result processing, and balancing loads are placed precisely.

EFFECT: enhanced precision of hydraulic turbine rotor wheel balancing, simpler calculation of balancing process.

7 cl, 11 dwg

Description

The invention relates to hydraulic engineering, precision mechanics, measuring equipment and can be used to determine the coordinates of the center of mass and balancing products of complex shape.

To eliminate imbalance of the impeller of a hydraulic turbine in all cases, various methods of technological balancing are used, which, however, do not provide the required level of accuracy due to the presence of errors, both during measurements and due to the accuracy of the equipment used to make these measurements .

So there is a method of balancing a hydraulic unit, which is performed as follows. The hydraulic unit is centered in the guiding segment bearings, dynamometers are installed under its rim, the bearing segments are bred, the rim is lowered onto the dynamometers and the unbalance value is determined from their readings from the following ratios:

$$S=\sqrt{({\displaystyle {\sum }_{i=\mathrm{one}}^n{P}_i\cdot X_i{)}^2}+({\displaystyle {\sum }_{i=\mathrm{one}}^n{P}_i\cdot Y_i{)}^2}};\varphi =\text{arctg}\frac{{\displaystyle {\sum }_{i=\mathrm{one}}^n{P}_i\cdot X_i}}{{\displaystyle {\sum }_{i=\mathrm{one}}^n{P}_i\cdot Y_i}};$$

where S is the static moment of the unbalanced mass;

P _i - the force acting on the i-dynamometer;

n is the number of dynamometers;

X _i and Y _i - coordinates of the installation of dynamometers;

φ is the angle showing the direction of displacement of the center of mass.

After that, eliminate the imbalance by setting the balancing weight, the static moment of which is equal to S, and the installation angle is

(см. Авторское свидетельство СССР №1150391, F03B 11/04, опубл. 15.04.85, бюл. №14). $${\mathrm{<figure-callout\; id="2"\; label="\phi "\; filenames="00000024.png,00000025.png"\; state="\{\{state\}\}">\varphi </figure-callout>}}_2=\varphi +\pi$$

(see USSR Author's Certificate No. 1150391, F03B 11/04, publ. 15.04.85, bull. No. 14).

The main disadvantages of this technical solution are low productivity and a large measurement error caused by the presence of subjectivity in assessing the vector and the magnitude of the wheel unbalance, due to the lack of installation automation, calculation of parameters and control over the course of balancing.

There is also known a method of balancing the impeller of a hydraulic turbine, which is characterized in that the wheel is centered on the lateral surface of the outer wall of the rim using a spring-loaded target core and stops in the form of prisms rigidly mounted on the working surface of the platform with force measuring sensors and forming a lateral touch point the surface of the wheel reference points of reference coordinates of the location of the load cells. At the same time, all force measuring sensors, and, accordingly, the working surfaces of the platforms, are set at the same level of the horizon. After that, the platforms are loaded with a balanced wheel, their position is fixed by a top-view camera, the resulting image is entered into the computer of the measurement and processing system, and using this system, including signal converters and a controller, the coordinates and value of the load per each platform are determined. Based on these results, the center of mass of the entire wheel is determined similarly, and the obtained coordinates of the center of mass are superimposed on the computer image of the impeller contour, the imbalance is determined, and the balancing weights are precisely set. The method is characterized by the fact that the system of measurements and processing of their results is formed from signal converters by the number of force sensors connected to the controller connected to the computer. Strain gauge sensors are used as load cells, and all load cells are coordinated to group on the platform surface according to the measuring range of the impeller mass, placing them according to the measurement value at the vertices of squares offset from each other (see RF Patent No. 2456566, G01M 1/12, published on July 20, 2012, Bulletin No. 20).

The specified invention for the problem to be achieved and the technical result achieved is the closest analogue to the claimed method and is adopted as a prototype.

However, all similar methods of balancing large and heavy products using platforms with sensors, including the closest analogue, are characterized by the following disadvantages, acquired and installed during production operation.

First of all, there is an overload of individual sensors on weight platforms due to the uneven alignment of the upper sensor supports of all platforms; the influence of platforms of different heights, as well as the influence of the inclination or deflection of the desktop surface on the balancing results. The balancing results under certain conditions may be affected by the lack of accounting for impeller discontinuities with the number of blades, the multiple number of weight measuring platforms and, as a result, the appearance of an additional “imaginary” unbalanced mass.

It became possible to solve the problem of eliminating the drawbacks of the analogue by changing the loading scheme of the weighing platforms and using the superposition method to ensure the invariance of the system with respect to the uneven installation of the table, platforms and the presence of discontinuities of the turbine impellers.

EFFECT: improving the accuracy of balancing is achieved due to the fact that initially the wheel is centered with the establishment of reference points for the coordinates of the location of the load sensors located on the surface of the platforms used to weigh the impeller. At the same time, a load is applied to the center of each platform using a power-introducing assembly for each impeller weight range. After that, characteristic points corresponding to the projections of the centers of the weight measuring platforms are selected by the method of superposition on the wheel surface and the impeller is rotated clockwise relative to the said platforms by a predetermined angle. Then, after each turn, a weight measurement is performed on each platform with each selected characteristic point of the same type, followed by arithmetic averaging of measurement results for all platforms at each same characteristic point and the total weight of the impeller at each characteristic point of the same name, after which it is determined in a known manner by calculation using a system of measurements and processing results, the imbalance and accurately establish the balancing weights.

The method is also characterized by the fact that the centering of the impeller of a hydraulic turbine is carried out along the lateral surface of the outer wall of the rim using a spring-loaded target core and stops in the form of prisms, rigidly mounted on the working surface of platforms with load cells. The accuracy of balancing is also influenced by the fact that the power-supply unit is made in the form of a hemispherical form of an emphasis installed exactly in the center of the platform. It also helps to improve the accuracy of impeller balancing and the measurement and processing system of their results, which is formed from the controller, signal converters, each connected with its input to the output of the load sensors and connected to the controller connected to the computer, and strain gauges are used as load sensors.

The method of balancing the impeller is also characterized by the fact that the centered impeller of the hydraulic turbine is fixed with a video camera and its image is entered into the computer of the measurement and processing system, and after determining the vector and center of mass of the entire wheel, they are superimposed on the computer image. An important requirement for the implementation of the balancing method is that the installation angle of the weighing platforms and the angle of rotation of the characteristic points selected on the impeller are taken to be 120 °, and the number of platforms is three.

The method of balancing the impeller of a hydraulic turbine is new, because in the sources of information the totality of the proposed features reflected in the claims, including in additional paragraphs, is not found.

The proposed method as a technical solution has an inventive step, because the totality and sequence of its actions performed using the superposition method to ensure the invariance of the system relative to the unevenness of the installation of the table, platform and the presence of discontinuities of the impellers of hydraulic turbines in the field of hydraulic engineering are not obvious.

The invention is illustrated by drawings, in which Fig. 1 shows a diagram of the installation of the impeller assembly at its balancing position, Fig. 2 shows a complete assembly with load cells, stops and target core (top view), Fig. 3 shows a section along A -A in figure 2. Figure 4 illustrates a top view of the platform with load cells spaced in squares and a power input device, Figure 5 shows a side view of the platform with a pullout where the power input unit is installed, Figure 6 shows a general view of the placement of the impeller on the platforms at an angle α = 120 ° with the selected characteristic points, and Figs. 7, 8 and 9 show diagrams of the rotation of the impeller by an angle of 120 ° at different positions of the same characteristic points, and Fig. 10 conditionally shows the position of the center of mass of the impeller, the radius and the imbalance relative to the X and Y axes.

The kit for oriented balancing of the impeller of a hydraulic turbine includes platforms 1 with load cells 2 and 3, an upstream video camera 4 and a system for measuring and processing their results, including signal converters (not shown in Fig.) Of each load sensor 2 and 3 connected to the controller 5, connected to the computer 6. The platforms 1 are square in shape with angular bevels 7, mainly at an angle of 45 °, and in relation to this form, the appropriate layouts are selected on and the working surfaces of the force-measuring sensor 8 2 small weight (3 m) and 3 large weight sensors (15 m). The placement of the load sensors 2 and 3 is oriented along the X and Y axes relative to the corner joints 9 of the bevels 7 and each of them is graphically located at the vertices of its square 10.

In the technical means used for balancing, including for platforms 1, the placement schemes of load sensors 2 and 3, shown in Fig. 4, are used.

The arrangement of load cells 2 on a small measuring range with the largest measurement limit (NPI) of 3 t is tilted to the Y axis, and the layout of force sensors 3 of a large measurement range with a 15 t NPI is opposite from the Y axis (Fig. 4).

Thus, the load cells 2 and 3 are grouped on the platform 1 according to the measuring range of the wheel mass, graphically placing them for ease of use at the nominal value of the measurement at the vertices of squares 10 offset from each other. The design of the platform 1 itself includes a lower base 11, on which the sensors 2 and 3 are mounted, a support adjustment mechanism 12 and the upper base closing them 13. By adjusting the support mechanism 12 of the sensors 2 and 3, the platform is leveled to a horizontal level for any measuring range of hydraulic impeller weight turbines (figure 3).

For oriented installation of the platform 1 relative to the impeller on its working surface 8 of the upper base 13, two stops 14 and a spring-loaded target core 15 are rigidly coordinate-mounted, forming reference points a, b, c and f at the touch points of the side surface 16 and the rim 17 of the impeller coordinates of the location of the load sensors 2 and 3. The stops 14, made in the form of prisms, and the target core 15 are motionlessly interconnected by a bar 18.

On the working surface 8 of all platforms 1, sighting lines 19, 20 and 21 are drawn, and on the lateral surface 16 of the rim 17, these lines are also marked, which is applied in the form of vertical marks 19, 20 and 21, placed equidistant from each other at an angle α = 120 °.

To ensure a uniform load of sensors 2 and 3, the working surface 8 of each platform 1 is equipped with a power-introducing unit 22 made in the form of a hemispherical stop fixed exactly in the center of the platform.

Each platform 1 is adjusted so that the dimensions between the reference points a, b, c and f formed by the ends of the stops 14 and the spring-loaded core 15 are constant and equal for all platforms 1, and the retractable target core 15 is located on any line of sight drawn on the side surface of the rim and the working surface 8 of the upper base 13. The marking and installation of the stops 14 is carried out with respect to the sensors 2 and 3 on all platforms 1 equally, forming a single coordinate system relative to the X and Y axes.

In platforms 1, for working on the first or second ranges, a group of sensors 2 or 3 is used, respectively. Tuning to a range (15 or 50 t) is carried out by removing from the contact of the upper supports of the regulation mechanism 12 of one of the sensors and replacing them with others, while ensuring the same signal to each sensor.

The design of the platforms 1 is such that each of the sensors 2 or 3, mounted on the lower base 11, is connected to a separate normalizing converter (not shown in Fig.), And the outputs of all the transducers are connected via a serial interface to a controller 5. Thus, when the load is applied to the platform by the output code G, the radius vector of the load application can be determined on each of the four sensors of the 2 or 3 ranges.

The top-view video camera 4, mounted cantilevered on a rack 23, is connected to the computer 6 and is designed to fix the position of the impeller installed at the balancing position with the subsequent introduction of its image on the display of said computer 6.

For transportation and installation on the position of balancing of the impeller, and later its rotation during weighing, it is equipped with a temporarily used device 24.

To eliminate the influence of incorrect alignment of the upper nodes 25 and 26 of the load cells 2 and 3, the non-horizontalness of the platforms, the overestimation of the platforms relative to each other, as well as the influence of discontinuities in the impellers of the hydraulic turbines, the superposition method was applied. The method of superposition consists in the fact that the overall result of exposure to the system of many factors is equal to the sum of the results of exposure to each factor (Internet site “bip-ip.com/pnntsip-superpozitii”). With regard to the proposed method of balancing the impeller of a hydraulic turbine, the essence is as follows: on the sighting lines 19, 20 and 21 of the rim 17, three characteristic points A, B and C are selected corresponding to the projections of the centers of the power-introducing unit 22 of the weighing three platforms 1 (Fig.6, 7, 8 and 9). With this approach, three measurements are taken when the impeller is rotated 120 °. Since the characteristic points are shifted together with the rotation of the impeller, each point A, B and C will be weighed on each of the three platforms, also installed at an angle α = 120 ° to each other.

Characteristic points A, B and C are selected on the rim 17 equidistant from the geometric center of the impeller and alignment with the center of the power-supply nodes 22 of all three platforms 1, whereby the support reaction F _A , F _B and F _{C of} each platform will be in their center and equal to the weight of the wheels G _A , G _B and G _C falling on each platform at the same points, namely F _A = G _A ; F _B = G _B and F _C = G _C.

And since the measurement of the weight of the impeller is carried out in three positions (1, 2, 3), shown in Figs. 7, 8 and 9 with fixed platforms 1, then the reaction of the supports, and therefore the weight at each point of each platform will be three times change its meaning, i.e.

$$\begin{array}{l}\begin{array}{l}{G}_{A\mathrm{one}}=G_{\mathrm{eleven}}\\ G_{B\mathrm{one}}=G_{21}\\ G_{C\mathrm{one}}=G_{31}\end{array}\}-PeR\mathrm{at}\mathrm{about}e\mathrm{and}smeRen\mathrm{and}e\\ \begin{array}{l}{G}_{A\mathrm{one}}=G_{12}\\ G_{B\mathrm{one}}=G_{22}\\ G_{C\mathrm{one}}=G_{32}\end{array}\}-\mathrm{at}t\mathrm{about}R\mathrm{about}e\mathrm{and}smeRen\mathrm{and}e(\mathrm{one})\\ \begin{array}{l}{G}_{A\mathrm{one}}=G_{13}\\ G_{B\mathrm{one}}=G_{23}\\ G_{C\mathrm{one}}=G_{33}\end{array}\}-tRetbe\mathrm{and}smeRen\mathrm{and}e\end{array}$$

where F _A1 , F _A2 and F _A3 is the reaction of the support at characteristic point A at three positions 1, 2 and 3 of the measurement of the impeller. Same thing at points B and C.

And, therefore, the average value for each characteristic point will be:

$$\begin{array}{l}{\overline{G}}_A=(G_{\mathrm{eleven}}+{\mathrm{<figure-callout\; id="22"\; label="G"\; filenames="00000022.png,00000023.png"\; state="\{\{state\}\}">G</figure-callout>}}_{22}+G_{33})/3={\displaystyle {\sum }_{\mathrm{one}}^3{G}_{Aij}/3},\\ {\overline{G}}_B=({\mathrm{<figure-callout\; id="21"\; label="G"\; filenames="00000028.png,00000029.png"\; state="\{\{state\}\}">G</figure-callout>}}_{21}+G_{32}+G_{13})/3={\displaystyle {\sum }_{\mathrm{one}}^3{G}_{Aij}/3}\text{(2)}\\ {\overline{G}}_C=(G_{31}+{\mathrm{<figure-callout\; id="12"\; label="G"\; filenames="00000024.png"\; state="\{\{state\}\}">G</figure-callout>}}_{12}+G_{23})/3={\displaystyle {\sum }_{\mathrm{one}}^3{G}_{Aij}/3}\end{array}$$

- арифметически усредненное значение нагрузки в точках A, B и C рабочего колеса, измеренное в трех позициях.where i is the platform number, j is the measurement number, $${\displaystyle {\sum }_{\mathrm{one}}^3{G}_i/3}$$

- arithmetically averaged load value at points A, B and C of the impeller, measured in three positions.

The method of static balancing the impeller of a hydraulic turbine is as follows.

The installation of platforms 1 under the impeller, in limbo, is carried out by sliding until the fixed stops 14 and the sighting core 15 touch the side surface 16 of the rim 17. In this case, the positioning of the platforms 1 relative to the center of rotation of the impeller is observed. The platforms 1 are installed with a sighting line 19 along the marking risk also 19, applied to the outer rim 17 of the impeller and precisely positioned with stops 14 and a sighting core 15, forming reference points a, b, c and f of the reference point of the location of the load sensors 2 and 3. At the same time all load cells 2 or 3, and accordingly the working surfaces 8 of the platforms 1 are set to the same level of the horizon, after which the platforms 1 are loaded with a balanced wheel, fix its position with the video camera 4 of the upper view and enter the image Downloading to computer 6 a system for measuring and processing results.

When the platforms 1 are loaded with the impeller, the signal from each sensor 2 or 3 is sent to the controller 5 and fed to the computer 6, automatically determining the coordinates of each sensor and the corresponding load on each platform 1. Due to the fact that each of the platforms 1 has four interrogated sensors each measurement range, this allows you to determine the coordinates of the application of forces on the platform as a whole without significant errors, and therefore, it is sufficient to accurately determine the center of mass and the vector of application of forces of the entire platform 1.

When balancing the impeller of a hydraulic turbine, only three platforms 1 are used.

Practical application of the method showed that the most appropriate weight measurement of the impellers of hydraulic turbines using three platforms 1, since the most stable position of the lower plane of the wheel is geometrically determined by three points.

The initial calculations will be the average loads determined for each characteristic point in accordance with the given formulas (1, 2).

The position of the center of mass of the impeller as a whole is determined by the formulas:

$$X_{R.\mathrm{to}}=\frac{{\displaystyle {\sum }_{\mathrm{one}}^3{X}_{ji}\cdot {\overline{G}}_{ji}}}{{\displaystyle {\sum }_{\mathrm{one}}^3{\overline{G}}_{ji}}}=\frac{{\overline{G}}_A\cdot X_A+{\overline{G}}_B\cdot X_A+{\overline{G}}_C\cdot X_C}{{\displaystyle {\sum }_{\mathrm{one}}^3{\overline{G}}_{ji}}}\text{(3)}$$

$$Y_{R.\mathrm{to}}=\frac{{\displaystyle {\sum }_{\mathrm{one}}^3{Y}_{ji}\cdot {\overline{G}}_{ji}}}{{\displaystyle {\sum }_{\mathrm{one}}^3{\overline{G}}_{ji}}}=\frac{{\overline{G}}_A\cdot Y_A+{\overline{G}}_B\cdot Y_A+{\overline{G}}_C\cdot Y_C}{{\displaystyle {\sum }_{\mathrm{one}}^3{\overline{G}}_{ji}}}\text{, (four)}$$

where X _r.k - the coordinate of the center of mass of the impeller along the X axis;

Y _r.k - the coordinate of the center of mass of the impeller along the Y axis;

- значение средней нагрузки, определяемой по каждой характеристической точке; $${\overline{G}}_A,{\overline{G}}_B\mathrm{and}{\overline{G}}_C$$

- the value of the average load determined for each characteristic point;

X _A , X _B and X _C - coordinates of the characteristic points relative to the X axis;

Y _A , Y _B and Y _C - coordinates of the characteristic points relative to the Y axis;

- общий вес рабочего колеса; $${\displaystyle {\sum }_{\mathrm{one}}^3{\overline{G}}_{ji}}$$

- total weight of the impeller;

- статический момент рабочего колеса относительно оси X; $${\displaystyle {\sum }_{\mathrm{one}}^3{X}_{ji}\cdot {\overline{G}}_{ji}}$$

- the static moment of the impeller relative to the axis X;

- статический момент рабочего колеса относительно оси Y. $${\displaystyle {\sum }_{\mathrm{one}}^3{Y}_{ji}\cdot {\overline{G}}_{ji}}$$

- the static moment of the impeller relative to the axis Y.

To increase the accuracy of calculation for all load cells, for example 2, of one platform, the load is transmitted through a hemispherical shape of the power supply unit 22 located in the center of each platform, the center of which coincides with the characteristic points A, B and C of the rim 17 after each of them rotates 120 ° .

After the first weighing of the impeller weighing 15 tons at position 1 (Fig. 7), its result at each characteristic point A, B and C located on each platform 1 and the total weight are entered by the measuring system into the table of computer 6. Then, the impeller is rotated wheels clockwise relative to fixed platforms 1 at an angle α = 120 °, while risk 19 with point A moves to position 2 and, accordingly, the remaining points B and C also move to new positions 3 and 1, and measure the weight per every point A, B and C, and the total weight of the entire impeller, the results of which are also recorded in the computer 6 (Fig. 8). After the last, third turn of the risk wheel 19 with point A, it will be in the third position, the measured results from which will also be sent to computer 6 and entered in the table (Fig. 11). After taking these three measurements at positions 1, 2, and 3 at characteristic points A, B, and C, the computer calculates in accordance with formulas (1) and (2) the arithmetic mean value of the load per each characteristic point of the impeller as a whole.

All the results of three-time weighing of the impeller of a hydraulic turbine weighing 15 tons are summarized in the table shown in Fig.11.

всех точек на всех трех позициях измерения составляет 14998 кг, и усредненный вес, приходящийся на каждую характеристическую точку A, B и C в сумме, также составляет 14997 кг, что подтверждает высокую точность балансировки предлагаемого способа. Таким образом, трехкратное изменение позиции взвешивания рабочего колеса относительно платформ 1 обеспечивает, во-первых, устранение мнимого дисбаланса, образующегося за счет несплошностей рабочего колеса, а во-вторых, исключает влияние неправильного выставления верхних узлов 25 и 26 силоизмерительных датчиков 2 и 3 платформ 1, негоризонтальности и завышенности их относительно друг друга.As follows from the table, each weighing of the impeller shows at each characteristic point the presence of a different load. The greatest load at each measurement position is added at point A, while at the same time at points B and C, approximate weight equality is observed. This indicates the presence in the zone of point A of a continuous section of the impeller and the imaginary imbalance created. However, the total average weight of the impeller $${\displaystyle \sum G_{ABC}}$$

of all points at all three measurement positions is 14998 kg, and the average weight per each characteristic point A, B and C in total is also 14997 kg, which confirms the high accuracy of the balancing of the proposed method. Thus, a threefold change in the position of weighing the impeller relative to the platforms 1 provides, firstly, the elimination of the imaginary imbalance formed due to discontinuities of the impeller, and secondly, eliminates the influence of incorrect exposure of the upper nodes 25 and 26 of the load cells 2 and 3 of the platforms 1 , non-horizontalness and overestimation of them relative to each other.

If it is necessary to measure impellers with a higher weight, for example, 50 or 100 tons, force sensors 2 with an NPI of 3 t are output by the control mechanism 12 from the zone of its contact with the plate 13, and sensors 3 with an NPI of 15 t are put into operation After carrying out the measurement operations to determine the weight, all further steps of the method are associated with the operation of the measurement system and the processing of their results.

The image of the impeller housing on the computer monitor 6, obtained using the top-view video camera 4 mounted on the console rack 21, shows the coordinate of the center of mass of the impeller housing and the radius vector

$$R_{\partial }=\sqrt{X_{R\mathrm{to}}^2+Y_{R\mathrm{to}}^2}\text{, (7)}$$

the connecting center of the impeller housing and its center of mass. The radius r, on which the balancing weight can be installed, is specified constructively. The diagram conventionally shows the position of the center of mass of the impeller, the magnitude and radius of its imbalance relative to the X and Y axes with three platforms (Fig. 10). In accordance with the scheme, the imbalance radius is determined by the formula:

$$R_{\partial }=\sqrt{X_{R\mathrm{to}}^2+Y_{R\mathrm{to}}^2}$$

Accordingly, the moment arising due to the mismatch of the center of mass and the axis of rotation of the wheel will be:

$$M=R_{\partial }\cdot G_{R\mathrm{TO}\mathrm{from}R.}\text{, (8)}$$

Where $$G_{R\mathrm{TO}\mathrm{from}R.}=G_{A\mathrm{from}R}+G_{B\mathrm{from}R}+G_{C\mathrm{from}R}-{\mathrm{<figure-callout\; id="0"\; label="G"\; filenames="00000027.png"\; state="\{\{state\}\}">G</figure-callout>}}_0$$

- радиус вектор смещения осей вращения и центра масс,where - $$R_{\partial }$$

is the radius of the displacement vector of the axes of rotation and the center of mass,

G _Asr , G _Bsr , G _Csr - the average weight of the impeller attributable to each of the platforms 1;

G ₀ - the weight of the device 24.

To perform balancing, a balancing weight is precisely imposed, the mass of which is determined from the equation:

$$G_b\cdot r=R_{\partial }\cdot G_{R\mathrm{TO}\mathrm{from}R.}\text{from where}{G}_b=\frac{R_{\partial }\cdot G_{R\mathrm{TO}\mathrm{from}R.}}{r},\text{(9)}$$

- балансировочный груз;Where $$G_b$$

- balancing load;

r is the radius of the wheel;

- радиус дисбаланса; $$R_{\partial }$$

- radius of imbalance;

- вес колеса. $$G_{R\mathrm{TO}\mathrm{from}R.}$$

- weight of the wheel.

Thus, in the process of balancing the impeller, the system for measuring and processing the results programmatically automatically displays on the computer monitor 6 the position of the center of mass relative to its rotation axis, and also determines the value of X _r.k. , Y _r.k. and R, and if R is found, it accurately sets the weight and location of the balancing weight, which increases the productivity of the unbalance measurements of the hydraulic turbine.

The proposed method provides high accuracy of the impeller balancing, as it has a low degree of measurement error and a high sensitivity threshold for torque, which are ensured by the constructive construction of platform 1 as a whole, as well as by the precise installation of force sensors 2 and 3 and prism stops 14 on its working surface 8 and its non-verticality.

So for the impeller with a diameter of 15 m, the error of the proposed method of balancing along the X and Y axes will be up to 3.0 mm, and its calculated sensitivity at the time of balancing will be in the range up to 180-230 kg · cm for the available platform accuracy 1.

The proposed method allows to increase the accuracy of balancing the impellers of hydraulic turbines, to expand the range of their balancing up to 150 tons due to the use of advanced platforms with the application of force on the load-bearing unit located in the center of each platform, and the use of software measurement and evaluation of results, as well as application three times measuring the weight of the impeller using the superposition method.

Currently, advanced platforms are manufactured, their tests are carried out by weighing a prototype of a turbine impeller, and positive results have been obtained confirming the achievement of a technical result, i.e. improving the accuracy of measuring the balancing method, balancing tests were carried out on the impeller of the Volzhskaya 21 turbine weighing ~ 80 tons; according to the test results, the equipment was put into commercial operation.

Claims (7)

1. The method of balancing the impeller of a hydraulic turbine, characterized by centering the wheel with the establishment of reference points for the coordinates of the location of the load sensors located on the surface of the platforms used to weigh the impeller, while providing a load application to the center of each platform using a power input unit for each working weight range wheels, after that, characteristic points corresponding to the projections of the cent of weighing platforms and rotate the impeller clockwise relative to the said platforms by a predetermined angle, and then, after each rotation, measure the weight on each platform with each selected characteristic point of the same type, followed by arithmetic averaging of the measurement results for all platforms at each characteristic characteristic point and the total weight of the impeller also at each characteristic point of the same name, after which the calculation is determined in a known manner In this way, using the measuring system and processing the results, the imbalance is accurately established and the balancing weights are established. 2. The method according to claim 1, characterized in that the measurement and processing system of the results is formed from signal converters by the number of load sensors connected to the controller connected to the computer. 3. The method according to claim 1, characterized in that the number of characteristic points is chosen equal to the number of weighing platforms. 4. The method according to claim 1, characterized in that the installation angle of the weighing platforms and the angle of rotation of the characteristic points selected on the impeller are taken equal to 120 °, and the number of platforms equal to three. 5. The method according to claim 1, characterized in that the centering of the impeller of the hydraulic turbine is carried out on the side surface of the outer wall of the rim using a spring-loaded target core and stops in the form of prisms, rigidly mounted on the working surface of platforms with load cells. 6. The method according to claim 1, characterized in that the power-supply unit is made in the form of a hemispherical form of an emphasis installed exactly in the center of the platform. 7. The method according to claim 1, characterized in that the centered impeller of the hydraulic turbine is fixed with a video camera and its image is entered into the computer of the measurement and processing system and, after determining the values of the vector and the center of mass of the entire wheel, overlay them on the computer image.

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