Impeller Static Balancing Device

Abstract

The present invention discloses an impeller static balancing device, comprising concentric rings, with a balancing disc sleeved on the outside of the concentric rings. The balancing disc is composed of an internal annular disc frame connected to a plurality of circumferentially distributed external brackets, with adjacent brackets having the same angle. Pressure sensors are provided within the brackets, and jacks and equal-height pads are provided between adjacent brackets. The brackets are rectangular, and scale lines starting from the center of the balancing disc are provided on the edges of the brackets. The present invention utilizes concentric rings, a balancing disc, a pressure sensor, and a jack to assemble an impeller static balancing device. The device has a simple structure, and the position of the pressure sensor can be adjusted according to the outer diameter of the impeller to be measured, thereby achieving an adjustable radius for measuring unbalanced torque. The device has good versatility, safe and convenient operation, and reliable accuracy.

Description

Technical Field

[0001] The invention belongs to the technical field of mechatronic detection devices and relates to an impeller static balancing device. Background Art

[0002] For large rotor parts such as dredging mud pump impellers, their operating speed is generally 250-350rpm, the maximum diameter is close to 3 meters, and the maximum weight is more than 10 tons. Due to casting errors, uneven material structure, shape errors of parts (especially non-machined parts), local shape asymmetry and other reasons, the main inertia axis of the impeller mass center and the rotation axis do not coincide with each other. When rotating, unbalanced centrifugal force will be generated. If the unbalanced centrifugal force is too large, it will cause the pump shaft, bearing box and pump body mounting base to vibrate, which will have a great impact on the safe operation of the entire mud pump. Therefore, the impeller needs to be statically balanced and calibrated before leaving the factory.

[0003] The traditional static balancing process for rotor parts mainly uses the "steel ball" static balancing method. The biggest disadvantage of this method is its low precision and poor repeatability. It also places very high demands on the surface hardness and finish of the balancing balls and mirror plates. In addition, for large parts, because the steel balls and mirror plates are in point contact, the excessive weight of the parts causes deformation of the bearing steel balls and mirror plates, which directly affects the measurement and balancing of the imbalance. Currently, the more advanced static balancing method is the stress rod balancing method, but this method has high requirements on the stress rod material. The elastic modulus of each stress rod must be measured individually, the processing cycle is long, and the layout of the strain gauges is very strict. The tooling cost is high, the assembly is inconvenient, and the use is cumbersome.

[0004] The commonly used static balancing process for mud pump impellers usually adopts a horizontal rotating shaft method. That is, a dummy shaft with the same diameter and concentricity as the impeller shaft end is installed at the impeller suction end. The impeller is then erected and placed on a bearing frame for rotation. After the impeller stops under the action of gravity, the weight is located at the lowest point of the impeller. Then, weights are added at the opposite position to balance the weight until the impeller stops at a random position. The mass of the weight added at this time is the weight of the impeller. This method has the following problems: 1) It is affected by factors such as the rotation flexibility of the bearing frame and the friction between the impeller dummy shaft and the bearing, resulting in large errors; 2) During operation, the impeller needs to be turned over and hoisted, which makes it easy to tip over and has poor safety; 3) The distance between the left and right bearing frames needs to be adjusted according to different impeller heights, and when the impeller is placed on the bearing frame, it will inevitably cause a certain impact on the bearing, which will cause damage to the bearing frame in the long run; 4) For each impeller with different shaft end diameter, a dummy shaft of the same diameter needs to be made, which is costly, time-consuming and labor-intensive. Summary of the Invention

[0005] The purpose of the present invention is to provide an impeller static balancing device, which solves the problems of large measurement error and low safety of the existing mud pump impeller static balancing device.

[0006] The technical solution adopted by the present invention is that the impeller static balancing device includes concentric rings, and a balancing disk is provided on the outside of the concentric rings. The balancing disk is composed of an internal annular disk frame and a plurality of external circumferentially distributed brackets. The angles between adjacent brackets are the same. A pressure sensor is provided inside the bracket, and jacks are provided between adjacent brackets.

[0007] The bracket is a rectangular bracket, and a scale line starting from the center of the balance disk is set on the edge of the bracket.

[0008] An axial threaded hole is provided on the concentric ring, and a mounting bolt is provided in the threaded hole.

[0009] Spacers of equal height are provided between adjacent brackets.

[0010] A supporting base is provided at the bottom of the pressure sensor.

[0011] There are three brackets distributed circumferentially outside the balancing disc.

[0012] The beneficial effects of the present invention are that the impeller static balancing device is assembled with concentric rings, a balancing plate, a pressure sensor and a jack, the structure is simple, the position of the pressure sensor can be adjusted according to the size of the outer diameter of the impeller to be measured, and the radius of the unbalanced torque measurement can be adjusted, the versatility is good, the operation is safe and convenient, and the accuracy is reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of an impeller static balancing device of the present invention;

[0014] Figure 2 This is a partial cross-sectional view of the impeller static balancing device of the present invention in use;

[0015] Figure 3 This is a position distribution diagram of three pressure sensors in an impeller static balancing device of the present invention.

[0016] In the figure, 1. concentric ring, 2. balance plate, 3. pressure sensor, 4. jack, 5. mounting bolts, 6. equal height spacers, 7. support base, 8. impeller to be measured, 21. annular disc frame, 22. bracket. DETAILED DESCRIPTION

[0017] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The present invention is a static balancing device for an impeller, referring to Figure 1, including a concentric ring 1, a balancing disk 2 is provided on the outside of the concentric ring 1, the balancing disk 2 is composed of an internal annular disk frame 21 and three external circumferentially distributed brackets 22, the angles between adjacent brackets 22 are the same, a pressure sensor 3 is provided inside the bracket 22, a support base 7 is provided at the bottom of the pressure sensor 3, and a jack 4 and equal-height pads 6 are provided between adjacent brackets 22.

[0019] The bracket 22 is a rectangular bracket, and a scale line starting from the center of the balancing disk 2 is set on the edge of the bracket to facilitate accurate adjustment of the position of the pressure sensor 3 inside the bracket 22.

[0020] An axial threaded hole is provided on the concentric ring 1 , and a mounting bolt 5 is provided in the threaded hole for fixedly connecting the concentric ring 1 and the mud pump impeller.

[0021] When using the impeller static balancing device of the present invention, the operating steps are as follows:

[0022] (1)Reference Figure 2 , first place the impeller static balancing device on the platform, then place the impeller 8 to be measured with the shaft end facing upward on the top of the weighing static balancing device, so that the impeller 8 to be measured bears the weight on the equal-height pad 6;

[0023] (2) Use the mounting bolts 5 to fix the concentric ring 1 and the impeller to be measured 8 together, so that the center of the impeller to be measured 8 coincides with the center of the balance plate and is close to the outer circle of the lower end surface of the impeller to be measured;

[0024] (3) Raise the jacks 4 so that the impeller 8 to be measured bears weight on the three jacks 4, then lower the three jacks simultaneously so that the impeller to be measured bears weight on the three sets of pressure sensors, and check the horizontal error of the impeller to be measured;

[0025] (4) Raise the jack, lift the impeller to be tested, and return the three sets of pressure sensors to zero;

[0026] (5) Lower the jack again synchronously so that the impeller to be tested bears the weight on the three sets of pressure sensors and read the data G on the three sets of sensors. A1 , G B1 , G C1 ;

[0027] (6) Repeat steps (4) and (5) twice, and record two sets of data G respectively. A2 , G B2 , G C2 and G A3 , G B3 , G C3 ;

[0028] (7) Rotate the impeller to be tested 180° and repeat steps (4), (5), and (6) three times, and then record three sets of data G' A1 , G'B1 , G' C1 , G' A2 , G' B2 , G' C2 and G' A3 , G' B3 , G' C3 ;

[0029] (8) Figure 3 As shown, when the three pressure sensors bear weight, three sets of data G will be read out. A , G B , G C , after decomposing the three readings into X and Y axes, we can get

[0030] G X =G A -(G B sin 30°+G C sin 30°) (1)

[0031] G Y =G C cos 30°-G B cos 30° (2)

[0032] According to formula (1) and (2), the total weight of the impeller G can be obtained 总 and angle θ:

[0033]

[0034] θ=arctan(G X / G Y ) (4)

[0035] (9) Take the average of the results of the first three measurements and the three sets of data measured after the impeller to be measured rotates 180°, and then take the average again to obtain the weight and angle of the impeller at the distribution circle of the pressure sensor;

[0036] (10) According to the measured weight angle and orientation of the impeller to be tested, remove the weight at the appropriate non-machined surface of the impeller, and remove the weight G 实 According to the moment balance principle, calculate as follows:

[0037]

[0038] where R 测 is the radius of the pressure sensor distribution circle, R 实 G is the actual de-weighting radius of the impeller to be measured, 测 is the eccentric weight measured at the pressure sensor.

[0039] (11) After removing the weight, the impeller is subjected to static balance measurement until the weight eccentricity is reduced to the allowable range.

Claims

1. Impeller static balancing device, characterized in that: The invention comprises a concentric ring (1), wherein a balancing disk (2) is sleeved on the outer side of the concentric ring (1), and the balancing disk (2) is connected by an internal annular disk frame (21) and a plurality of brackets (22) distributed in the outer circumference. The angles between adjacent brackets (22) are the same. A pressure sensor (3) is arranged inside the bracket (22), and a jack (4) is arranged between adjacent brackets (22). The bracket (22) is a rectangular bracket, and a scale line with the center of the balancing disk (2) as the starting point is arranged on the edge of the bracket (22). An axial threaded hole is arranged on the concentric ring (1), and a mounting bolt (5) is arranged in the threaded hole. An equal height pad (6) is arranged between adjacent brackets (22). A support base (7) is arranged at the bottom of the pressure sensor (3). Three brackets (22) are distributed in the outer circumference of the balancing disk (2). The position of the pressure sensor (3) can be adjusted according to the outer diameter of the impeller to be measured, so as to achieve an adjustable radius for measuring the unbalanced torque.

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