RU212633U1 - SINGLE SHAFT SCREEN - Google Patents

Abstract

This utility model relates to the field of mechanical vibration technology, in particular to a vibrating screen for screening and feeding material, made with one shaft and with the possibility of changing the trajectory of movement. The technical result of the utility model is to reduce the stresses in the sidewalls at the places where the support beams are embedded in the box, as well as to simplify the design and reduce the weight of the screen. The specified technical result is achieved due to the fact that an inertial screen with one shaft and with the possibility of changing the trajectory of movement is claimed, containing a vibration box, supports, spring supports with a sole, one vibration shaft with a vibrator attached to it, an engine, a screening sieve located obliquely; while the vibration shaft is mounted on a vibration box, characterized in that the spring supports are arranged in pairs, each spring support consists of a bracket, springs and a sole, and the springs themselves are fixed in guide cups in the bracket and in the sole; each spring support is installed on the trunnion of the vibration box and is fixed to it through the bracket; the drive of the vibration shaft from the engine is made through the petal clutch; the vibration box consists of two sidewalls made of sheets of low-alloy structural steel, interconnected by two rows of tie-beams made of pipes, and the tie-beams are movably connected to the sideboards through elastic rubber bushings.

Description

The present solution relates to the field of mechanical vibration technology and, in particular, to a vibrating screen for sifting and feeding material, made with a single shaft and with the possibility of changing the trajectory of movement.

The current conventional mechanical vibratory devices can be divided into three categories, circular motion, linear motion, and elliptical motion based on the motion path. Conventional mechanical vibrating devices can be divided into three kinds, single shaft, double shaft and three shaft, based on the structure of the vibrating device. Various designs of the vibrating device provide movement paths, as described below.

1. The trajectory of the circular motion is implemented using a vibration device.

With the help of a vibrating device with one shaft, the trajectory of circular motion is obtained. The advantages of the single shaft vibrating device is that the vibrating device not only has a vibrating force component in the normal direction, but also has a vibrating force component in the tangential direction, and critical materials cannot easily block the openings of the screen cells. The disadvantages of the single shaft vibrating device is that when the vibrating device in motion interacts with the spring located in the vibrating box, the materials can only move up and down when screening, but cannot move horizontally for feeding, since the horizontal component of the force is extremely small. Therefore, all commercially available single-shaft devices provide an inclined installation using gravity to obtain horizontal movement for feeding. As a result of the inclined installation, the materials descend too quickly and are not completely screened. Thus, screening is unsatisfactory.

2. The trajectory of the linear movement is realized with the help of a vibration device with two shafts.

With the help of a vibration device with two shafts, a linear motion trajectory is obtained. The advantage of the two-shaft vibrating device is that the available vibrating guiding angle can be adjusted in the range of 0° to 90° by changing the phase angles of the eccentrics of the two vibrating shafts, direction angles in the range of 30°-60° are usually chosen for use. Accordingly, the materials can be moved up and down for vertical screening, and can also be moved horizontally for transport, so that the two-shaft vibrating device can be installed horizontally in operation. Due to the horizontal installation, the materials are screened completely and the screening performance is excellent. The disadvantage of the double shaft vibrator is that due to the linear movement, the double shaft vibrator can vibrate in the normal direction, but cannot vibrate in the tangential direction, so that critical materials can easily block the meshes of the sieve, and the screening performance is reduced. .

3. The elliptical motion trajectory is realized with a three-shaft vibrating device.

Using a vibrating device with three shafts, an elliptical movement path is obtained. The advantages of the three-shaft vibrating device combine the advantages of circular motion and linear motion. The three-shaft vibrating device can be installed horizontally in operation, and critical materials cannot easily block the openings of the cells. However, the disadvantages of the three-shaft vibrating apparatus are that the structure is complicated, the manufacturing cost is high, and the power consumption is significant. When the three-shaft vibrating device as well as the two-shaft vibrating device are adjusted in direction angle, the vibrating device should be opened to remove the gear mechanism, i.e. regulation of the phase angle difference of the eccentrics of the vibration shaft, which is laborious. Users can easily make a mistake when adjusting the phase angle difference of the eccentric of the vibration shaft.

So, patent RU194754U is known, published: 12/23/2019, in which a vibrating screen is disclosed, including at least two cardan shafts, at least two rubber couplings, at least two lifting beams, a drive, a vibration exciter, at least at least two sides made of solid sheet material, while the sides are fastened together by transverse beams having a square section, and decks are installed on the beams with guides fixed to them, made with a lock, a subvibrator beam is installed between the sides, screening beams are fixed on the guides surfaces.

The technical problem of the analogue is that in this screen there is stress in the sidewalls at the places where the support beams are embedded in the box.

It is partially eliminated by preliminary heat treatment of the transverse beams or their coating with an elastic material. But this only entails an increase in the strength characteristics of the transverse beams and increases their reliability, without affecting the reduction in stresses in the sidewalls in the places where the support beams are embedded in the box.

In addition, the presence of several shafts complicates and increases the weight of the screen.

Thus, the single shaft vibrator of the conventional technique is most preferable, its structure is simple, but the single shaft vibrator should be installed obliquely, and the screening performance is greatly reduced.

The biggest disadvantage of the conventional technique is that the vibratory device can realize only one movement path, and the device cannot be switched to other movement paths.

There is a technical solution, which is chosen as a prototype and described below, for which several motion trajectories are provided, but it also has its drawbacks.

The closest analogue is patent RU2567250, published: 11/10/2015, which describes a vibration device for screening and feeding material, made with one shaft and with the possibility of changing the trajectory of movement and containing: a vibration box, a lower base plate, a vibration spring, a vibration shaft; wherein the vibration shaft is mounted on the vibration box, and the vibration spring is installed between the vibration box and the lower base plate; moreover, on the two sides of the vibration box, a plurality of groups of rod nodes are installed, limiting the trajectory of movement and located obliquely; wherein each group of rod nodes limiting the motion trajectory contains two rod nodes limiting the motion trajectory, which are located symmetrically on both sides of the vibration box, and both ends of each rod node limiting the motion trajectory are pivotally attached to the vibration box and the lower base plate.

The technical problem of the prototype is that each rod node, which limits the trajectory of movement, is installed as a structure that regulates the vibration balance. In this case, the upper end of the rod, which limits the trajectory of movement, is installed in a sliding sleeve. There are several such rods on the box of the vibrating device in the prototype.

As a result, the weight of the device greatly increases, and the device itself is structurally complicated.

In addition, the prototype is also characterized by the problem, as for the above analogue - the presence of stresses in the sidewalls in places where the support beams are embedded in the box.

The objective of the present utility model is to eliminate these shortcomings of the known solutions while maintaining the advantage of providing multiple motion paths with a single shaft.

The technical result of the utility model is to reduce the stresses in the sidewalls in the places where the support beams are embedded in the box, as well as to simplify the design and reduce the weight of the screen.

The specified technical result is achieved due to the fact that an inertial screen with one shaft and with the possibility of changing the trajectory of movement is claimed, containing: a vibration box, supports, spring supports with a sole, one vibration shaft with a vibrator attached to it, an engine, a screening sieve located obliquely ; while the vibration shaft is mounted on a vibration box, characterized in that the spring supports are arranged in pairs, each spring support consists of a bracket, springs and a sole, and the springs themselves are fixed in guide cups in the bracket and in the sole; each spring support is installed on the trunnion of the vibration box and is fixed to it through the bracket; the drive of the vibration shaft from the engine is made through the petal clutch; the vibration box consists of two sides made of sheets of low-alloy structural steel, interconnected by two rows of tie-beams made of pipes, and two tiers of screening surfaces, the tie-beams being movably connected to the sides through elastic rubber bushings.

Preferably, the vibrator consists of a shaft with an eccentric middle part, two bearing assemblies connecting the vibrator with the box, unbalance of the main and additional ones fixed at the ends of the shaft, the middle part of the vibrator being formed by a metal pipe with flanges at the ends and forming a crankcase for liquid lubrication, bearing assemblies equipped with double-row spherical roller bearings, the inner ring of one of the bearings is fixed on the shaft rigidly, and the second - "floating" along the axis of the shaft.

Preferably, the bearing units on the inside of the box are tightly closed with a pipe, and on the outer sides - with conical bushings, as well as oil-drop and sealing rings, also the bearing units have holes closed with screw plugs for filling fresh and draining used grease, as well as for level control lubricants.

Preferably, rubber bushings on both sides of each bead are secured to the flanges with high strength bolts.

Preferably, the two cross-beams have trunnions for mounting the box on spring supports.

The tie-beam pipes can be fitted with a rubber lining.

The screen can be configured to place the motor on either side of the vibration box.

The screen may be made containing at least one additional sieve.

Preferably, stiffening ribs are installed on the sides of the vibration box at a certain angle and in such a way that when the screen is installed in the working position, the stiffening ribs are located strictly vertically.

Brief description of the drawings

Figure 1 shows a view of the screen in the volume from the side opposite the engine.

Figure 2 shows a view of the screen in the volume from the side of the engine.

Figure 3 shows a diagram of the screen (top view).

Figure 4 shows a diagram of the screen (view from the end side).

Figure 5 shows a diagram of the screen (side view from the side of the engine).

Figure 6 shows the device spring support.

Figure 7 shows the device of the vibrator.

Figure 8 shows a diagram of the screen (side view from the side opposite to the motor fixing) and the supporting nodes close-up.

Figure 9 shows a diagram of the limits of the angular displacement of unbalances.

On the drawings: 1 - sidewall of the vibration box, 2 - connection-beam support, 3 - sieve attachment beam, 4 - screening sieve, 5 - tightening beam, 6 - stiffener, 7 - vibrator, 8 - spring support sole, 9 - spring , 10 - bracket, 11 - trunnion, 12 - motor, 13 - petal coupling, 14 - hole in the bracket for the trunnion, 15 - vibration shaft, 16 - vibrator tube, 17 - bearing assembly, 18 - additional weights, 19 - main weight , 20 - oil baffle washer, 21 - sealing ring, 22 - level control plug, 23 - conical bushing, 24 - filling plug, 25 - flange, 26 - rubber bushing, 27 - high-strength fasteners, 28 - bearing housing.

Implementation of the utility model

The screen (see Fig.1-5, Fig.8) consists of the following main units: boxes; vibrator 7; engine 12; spring supports; petal clutch 13.

Each spring support (see Fig.6) consists of a bracket 10, springs 9 and a sole 8. The springs 9 are fixed in guide cups in the bracket 10 and in the sole 8. Each spring support is mounted on the trunnion 11 of the vibration box and is fixed to it through the bracket 10, for which a hole 14 is made in the bracket 10 for the trunnion 11.

The stiffness of the springs 9 is selected in such a way that during the operation of the screen, minimal forces are transmitted to the overlap, and at the same time, there is no collision of the coils and separation of the springs from the supporting surfaces in contact with them when the screen passes through the resonant mode during starts and stops.

The drive of the vibration shaft 15 (see Fig.7) of the vibrator 7 from the engine 12 is made through the petal clutch 13.

The vibration box consists of two boards 1 made of sheets of low-alloy structural steel, interconnected by two rows of tie-beams 2 made of pipes, and two tiers of screening surfaces, on each of which a sieve 4 can be installed.

The sieves themselves 4 are fixed to the longitudinal beams 3 for attaching the sieves, which, in turn, are fixed to the cross-link-support beams 2.

Connection-beams 2 are movably connected to the sides, through elastic rubber bushings 26 (see Fig.8). Such a connection of the bond-beams 2 with the sidewalls 1 significantly reduces the stress concentration in the sidewalls 1 in the places where the bond-beams 2 are embedded, in comparison with the known solutions: RU194754U and RU2567250.

At the same time, due to the fact that, in comparison with analogue RU194754U, it is not required to carry out preliminary heat treatment of the transverse beams and their coating with an elastic material, the design is simplified and the weight of the screen is reduced in comparison with this analogue.

Flanges 25, compressing rubber bushings 26 on both sides of each bead 1 are attached to the latter using high-strength fasteners 27 (for example, bolts). High-strength bolts are tightened with a torque wrench.

Two cross-beams 2 have trunnions 11 designed to install the box on spring supports.

Link-beams 2 and shaft 15 (pipe) of the vibrator 7 can be protected from abrasion by a rubber bushing 26.

The cross-link-beams 2 perform two functions: they serve as connecting elements between the sides 1 and are a support for the screening surfaces.

The load-bearing beams 2 and other supporting structures, such as tie beams 5, must bear the static and dynamic load arising from the weight and vibrations of the screen.

The vibrator itself (see Fig.7) consists of a shaft 15 with an eccentric middle part, two bearing assemblies 17 connecting the vibrator with the box, the main unbalance 19 and additional unbalances 18, fixed at the ends of the shaft 15.

At the same time, the middle part of the vibrator is formed by a metal pipe 16 with flanges 25 at the ends and forms a crankcase for liquid lubrication.

Bearing units 17 are equipped with double-row spherical roller bearings. The inner ring of one of the bearings is rigidly fixed on the shaft, and the second is “floating” along the axis of the shaft 15 to compensate for dimensional errors made during the manufacture and assembly of assembly units and parts, as well as temperature changes in the linear dimensions of the mating elements.

Bearing assemblies 17 are tightly protected from clogging and oil leakage from the inside of the box by pipe 16, from the outside - by conical bushings 23, as well as oil-dumping washers 20 (oil baffle washer) and sealing rings 21.

Bearing assemblies 17 have holes closed with screw filling plugs 24, which are used to fill in fresh and drain used grease, as well as to control the level of grease. The location of these holes in the bearing caps and bearing assemblies 17 are designed for box inclination angles ranging from 15 to 20°. Excess oil is poured out through the level control overflow plugs 22, which must be removed at each filling, then the plugs should be screwed back into place.

To be able to regulate the amplitude over a wide range, additional unbalances 18 are provided in the unbalances in addition to the main one 19.

When the vibrator shaft rotates, the unbalanced masses 18, 19 develop a perturbing force, which gives the screen box flat circular vibrations.

The claimed screen can be represented by versions that have differences:

according to the location of the engines (left or right), for this, the clutch mounting disk must be installed on the desired side; right or left execution is determined relative to the direction of movement of the material through the screen;

by the number of sieves (one tier, two-tier).

By eliminating the rod assemblies from the design of the screen and replacing the function of the vibration regulator with the installation of additional unbalances 18, the weight of the screen is significantly reduced in comparison with the prototype, and the device itself has become structurally simpler.

The principle of operation of the screen is as follows.

For installation, operation and repair in this screen, special tools and devices are not required. For these purposes, universal tools and devices available at any enterprise are sufficient.

Before starting operation, the screen must be run in idle for 2 hours, after which all bolted connections must be carefully checked and tightened.

Before running the screen, additional unbalances 18 must be rotated 180° upward relative to the main unbalance 19 (min amplitude) (see Fig.9).

Additional unbalances 18 on vibrator 7 must be deployed by one

and the same angle α on the right and left sides of the vibrator (see Fig.9).

The screen box, based on the supporting structures through spring supports, performs circular oscillatory movements under the action of forces excited by the vibrator 7, which provide vibrations of the box and at the same time are shock absorbers that isolate building structures from dynamic loads acting in the oscillatory system.

The rotation of the shaft 15 of the vibrator 7 is transmitted from the engine 12 through the petal clutch 13.

The screen can only work with an inclined arrangement of the screening surfaces (from 12° to 25°), since in this case the movement of the material occurs mainly under the action of the component of gravity directed along the sieve.

The principle of operation of the screen is that under the action of the rotating unbalanced masses of the vibrator, the screen box begins to make circular or elliptical oscillatory movements in the vertical plane. As a result of vibrations of the box, the material is thrown up on the grids of sieves 4 of the screen, rigidly fixed on the box through beams 3, and is divided into two classes: above the sieve and under the sieve.

The trajectory of movement of the points of the box: in the center, in the zone of the vibrator, - in the form of circles; at the ends, in the loading area, - in the form of ellipses; the slope of which depends on the direction of rotation of the vibrator shaft in relation to the movement of the screened material through the sieves.

When the vibrator rotates in the direction of material movement, the screen develops maximum performance. With the opposite rotation of the vibrator, the speed of movement of the material through the sieves slows down, the performance of the screen decreases, but the screening efficiency increases.

To control the operation of the screen, you can use the following instrumentation:

Thermometer type U52-160-104 GOST 2823-73;

Thermometer type IO-30 TU I-188-70;

Vibrograph type VR-1A TU 25-06-795-71.

Since these devices are not required for permanent operation, they are not included in the delivery set with a screen, measurements can be made with other devices of a similar purpose.

Instead of a vibrograph, a measuring wedge can be used to measure the amplitude of vibrations.

The required oscillation amplitude is obtained by changing the position of additional unbalances 18. Operation of the screen with an asymmetric arrangement of additional unbalances 18 is not allowed.

The procedure for monitoring the operability of the screen is to measure the parameters, regulate and adjust.

Control the temperature of the vibrator bearings as follows:

de-energize the drive motor 12;

after a complete stop of the shaft 15 of the vibrator 7, unscrew from the bearing housing 28 one drain plug;

thermometers are inserted into the holes of the housings 28 and fixed with plasticine or in another way;

take into account the readings after their stabilization.

The technological efficiency of screening is determined as a percentage by the formula:

where α is the percentage of the sifted fraction in the source material;

β is the percentage of the screened fraction and the oversize product.

The sampling procedure is regulated by the instructions of the enterprise where the screen is installed.

The screen is designed for classification of bulk materials with bulk density up to 2.8 t/m ³ and fineness up to 900 mm; on operations of dry classification of loose materials with humidity up to 5% and temperature up to 100°С. The task of the screen is to divide the screened material into three classes of fineness; the screen is used mainly in processing plants as process equipment.

The claimed technical solution was tested in practice. The experimental model has passed technical tests. They showed that all of the above design features allow the screen to work in harsh conditions and provide plant productivity up to 1500 t / h.

The technical characteristics of the screen, obtained from the test results, are shown in table 1.

Table 1

No. Name of the main parameters Norms on the main parameters for a screen type one Screening surface dimensions, mm:
width (limit deviations ±2%)
- length, no more 2500
7000 2 Number of tiers of sieves 1 or 2 3 Amplitude (half-range) of vibrations, mm, within 5.0-9.5 (2.5-4.75) four The number of oscillations in 1 min. 730 - 960 5 Size of pieces of food, mm, no more 900 6 Feeding capacity, t/h, solid, no more 1500** 7 Screen installation angle (possible tilt, in degrees) 12-25 eight Rated power of electric motors, kW, no more 37 9 Frequency converter Yes ten Overall dimensions of the oscillating part of the screen, mm, not more than:
- length;
- width;
- height. 7000
3256
2000 eleven Screen weight without motors and screening surfaces, kg, not more than 10742 12 Weight of the screen with screening surfaces with a spraying device, with a drive, a set of spare parts and accessories, kg, no more than: 15900

The composition of the product investigated according to Table 1 of the screen is shown in Table 2.

table 2

Name Quantity per screen execution Complete box, pcs. one Vibrator, pcs. one Spring support, pcs. four Number of springs in the support, pcs. 5 Petal clutch, pcs. one Screening sieves, pcs. 1 and 2 Frequency converter, pcs. one Engines, pcs. one

Claims (6)

1. An inertial screen with one shaft and with the possibility of changing the trajectory of movement, containing a vibration box, supports, spring supports with a sole, one vibration shaft with a vibrator attached to it, an engine, a screening sieve located obliquely; while the vibration shaft is mounted on a vibration box, characterized in that the spring supports are arranged in pairs, each spring support consists of a bracket, springs and a sole, and the springs themselves are fixed in guide cups in the bracket and in the sole; each spring support is installed on the trunnion of the vibration box and is fixed to it through the bracket; the drive of the vibration shaft from the engine is made through the petal clutch; the vibration box consists of two sidewalls made of sheets of low-alloy structural steel, interconnected by two rows of tie-beams made of pipes, and the tie-beams are movably connected to the sideboards through elastic rubber bushings; The vibrator consists of a shaft with an eccentric middle part, two bearing assemblies connecting the vibrator with the box, the unbalance of the main and additional, fixed at the ends of the shaft. 2. The screen according to claim 1, characterized in that the middle part of the vibrator is formed by a metal pipe with flanges at the ends and forms a crankcase for liquid lubrication, the bearing assemblies are equipped with double-row spherical roller bearings, the inner ring of one of the bearings is rigidly fixed to the shaft, and the second - "floating" along the axis of the shaft. 3. A screen according to claim 2, characterized in that the bearing assemblies are tightly closed with a pipe on the inside of the box, and with conical bushings, as well as oil-dropping and sealing rings on the outer sides, also the bearing assemblies have holes closed with screw plugs for filling fresh and descent of used grease, as well as to control the level of grease. 4. The screen according to claim 1, characterized in that the rubber bushings on both sides of each bead are fixed to the flanges with high-strength bolts. 5. Screen under item 1, characterized in that it is made with the possibility of placing the engine on any of the sides of the vibration box. 6. Screen according to claim. 1, characterized in that it is made containing at least one additional sieve.

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