WO2023194512A1

WO2023194512A1 - Vibratory machine and method for operating the vibratory machine

Info

Publication number: WO2023194512A1
Application number: PCT/EP2023/059094
Authority: WO
Inventors: Heinrich Kühlert
Original assignee: Kuehlert Heinrich
Priority date: 2022-04-06
Filing date: 2023-04-06
Publication date: 2023-10-12
Also published as: DE102022108307B3

Abstract

The invention relates to a vibratory machine having at least one vibrating conveyor arranged in a longitudinal direction and an exciter system for generating an exciter force acting on the vibrating conveyor, the exciter system having at least one first and one second exciter unit, which are each formed from at least two counter-rotating imbalance drives. According to the invention, at least one of the imbalance drives of the first exciter unit is arranged below and one of the imbalance drives of the second exciter unit is arranged above a centre of gravity axis of the vibrating conveyor.

Description

Oscillating machine and method for operating the oscillating machine

Description:

The present invention relates to an oscillating machine with at least one oscillating trough arranged along a longitudinal direction and an excitation force system for generating an excitation force acting on the oscillating trough and preferably extending through the center of gravity, the excitation force system having at least a first and a second excitation unit, each of which consists of at least two in opposite directions rotatable unbalance drives is formed. In the context of the invention, a longitudinal direction means a direction in which the oscillating trough has its essential extent. The transverse direction, on the other hand, refers to a direction that runs along the width of the vibrating trough.

Oscillating machines of the type described above are basically known from the prior art and can be designed, for example, for screening and/or conveying bulk materials. In the case of a vibrating trough designed as a sieve trough, the floor usually has a large number of openings, although of course several floors can also be arranged one above the other and the openings in the individual floors differ from one another. As a result of the excitation force acting on the bulk material, on the one hand it is transported along the longitudinal direction, with grains that are smaller than the openings falling through them, while larger grains remain on the respective floor and are transported further along the vibrating trough.

In contrast, an oscillating trough designed as a conveyor trough usually has a closed bottom, since the bulk material is only to be transported along the longitudinal direction. For this purpose, the oscillating trough is caused to oscillate by the excitation force, so that on the oscillating trough

arranged bulk material is thrown a little further with each vibration. Since the bulk material is thrown over only a comparatively small distance with each vibration, such a throw is also referred to as a micro-throw, with the actual transport process being a sequence of several micro-throws arranged one behind the other.

In order to realize such a micro-throw, the excitation force must act obliquely on the conveyor trough, whereby the inclination is decisive for the throwing angle of the micro-throw. Against this background, this inclination is also referred to as the angle of attack.

The invention relates to oscillating machines in which the excitation force is generated via two excitation units, each of which is formed from at least two counter-rotating unbalance drives. These two unbalance drives of an excitation unit have a phase offset from one another, which results in the inclination of the excitation force.

A generic oscillating machine is known, for example, from DE 10 2017 218 371 B3. This is a sieve system, whereby the vibrating trough is designed as a sieve box with several through holes arranged in a base. In addition, the unbalance drives of the exciter units are arranged in the side walls of the vibrating trough so that the floor can be completely used for conveying and screening the bulk material. A special feature here is the arrangement of the exciter units. These are arranged in so-called node sections of the vibrating trough. These node sections refer to so-called vibration nodes of the vibrating trough. These are areas of the oscillating trough which, according to the first natural mode of the oscillating trough, have no or only an insignificant change in position

experience.

Here, the introduction of an excitation force through the center of gravity causes a first-order eigenmode, with the ends and the middle section of the conveyor trough in particular being shifted alternately up and down and thus represent the areas of maximum deflection. In contrast, starting from a first-order eigenmode, there is a so-called oscillation node between the middle section and the end, the position of which remains unchanged or almost unchanged. By arranging the excitation units in these node sections, the deflection of the oscillating trough can be significantly reduced.

Based on the generic oscillating machines, the excitation units can thus be arranged in an advantageous manner in node sections of the oscillating trough, while at the same time the excitation force can be guided through the center of gravity of the oscillating trough. In such a case, it can be avoided that a tilting moment is generated about the center of gravity axis as a result of the excitation force and that the oscillating trough therefore only carries out a translational movement.

Particularly with screening machines, but also with comparatively long oscillating troughs, the problem arises that the center of gravity only runs slightly above the bottom of the oscillating trough, since the side walls make no or no significant contribution to the total weight of the oscillating trough. A direct arrangement of the unbalance drives in the ground is excluded, with at least an arrangement of the unbalance drives close to the ground being aimed for. However, this leads to another problem, as the imbalances of the unbalance drives within the vibrating trough

be arranged, as is the case, for example, with DE 10 2017 281 371 B3. This in turn leads to the unbalance drives blocking the conveying path depending on the amount of bulk material used and at the same time being easily damaged by the bulk material being transported along. Conversely, only a very small amount of bulk material can be transported or sieved using a generic vibrating machine if the bulk material should not touch the individual unbalance drives.

In addition, even a slight deviation from the arrangement outside the center of gravity plane defined by the center of gravity axis means that the excitation force can no longer be guided through the center of gravity axis if the unbalance drives are to continue to be arranged in node sections of the oscillating trough. The greater the distance between the center of gravity plane and the excitation units, the greater the distance between the excitation force generated by the excitation units and the center of gravity axis. This deviation from the center of gravity axis results in a tilting moment caused by the excitation force around the center of gravity axis.

Against this background, the present invention is therefore based on the object of proposing an arrangement of the unbalance drives in which, on the one hand, the freest possible arrangement of the unbalance drives is possible and at the same time it is ensured that the excitation force is guided through the center of gravity axis.

The object and solution to this problem is an oscillating machine according to claim 1 and a method for operating the oscillating machine according to claim 14. Accordingly, it is now important that at least one of the unbalance drives of the first exciter unit is below and

one of the unbalance drives of the second exciter unit are arranged above a center of gravity axis of the oscillating trough. Here, the terms “below” and “above” refer to a vertical direction, which is arranged perpendicular to the longitudinal direction and the width direction and essentially defines the height of the vibrating trough.

Such a configuration makes it possible to arrange the unbalance drives freely within certain limits, with the arrangement of an unbalance drive of the first excitation unit below the center of gravity axis and the arrangement of an unbalance drive of the second excitation unit above the center of gravity axis ensuring that the excitation force is always guided through the center of gravity axis can be. This of course requires that the two excitation units are set up and arranged to each generate a partial excitation force, which are identical in terms of their force vector, so that the two partial excitation forces run parallel to one another. In addition, the two excitation units are preferably arranged in such a way that the partial excitation forces generated by the excitation units are introduced at force introduction points which have the same distance from the center of gravity axis in both the longitudinal direction and the vertical direction.

According to a preferred embodiment of the invention, all unbalance drives of the first exciter unit are arranged below and all unbalance drives of the second exciter unit are arranged above the center of gravity axis of the vibrating trough. This means that the first exciter unit is arranged completely above and the second exciter unit completely below the center of gravity axis, so that the exciter units are arranged at an angle with respect to the vibrating trough. The two unbalance drives of an exciter unit each have a rotation axis, with the connection between the

both axes of rotation of an exciter unit is understood as a drive connecting line. The respective center points of the drive connecting lines of the first and second exciter units define an exciter connecting line, which preferably runs through the center of gravity axis. According to such a configuration, it is ensured that the excitation force is then also conducted through the center of gravity axis. In the case of an oblique arrangement, the exciter connecting line runs at an angle to the bottom of the vibrating trough, the angle preferably being between 10 and 80°, particularly preferably between 20 and 70°.

Such an oblique arrangement of the excitation units can be particularly advantageous in screening machines, since the first excitation unit can be arranged, for example, at the sieve inlet, whereby there is a comparatively large amount of bulk material at this point and a certain application height is therefore required. A sufficient height between the first exciter unit and the bottom of the vibrating trough ensures that the bulk material cannot move past the unbalance drives. At the end of the oscillating trough, the second exciter unit can then be arranged below the center of gravity axis or below the bottom of the oscillating trough, whereby due to the relatively small remaining proportion of the bulk material, excessive load on the unbalance drives due to falling material is avoided. Of course, such an arrangement can also be used in conveyor troughs.

The special feature of an inclined arrangement of the excitation units is that the individual partial excitation forces must be divided into a vertical and a horizontal force component in order to define the loads on the vibrating trough. However, the principle can be assumed that horizontal forces in the longitudinal direction

run, are of minor importance for the oscillating trough, since the oscillating troughs are designed to be rigid in the longitudinal direction. Only the vertical force components are important, so that there are no differences in this regard with regard to the design of an oscillating trough in which the excitation units are arranged straight and not at an angle to one another.

Although an oblique arrangement represents a particularly advantageous embodiment, an embodiment is also within the scope of the invention in which the exciter units are arranged parallel to the oscillating trough or in which the exciter connecting line runs parallel or congruent to a center of gravity plane defined by the center of gravity axis. The design differs from the prior art in this case only in that both exciter units each have an unbalance drive below and an unbalance drive above the oscillation axis. In contrast to arranging all unbalance drives above the center of gravity level, this also ensures that the excitation force is guided through the center of gravity axis. Since both excitation units now each have an unbalance drive below the center of gravity, such a design is particularly suitable for conveyor troughs, although such a design is of course also possible for screening machines. However, corresponding shields for the unbalance drives arranged below the center of gravity axis are then advantageous in order to protect the unbalance drives from falling bulk material.

Based on an embodiment with an oblique arrangement of the exciter units, a preferred embodiment provides that the drive connecting line of the first exciter unit and the second exciter unit are arranged parallel to one another or congruent. With a congruent arrangement, all axes of rotation run along the exciter connection line,

while in a parallel arrangement the unbalance drives of an exciter unit are arranged offset from the exciter connecting line. According to such an embodiment, it is then preferably provided that one of the unbalance drives is arranged above and the other unbalance drive of an exciter unit is arranged below the exciter connecting line. Regardless of whether a congruent or parallel arrangement of the drive connecting lines is provided, it is above all crucial that both excitation units are arranged with identical distances in the longitudinal and vertical directions with respect to the center of gravity axis.

According to a preferred development of the invention, the unbalance drives of an exciter unit have an adjustable phase offset. The phase offset refers to the time offset at which the imbalances of the unbalance drives of an exciter unit reach a specific reference position, e.g. B. the perpendiculars happen. Based on one revolution, this immediately results in an offset angle.

According to a preferred development of the invention, the partial excitation forces generated by the excitation units act on the conveyor trough at an angle of attack. As already explained previously, this setting angle can be defined in particular by the phase offset of the two unbalance drives of an exciter unit relative to one another. In the context of the invention, the angle of attack is in particular between 0 and 90°, particularly preferably between 20 and 60°.

A preferred development of the invention further provides that the excitation units are arranged in oscillation node sections of the oscillating trough with respect to a vertical force component of the partial excitation forces. These vibration node sections refer to sections

with respect to the longitudinal direction. The oscillation node sections preferably extend within a radius around an oscillation node of the oscillating trough, the radius being less than 20%, preferably less than 10%, of the length of the oscillating trough running along the longitudinal direction.

As already explained above, it is therefore possible to arrange the unbalance drives in such a way that they each generate a partial excitation force, the vertical force components of which act on the vibrating trough in the respective node section. By offsetting the unbalance drives from one another or by arranging the unbalance drives below and above the center of gravity axis, the excitation force defined by the partial excitation forces can also be directed through the center of gravity or through the center of gravity axis of the vibrating trough.

According to a preferred embodiment of the invention, the excitation units are arranged and set up in such a way that they generate opposite torques in an intended operating state. It should be noted that the unbalance drives generate a force, regardless of the position of the unbalances, which creates a moment around the center of gravity. Depending on the position of the two unbalance drives of an excitation unit, the torques can balance each other out or can also be amplified to a common torque. Since moments are not tied to specific points of attack along the oscillating trough, these can also cause the oscillating trough to tilt. By designing the two excitation units in opposite directions with regard to the torques generated, these can preferably be completely compensated for. This is possible, for example, by arranging the individual unbalance drives of the excitation units next to one another in the longitudinal direction, with the outer unbalance drives having a first direction of rotation and the inner one in a normal operating state

Unbalance drives have a second direction of rotation, with the first and second directions of rotation being opposite.

If the excitation units are set up in such a way that they cause opposite torques, a total excitation force can be generated, which on the one hand runs through the center of gravity axis and the vertical force components of the partial excitation forces are arranged on lines of action within center of gravity node sections of the oscillating trough. This allows an oscillating machine to be operated in a particularly stable state, in which only the excitation force required for operation has a significant effect on the oscillating trough.

The vibration machine according to the invention can be designed either as a screening machine with a vibrating trough designed as a sieve trough or as a conveyor machine with a vibrating trough designed as a conveyor trough. In the case of a conveyor trough, the bottom of the vibrating trough is closed. In a screening machine, on the other hand, the floor has a number of openings through which the bulk material transported on the vibrating trough can fall through. In principle, it is also within the scope of the invention if several floors arranged one above the other are provided, which differ from one another in terms of the size of the openings. In particular, the openings become smaller from a top floor to a bottom floor.

According to a preferred development, the oscillating trough is delimited at the lateral ends via side walls, with an excitation system being arranged in one of the side walls. For example, the vibrating trough can have two side walls that laterally delimit the floor. An excitation system, each with a first and a second excitation unit, is then preferably arranged in both side walls, according to a preferred

Embodiment of the invention, the excitation systems are identical and arranged identically in the side walls.

According to a preferred embodiment, a control system is also provided which is connected to the unbalance drives and which is intended and set up to control or regulate the phase offsets, the direction of rotation and/or the rotation speed. In order to avoid forced synchronization, a frequency converter is preferably provided, via which the two unbalance drives of an unbalance drive pair can be operated separately from one another.

The invention furthermore relates to a method for moving bulk material with a vibrating machine according to claim 13, wherein the bulk material is applied to the vibrating trough and at least two excitation units arranged one behind the other along the longitudinal direction generate partial excitation forces which act on the conveyor troughs at an angle of attack.

According to a preferred development of the invention, the excitation units are arranged and set up in such a way that the excitation force generated by the partial excitation forces is directed on a line of action through the center of gravity axis of the oscillating trough.

The unbalance drives of the excitation units are preferably arranged one behind the other in the longitudinal direction, with the outer unbalance drives rotating in a first direction of rotation and the inner unbalance drives rotating in a second, opposite direction of rotation.

In addition, the unbalance drives of an excitation unit preferably rotate with a phase offset to one another, with both excitation units rotating at the same time

Phase offset can be operated.

According to a preferred embodiment, the phase offset is also adjustable or can be adjusted during ongoing operation.

The control system discussed in connection with the oscillating machine is intended and set up in particular to operate the conveyor system in accordance with the process description.

The invention of an exemplary embodiment is explained in more detail below. Show it:

1 shows a vibration machine according to the prior art,

2 shows the oscillating machine according to FIG. 1 in a side view,

Fig. 3 shows the oscillating machine according to the invention according to a first

design,

Fig. 4 shows the oscillating machine according to the invention according to a second

design,

Fig. 5 shows an oscillating machine according to the invention according to a third embodiment.

1 shows an oscillating machine according to the invention with a oscillating trough 1 arranged along a longitudinal direction L. The oscillating trough 1 has a base 2 with a plurality of openings 3. This makes it clear that the vibrating trough 1 shown in FIG. 1 is designed as a sieve trough.

In principle, it is also within the scope of the invention that the oscillating trough 1 can be designed as a conveyor trough, in which case no openings 3 are arranged in the floor 2.

In addition, side walls 4a, 4b are provided, in each of which an excitation system consisting of a first excitation unit 5, 5 'and a second excitation unit 6, 6' is arranged. Via these excitation units 5, 5 ', 6, 6' it is possible to cause the vibrating trough 1 to vibrate, in which case a bulk material arranged on the floor 2 of the vibrating trough 1 is then transported along the longitudinal direction L and via the openings 3 in the floor 2 is sieved.

Each of the exciter units 5, 5', 6, 6' consists of two counter-rotating unbalance drives 7a, 7b, 8a, 8b, whereby it can be seen that these unbalance drives 7a, 7b, 8a, 8b are arranged above a center of gravity plane 10 defined by the center of gravity axis 9 are. It should be noted here that such oscillating troughs 1 are essentially defined in terms of their weight by the very solid base 2. The side walls 4a, 4b, on the other hand, are comparatively thin and only contribute insignificantly to the overall weight. The result of this is that the center of gravity axis 9 and thus also the center of gravity plane 10 only run slightly above the ground. A direct arrangement of the unbalance drives 7a, 7b, 8a, 8b in the center of gravity plane 10 is therefore very difficult. It should also be noted here that the unbalance drives 7a, 7b, 8a, 8b usually extend into the area of the vibrating trough 1 in which the piece goods are transported. They thus block the conveying space to some extent, which means that it is necessary to arrange them at a corresponding height in the side walls 4a, 4b.

The consequences of such a design can be clearly seen in particular in FIG. 2. The unbalance drives 7a, 7b, 8a, 8b each generate a force,

wherein the partial excitation force of the excitation units 5, 6 leads to an excitation force 11 which moves the vibrating trough 1. Depending on the position of the imbalances of the unbalance drives 7a, 7b, 8a, 8b, the excitation force 11 is stronger or weaker or runs in opposite directions. However, the excitation units 5, 6 are designed and set up in such a way that forces in the longitudinal direction L are compensated for so that the excitation force 11 always runs along the same line of action 12.

The arrangement of the excitation units 5, 6 above the center of gravity plane 10 means that the excitation force 11 cannot be guided through the center of gravity axis 9. The result of this is that the excitation force 9 generates a tilting moment about the center of gravity axis 9, which must be compensated for by appropriate structural measures of the screening machine. This tilting moment is stronger the further away the excitation force 11 is from the center of gravity axis 9. Accordingly, a higher arrangement of the excitation units 5, 6 above the center of gravity plane 10 leads to an increasing tilting moment. Especially if large masses of bulk material are to be transported on the floor 2 of the vibrating trough 1, it may be necessary to arrange the unbalance drives 7a, 7b, 8a, 8b as high as possible. Accordingly, according to the state of the art, a compromise must be sought, which is based on the structural mechanical load and arrangement of the screening machine on the one hand and on the performance of the screening machine on the other hand.

Fig. 3 shows the screening machine according to the invention in a simplified representation, in which the side walls 4a, 4b in particular have been omitted. The bottom 2 is also only indicated with a top side.

According to FIG. 3, the unbalance drives 7a, 8a are now in the vertical direction

V above and the unbalance drives 7b, 8b below the center of gravity level 10

arranged, with the unbalance drives 7a, 7b, 8a, 8b arranged above and below having the same distance in the vertical direction V from the center of gravity plane 10. The result of this is that an excitation force 11 is now generated, which runs with its line of action 12 through the center of gravity axis 9. By arranging the unbalance drives 7a, 7b, 8a, 8b, a screening machine can now be created which is designed without a tilting moment with regard to the partial excitation forces generated by the excitation units 5, 6. In addition, the unbalance drives 7a, 7b of the first excitation unit 5 and the unbalance drives 8a, 8b of the second excitation unit 6 have opposite directions of rotation, which are shown by the corresponding arrows. What is important here is that the outer unbalance drives 7a, 8b rotate in a first direction and the inner unbalance drives 7b, 8a rotate in an opposite second direction. As a result, both excitation units 5, 6 generate, depending on the position of the unbalances, a torque of the same magnitude, but which acts in different directions, so that the moments generated by the excitation units 5, 6 balance each other out.

The two excitation units 5, 6 each also have a drive connecting line 13, 14, which connect the rotation axes of the unbalance drives 7a, 7b, 8a, 8b of an excitation unit 5, 6 to one another. 3, the center of these drive connecting lines 13, 14 lies in the center of gravity plane 10, with the distance between the center points and the center of gravity axis 9 being identically large. Furthermore, it can be seen from FIG. 3 that the drive connecting lines 13, 14 are arranged parallel to one another.

4, the excitation units 5, 6 are arranged obliquely with respect to the center of gravity plane 10 but also with respect to the floor 2, the angle y corresponding to approximately 30°. The result of this is that the unbalance drives 7a, 7b of the first excitation unit 5 are located above the in the vertical direction

Center of gravity plane and the unbalance drives 8a, 8b of the second exciter unit 6 are arranged below the center of gravity plane 10. Here too, this has the consequence that the generated excitation force 11 runs with its line of action 12 through the center of gravity axis 9.

In addition, it can also be seen that the first excitation unit 5 is arranged in a vibration node section 15 around the vibration node 16 and the second excitation force 6 is arranged in a vibration node section 17 around the vibration node 18. The drive connecting lines 13, 14 are also arranged parallel to one another here and have the same distances from the center of gravity axis 9 in both the vertical direction V and in the longitudinal direction L.

5, it is now provided that the unbalance drives 7a, 7b, 8a, 8b are arranged on a common line, so that the drive connecting lines 13, 14 coincide with one another. Once again, the first exciter unit 5 is arranged above and the second exciter unit 6 is arranged below the center of gravity plane 10.

Claims

Claims: Vibrating machine with at least one vibrating trough arranged along a longitudinal direction and an excitation system for generating an excitation force acting on the vibrating trough, the excitation system having at least a first and a second excitation unit, each of which is formed from at least two counter-rotating unbalance drives, characterized in that at least one of the unbalance drives of the first exciter unit is arranged below and one of the unbalance drives of the second exciter unit is arranged above a center of gravity axis of the oscillating trough. Vibrating machine according to claim 1, characterized in that all unbalance drives of the first exciter unit are arranged above and all unbalance drives of the second exciter unit are arranged below the center of gravity axis of the vibrating trough. Vibrating machine according to claim 1 or 2, characterized in that a drive connecting line between rotation axes of the unbalance drives of the first exciter unit and a drive connecting line between rotation axes of the unbalance drives of the second exciter unit are arranged parallel to one another or congruent. Oscillating machine according to claim 3, characterized in that an exciter connecting line running between the centers of the drive connecting lines is arranged at an angle to the conveyor trough and runs through the center of gravity axis.

5. Vibrating machine according to claim 4, characterized in that the unbalance drives of an exciter unit are arranged on the exciter connecting line.

6. Vibrating machine according to claim 4, characterized in that the unbalance drives of an exciter unit are arranged offset from the exciter connecting line, the arrangement of the unbalance drives with respect to the exciter connecting line being identical in the first and second exciter units.

7. Oscillating machine according to one of claims 1 to 6, characterized in that the unbalance drives of an exciter unit have an adjustable phase offset with respect to a horizontal plane.

8. Vibrating machine according to one of claims 1 to 7, characterized in that the partial excitation forces generated by the excitation units act on the conveyor trough at an angle of attack.

9. Vibration machine according to one of claims 1 to 8, characterized in that the excitation units are arranged in vibration node sections of the vibration trough with respect to a vertical force component of the partial excitation forces.

10. Oscillating machine according to claim 9, characterized in that the oscillation node sections extend within a radius around a oscillation node of the oscillating trough, the radius being less than 20%, preferably less than 10%, of the length of the oscillating trough running along the longitudinal direction (L). .

11. Vibrating machine according to one of claims 1 to 10, characterized in that the vibrating trough is designed as a sieve trough or as a conveyor trough. 12. Oscillating machine according to one of claims 1 to 11, characterized in that the oscillating trough is delimited at the lateral ends via side walls, with an excitation system being arranged in one of the side walls. 13. Oscillating machine according to one of claims 1 to 12, characterized in that a control system is provided which is set up to control the phase offsets, the direction of rotation and / or the rotation speed of the unbalance drives. 14. A method for moving bulk material with a vibrating machine according to one of claims 1 to 13, wherein the bulk material is applied to the vibrating trough and at least two excitation units arranged one behind the other along the longitudinal direction generate partial excitation forces which act on the conveyor trough at an angle of attack.