EP1142651B1 - Screening device - Google Patents

Abstract

The sifting device (1) has a vibrating carrier frame with vibration drive, and another vibrating frame (6) coupled to it by spring elements (5) in the form of torsion-rod springs. Both frames have cross-bearers (8) one behind the other alternately in the vibration direction, in which they are alternately clamped and released.

Description

The present invention relates to a screening device according to the preamble of Claim 1.

Such a screening device is used in particular for so-called difficult-to-screen goods, such as moist, sticky, caking and / or long-fiber goods.

DE 35 03 125 C2, which forms the starting point of the present invention, discloses a screening device with the features mentioned, which one in Vibration-adjustable support frame and one on the support frame of spring elements has swinging swing frame. The cross members of the swing frame extend through window-like openings in the side cheeks of the support frame through to the outside, where they are connected to the longitudinal members of the swing frame are. Are preferably designed as thrust rubber blocks spring elements distributed on each longitudinal beam in the longitudinal direction in several places, in pairs arranged opposite on both sides of a side member. The push rubber blocks represent the only mounting of the swing frame on the support frame, so that the swing frame is largely determined by the push rubber elements can perform linear swinging movement relative to the support frame. to Vibration generation is the supporting frame, especially as a circular oscillator trained vibratory drive assigned exclusively to the support frame and only acts indirectly on the swing frame via the push rubber blocks. The swing frame can swing freely. This known screening device has some drawbacks.

The spring constant of push rubber blocks is strongly dependent on the temperature the push rubber blocks. Accordingly, the vibration behavior is strongly temperature-dependent.

Push rubber blocks are subject to a relatively strong aging. Accordingly the vibration behavior changes over time; especially worsened it is.

When swinging, a relatively large internal friction of the push rubber blocks be overcome so that a strong warming occurs. The push rubber blocks however, may not exceed certain limit temperatures because they otherwise harden. Accordingly, the strength in the known screening device the vibration - amplitude and frequency or average speed and acceleration - very limited. The oscillation frequency that can be achieved over a longer period of time is essentially a maximum of 800 vibrations per min.

By clamping the longitudinal beams between the two opposite pairs Push rubber blocks are supposed to be the vibrating forces - i.e. vibrations - transverse to the essentially horizontal tensioning wave vibration of the oscillating frame can be suppressed, so that essentially only a linear vibration occurs. The superposition of a transverse vibration is in the known screening device but not to be avoided entirely, so that the pushing rubber blocks additionally in swing in this transverse direction and are accordingly additionally heated, what is ultimately the maximum available for the expansion shaft vibration Vibration frequency and / or amplitude also reduced.

When sieving, the material to be sieved is usually to be in a sieving direction over that of the Sieve plate elements formed are promoted. To this end, the Vibrating frame acting normally a correspondingly directed Main direction of action. In order to achieve sufficient funding in the direction of the screen, is, however, an inclination of the screen frame or the tension shaft vibration required. In the known screening device is usually straight Training the longitudinal beam of the swing frame an inclination of the swing frame of about 12 ° to 16 ° with respect to the horizontal is required to achieve adequate Get funding in the direction of the screen. Due to the overall length, this leads to a such screening device to an undesirably large height.

AT 258791 discloses a different type of screening device with two opposite directions vibrating masses, such as sieve channels or conveyor channels. Instead of pushing rubber blocks are torsion spring elements with swing arms for coupling the two masses intended. Each torsion spring element has several concentric rubber rings and intermediate metal rings, so that there are the same or similar disadvantages as with push rubber blocks and as described above.

The present invention has for its object to provide a screening device Specify in particular free-swinging oscillating frame of the tensioning wave oscillation type which is an effective screening, especially of difficult-to-screen goods enables and in particular an avoidance or at least minimization of Disadvantages of the prior art with a simple, compact structure and more universal Applicability and adaptability allowed.

The above object is achieved by a screening device according to claim 1. advantageous Further training is the subject of the subclaims.

An essential idea of the present invention is to design torsion bar springs Spring elements, which are installed in particular transversely to the direction of the vibrating shaft are for the movable coupling of the swing frame to the support frame and in particular for the exclusive storage of the swing frame on the support frame provided. This leads to several advantages.

The preferably made of steel torsion bar spring elements are very resilient and accordingly allow - even over long periods - a vibration with large amplitude and high frequency. Accordingly, you can a higher acceleration when tensioning the sieve plate elements and consequently higher or improved sieving performance can be achieved. A higher acceleration is also beneficial for conveying the screenings in the direction of the screen. This is with a Reason that the inclination of the swing frame or the tension shaft swing direction essential in the proposed screening device compared to the prior art, for example, be reduced to 3 ° to 5 ° from the horizontal can, which results in a considerably lower overall height.

The provided torsion bar spring elements are much less sensitive as push rubber blocks. In particular, the torsion bar spring-like elements practically not temperature-dependent, so that it can be used more universally and there is no risk of overheating. Plus the lifespan the torsion bar-like spring elements significantly larger than that of Thrust rubber blocks. As a result, there are lower operating and maintenance costs.

A simple, inexpensive construction of the screening device is made possible by that the swing frame exclusively from the torsion bar spring elements is mounted on the support frame, additional guide elements for guiding the swing frame so are not required.

Even if the main direction of action of the vibratory drive is at an angle to the usual Tension shaft vibration direction runs, in particular to promote the good Reaching screenings in the direction of screening, the spring elements can be a nuisance Vibration of the vibrating frame at least transversely to the direction of the swinging shaft largely prevent. In this respect, the torsion bar spring-like elements superior to conventional rubber elements.

Another aspect of the present invention is that the screening device is operated or can be operated with an oscillation frequency that is higher than in the prior art, namely with at least 850 oscillations per min and in particular with approximately 890 oscillations per min. In particular, an average speed of the oscillating frame relative to the supporting frame of preferably at least 11 m / min and an average acceleration of preferably at least 2.2 m / s ^{2 are} achieved. In this way, a particularly strong tension wave oscillation can be achieved, which enables more effective screening. Furthermore, a better conveyance of the material to be screened is achieved in the conveying direction, so that the inclination of the oscillating frame or the tensioning shaft oscillation can be reduced significantly, in particular to 3 ° to 5 ° to the horizontal, and accordingly the required overall height of the screening device can be reduced.

Another idea of the present invention is to provide bearing assemblies which comprise the spring elements and the swing frame with the support frame preferably only connect or couple. So be a simple setup and allows easy assembly of the screening device. Will continue enables a very simple structural design and adaptation of the screening device, because, for example, standardized bearing assemblies as required, such as Length of screening device and / or mass of the (loaded) swing frame, in required number and / or arrangement for mounting the swing frame on Support frames can be used.

Fig. 1

eine schematische, perspektivische Teilansicht einer vorschlagsgemäßen Siebvorrichtung;

Fig. 2

eine schematische Seitenansicht der Siebvorrichtung gemäß Fig. 1;

Fig. 3

einen schematischen Längsschnitt der Siebvorrichtung in einer etwas modifizierten Ausführungsvariante; und

Fig. 4

eine vereinfachte Draufsicht der Siebvorrichtung gemäß Fig. 3.

Further details, features, properties, advantages and objectives of the present invention are explained in more detail below with reference to the drawing of a preferred exemplary embodiment. It shows:

Fig. 1

a schematic, perspective partial view of a proposed screening device;

Fig. 2

is a schematic side view of the screening device of FIG. 1;

Fig. 3

a schematic longitudinal section of the screening device in a slightly modified embodiment; and

Fig. 4

3 shows a simplified top view of the screening device according to FIG. 3.

1 to 4 show a proposed screening device 1 in two slightly different Variants that will be explained in detail later.

The screening device 1 has a support frame 2 which is connected by means of an associated 3 vibratory drive 3 indicated by dashed lines can be set in vibration. In particular, the oscillating drive 3 is connected to the support frame 2 or from held this. The vibratory drive 3 can in particular as a balancing motor, directional vibratory drive or circular vibratory drive. In particular, it is about is a linear oscillator, that is, at least essentially only generates linear vibrations.

The support frame 2 is mounted such that it can swing. This is the case with the illustration example the support frame 2 is supported by schematically indicated support springs 4 and especially mounted on it.

On the support frame 2, in turn, spring elements 5 are supported, via which a swing frame 6 is resiliently coupled to the support frame 2. The spring elements 5 were or at the same time lead the swing frame 6, so that additional Swing frame 6 with the support frame 2 connecting guide elements or the like. are not required.

The swing frame 6 is mounted on the support frame 2 such that it is at least in essentially free in a tensioning shaft vibration direction 7 - that is, not positively controlled, but under the influence of the spring elements 5 - can move back and forth to to execute an oscillation referred to here as a tension shaft oscillation. Preferably can the swing frame 6 at least essentially exclusively in Swing the tension shaft oscillation direction 7.

1, 3 and 4 it can be seen that cross member 8 on the support frame 2 and on the swing frame 6 are arranged or mounted on these. The cross members 8 extend here at least essentially horizontally and transversely to the direction of the shaft oscillation 7. The cross members 8 are one behind the other in the direction of the oscillation shaft 7 at least essentially arranged in one plane and alternately either carried by the support frame 2 or by the swing frame 6. If the Oscillating frame 6 oscillates back and forth in the tensioning shaft oscillation direction 7 accordingly, the distances between adjacent cross members 8 alternately enlarged and reduced. This leads to the fact that 8 carried by the cross members Sieve plate elements 9, which are preferably each from one to the next cross member 8 stretch, alternately tensioned and relaxed. This leads to a high acceleration of screen material lying on the screen tray elements 9 (not shown), so that even difficult-to-screen material can be screened or classified.

The sieve bottom elements or mats 9 are in particular individually replaceable and sufficiently flexible, as is generally known from the prior art.

1, the swing frame 6 has four cross members 8 and is in the area of its end or transverse sides 10 of the spring elements 5th swinging mounted on the support frame 2. The spring elements 5 form bearing assemblies 11 for the swing frame 6, the structure of which will be explained in more detail later. at 1 is a bearing assembly 11 in the area a transverse side 10 of the swing frame 6 arranged. The swing frame 6 is here thus only connected to the support frame 2 via two bearing assemblies 11 and above spring-elastic coupled to carry out the expansion shaft vibration. The bearing assemblies 11 can, however, also be moved inwards from the transverse sides 10 be arranged.

The screening device 1 can have a plurality of such, relatively short swing frames 6, which are arranged one behind the other and coupled to the same support frame 2 are.

However, the screening device 1 can also be a "longer" one - that is, with more cross members 8 provided - swing frame 2, as in the variant 3 and 4. Also in this embodiment variant, the swing frame is 6th for example, only supported on the support frame 2 again by means of two bearing assemblies 11 and swinging. However, more than two bearing assemblies can be used 11 may be provided. In particular, if necessary, each cross member, for example 8 or every second cross member 8 of the swing frame 6 a bearing assembly 11 for storage of the swing frame 6 may be assigned. This enables the Using the same bearing assemblies 11 for different screening devices 1 with Vibration frames of different lengths 6.

The preferred construction of a bearing assembly 11 is explained in more detail below.

1 and 2 show that two spring elements 5 of a bearing assembly 11 each the support frame 2, namely opposite longitudinal cheeks or sides of the Support frame 2 are connected, their longitudinal axes, which correspond to torsion axes 12, are aligned coaxially. These two spring elements 5 are opposite one another attached to the support frame 2.

To simplify the end fastening or clamping of the spring elements 5 are preferably mounting flanges 13 at the ends to be attached the spring elements 5 are integrally formed. The mounting flanges 13 have, for example corresponding recesses or through holes on the edge on, so that the mounting flanges 13 in particular by means of not shown Screw connections can be connected to adjoining parts.

The spring elements 5 are preferably solid and made of steel.

For an ideal spring behavior of the spring elements 5 - a desired spring constant the torsion about the torsion axis 12 on the one hand and sufficient spring hardness and resilience with respect to the load of the spring elements 5 across Torsion axis 12 in the vertical direction on the other hand - to reach the spring elements 5 preferably have a varying along their longitudinal axis Cross-section, which is formed the least, for example, in the middle his. In particular, the spring elements 5 (of course without considering the Fastening flanges 13) are at least slightly conical, as is not the case in FIG. 2 indicated to scale. In this case, the two are with the support frame 2 connected spring elements 5 preferably with their ends of larger cross section on the support frame 2 - by means of the mounting flanges 13 - attached.

At the free, mutually facing ends of the spring elements attached to the support frame 2 5 are connected to swivel arms 14, in particular via the corresponding ones Fastening flanges 13 are connected to the spring elements 5 and transversely or radially with respect to the longitudinal or torsion axes 12 of these two spring elements 5 protrude. The pivot arms 14 extend at least essentially here and at least in its neutral position, i.e. in the undeflected state, perpendicular to the direction of the oscillating shaft 7 towards the oscillating frame 6. In which illustrated and preferred embodiment, the bearing assembly 11 is at least essentially between the swing frame 6 and below the same arranged. Accordingly, the swivel arms 14 at least extend here essentially vertically upwards towards the swing frame 6. However, are here other constructive solutions are of course also possible.

The swivel arms 14 are at their ends 15 facing the swing frame 6 the swing frame 6 - in particular with side members 16 of the swing frame 6 - articulated or pivotally connected. Here is a swivel connection to the swing frame 6 in turn realized by spring elements 5. However, can the swivel arms 14 in the region of their ends 15 also via a not shown Pivot bearing o. The like. To be connected to the swing frame 6.

According to the preferred embodiment, the spring elements 5, the Couple the swivel arms 14 to the swing frame 6, identical to the spring elements 5, which connect the swivel arms 14 to the support frame 2.

Alternatively, the "lower" - connected to the support frame 2 - spring elements 5 to be replaced by the aforementioned swivel bearings or the like, if the remaining, "upper" - connected to the swing frame 6 - spring elements 5 have sufficient spring hardness to achieve the desired vibration behavior to be able to reach the screening device 1.

The spring elements 5 close with their "thicker" - the larger cross section having - end to the associated swivel arm 14 in the region of its end 15 and extend in pairs with coaxial torsion axes 12 from each other away to the swing frame 6, where the spring elements 5 with their "thinner" ends via their mounting flanges 13 with the swing frame 6 or its longitudinal members 16 are connected.

The swing frame 6 has a smaller width than that in the example shown Support frame 2 on or is arranged in this. In order to have a uniform spring element 5, the width difference can be adjusted by appropriate Spacers, intermediate washers or the like, not shown, are compensated. Preferably, however, the swivel arms 14 are each double, opposite cranked, as can be seen in FIG. 2, by the aforementioned width difference compensate.

In the preferred embodiment, all spring elements 5 therefore extend one Bearing assembly 11 and in particular all spring elements 5 of all bearing assemblies 11 at least substantially parallel to one another, the spring elements 5 in each case are arranged in pairs coaxially and spaced apart.

The two pivot arms 14 of a bearing assembly 11 are preferably over at least a torsionally rigid, in particular tubular connecting element 11 with each other connected. Depending on the construction, the connecting element 11 can also be used directly on the associated spring elements 5 or their fastening flanges 13 attack and so two spring elements 5 with coaxial torsion axes 12 together connect. In the latter case, the swivel arms 14 are in turn fixed to the connecting element 17 connected.

Preferably two connecting elements 17 are provided, which are essentially between the upper spring elements 5 and the lower spring elements 5 one Bearing assembly 11 extend and so with the swivel arms 14 a trapezoidal Form stiffening element that on the one hand with the supporting frame via the spring elements 5 2 and on the other hand is connected to the swing frame 6.

The connecting elements 17 are preferably screwed to the swivel arms 14, for example, that screws or bolts by assigned Mounting flanges 13 of spring elements 5 and corresponding sections the swivel arms 14 screwed into the connecting elements 17 are. This enables simple assembly and replacement of Components, if necessary. For example, the swivel arms 14 and However, connecting elements 17 are also welded to one another or in some other way To be connected wisely.

The stiffening caused by the connecting elements 17 leads to the wearing properties (Vertical load) and the spring properties (Torsion of the spring elements 5 for the tensioning shaft oscillating movement of the oscillating frame 6) a bearing assembly 11 on both sides with respect to the longitudinal axis of the Screening device 1 are largely the same, so that there is a symmetrical Vibration behavior of the vibrating frame 6 and the screening device 1 with respect to them Longitudinal axis results and a torsional vibration of the vibrating frame 6 around its Longitudinal axis is avoided.

The aforementioned spring-elastic storage and guidance of the swing frame 6, exclusively by the spring elements 5 and swivel arms 14 or the like held thereby, leads to a simple, inexpensive construction.

The aforementioned bearing assemblies 11 convey a in a simple manner effective guidance of the swing frame 6, the swing frame 6 relatively or at least sufficiently light in the direction of the vibrating shaft 7 can be moved back and forth. Due to the torsion of the spring elements 5 in the tension shaft vibration the vibrating frame 6 does not lead in a strictly straight or linear manner Swinging movement, but moves on a slightly curved Circular path back and forth. However, since the deflection or vibration amplitude is proportional is small, in particular is approximately ± 3.2 to 3.5 mm, the Oscillating movement can be viewed at least essentially as linear. moreover Experiments have shown that this tensioning wave oscillating movement is a very effective one Seven enables.

A particular advantage of the proposed screening device 1 is that the Damping the vibration of the swing frame 6 with respect to the support frame 2 is relatively low, so that relatively little damping work during operation must be applied and unnecessary heating of the moving or the elastically deforming parts, in particular the spring elements 5, avoided becomes.

The oscillating frame 6 is at least essentially within the example shown of the support frame 2 arranged. In particular, are longitudinal beams 16 of the swing frame 6 arranged within the side cheeks of the support frame 2. this makes possible a simple structure, since the cross member 8 of the swing frame 6, the side cheeks of the support frame 2 do not penetrate. However, it goes without saying here other designs are also possible.

The tensioning shaft oscillation direction 7 or main extension plane of the oscillating frame 6 is in the representation example to the horizontal 18 in the direction of sieve 19, that is in the direction in which screenings are transported or conveyed via the screen tray elements 9 is, unless it falls through the sieve plate elements 9 to the Angle a inclined. The angle of inclination a is preferably approximately 3 ° to 5 °. This is surprisingly small, but is sufficient for the proposed screening device 1 for funding in the direction of sieve 19.

The main vibration direction 20 of the vibration drive 3 exerted on the support frame 2 Vibration is against the direction of the screen 19 to the horizontal 18 around the Angle b inclined. The angle of inclination b here is preferably between 30 ° and 50 °, in particular essentially 40 °.

The screening device 1 is preferably designed such that the resonance frequency at least 1100 vibrations per min. and especially at least 1200 Vibrations per min. is. This enables subcritical operation of the Screening device 1, that is to say an oscillation below the resonance frequency, opposite the prior art significantly higher vibration frequency.

The proposed screening device 1 is preferably designed such that it with an oscillation frequency of at least 850 oscillations per min. and in particular with essentially 890 vibrations per min. or higher is operable. The vibratory drive 3 is designed accordingly. The vibrating frame 6 then executes a tensioning shaft vibration in the tensioning shaft vibration direction 7. The amplitude is in particular approximately ± 3.2 to 3.5 mm. So are an average speed of the swing frame 6 relative to the support frame 2 of more than 11 m / min. and an average acceleration of at least 2.2 m / s ² can be achieved. In this way, a tension wave oscillation which is substantially stronger than in the prior art can be realized, which accordingly results in more effective screening and better conveying of screenings in the direction of screening 19.

In the vertical and horizontal direction, the spring elements 5 act as spiral springs. The natural frequency of the vibration system in these directions is far above the drive frequency. Correspondingly, this is done in these directions no resonant vibrations.

The torsion bar spring-like spring elements 5 have a very high energy storage capacity on. Therefore, a large mass can be made with relatively few spring elements 5 be moved, with no damping compared to push rubber elements and the frequency range is not due to self-heating and other influences, how temperature and aging are significantly restricted or changed. A Adaptation to the respective conditions can easily be done by varying the diameter and / or length of the spring elements 5.

The use of torsion bar spring elements 5 allows a completely revealing Choice of the vibration parameters and the size of the screening device 1. Result So there are greater structural freedoms compared to the prior art.

Claims (12)

1. Screening device (1) with a carrying frame (2) which can be set in oscillation, with an oscillating drive (3) assigned to the latter and preferably acting solely on it, and with an oscillating frame (6) which is mounted on the carrying frame (2) and is coupled spring-elastically to the latter via spring elements (5) and which can oscillate preferably freely at least essentially in a tension wave oscillation direction (7), the carrying frame (2) and the oscillating frame (6) having crossmembers (8) which are arranged alternately one behind the other in the tension wave oscillation direction (7) and carry screen tray elements (9) which can be alternately tensioned and detensioned in the tension wave oscillation direction (7), characterized in that the spring elements (5) are designed in the manner of a torsion bar spring.
2. Screening device according to Claim 1, characterized in that the oscillating frame (6) is connected or coupled to the carrying frame (2) solely via the spring elements (5).
3. Screening device according to Claim 1 or 2, characterized in that the spring elements (5) are designed to run at least essentially rectilinearly and/or their longitudinal axes correspond to their torsion axes (12), and/or in that the torsion axes (12) of the spring elements (5) run at least essentially perpendicularly to the tension wave oscillation direction (7) and, in particular, parallel to the main direction of extent of the crossmembers (8).
4. Screening device according to one of the preceding claims, characterized in that the spring elements (5) are of solid design and/or that the spring elements (5) are designed conically and/or have a cross section varying along their longitudinal axes.
5. Screening device according to one of the preceding claims, characterized in that each spring element (5) has at least at one end, preferably at both ends, a fastening flange ( 13) integrally formed in one piece.
6. Screening device according to one of the preceding claims, characterized in that pivoting arms (14) connected to the spring elements (5) and projecting transversely to the longitudinal and/or torsion axis (12) of the spring elements (5) are provided for coupling the oscillating frame (6) to the carrying frame (2), in particular each pivoting arm (14) being connected, on the one hand, via a spring element (5) to the carrying frame (2) and, on the other hand, via a spring element (5) to the oscillating frame (6) and/or being preferably double-bent.
7. Screening device according to one of the preceding claims, characterized in that in each case a spring element (5) connected to the carrying frame (2) is connected via a pivoting arm (14) held by the said spring element to a further spring element (5) which is itself connected to the oscillating frame (6), in particular the pivoting arms (14) being preferably double-bent.
8. Screening device according to one of the preceding claims, characterized in that the spring elements (5) are arranged in pairs coaxially, in particular pairs of spring elements (5) having arranged between them in each case a connection element (17) which connects in a torsionally fixed or torsionally rigid manner the two spring elements (5) or the pivoting arms (14) connected to the latter.
9. Screening device according to one of the preceding claims, characterized in that the spring elements (5) are arranged solely in the region of the two transverse sides (10) of the oscillating frame (6) and/or within the carrying frame (2), and/or in that the spring elements (5) are designed as preferably solid torsion bar springs.
10. Screening device according to one of the preceding claims, characterized in that the oscillating frame (6) is arranged at least essentially within the carrying frame (2).
11. Screening device according to one of the preceding claims, characterized in that the oscillating frame (6) is connected or coupled to the carrying frame (2) via at least two bearing subassemblies (11) which comprise the spring elements (5).
12. Screening device according to one of the preceding claims, characterized in that the screening device (1) is designed in such a way that it can be operated with an oscillation frequency of at least 850 oscillations per minute.

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