EP3356048B1 - Rotor for a comminuting device - Google Patents

Description

The invention relates to a rotor for a device for comminuting feed material, comprising a drive shaft, a plurality of rotor disks seated on the drive shaft and comminution tools arranged in the region of the outer circumference of the rotor disks; The invention further relates to a device for comminuting feed material.

Rotors are used in devices for comminuting feedstock for coarse or fine comminution or disagglomeration of the feedstock by impact, shear or impact forces. For this purpose, in the outer peripheral region of the rotor disks, which are arranged as hubs on at least one drive shaft, arranged on or between the rotor disks comminution tools such as knives, hammers or blow bars. The most radially supplied to the rotating rotor feed material, such as metal scrap, textiles or granular feed, is detected and crushed by the crushing tools of the rotor, often in conjunction with statically arranged in the housing of the device elements such as baffles (stator). Impact hammer mills, for example, are used in the course of cement production for processing (comminution and simultaneous drying) of the raw meal. In addition to embodiments with blow bars thereby pendulum, ie pivotally arranged on axle rods hammers are provided as comminution tools in the frequent case, which align themselves with rotation under centrifugal force and impact or. Exert impact forces on particles of the feed material. Embodiments of impact hammer mills are described, for example, in the publications DE 24 16 499 C3 and DE 10 2006 033 300 A1 taught. Another embodiment of such Hammer mill with swinging on a rotor hammer elements is in the German patent application DE 198 48 866 A1 disclosed.

The torque transmission from the driven shaft to the comminution tools, which is relevant for the comminution devices supported on the rotor principle, takes place via the rotor disks. Of particular importance for an effective and trouble-free operation of the rotor and thus the comminution device is therefore the connection between the rotor disks and the drive shaft. Frequently, this shaft-hub connection is realized by a feather key connection, that is, a torque transmission by means of a feather key inserted in a groove, as for example in the document DE 39 38 725 A1 taught. Normally, the rotor discs are thereby loosely pushed onto the shaft and laterally secured, for example with stops against displacement, so that in particular the simplest, quickest possible assembly or disassembly of individual, worn discs is possible. Due to the given play in the connection of the disks to the shaft, however, there is a danger of the rotor disks from being thrown out of their intended equilibrium or operating position, especially in the case of the high torques typical for impact hammer mills and not only radially occurring forces upon impact with the feed particles damage to the discs can lead to shaft breakage. Also, a lateral hiking of the discs can not be ruled out.

Similar difficulties can be found in the document EP 2 098 297 B1 disclosed rotor for comminuting feed material, comprising in particular a drive shaft, rotor disks and crushing tools occur. Not all rotor discs are firmly connected to the shaft here. Rather, a power transmission takes place between the rotor disks, wherein only the outer rotor disks are connected to the shaft by frictional engagement. Not only does a deflection of the central rotor disks at particularly high torque and force loads seem only by particularly stable, complex power connections to be excluded between the panes. In addition, the proposed, complex clamping sets for the production of the frictional engagement of the outer plates due to the transmission of the discs with each other allow some slip between the shaft and rotor discs at peak loads, which can also lead to a disadvantageous leaving the discs from their intended operating position.

A rotor according to the preamble of claim 1 is disclosed in the German Offenlegungsschrift DE 2 145 868 A1 disclosed. There, in a rotor for hot air flowed through collision mills with two end plates, which are fixedly connected to one another with a drum shell surrounding the shaft, the shaft is divided within the rotor. The projecting into the rotor interior ends of the two shaft parts is held by a sleeve axially movable in alignment with each other. It is an impact mill with only two rotor disks.

The object of the invention is therefore to provide a rotor for a device for comminuting feed material, in which the risk of a rupture of the rotor disks and a lateral wander of the rotor disks is reduced.

The object of the invention is achieved by a rotor for a device for comminuting feed material with the features of claim 1. Further advantageous embodiments are specified in the subclaims to claim 1 and a corresponding apparatus for comminuting feed material in claim 6.

According to the invention, it is thus provided that at least one retaining flange for connecting the rotor disk to the drive shaft is provided in the rotor for each rotor disk, wherein the at least one retaining flange is inseparably connected to the drive shaft and is detachably connected to the rotor disk. Of known forms of connection between drive shaft and rotor disks, such as the use of feather keys, therefore, on the one hand in favor of the use of fixedly connected to the shaft flanges, as connecting parts between the shaft and the flanges held by the hubs, ie the rotor discs, gone away. In a particularly preferred embodiment of the invention, the retaining flanges are permanently connected by welding with the shaft. According to the invention, on the other hand, it is provided that each rotor disk of the rotor is detachably connected to at least one retaining flange. About this connection takes place the transmission of torque from the drive shaft to the rotor disk. The solubility of the compound in this case allows a rapid, separate replacement of individual rotor discs, which are exposed to heavy wear during operation, in particular due to the multiple impact of particles of the feed. By connecting each individual rotor disk with at least one retaining flange, each individual rotor disk is protected against lateral migration. The person skilled in the art will choose the strength of the connection according to the forces and torques occurring during typical operation of the rotor in the comminution device. A lateral migration of the rotor disks by the action of non-radial forces, as they are typical for example due to the trajectories of the feed material in impact hammer mills, is prevented more effectively than with loosely pushed onto the shaft rotor disks with laterally provided stops.

In the invention, the rotor disks are connected to the respective retaining flanges by screw connection. The compound according to the invention can be produced by the use of one or more connecting parts designed as discs, brackets, plates or the like elements laterally overlap the shaft-hub connection of the rotor disc and retaining flange and are bolted to the retaining flange and the rotor disc. retaining flanges and rotor disks are then joined together sufficiently firmly but releasably connected in an indirect manner. The inventive compound of each disc with at least one retaining flange, realized by screw, no loose-fitting rotor discs are present in the rotor. Due to the fixed, backlash-free connection between the rotor disk and the retaining flange acting as part of the shaft, the risk of deflecting rotor disks from their intended equilibrium position, that is to say knocking out the rotor disks, is largely prevented. Due to the typically impacting load of the rotor in impact hammer mills, this is of great advantage for this type of comminution device.

According to the invention it is provided that the retaining flanges are formed annularly around the shaft and each rotor disk is held by exactly one retaining flange. The rotor disk has a circular hub bore for the connection to the retaining flange. As viewed from the axis of rotation of the shaft, each rotor disk thereby has a radial inner side, that is to say an inner boundary surface lying toward the shaft-in the geometrically idealized case of a circular ring cylinder-the inner lateral surface. It is envisaged that in this shaft-hub system, the rotor disk rests with its radial inner side or surface on the radial outer side or surface of the associated retaining flange. For increased stability of the connection, these surfaces lie as mating surfaces and in effect as a centering surfaces (for the positioning of the disc) to each other. The fit between shaft (retaining flange) and hub (rotor disk) can be a clearance clearance with little play in the case of crushing devices in which only small forces and torques occur during operation. In the normal case, especially in impact hammer mills, however, backlash-free connections in the form of transition fits are to be preferred for the sake of avoiding rupture of the rotor disks. Only in exceptional cases of particularly great forces and moments will an over-fitting be realized; their press fit in particular the disadvantage of a complex assembly / disassembly of the rotor disks. The actual non-positive connection between the rotor discs and the corresponding respective retaining flanges is made in this embodiment of the invention by a screw, are firmly bolted to the rotor disc and retaining flange each with one and the same connection element. This may in particular be a laterally arranged plate which covers both the rotor disk and the associated retaining flange in the area of the mating surfaces lying one on top of the other. Suitable, for example, a connecting plate in the form of a concentric with the rotor disk arranged annular disk on one side of the rotor disk, wherein the plate for reasons of ease of assembly consists of several separate parts, for example, consists of two Halbkreisringscheiben. It makes sense to use on the other side of disc or flange to further secure the screw analogous another multi-piece connection plate and tighten nuts.

In a further embodiment of the embodiment of the invention described above, provisions are made which allow a relatively simple and rapid assembly of the rotor disks. During assembly, the rotor disks are pushed in the axial direction, ie along the shaft, over the drive shaft with the retaining flanges. For this purpose, each retaining flange distributed over its outer circumference recesses (flange recesses), which are similar to tuning forks or gears radially outward and open to the side surfaces. Between each two adjacent recesses remain in the outer peripheral region of the retaining flange web-like parts of the retaining flange, referred to as flange webs. In an analogous manner, the rotor disk associated with the respective retaining flange has recesses (disk recesses) and disk webs distributed over its inner circumference. In this case, flange recesses and ribs correspond to the disc recesses and ribs, so that in the fully assembled rotor, ie in the operating state, the radial outer sides of the flange webs and the radial (inwardly toward the shaft) sides of the respective disk webs as centering surfaces with the already described fit to each other. Accordingly, the recesses of rotor disk and retaining flange adjoin one another and form common recesses. For a simplified mounting of the rotor disk on the associated retaining flange given along the circumference expansions of the flange recesses are dimensioned such that in at least one rotated relative to the mounted state position of the rotor disk to the retaining flange of each flange recess a disk web with lesser along the Circumference of given extent opposite. It follows that also the corresponding disc recesses are dimensioned such that each disc recess faces a flange web of lesser extent along the circumference. To mount so the rotor disk relative to the support flange is rotated so that without friction-induced blocking during axial sliding the recesses of the disc above the webs of the flange and the recesses of the flange can be performed below the webs of the disc. After this sliding the rotor disk is then rotated to the retaining flange in the end position, in which the outer surfaces of the corresponding webs with fit as centering surfaces lie on each other. Advantageous for the screw connection only a small depth of the recess is needed here.

Typically, the rotor disks and retaining flanges are each of the same type, so that they coincide in shape and size, ie each congruent to each other. In an advantageous specific embodiment of the above-described embodiment of the invention, both the flange recesses are congruent to each other, as well as the disc recesses to each other. Furthermore, in order to promote uniform material loading of the retaining flanges and the rotor disks, the flange recesses, and thus also the disk recesses and the flange and disk webs, evenly distributed on the circumference of each retaining flange or each rotor disk. With regard to this distribution there is therefore rotational symmetry or radial symmetry. For example, the recesses are offset from each other by an angle of 60 ° with respect to a rotation about the axis of rotation of the shaft. For the simplification of the assembly step of pushing a rotor disk over the retaining flanges along the drive shaft, it is sufficient and advantageous for the stability of the connection given by the largest possible centering surfaces if the flange recesses are only slightly larger in their (all dimensions) areal extent along the outer radial circumference are given as the along the outer periphery given (areal) expansion of a flange web. The same applies accordingly for recesses and webs of the rotor disks and the corresponding ratio of the corresponding sections of disks and flanges to each other. Preferably, therefore, the longitudinal extent of the recesses of the flanges or discs (based on the minimum dimension) by about 0.5% to a maximum of 10% greater than to choose the extension of the webs (based on the maximum dimension).

Also, such a dimension of webs and recesses is possible that in an alternative arrangement, the webs are pushed into the recesses in the manner of a connector. Although an interlocking connection between disks and flanges is additionally produced by such engagement, it is difficult to produce the screw connection.

The rotor according to the invention is suitable for all kinds of feedstock chopping machines whose crushing operation is based on the rotation of a rotor-milled rotor, often in cooperation with a stator provided correspondingly in or as the casing of the apparatus. By using a rotor in one of the embodiments according to the invention within the comminution unit of known per se, With the rotor principle working comminution devices, the invention also includes devices for comminuting feed material having a rotor according to the invention in one of the described embodiments.

Since the rotor according to the invention is advantageous due to the backlash-free connection of the rotor disks to the drive shaft, in particular for use in impact hammer mills, an advantageous embodiment of the invention provides that the comminution tools are in the form of hammers. As known from generic hammer mills and impact hammer mills, the hammers are pivotally arranged on axle rods which, usually parallel to the drive shaft, pierce the rotor disks.

An important embodiment of the device for comminuting feed material, which comprises a rotor according to the invention, provides that the comminution tools of the rotor are designed as hammers, blow bars or similar known impact tools and that the rotor is assigned an impact hammer mill stator. The rotor according to the invention is therefore part of an impact hammer mill, whose comminution unit comprises not only the rotor but also a stator which is typical for impact hammer mills. By way of example, the stator has impact elements fixedly arranged in an additional impact space, such as e.g. Impingement strips, to which the particles of the charge of transport collected by the hammers of the rotor are hurled and thereby (pre-) shredded.

Fig. 1

einen erfindungsgemäßen Rotor für eine Vorrichtung zum Zerkleinern von Aufgabegut,

Fig. 2

eine Darstellung des Rotors im Längsschnitt mit verschraubten Rotorscheiben,

Fig. 3

eine Antriebswelle mit verschweißten Halteflanschen ohne Rotorscheiben,

Fig. 4

einen Querschnitt durch eine Rotorscheibe auf einem Halteflansch,

Fig. 5

einen Querschnitt durch eine Rotorscheibe in Montageposition zum Halteflansch, und

Fig. 6

einen Querschnitt durch eine Rotorscheibe in montierter Position zum Halteflansch.

The invention will be explained in more detail with reference to the following figures. It shows:

Fig. 1

a rotor according to the invention for a device for comminuting feedstock,

Fig. 2

a representation of the rotor in longitudinal section with bolted rotor disks,

Fig. 3

a drive shaft with welded retaining flanges without rotor discs,

Fig. 4

a cross section through a rotor disk on a retaining flange,

Fig. 5

a cross section through a rotor disk in mounting position to the retaining flange, and

Fig. 6

a cross section through a rotor disk in mounted position to the retaining flange.

In FIG. 1 a rotor 1 according to the invention for a device for comminuting feed material, for example for an impact hammer mill used in cement production, is shown. Not shown are the shredding tools. However, axial holes 3 arranged in the outer region of the rotor disks 2, which are provided for axle rods, on which pivotable comminution tools, in particular hammers, are arranged in the region between the rotor disks 2, can be seen. Upon rotation of the rotor 1, the hammers pivot following the centrifugal force in a radially outward position in which they protrude beyond the outer edge of the disc and act on crushing particles of the feedstock. The rotor disks 2 are arranged on a drive shaft 4. Each rotor disk 2 is arranged on an annular retaining flange 5.

FIG. 3 shows in a schematic representation of the retaining flanges 5 on the drive shaft 4. By welding the retaining flanges 5 are inventively inextricably connected to the drive shaft 4.

In FIG. 2 is in a rotation axis of the drive shaft 4 containing longitudinal section through the rotor 1 from FIG. 1 In particular, to recognize the fixed, but releasable connection of the rotor disks 2 with the associated retaining flanges 5. In the region of the superimposed mating surfaces of rotor disk 2 and retaining flange 5, a connecting element 6 designed as a connecting plate is arranged on each side. Both rotor disk 2 and the associated retaining flange 5 are by means of screws 7 and nuts 8 on the connecting elements 6 bolted. Thus, a backlash-free connection according to the invention is produced between the rotor disk 2 and the retaining flange 5, via which the forces and torques are transmitted and during operation of the rotor 1 no beating of the rotor disks 2 and no lateral migration of the rotor disks 2 along the drive shaft 4th can occur. As in FIG. 1 shown, the connecting elements 6 are given in the illustrated embodiment as circular ring disks, which are designed in two parts for easy assembly.

FIG. 4 shows a connected via a retaining flange 5 with the drive shaft 4 rotor disk 2 in cross-sectional view. Arrangements according to the invention for problem-free mounting of the rotor disks 2 in this operating position are limited to those in the inner region FIGS. 5 and 6 represented with the respective enlargements of the areas X and Y. The retaining flange 5 has in this case along its outer circumference uniformly distributed flange recesses 9 and flange webs 10 between each two adjacent flange recesses 9. Correspondingly, the rotor disk 2 also has correspondingly uniformly distributed disk recesses 11 and disk webs 12 along its inner circumference. The recesses 9, 11 are slightly larger in terms of their extent along the circumference than the webs 10, 12, so that in the position of rotor disk 2 and retaining flange 5 to each other, as in FIG. 5 is shown, a clearance is given.

In the FIG. 5 shown position shows the relative to the rotation angle about the rotation axis of the shaft 4 rotated position of the rotor disk 2 to the retaining flange 5. Here are flange recesses 9 and disk webs 12 and flange webs 10 and disk recesses 11 opposite. This allows a largely low-friction, blockade-free sliding of the rotor disks 2 via or on the retaining flanges 5 in the axial direction during assembly of the rotor disks 2.

In contrast to the mounting position off FIG. 5 shows FIG. 6 the position of rotor disks 2 and retaining flanges 5 in the fully assembled state, ie in the operating state. This is achieved by the rotor disk 2 from the mounting position ( FIG. 5 ) is rotated so far that the flange webs 10, the corresponding disc webs 12 and thus the flange recesses 9 are the corresponding disc recesses 11 opposite. In the illustrated embodiment with 6 recesses (and 6 webs) this corresponds to a rotation through an angle of 30 °. As a result, it is achieved in this shaft-hub system that the top surfaces of the disk webs 12 and flange webs 10 lie on one another as mating surfaces or centering surfaces ( FIG. 6 ), wherein a play-free fit is present. The particularly advantageous for impact hammer mills backlash-free, tight fit of the rotor disks 2 on the drive shaft 4 by means of retaining flanges 5 is thus ensured as well as a comparatively simple (de-) mounting the rotor disks 2 exposed to wear. <I> LIST OF REFERENCES </ i> 1 rotor 8th mother 2 rotor disc 9 Flange recess 3 axle hole 10 Flange web 4 drive shaft 11 Disk recess 5 retaining flange 12 Disk web 6 connecting element 7 screw

Claims (7)

1. Rotor (1) for a device for disintegrating feedstock, comprising

   - a drive shaft (4),

   - a plurality of rotor disks (2) which sit on the drive shaft (4) and

   - disintegration tools which are arranged in the region of the outer circumference of the rotor disks (2), wherein
   at least one retaining flange (5) is provided for each rotor disk (2) for connecting the rotor disk (2) to the drive shaft (4), wherein the at least one retaining flange (5) is connected non-detachably to the drive shaft (4) and is connected detachably to the rotor disk (2), wherein

   - precisely one retaining flange (5) is provided for each rotor disk (2), wherein the retaining flange (5) is realized in a circular manner about the drive shaft (4), characterized in that

   - each rotor disk (2) rests with fit by way of its radial inner side, which is provided by a hub bore, on the radial outer side of the corresponding retaining flange (5), and in that

   - each rotor disk (2) and the corresponding retaining flange (5) are connected together in a non-positive manner to at least one connecting element (6) by means of the respective screw connection.
2. Rotor (1) according to Claim 1,
   characterized in that
   the retaining flanges (5) are connected to the drive shaft (4) by means of weld connection.
3. Rotor (1) according to Claims 1 and 2,
   characterized in that

   - each retaining flange (5) comprises open recesses (9) which are distributed over the outer circumference, wherein every two adjacent flange recesses (9) leave between them a flange web (10),

   - the rotor disk (2), which is assigned to the respective retaining flange (5), comprises open disk recesses (11) and disk webs (12), which are distributed over its inner circumference and correspond to the flange recesses (9) and flange webs (10), wherein with the rotor (1) in the assembled state, the radial sides of the flange webs (10) and of the corresponding disk webs (12) rest one on top of another as centering surfaces with fit, and in that

   - for simplifying an assembly step, which consists in pushing the rotor disk (2) in an axial manner onto the assigned retaining flange (5), the extents of the flange recesses (9) provided along the circumference are dimensioned such that in at least one position of the rotor disk (2), rotated in relation to the assembled state, with respect to the retaining flange (5), each flange recess (9) has situated opposite thereto a disk web (12) with a smaller extent provided along the circumference.
4. Rotor (1) according to Claim 3,
   characterized in that

   - the rotor disks (2) are congruent to one another,

   - the retaining flanges (5) are congruent to one another,

   - the flange recesses (9) are distributed uniformly on the circumference of every retaining flange (5) and are congruent to one another,

   - the disk recesses (11) are congruent to one another, and in that

   - the extent of a flange recess (9) provided along the outer circumference is greater, in a preferred manner is greater to a small extent (by approximately between 0.5 % and approximately 10 %), than the extent of a flange web (10) provided along the outer circumference.
5. Rotor (1) according to one of Claims 1 to 4,
   characterized in that
   hammers are provided as disintegration tools, wherein the hammers are arranged so as to be pivotable on axial rods which penetrate the rotor disks (2).
6. Device for disintegrating feedstock,
   characterized in that
   the device for disintegration comprises a rotor (1) according to one of Claims 1 to 5.
7. Device for disintegration according to Claim 6,
   characterized in that

   - the disintegration tools of the rotor (1) are realized as hammers, and

   - the rotor (1) has assigned thereto an impact hammer mill stator.

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