EP1192997A1 - Rotor in the closed type for impactors - Google Patents

Abstract

The rotor body comprises a cylinder type casing (2) supported on a shaft by rotor discs (18) which are cast in one piece with the casing (2). The rotor casing has a single wall and the circumferential slits (4) for holding the impact strips (5) are formed in the cast body itself. the rotor casing has only one rotor disc which is held on the shaft (20) with force locking engagement through a tension element.

Description

The invention relates to a rotor in a closed design for impact mills, the Rotor body consisting of a cylindrical jacket and this on a shaft bearing rotor disks and made of cast steel, the rotor casing provided on the outside with circumferential slots parallel to the rotor axis for receiving and Bracket for blow bars.

Such a rotor is known from DE-GMS 1831058 and is here with a circulator designated for centrifugal impact mills. The cylindrical rotor shell - the term Cylinder is not to be taken literally, the shape can also be a straight prism correspond, as here in the prior art - is off with this construction Spacers having hollow chambers formed between rotor disks arranged are welded to these. The spacers are also together welded and basically the peripheral slots receiving the blow bars of the rotor shell. These circumferential slots also penetrate the outer ones Rotor disks so that the blow bars are inserted axially into the slots and by means of Undercuts in the circumferential slots and cast on the blow bars Ribs are held radially against centrifugal force. The said spacers have pins on their end faces, which are inserted into the bores of the disks and are welded into it. The utility model mentioned is the material Cast steel or cast steel not removable, but it is in the Owner named utility model to the legal predecessor of the current Applicant, so that a corresponding level of knowledge is available here.

However, the manufacture of such a rotor is very complex. Apart from that for the spacers due to their cavity and the complicated shape the models are very expensive and lost model cores are also used practice has shown that the necessary weight tolerances in relation to the The center of gravity of the individual spacers cannot be adhered to, so it the unbalanced unbalance of the fast rotating rotor occurs. Especially however, the weld seam provided at the bottom of the circumferential slots is disadvantageous Connection of the spacers to each other, since it is very difficult to do common Lead welding tongs through the circumferential slots to the connection point. In addition, the holes in the side rotor disks must be in proportion the pegs of the spacers and to the welds basically the Circumferential slots must be made very precisely to avoid imbalance in the rotor. Since the circumferential slots in the rotor casing for receiving the blow bars each are provided between two castings that are not precise enough with each other can be welded, the bracket of the blow bars is both radial Direction as well as in relation to their installation position itself imprecise, which is the case with Blow bars made of highly hard cast materials can also lead to breaks. remedy can only be created here if the seats of the blow bars after assembly of the rotor are machined, which leads to an increase in price.

All these difficulties have meant that such rotors hardly find their way into the Have found a market.

The invention has for its object a rotor of the type mentioned to improve so that these problems do not arise and the rotor is also simple and cheap to manufacture. At the same time, the invention aims at a weight saving compared to the rotor according to the prior art To improve the moment of inertia by moving the masses to the outside.

This problem is solved in that the rotor shell and the bearing it Rotor disks cast in one piece and the rotor shell essentially is single-walled, the peripheral slots for receiving and holding the Blow bars are provided in the cast body itself. This will be essential achieved more precise dimensions with respect to the contour of the circumferential slots, so that a mechanical rework is unnecessary. Through the single-walled training of Rotor shell is saved casting material or this is placed further outside, what improves the moment of inertia of the finished rotor. Molding the models is simpler in the rotor according to the invention, which further saves costs benefits.

This advantage is particularly important for narrow impact mills, since here the Rotor shell only needs to have a rotor disc, which by means of a Clamping element or clamping set is held non-positively on the shaft. If necessary, the rotor disc is equipped with a wider hub that the Clamping element or more of them.

But this design is also particularly advantageous for wider impact mills, in which the Rotor shell is divided into annular disc elements, each disc element with a rotor disk is provided, which by means of a clamping element or clamping set the shaft is held non-positively and thus one of several disc elements existing rotor is formed.

From US-PS 3,151,816 a rotor in closed design for impact mills is indeed known, which is also disc-shaped, but are used Sheets burned out of mild steel sheets and are welded to Rotor body assembled. Not every disk is held on the shaft, but only the outer discs and the disc in the middle. The one in between Lying disks are made of disk rings with a larger inner diameter formed in order to be able to attach additional internal welds. This design is complex and expensive, especially since the elements are not cast from cast steel are. According to the invention, rotors for wider impact mills are also based thereon dispenses with the annular disc elements to each other by welds connect. The disc elements lie against each other with their outer wreaths thus form the closed rotor shell characteristic of the one in question here closed type.

However, a preferred embodiment of the rotor according to the invention is also given if the rotor shell is divided into shells that are outside the circumferential slots for the blow bars to a closed rotor shell through longitudinal welds are connected so that the peripheral slots for receiving and holding the Blow bars are provided in the cast body itself and the rotor shell with it bearing rotor disks is also connected by welds.

The number of shells results from the number of and depending on the rotor size Intended blow bars. So is in a further embodiment Invention provided that the rotor shell is formed from 4 shells, the latter connecting longitudinal welds in radial outer, parallel to the Circumferential slots for the blow bars extending slot-like depressions of the Rotor shell are provided and these recesses in the direction of rotation of the rotor in front of the blow bars or in front of the circumferential slots for receiving the blow bars are arranged.

It is advantageous if the shells are hollow and the cavities are radial and have circumferentially aligned reinforcing ribs and the Close the reinforcing ribs inwards with a radius that corresponds to the radius of the Corresponds to rotor disks.

It is also advantageous if the slot-like depressions and thus the Welds are covered by plates, which form-fitting guide pieces having axially insertable into the recesses and by means of the positive Connection is held against the outward centrifugal forces. These plates protect the welds but at the same time the rotor shell, which at this point shortly before the blow bars, particularly high wear-causing stress exposed, effective. They are also easy to replace.

Furthermore, the invention provides that the rotor shell is divided into segments that starting from the blow bars against the direction of rotation of the rotor have a spiral surface surface inclined in the direction of the axis. Such a inclined surface of a rotor is of conventional design (none Construction from cast steel) but known from DE-AS 1 053 899.

The application of the invention is particularly advantageous when using one-sided impact bars, which are in the circumferential slots of the rotor can be used in a form-fitting manner to the rear - against the direction of rotation of the Rotors - and facing this have an offset, with which they in a engage and counter the longitudinal undercut of the circumferential slots the centrifugal force of the rotating rotor are held, with a contact surface with which the Blow bars are held against a system of the rotor and with a support surface, over which the blow bars by means of a support or contact piece with the Undercut in the circumferential slots. The invention provides for this before that to hold the blow bars on their arcuate Offsets the circumferential slots in the rotor shell an approximately radially aligned have over the width of the rotor extending plane as a contact surface, which in the arcuate undercut runs out and the circumferential slots compared to this arcuate undercut taking into account the thickness the blow bars have a contact piece with an arcuate support surface, the fulcrum of the smaller radius of the arc on the contact surfaces in one considerable distance from the fulcrum of the larger radius of the arc on the Support surface is arranged in the direction of the impact circle of the blow bar and the two Pivots in a line run approximately parallel to the face of the blow bar, the contact surfaces in an extension of the smaller arch in one blunt Angle to each other.

It is advantageous if the distance between the centers of rotation of the radii remaining height of the blow bars installed in the rotor a ratio of 1: 7 to 1:15, preferably 1:10.

Thus, the angle between the extension of the smaller arc lying contact surfaces are 120 °

It is advantageous if the support or contact piece is designed to be exchangeable.

In a further embodiment of the invention it is provided that the peripheral slots for Inclusion of the blow bars on their inner approximately radially extending and longitudinal over the rotor width aligned one of the end face on the Bending the blow bars facing, extending over the width of the rotor Have segment-shaped groove, so that in the space between the segment-shaped groove in the circumferential slots and a segment-shaped Grooving of the built-in blow bars a profile bar can be inserted, the preferably consists of plastic.

In a further embodiment of the invention is in the area of the contact surfaces for the Blow bars attached to the contact surfaces slightly protruding cams over which a recess provided in the blow bars can be put over. With that, in a particularly simple way to achieve a lateral locking of the blow bars when they are tilted into the working position (in contact with the contact surface).

There are many rotors for impact mills with impact bars that can be loaded on one side known. For example, US Pat. No. 3,151,816 shows such a rotor, the As previously mentioned, the rotor body is welded together from individual disks. The blow bars used here are also to the rear, but rectangular cranked and undercut an undercut of the circumferential slots in the rotor body. The blow bars have a bevel facing the rotor on their front side on which the blow bars are supported against wedges and thereby the Blow bars are held in engagement with the undercut. The blow bars are therefore firmly clamped by means of the wedges, are not self-locking. they are also cannot be tipped over with a rounded undercut and are therefore more difficult to expand. This also applies to other known rotors, their Blow bars in addition to wedge-shaped support parts Screw connections are fixed to the rotor body (DE-PS 16 07 552, AU-PS 253 653).

Rotors for impact mills, whose rotor body is made entirely of cast steel known from DE 41 02 692 C1 and DE 198 13 310 C1. These publications show on their hubs welded discs that are aligned with each other Have edge recesses for receiving the blow bars. It is about this so-called open disc rotors, in which the problems that the invention presents solve with regard to rotors in a closed design, do not occur at all. These rotors belong to a different genus.

Fig. 1 zeigt einen Querschnitt des Rotors mit eingebauten Schlagleisten,

Fig. 2 zeigt einen Längsschnitt durch den Rotor mit eingesetzter Welle,

Fig. 3 zeigt einen Ausschnitt der Fig. 1 in größerem Maßstab

Fig. 4 zeigt eine alternative Ausbildung des Rotors in Seitenansicht,

Fig. 5 zeigt einen Längsschnitt durch einen aus mehreren Scheibenelementen zusammengesetzten Rotor für breitere Prallmühlen und

Fig. 6 zeigt einen Ausschnitt von Fig. 4 in größerem Maßstab.

The preferred embodiment of the invention is shown in the drawing.

1 shows a cross section of the rotor with built-in blow bars,

2 shows a longitudinal section through the rotor with the shaft inserted,

Fig. 3 shows a section of Fig. 1 on a larger scale

4 shows an alternative embodiment of the rotor in side view,

Fig. 5 shows a longitudinal section through a rotor composed of several disk elements for wider impact mills and

Fig. 6 shows a section of Fig. 4 on a larger scale.

As shown in FIG. 1, the rotor 1 consists of a rotor shell 2, which consists of four shells 3 is composed. The shells have ends that run parallel to the rotor axis Z. Circumferential slots 4 (based on the finished rotor), in the blow bars 5 are used. The shells 3 are one with the other outside the circumferential slots annular structure, the rotor shell 2, connected by longitudinal welds 6.

So that these longitudinal weld seams are protected against wear, they are parallel to the circumferential slots arranged slot-like depressions 7 provided are formed in half from the longitudinal edges 8 of the shells 3. The recesses 7 have Guide pieces 9, in the guide pieces 10 form-fitting guides 11 intervention. The form-fitting guide pieces 10 are on the underside of plates 12 attached, which can be inserted axially into the recesses. The plates 12 cover the longitudinal weld seams 6 and protect them from wear. simultaneously 7 counterweights can be introduced into the wells, if these The rotor must be balanced. The plates themselves are out highly wear-resistant material, but can also surface Welds must be protected with suitable materials.

The rotor shell 2, which can also be cast in one piece, is in a known manner divided into segments 13 starting from the blow bars 5 against the Direction of rotation of the rotor 1 in the direction of the Z axis is an inclined, spiral Have jacket surface 14. The segments 13 or shells 3 can, as in the Shown example, be hollow, it is then appropriate in the Provide cavities 15 reinforcing ribs 16, these reinforcing ribs and the longitudinal edges 8 of the rotor shell 2 form a circular end 17 on the inside form over which the rotor shell on at least two both ends of the rotor provided rotor disks are supported.

As can be seen from FIG. 2, the rotor mat 2 is through with the rotor disks 18 Welded seams 19, but can also be made in one piece with the rotor disks be cast if the rotor shell 2 is not divided into shells 3. Like Fig. 2 further shows, there are more inside outside the rotor disks Reinforcing ribs 16 are provided. A shaft 20 is also shown in this FIG. which is inserted into the rotor with known fasteners.

1 makes clear, the circumferential slots 4 for the blow bars 5 in Cast body provided.

Fig. 3 shows the preferred embodiment of the invention based on one side actionable blow bars is cut, in detail on a larger scale. The Rotor shell 2 has a number of circumferential slots 4, into which the blow bars 5 from are pushed in from the side. The blow bars themselves point with their rotor turned towards the longitudinal end of an arcuate bend 21 and reach under thus an arcuate undercut 22 of the circumferential slots, thereby counteracting them to be thrown out are kept. Opposite the arched Undercut there are basically 23 of the circumferential slots in contact pieces 24, which also have an arcuate surface as a support surface 25. The radius R1 the arcuate undercut 22 and the radius R2 of the arcuate Support surface 25 differ not only in terms of the thickness of the blow bars, but their pivots are also spaced from each other, namely the Pivotal point 26 of the smaller radius R1 at the undercut 22 at a distance Dimension X from the pivot point 27 of the larger radius R2 of the arc on the support surface in Arranged in the direction of impact circle 28, the two pivot points in a line L in are aligned approximately parallel to the blow bar front surface 29.

The blow bars 5 are based on an extending over the width of the rotor 1 Level contact surface 30 of each circumferential slot 4 from which the energy of Rotor is led into the blow bars. The contact surface 30 runs in one obtuse angles to the contact surface at the other end of the smaller arc.

This design of the blow bar holder ensures that the blow bars itself in the working position between the arcuate support surface 25 and the Clamp arcuate undercut 22 and thus completely against flying out of the rotating rotor are secured. On the other hand hereby achieved that between the contact surface 30 and the surface of the Undercut 22 and the support surface 25 and the corresponding ones Surfaces of each blow bar 5 in the installed position of the same no gaps are where fine material can accumulate. The expansion of the blow bars designed yourself very easy. These only need to be tilted forward a little, which means due to the arrangement of the pivot points 26/27 the clamping of the blow bars themselves loosens and a gap is formed between the contact surfaces, so that the blow bars can be easily pulled out to the side. This means that when the Rotor 1 does not accidentally tilt and rattle the blow bars 5, relieved due to the resulting gaps, the blow bars on the rotor facing end face of the offset 21 one over the length of the blow bars themselves extending segment-shaped groove 31 with a corresponding Groove 32 in the approximately radially extending and along the rotor width aligned boundary surface 33 of the circumferential slots 4 of the rotor corresponds. Between these grooves, which together form a circular cross section deliver, a round profile rod 34 can be introduced, which expediently Plastic is made.

The contact pieces 24 are expediently designed to be interchangeable and are attached to the rotor jacket 2 by means of screw connections 35.

Fig. 4 shows a special embodiment of the rotor according to the invention, the rotor shell 2 is cast together with the rotor disk 18 in one piece and forms one annular disk element 36. The circumferential slots 4 for the blow bars 5 are thus provided in the cast body itself. Rotors for wider impact mills can be, like Fig. 5 makes it clear, in a very simple manner by combining several Manufacture disk elements 36, the rotor disks 18 with clamping elements 37 are equipped with which you are held non-positively on the shaft 20. The Rotor shells 2 of the disk elements 36 lie against one another and thus form one closed wide casing, just a rotor made of cast steel in a closed design. The clamping elements 37 are designed so that they each disk element 36th Fix non-positively, i.e. non-rotatably, on shaft 20. The clamping elements 37 of the outer disk elements 36 are covered with a protective device 38.

As FIG. 6 shows, the contact surface 30 of the rotor shell 2 is with a cam 39 equipped, which extends somewhat into the circumferential slot 4, the blow bar 5 has on its back a slot-like recess 40 with which the blow bar slipping the cam over when tilting into the system. So the blow bars in the rotor according to the invention automatically against lateral migration out of the rotor secured. With 5 'the blow bar in the forward tilted position is designated (shown in dashed lines), which is so loose and can be pulled out of the circumferential slot 4 is.

The blow bar itself is the subject of a separate patent application.

Claims (15)

Closed rotor design for impact mills, the rotor body consists of a cylindrical jacket and rotor disks supporting it on a shaft and made of cast steel, the rotor jacket is provided on the outside with circumferential slots parallel to the rotor axis for receiving and holding blow bars, characterized in that the rotor jacket ( 2) and the rotor disks (18) supporting them are cast in one piece and the rotor jacket (2) is essentially single-walled, the peripheral slots (4) being provided for receiving and holding the blow bars (5) in the cast body itself. Rotor according to claim 1 for narrow impact mills, characterized in that the rotor casing (2) is only provided with a rotor disc (18) which is held on the shaft (20) by means of a tensioning element or tensioning set (37). Rotor according to claim 1 for wide impact mills, characterized in that the rotor casing (2) is divided into annular disc elements (36), each disc element (36) is provided with a rotor disc (18) which is attached by means of a clamping element or clamping set (37) the shaft (20) is held non-positively and thus a rotor (1) consisting of a plurality of disk elements (36) is formed. Closed rotor design for impact mills, the rotor body consists of a cylindrical jacket and rotor disks supporting it on a shaft and made of cast steel, the rotor jacket is provided on the outside with circumferential slots parallel to the rotor axis for receiving and holding blow bars, characterized in that the rotor jacket ( 2) is divided into shells (3) which are connected outside the circumferential slots (4) for the blow bars (5) to form a closed rotor shell (2) by longitudinal weld seams (6), so that the circumferential slots (4) for receiving and holding the Blow bars (5) are provided in the cast body itself, and that the rotor casing is also connected to the rotor disks (18) supporting it by weld seams (19). Rotor according to claim 4, characterized in that the rotor casing (2) is formed from 4 shells (3), the longitudinal weld seams (6) connecting these in radial outer, slot-like depressions running parallel to the circumferential slots (4) for the blow bars (5) (7) of the rotor jacket (2) are provided and these depressions are arranged in the circumferential direction of the rotor in front of the blow bars or in front of the circumferential slots (4) for receiving the blow bars. A rotor according to claim 4, characterized in that the shells (3) are hollow and the cavities (15) have reinforcing ribs (16) oriented radially and in the circumferential direction and the reinforcing ribs terminate inwards with a radius which corresponds to the radius of the rotor disks (18 ) corresponds. Rotor according to claim 5, characterized in that the slot-like depressions (7) and thus the longitudinal weld seams (6) are covered by plates (12) which have positive-locking guide pieces (10) which can be inserted axially into the depressions (7) and by means of the positive-locking connection (11) are held against the outward centrifugal forces. A rotor according to claim 1 or 4, characterized in that the rotor casing (2) is divided into segments (13) which, starting from the blow bars (5) counter to the direction of rotation of the rotor (1), have a spiral inclination in the direction of the axis (Z) Have jacket surface (14). Rotor according to claim 1 or 4 for one-sided impact bars, which can be positively inserted into the circumferential slots of the rotor, which have an offset towards the rear - against the direction of rotation of the rotor - and facing it, with which they engage in a longitudinal undercut of the circumferential slots and counter to the Centrifugal force of the rotating rotor are held, with a contact surface with which the blow bars are held against contact of the rotor and with a support surface, via which the blow bars engage with the undercut in the circumferential slots by means of a support or contact piece, characterized in that that to hold the blow bars (5) on their arcuate bends (21), the circumferential slots (4) in the rotor shell (2) have an approximately radially oriented, extending across the width of the rotor shell plane as contact surface (30), which in a arched rear chopping (22) and the circumferential slots (4) have an abutment piece (24) with an arcuate support surface (25) with respect to this arcuate undercut, taking into account the thickness of the blow bars (5), the pivot point (26) of the smaller radius (R1) of the arc on the contact surfaces (30) at a considerable distance (dimension X) from the fulcrum (27) of the larger radius (R2) of the arc on the support surface (25) in the direction of the impact circle (28) of the blow bar (5) and the The two pivot points in a line (L) run approximately parallel to the striking surface (29) of the striking bar, the contact surfaces (30) being at an obtuse angle (α) to each other in the extension of the smaller arc. Rotor according to claim 9, characterized in that the distance (X) of the pivot points (26/27) of the radii (R1 / R2) to the remaining height (Y) of the blow bars (5) built into the rotor has a ratio of 1: 7 to 1:15, preferably 1:10 Rotor according to claim 9, characterized in that the obtuse angle (α) between the contact surfaces (30) lying in the extension of the smaller arc is 120 °. Rotor according to claim 9, characterized in that the support or contact piece (24) is designed to be exchangeable. Rotor according to claim 9, characterized in that the peripheral slots (4) for receiving the blow bars (5) on their inner, approximately radially extending and longitudinally aligned over the rotor width limiting surface (33) one of the end face on the bend (21) Have impact-shaped segment-shaped groove (32) extending over the width of the rotor. Rotor according to claim 13, characterized in that a profile rod (34) can be introduced into the space between the segment-shaped groove (32) in the circumferential slots (4) and a segment-shaped groove (31) of the built-in blow bars (5). Rotor according to claim 1 or 9, characterized in that in the area of the contact surfaces (30) for the blow bars (5) there is a cam (39) slightly projecting over the contact surfaces, via which a recess (40) provided in the blow bars (5) is provided. is turnable.

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