GB2056878A

GB2056878A - Rolling mill for grinding purposes

Info

Publication number: GB2056878A
Application number: GB8019789A
Authority: GB
Original assignee: Buehler Miag GmbH
Current assignee: Buehler Miag GmbH
Priority date: 1979-06-22
Filing date: 1980-06-17
Publication date: 1981-03-25
Also published as: ES8102705A1; DE2925126A1; GB2056878B; FR2459684A1; FR2459684B1; JPS565148A; DE2925126C2; ES492603A0

Abstract

A rolling mill for grinding purposes comprises at least one pair of rollers, with one roller of each pair being mounted in two fixed bearing members 6 and the other roller being mounted in two movable bearing members 7, of which associated fixed and movable bearing members rest against each other and are connected to each other by an engagement and disengagement mechanism and a device 27, 28 for adjusting the width of the grinding gap between the rollers. The connection by a cylinder 23 is such as to result in a system in which the forces resulting from the grinding operation and acting on the two rollers cancel one another out. In order to facilitate replacement of the rollers, each fixed bearing member is adjustably fixed to a side portion of the rolling mill which lies normal to the longitudinal axes of the rollers. This side portion 8 simultaneously serves as a wall of the grinding chamber and is mounted so as to be capable of being pulled away in the longitudinal direction of the rollers. <IMAGE>

Description

SPECIFICATION Rolling mill for grinding purposes The invention relates to a rolling mill for grinding purposes.

Rolling mills for grinding purposes have been proposed in German Patent Specification No. 854,872 which have at least one pair of rollers, one roller of each pair being mounted in two fixed bearing members and the other roller being mounted in two movable bearing members, and in which associated fixed and movable bearing members rest against one another and are connected to one another by means of an engagement and disengagement mechanism and an adjusting device for the grinding gap to form an inherently closed connection.

Compared with the numerous older rolling frame designs in which the grinding forces are introduced into the roll housing, rolling mills of this proposed construction have the advantage that they constitute a system which is totally enclosed in terms of the forces present, since the forces from the grinding operation cancel each other out. A further advantage is that these rolling mills generaily form compact units which include, in addition to the two rollers, all the bearings, linkage and securing members, adjusting means and guide means for the material and the components of the drive associated with the rollers, and can thus be assembled or dismantled as a complete unit (see German Offenlegungsschrift No. 25 39 153).

However, the possibility of replacing socalled roller sets of this kind in a roller frame with relative ease, when the rollers have become worn, for example, has to be set against the need to store these entire roller sets and to have lifting equipment available (since the roller sets are preferably intended for high outputs and are therefore very heavy). Moreover, the subsequent dismantling of the roller sets as such in order to change a roller is relatively complicated and is therefore not economically viable for certain applications, such as the grinding of malt, seeds, etc. at lower outputs.

It is an object of the invention to provide an improved rolling mill for low or medium pressure levels, so arranged that, without substantially forfeiting the advantages of the so-called roller set, rollers can easily be replaced directly at the site of the machine, i.e. even by untrained personnel and without the use of lifting gear.

According to the invention, there is provided a rolling mill for grinding purposes, wherein the mill comprises at least one pair of rollers one roller of each pair being mounted in two fixed bearing members and the other roller being mounted in two movable bearing members of which associated fixed and movable bearing members rest against each other and are connected to each other by an en gagement and disengagement mechanism and a device for adjusting the width of the grinding gap between the rollers, the connection being such as to result in an inherently closed force flow system, and wherein each fixed bearing member is adjustably fixed to a side portion of the rolling mill which lies normal to the longitudinal axes of the rollers, this side portion simultaneously acting as a wall partly defining a grinding chamber and mounted so as to be capable of being pulled away in the longitudinal direction of the rollers. Thus, by simply pulling away one or both side portions of the rolling mill, the rollers are made accessible and can readily be removed using a simple support means. Moreover, the side portions of the rolling mill which are constructed as smooth walls on the side facing the grinding chamber render a separate wall for the grinding chamber unnecessary and at the same time ensure good sanitary conditions and provide a good seal.

The side portion of the rolling mill preferably consists of a plate surrounded by a box frame and fixedly connected thereto, and each plate is provided with two fittings for receiving the fixed bearing member. The construction is both economical and stable; in conjunction with the extent of the box frame in the direction leading away from the grinding chamber and the depth of the frame, the following advantages are obtained without any additional components:: -unobstructed access to the fixed and movable bearing members and to the bearings, the foreign body securing means or engagement and disengagement mechanism and adjustment means, -total enclosing of all these members in the longitudinal direction of the roller, -the possibility of attaching the rolling mill itself and its top and side walls, -the possibility of assembling a plurality of rolling mills one above the other.

Finally, adjusting screws for adjusting the fixed bearing member in a plane parallel to the plate are conveniently provided in a vertical wall of the box frame. This adjustment is carried out before the mill is set in operation.

Because the fixed bearing member is conneted to the movable bearing member, they are both adjusted together in one operation.

In order to enable the invention to be more readily understood, reference will now be made to the accompanying drawings, which illustrate diagrammatically and by way of example an embodiment thereof, and in which: Figure 1 is an end elevation of a rolling mill, and Figure 2 is a section on the line Il-Il in Fig.

1.

Referring to the drawings, there is shown a rolling mill 1 consisting of two grinding rollers 2 and 3 which are each mounted at both ends with their bearing pins 4 and 5 respectively in two fixed bearing members 6 and loose bearing members 7. The bearing members 6 and 7 are held by two side portions 8 of the rolling mill. A side portion 8 consists of a plate 9 and a frame 10 welded thereto and acts both as a support and as a wall bounding a grinding chamber 1 5. Vertical and horizontal walls 1 Oa and 10b of the frame 10 form abutment surfaces for top and side walls 11 and 12, respectively, surrounding the rolling mill; the horizontal walls 1 Ob may also serve as abutment and fixing surfaces for additional rolling mills if several rolling mills are assembled to give a plurality of grinding passages.

Nuts 1 3 are welded on to the vertical walls 1 Oa of the frame 10 for fixing the side walls 1 2. Two circular recesses 14 are formed in the plate 9 for the passage of the bearing pins 4 and 5. The recesses 14 are sealed off, in the direction remote from the grinding chamber 15, by sealing rings 29 which are fixed to bearing covers 1 6 b by means of bolts 30.

The fixed bearing member 6, consisting essentially of a fixed bearing lever 1 8 and provided with roller bearings 17, a bearing chuck 1 7a, a seal 1 7b and bearing covers 1 6a and 1 6b, is screwed by means of two screws 1 9 to two fittings 20 in the form of spacers which are welded 3n to the plate 9.

The loose bearing member 7, consisting essentially of a loose bearing lever 21 and also provided with roller bearings 17, a bearing chuck 1 7 a, a seal 1 7b and bearing covers 1 6a and 166, is pivotally connected to the fixed bearing member 6 by a bok 22.

The lower ends of the bearing levers 1 8 and 21 located opposite each other are hingedly connected to each other by a horizontally positioned pneumatic cylinder 23, thus forming, between the rollers 2 and 3, the fixed bearing member 6 and the loose bearing member 7, a system which is sealed off in terms of force and in which the forces resulting from the grinding operation and acting on the two rollers 2 and 3 cancel one another out. Moreover, by corresponding prestressing, the cylinder 23 used for engaging and disengaging the loose bearing member 7 or the loose roller 3 allows the loose roller 3 to travel to the side if overloading occurs. A grinding gap 24 is adjusted by turning a stop screw 25.

On the vertical well 1 0a of the frame 10 which faces the fixed bearing member 6 there is a device for adjusting the grinding rollers 2 and 3. This device consists of a plate 27 welded to the frame 10 and two adjusting screws 28. After loosening the screws 1 9, or before these screws 1 9 are tightened, the grinding rollers 2 and 3 are adjusted at both ends so as to be axially parallel using the adjusting screws 28; because the fixed and loose bearing members are connected to each other, this need only be done to the fixed bearing member 6. There is a wide range of adjustment for the loose bearing member 7, thanks to the conditions of leverage.

In order to replace the grinding rollers 2 and 3, these rollers are first supported at both ends by a simple support means 26 indicated in the drawings. Then the front bearing covers 1 6a are removed and the chucks 1 7a are released. The screw connections between the frame 10 and the top and side portions 11 and 1 2 are undone and then the complete side portions 8 of the rolling mill can be pulled off the bearing pins 4 and 5. The grinding rollers 2 and 3 are replaced, and the rolling mill is reassembled in the reverse or der.

Claims

1. A rolling mill for grinding purposes, wherein the mill comprises at least one pair of rollers one roller of each pair being mounted in two fixed bearing members and the other roller being mounted in two movable bearing members of which associated fixed and movable bearing members rest against each other and are connected to each other by an engagement and disengagement mechanism and a device for adjusting the width of the grinding gap between the rollers, the connection being such as to result in an inherently closed force flow system, and wherein each fixed bearing member is adjustably fixed to a side portion of the rolling mill which lies normal to the longitudinal axes of the rollers, this side portion simultaneously acting as a wall partly defining a grinding chamber and mounted so as to be capable of being pulled away in the longitudinal direction of the rollers.

2. A rolling mill as claimed in Claim 1, wherein each side portion of the rolling mill consists of a plate surrounded by a box frame and fixedly connected thereto, and wherein each plate is provided with two fittings for the fixed bearing member.

3. A rolling mill as claimed in Claim 2, wherein the box frame extends in the direction leading away from the grinding chamber.

4. A rolling mill as claimed in Claim 3, wherein the walls of the box frame are constructed as abutment and fixing surfaces for the rolling mill itself and for top and side walls which surround the rolling mill longitudinally.

5. A rolling mill as claimed in Claim 3 or 4, wherein the walls of the box frame are constructed as abutment and fixing surfaces for additional similar rolling mills.

6. A rolling mill as claimed in any one of Claims 2 to 5, wherein the box frame has a depth such that in the direction remote from the grinding chamber it totally encloses the bearing members and all the parts connected thereto.

7. A rolling mill as claimed in any one of Claims 2 to 6, wherein adjusting screws for adjusting the fixed bearing member in a plane parallel to the plate are provided in a vertical wall of the box frame.

8. A rolling mill for grinding purposes substantially as hereinbefore described with reference to the ,Bccompanying drawings.