DK157478B - VERTICAL ROLLS - Google Patents

Description

in

DK 157478 B

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to a vertical rolling mill, which is rotatable with a vertical axis rotatable measuring table and at least one with a stationary, approximately horizontal rotatable milling roller, which is pressed down against the measuring table by a bias.

In known mills of the above-mentioned type, the axis of the roller lies in an axial plane through the measuring table, so that the roller tracks with the measuring path of the measuring table, i.e. that the tangents to the paint roller and the paint web in their common contact points are parallel.

Theoretically, therefore, no greater axial stresses on the grinding roller could arise from the pressure exerted by the material layer to be milled between the grinding roller and the grinding web; but in practice it has been found that the paint roller is in fact subject to rather large outward axial stresses, which in turn causes rather large effects on the bearing roller bearings and thus relatively short life of these.

These axial stresses are due to the fact that there is one relatively large difference in height of the layer thickness of the material before it enters and is compressed and the layer thickness of the compressed material layer under the roller. Therefore, the center of gravity of the material layer pressure against the grinding roller is not located vertically below the grinding roller, but a small distance ahead of the grinding roller seen in the direction of rotation of the measuring table. Thus, the tangent of the measuring table and thus the direction of the printing pressure at this location in front of the painting roller is not directed perpendicular to the aforementioned axial plane through the center of the roller. The grinding roller, and thus its bearings, is therefore influenced by the material with a force with a component in the axial direction of the roller.

The object of the invention is therefore to eliminate or at least reduce the aforementioned outward axial stresses on the roller bearings.

This is achieved according to the invention in that the axis of the grinding roller forms such an angle with the axial plane of the measuring table through the center of the roller that the roller is viewed from above from the inclination! with its front facing the material flow applied to the measuring table, closer to the axis of the measuring table than its rear.

It has been found that it is possible by such a rotation of the axis of the roller out of said axial plane of the measuring table

DK 157478B

2 to reduce the axial stresses on the paint roller resulting from the pressure against the material layer on the measuring table, thereby increasing the life of the paint roller bearings. This is because the painting pressure affects the roller more precisely and ideally at right angles to the roller axis.

The invention will be explained in more detail below with the aid of an embodiment of a mill according to the invention and with reference to the drawing, in which figure 1. schematically shows part of the mill as seen from the 10 "side and partly in vertical section, figure 2. the same mill part as seen from above, and Figure 3 · a detail of the left side of Figure 2 on a larger scale.

The drawing shows a measuring table 1 which rotates about a vertical axis supported and driven by an assembly inside the housing 2. Against the measuring table 1, in this example, three grinding rollers 3 which paint a material layer not shown on the measuring table 1 rest and roll. . Each roller 3 is mounted on a fixed shaft 4, which together with the shafts of the other rollers is fixed to a common central frame 5 ·

The shafts 4 may be attached in several ways to the frame 5j e.g. as shown by means of a flange 6 on each shaft and corresponding flanges 7 on the frame 5 · On the outer end of each shaft 4T is rotatably mounted a bracket 8, to which a drawbar 9 is attached and bias the roller against the measuring table 1f. eg. by means of a hydraulic cylinder 10 which is pivotally secured in a bracket 11 which is anchored to the foundation of the mill. The cylinder 10 may optionally be replaced by a system of springs.

The shafts 4 are held against movement in the direction of rotation of the measuring table, e.g. as shown in FIG. 2 by means of horizontal pull rods 12 attached at one end to the brackets 8 and at the other end connected, for example, to the mill housing not shown.

For example, the supply of the material to be ground may be effected "centrally on the measuring table 1 through an opening 13 in the middle of the frame 5. A stub ring 14 serves to determine the thickness of the material layer on the measuring table 1.

DK 157478B

3

As can be seen in Figures 1 and 2, and as will be explained in more detail in connection with Figure 3, the grinding rollers are slightly traced inwardly with the front of the rolling webs closer to the mill axis than the rear of the rolling webs, in relation to the direction of rotation of the drilling board 15 · In Figure 3 16 the vertical axis of the mill, ie. the rotation table lfs axis of rotation, 17 the center of the roller and 18 an axial plane determined by the axis 16 and the center of the roller 17. As can be seen, the axis 19 of the roller is rotated in a horizontal 10 plane a small angle α, preferably of the size between 1 ° and 5 ° in out of the axial plane. 18 and in the opposite direction of the measuring table rotation direction 15 ·

By 20 is indicated the point of attack of the printing press on the paint roller, and the size of the angle a is determined in such a way that the tangent of the measuring table at point 20 is perpendicular to the rolling axis 19 · Since the painting pressure is thus also in a plane perpendicular to the rolling axis 19, the grinding pressure will not affect the grinding roller in its axial direction, and the axial pressure in the roller bearings will be reduced relative to a roller whose 20 axis was in the axial plane 18.

It should be noted that the said reduction of the axial impact on a grinding roller is not limited to rollers rolling on a horizontal grinding path, but also applies to a more or less inclined downward slope towards the mill's 25 axis vertical grinding path.

Claims (2)

A vertical roller mill having a measuring table rotatable about a vertical axis and at least one milling roller rotatable about a stationary, approximately horizontal axis, which is pressed down against the measuring table by a bias, characterized in that the axis of the painting roller (19) forms such an angle ( a) measuring the axial plane (18) of the table through the center of the roller (17), the top view of the roller (3) with its front facing the material flow applied to the measuring table (1), closer to the axis (16) of the measuring table (1) than its back. 10 Mill according to claim 1, characterized in that the size of the angle a is between 1 ° and 5 °.