DE1811187A1 - Two press grinder - Google Patents

Description

ap / A 2898 J.M. Voith GmbH

Keyword: "Eccentric Sander" Heidenheim (Brenz)

Two press grinder

The invention relates to a two-press grinder for producing wood pulp, with a shaft arranged horizontally attached grinding stone rotating in a certain direction, and with two the grinding wood against the surface of the grinding stone pressing presses arranged on opposite sides, each with a horizontal press axis.

With such a two-press grinder, grip the grindstone its own weight as well as forces generated by the pressing pressures. The magnitudes and directions of these forces depend on in which horizontal plane the presses are arranged with their press axes in relation to the shaft axis of the grindstone. Are the If the pressing axes are arranged in the same horizontal plane as the shaft axis, e.g. according to DBGM 1 975 587, the pressing pressures each have a horizontal force and a circumferential force. The circumferential forces act as reaction forces against the peripheral speed, see above that the circumferential force generated by one press is directed upwards, which is directed downwards by the other. Unless the 'pressing pressures are equal, the horizontal forces acting on the shaft bearings and the circumferential forces against each other cancel each other out So the bearing of the grindstone shaft does not, so that only the weight of the stone has to be absorbed by the bearings. This then rests on the lower portion of the bearing surfaces of the shaft. If one of the presses is loaded less than that other, which is due to the different nature of the wood cannot be avoided, or this press is used for the purpose

009824/0995

their loading with grinding wood completely relieved, so over- .. weighs the horizontal force generated by the other press and., circumferential force. Since the circumferential force is often greater than the Stone weight> this can be overcompensated, so the off Stone weight, horizontal force and circumferential force resulting Force to be directed upwards, so that contrary to the aforementioned Case, now the upper area of the storage area is loaded will. Because the shaft is opposite to the bearing surface surrounding it has radial play, it is moved soon upwards soon downwards at different pressures in the two presses, it can also be printed on one or the other side in the upper or lower area. A Such constant changes in the position of the grinding stone shaft make the construction of the bearing more difficult with regard to lubrication, causes the shaft to run unevenly and can affect the quality of the grinding. ·

In another known type of a. Double press grinder, (US Pat. No. 1,917 A20) are the presses with their two press axes arranged below the horizontal plane laid by the shaft axis. Due to this arrangement, the pressure of both Pressing apart from the horizontal force and the circumferential force still ever a vertically upward force component that counteracts the weight of the stone. With that, however, should Another problem to be solved than the one presented here: One wanted to achieve that the stone weight at least partially compensated, and is completely canceled at correspondingly large pressing pressures, so that the bearings of the shaft. become unencumbered. Since the The size of the pressing pressures, however, is not freely selectable, but is determined according to technological aspects, can turn result in an overcompensation of the stone weight (with the shaft resting on the upper area of the bearing surface), or a Undercompensation (with adjacent to the lower bearing surfaces Shaft), so the grindstone shaft oscillates between the upper and the lower part of their bed back and forth, so that the disadvantages mentioned exist. .

009824/0995

Two press grinders are also known (US Pat. No. 1,757,03I), in which the pressing axes are arranged at an angle to the horizontal plane laid by the shaft axis, namely in such a way that the pressure always pushes the stone downwards. However, this V-shaped arrangement of the presses creates an oblique angle Formation of the press frames, filling chutes, etc. with it, which is disadvantageous in production, and also makes it more difficult to lubricate the sliding surfaces compared to a horizontal arrangement the press cylinder.

The invention has the object of providing a press grinder with two horizontally disposed press axles such trainees' .m form that the grind stone shaft is always applied on the same side of its bearing surface with changing pressing pressures.

This object is achieved according to the invention in that at least that press is arranged with its pressing axis above the axis of rotation of the grindstone which is on the side on which the peripheral speed is directed downwards. This arrangement generates a force component directed vertically downwards in addition to the circumferential force and the horizontal force. This counteracts the circumferential force directed upwards on this end face and thus reduces the tendency of the grinder shaft to rest against the upper area of its bearing surfaces, i.e. it reduces the pressure on the shaft M in the upper area of the bearing surfaces. This is also the case when the pressing pressure generated by the other press and thus the associated downwardly directed circumferential force decreases or when the grindstone even runs empty. In every case, it is the lower bearing surface area that takes the main load, so that the lubrication can primarily concentrate on this area. The above-mentioned vertically downwardly directed force is greater, the further the pressing axis is arranged above the shaft axis. If the distance between the two axes is chosen to be sufficiently large, the vertical force, together with the stone weight, can completely compensate for the upwardly directed circumferential force, so that the shaft is only in the lower area

009124/0995 ./.

their storage area. "Swimming" of the wave, i.e. swinging up and down, is then avoided. This will a smooth run of waves and stones and thus an even shuff quality is achieved.

So while one of the two presses, namely the peripheral speed on the side facing downwards, in any case is to be arranged with its pressing axis above the shaft axis, the other press can be in the same Horizontal plane can be arranged like the shaft axis or even below this horizontal plane; because that produced by it j- | Circumferential force acts downward, pushes it regardless of size their contact pressure the shaft always in the desired manner against the lower area of the bearing surface. To simplify manufacturing of the grinder is provided in a further embodiment of the invention, the two presses with their press axes to be arranged in the same horizontal plane, so that the pressing axes are aligned with one another.

Of course, the application of the invention is not limited to a grinder in which the sanding wood through Pressing is pressed against the peripheral surface of the stone, rather, revolving chains can take the place of the presses. The only thing that is essential is that the grinder should be able to do two things has grinding zones located on opposite sides of the stone.

The invention is explained in more detail with reference to the drawing. In this demonstrate:

Fig. 1 is a schematic representation of a two-press grinder with the vectors of the forces acting on the grindstone,

FIG. 2 is a diagram of the vertical vectors of the one press of FIG. 1.

Q0982W0995

The one in Pig. I grinder has two horizontal presses I, II , which are arranged with their pressing axes above the axis of rotation of the grindstone S. In each of the two presses there is a pressing pressure P or P. Due to the arrangement of the pressing axes above the axis of rotation of the grinding stone, the pressing pressures P ₁ and P ₃ each generate a force acting on the grinding stone S, R and R ·. These can be broken down into horizontal components P _U1 , P " _o and vertical components

JtIl nc

Disassemble P. Pp. In addition to the weight G of stone and shaft, the two circumferential forces U. and U _{3 act} on stone S, each in turn separable into horizontal components U "·" Upio and vertical components U- ,, Uq. I ⁿ the present case, the compression pressures P and P, and thus the acting on the stone, each corresponding forces according to their size the same. It can be seen that the resultant, not shown here, of all forces acting on the grindstone must have a downward component, so that in the case of equality of forces shown here, the lower part of the bearing surface of the shaft bearing is loaded.

If the press II fails, only the weight G and the _{forces generated by the force P 1 act} on the grindstone S. All vertical components of these forces (including weight G) are shown in FIG. The resultant R of these vertical components again points downwards, which means that in this case too the lower part of the bearing surfaces of the shaft bearings is loaded.

Heidenheim, November 22nd 1Q68

DrW / EHb 009824/0 99

Claims (2)

ap / A 2898 ■■ ί ■ ;; ■ patent claims 1. Two-press grinder for producing wood pulp, with a horizontally mounted shaft in with a certain direction of rotation, and with the grinding wood against the surface of the grinding stone pressing, arranged on opposite sides of the grinding stone presses each with horizontal Press axle, characterized in that at least one Press (I) with its pressing axis above the axis of rotation of the Grinding stone (S) is arranged, which you can see on the side of the grindstone (S), on which its peripheral speed is directed downwards. 2. Two press grinder according to claim 1, characterized in that that the two presses (I, II) are arranged with their pressing axes in the same horizontal plane. Heidenheim, the
DrW / EHb