US3841573A

US3841573A - Grinding apparatus for fibrous material

Info

Publication number: US3841573A
Application number: US00288944A
Authority: US
Inventors: A Kahmann
Original assignee: Escher Wyss GmbH
Current assignee: Sulzer Escher Wyss GmbH
Priority date: 1971-09-17
Filing date: 1972-09-14
Publication date: 1974-10-15
Anticipated expiration: 1991-10-15
Also published as: DE2146547A1; JPS4848705A; AT319728B; FR2152281A5; JPS5527197B2; BR7206437D0; IT964369B; GB1406816A; CA971018A; SE393646B; DE2146547B2

Abstract

Grinding device, more especially a disc refiner for the paper industry, which grinding device comprises, in a housing having two end covers, a rotor and a stator which is displaceable axially relatively to the rotor and which is guided radially but non-rotatably relatively to the housing in guideways on the housing, which stator is connected to a cylindrical part which is coaxial with the stator and with the grinding device and which extends outwardly through a central opening in one of the end covers and is sealed off relatively to the central opening, the improvement that said guideways for said stator are situated outside the range of the stock to be ground.

Description

United States Patent [1 1 [111 3,841,573 Kahmann Oct. 15, 1974 [541 GRINDING APPARATUS FOR FIBROUS 2,971,704 2/1961 .lohansson 241 2591 x M ERI L 3,212,721 10/1965 Asplunt et a1. 241/37 3,717,308 2/1973 Reinhall 241/244 [75] lnventor: Albrecht Kahmann, Weingarten,

. Germany Primary ExaminerRoy Lake [73] Assigne'e: Escher Wyss G.m.b.l-l., Ravensburg, Assistant Examiner-Heward Goldberg Germany Attorney, Agent, or Firm-Robert A. Ostmann [22] Filed. Sept. 14, 1972 ABSTRACT [211 App!- 288944 Grinding device, more especially a disc refiner for the paper industry, which grinding device comprises, in a [30 Foreign Appncation priority Data housing having two end covers, a rotor and a stator Swt 17 1971 Germany 2146547 which is displaceable axially relatively to the rotor and which is guided radially but non-rotatably relatively to [52] U S U 241/245 241/259 2 the housing in guideways on the housing, which stator [51] 7/06 B026 7/1'4 is connected to a cylindrical part which is coaxial with [58] Field 245 5 1 259 2 the stator and with the grinding device and which ex- 5 25 3 tends outwardly through a central opening in one of the end covers and is sealed off relatively to the cen- [56] References Cited tral opening, the improvement that said guideways for said stator are situated outside the range of the stock UNITED STATES PATENTS to be ground 2,412,680 12/1946 Fisher et a1. 24l/259.l 2,930,534 3/1960 Baxter 241/2591 x 3 Clalms, 1 Drawing Figure 20 13' 11; 5, 1. 4 5 22 Q 19 6 i L L j g 1 8 F'T} L 11 51:; 1o 7 .J

1 s E 23 13 12 L 6% 1 B GRINDING APPARATUS FOR FIBROUS MATERIAL BACKGROUND OF THE INVENTION The invention relates to a grinding device, more especially a disc refinerfor the paper industry, which device comprises, in a housing having two end covers, a rotor and a stator which is displaceable axially rela' tively to the rotor and which is guided radially but nonrotatably in relation to the housing in guideways on the housing, which stator is connencted to a cylindrical part which is coaxial with the stator and the grinding device, the said part extending outwardly through a central opening in one of the end covers and being sealed'off relatively to the central opening.

Such grinding devices are used in the paper industry for preparing the stock to be treated in a paper machine. Since the guideways in the known constructions are arranged on the periphery of the displaceable stator in the housing, the fibres which are inthe stock cause a clogging of the guideways. In time, the displacement of the stator for the mutual adjustment relatively to the rotor is blocked and as a result it becomes necessary to stop the grinding device.

Constructions are also known in which the stator is guided by means of rods which are perpendicular to it and which are mounted for sliding movement in the end cover. The deposited fibres also remain adhering to these rods and in time block the displacement.

The worst feature with all prior constructions is that the blocking action is not even at the separate guiding points and the stator assumes an angle and thereby becomes jammed. Since strong pressuresare used for the displacement, this leads to serious damage to the grinding device.

SUMMARY OF THE INVENTION The invention has for its object to increase the freedom from disruption and the effective life of the grinding device.

According to the invention, this object is achieved by the guideways of the displaceable stator being disposed outside the range of the stock which is to be ground.

This is achieved in advantageous manner by the guideways being arranged on the outside of the end cover and being connected to the cylindrical part by connecting elements lying outside the range of the stock which is to be ground, and advantageously the guideways are arranged with circular symmetry around the axis of the grinding device and with advantage each guideway comprises a sleeve which is parallel to the axis of the grinding device and a bolt mounted for displacement in the said sleeve, the guideways being connected by arms to the cylindrical part.

BRIEF DESCRIPTION OF THE DRAWING One constructional example of the invention is hereinafter more fully described by reference to the accompanying drawing.

The drawing shows a grinding device according to the invention in longitudinal section.

DESCRIPTION OF THE PREFERRED EMBODIMENT The shown device is a tandem-disc refiner, which comprises a rotor 4 in a housing 1 which has a first end cover 2 and a second end cover 3. The rotor 4 is supported by means of a shaft 7 between a stator 5which is fixed on the end cover 2 and a displaceable stator 6. The shaft 7 is mounted in a bearing block 8 so as to be fast radially of the housing 1 but axially displaceable, and is sealed off. It is connected while being axially displaceable to a driving motor (not shown). The displaceable stator 6 is formed with a central opening9 and is connected by means of spokes 10 to a cylindrical part 11 which is coaxial with the stator and the grinding device, the said part extending outwardly through a central opening 12 of the end cover 3 and being sealed off relatively to the central opening 12. The stator 6 is displaceable axially in relation to the rotor 4, but with respect to the housing 1, this stator 6 is guidedradially and non-rotatably be means of guideways 13. The guideways 13, of which those indicated ad 13' and 13" are visible in the drawing, are situated outside the range of the stock which is to be ground. What is understood by the range of the stock is the region of the passage of I the stock through the grinding device. The stock, arriving through the entry opening 14 which opens tangentially into the housing 1, is moved in approximately helical form in the space between the end cover 3 and the displaceable stator 6,.passes through the opening 9 and advances partially through the gap 15, partially through the rotor 4 formed with openings 16 and through the gap 17, whereafter it leaves the grinding device through an outlet opening 18.

The guideways 13 are arranged on the outside of the end cover 3 and are connected to the cylindrical part 11 by connecting elements, a bolt 19 and an arm 20. These

elements

19 and 20 also lie outside the range of the stock to be ground. The guideways 13 are arranged, each offset by so as to have circular symmetry around the axis of the grinding device. In the longitudinal section, only the guideway indicated at 13' is to be seen. The second, in side elevation, is indicated at 13'. The third guideway cannot be seen in the drawing. Each guideway 13 comprises a sleeve 21 which is parallel to the axis of the grinding device and is fixed on the end cover 3, and a bolt 19 mounted to be displaceable in the sleeve 21. The bolt 19 is fixed on the arm 20, which is connected at the other end to the cylindrical part 11. Because of the arrangement of the guideways 13 outside the range of the stock to be ground, the fibres which are in this stock are unable to interfere with the freedom of movement of the guideways.

The movement of the displaceable stator 6 is assured by means of a hydraulic servomotor 22, of which the piston 23 is connected to the cylindrical part 11. The part 11 serves as a piston rod of the motor 22.

I claim:

1. A grinding device including a housing having two end covers and containing a stator disc which is provided with a central opening and which, with an adjacent one of said end covers, bounds a space which is charged with stock during operation of the grinding device, the stator disc being movable axially relatively to a rotor disc with which it defines a grinding gap and being connected with a cylindrical part which is coaxial with that disc and the housing and projects from the latter through a central opening in said adjacent end cover and is sealed relatively thereto; a servomotor connected to the cylindrical part and serving to effect axial movement of the stator disc; and guideway means, including cooperating elements connected; respectively with the stator disc and the housing, for guiding adjacent end cover and to said cylindrical part.

3. A grinding device as defined in claim 1 in which the cooperating elements of each guideway means comprise a sleeve which is parallel with the cylindrical part, and a bolt mounted in the sleeve for reciprocation relatively thereto; and one, element of each guideway means is connected with the stator disc through an arm fixed to the cylindrical part.

Claims

1. A grinding device including a housing having two end covers and containing a stator disc which is provided with a central opening and which, with an adjacent one of said end covers, bounds a space which is charged with stock during operation of the grinding device, the stator disc being movable axially relatively to a rotor disc with which it defines a grinding gap and being connected with a cylindrical part which is coaxial with that disc and the housing and projects from the latter through a central opening in said adjacent end cover and is sealed relatively thereto; a servomotor connected to the cylindrical part and serving to effect axial movement of the stator disc; and guideway means, including cooperating elements connected; respectively with the stator disc and the housing, for guiding said stator disc for said axial movement; and characterized in that there are a plurality of said guideway means which are distributed equiaNgularly about the axis of the cylindrical part and which are situated outside said space charged with stock, whereby clogging of the guideway means by the stock is precluded.

2. A grinding device as defined in claim 1 in which the cooperating elements of the guideway means are connected, respectively, to an outside surface of said adjacent end cover and to said cylindrical part.

3. A grinding device as defined in claim 1 in which the cooperating elements of each guideway means comprise a sleeve which is parallel with the cylindrical part, and a bolt mounted in the sleeve for reciprocation relatively thereto; and one element of each guideway means is connected with the stator disc through an arm fixed to the cylindrical part.