EP2883612A1 - Rolling mill and assembly for driving a rolling mill - Google Patents

Abstract

The object of the invention is that a roller mill with a displaceable roller (1 ') is driven via an electric motor (2) with a rotor (21) displaceably mounted in the axial direction. In this case, the displaceable roller (1 ') is mounted in the axial direction and in the radial direction. A constant length joint shaft (3) is disposed between the electric motor (2) and the slidable roller (1 ') so that the rotational movement of the rotor (21) can be translated into rotational movement of the slidable roller (1'). In the case of a displacement of the displaceable roller (1 ') orthogonal to the axial direction of the displaceable roller (1') same joints of the joint shaft, the resulting angular displacement of the shaft of the displaceable roller (1 ') and the shaft of the electric motor (2). The resulting change in the distance between the shaft of the displaceable roller (1 ') and the shaft of the electric motor (2) compensates for the rotor (21) by an axial movement.

Description

TECHNICAL AREA

The present invention relates to the field of roll mills. It relates to a roller mill with two counter-rotating rollers, which are rotatably mounted in a frame, and an arrangement for driving such a roller mill.

STATE OF THE ART

Roll mills are used for grinding materials, in particular ores and cement. Roll mills typically have a roll diameter of 0.8 to 3 meters and a drive power of 0.2 to 5 megawatts. They are particularly energy efficient compared to other mill types. Such a roller mill is used for example in DE 4028015 A1 described.

As in Fig. 1 schematically illustrated, a roller mill comprises two counter-rotating rollers 1,1 ', which rollers 1,1' are mounted horizontally and parallel to each other in a frame rotatably. One of the two rollers 1 is usually fixed in the radial direction and another of the two rollers 1 'is pressed by a spring system on the fixed roller 1. Each roller 1,1 'has a grinding surface. The opposite grinding surfaces of the rollers 1,1 'form a wedge. Material is filled from above between the rollers 1,1 'in the wedge, guided by the rotation of the rollers 1,1' down and crushed by the wedge. The rotation of the rollers 1,1 'via a drive. In known drives for roll mills, an electric motor via movable mechanical elements with one of the rolls or indirectly connected to both rolls.

Fig. 2 shows a roller mill with two drives. Depending on a drive is assigned to one of the rollers 1,1 'and includes an electric motor 2, a propeller shaft 3 and a planetary gear 4. The connection of the radially displaceable roller 1' with the stationary electric motor 2 via the propeller shaft 3. Optionally, it is also possible in that the articulation shaft is connected directly to the shaft of the displaceable roller and the planetary gear is arranged between the articulated shaft and the electric motor. In such an arrangement, such as in DE 10211000749 A1 described, the electric motor and the planetary gear are stationary. Optionally it is also possible to use a motor and a gearbox to drive both rollers. In this case, the transmission distributes the torque to both rollers. Optionally, it is also possible that the electric motor delivers the desired speed for the rollers without a speed adjustment of a transmission. In this case, the drive does not comprise a gearbox and the electric motor is connected directly to the roller via the cardan shaft.

Fig. 3 shows two rollers with one drive each. A displacement of the displaceable roller 1 'causes the shaft of the stationary electric motor 2 and the shaft of the displaceable roller 1' are no longer aligned. The radial displacement between the shafts is compensated by movements in joints 31 of the propeller shaft 3. Since the displaceable shaft 1 'shifts substantially orthogonal to the axial direction, the distance between the joints 31 of the joint shaft 3 is extended. The necessary length adjustment of the propeller shaft 3 is realized by a telescopic mechanism 32.

Fig. 4 shows a hinge shaft with a telescopic mechanism. In this case, the propeller shaft 3 between the joints 31 in the axial direction of the propeller shaft 3 displaceable, straight spur gear teeth 32. This makes possible, that the propeller shaft 3 has a variable length and can transmit a torque. The problem with this solution is that a propeller shaft with telescopic mechanism is very expensive and maintenance-intensive. The sliding surfaces of the toothing must always be lubricated. Due to the very dirty and dusty working environment, which work environment is caused by the grinding process, a very frequent maintenance, such as in a weekly rhythm, is necessary. Otherwise, there is not enough lubricant on the toothing and there is a massive abrasion and wear due to friction in the area of the toothing. But even with sufficient maintenance, propeller shafts with telescopic mechanisms in this arrangement prove in mill rolls due to notch effects and the axial movement in a confined space as prone to error and often lead to failure of the mill.

Fig. 5 shows a displaceable roller 1 'with an associated drive. The displaceable roller 1 'has a radial bearing 11 and an axial bearing 12. Alternatively, one of the radial bearings can be combined with the axial bearing in a combined axial-radial bearing. An electric motor 2 has a rotor 21 and a stator 22. The rotor is supported by a radial bearing 23 and an axial bearing 24. A pivot shaft 3 connects the displaceable shaft 1 'with the rotor 21 of the electric motor 2. The necessary length adjustment of the propeller shaft 3 with a displacement of the displaceable shaft 1' is realized by a telescopic mechanism 32.

PRESENTATION OF THE INVENTION

The object of the present invention is to provide a roller mill and an arrangement for driving a roller mill, which are less maintenance-intensive and less error-prone.

This object is achieved by a roller mill and an arrangement for driving a roller mill with the features of the independent claims. Preferred embodiments are subject of the dependent claims.

The object of the invention is that a displaceable roller of a roller mill is connected to an electric motor via a hinge shaft of invariable length. The displaceable roller is mounted in the axial and radial directions. The electric motor has a rotor which can be displaced in the axial direction. By this floating mounting of the rotor of the electric motor, it is possible to change the distance between the fixed stator of the electric motor and the displaceable shaft due to displacements of the displaceable shaft orthogonal to the axial direction of the displaceable shaft without using a telescopic mechanism and using a propeller shaft to compensate for constant length. This allows a simpler design with a lower maintenance requirement and a lower susceptibility to errors.

BRIEF DESCRIPTION OF THE FIGURES

Figur 1

eine schematische Darstellung des Mahlprozesses einer Walzenmühle gemäss dem Stand der Technik;

Figur 2

eine perspektivische Darstellungen einer Walzenmühle mit zwei Antrieben gemäss dem Stand der Technik;

Figur 3

zwei Walzen mit je einem Antrieb gemäss dem Stand der Technik in einer Draufsicht;

Figur 4

eine Gelenkwelle mit Teleskopmechanismus gemäss dem Stand der Technik in einer Draufsicht;

Figur 5

eine schematische Darstellung eines Axial-schnittes einer verschiebbaren Walze mit einem Antrieb gemäss dem Stand der Technik; und

Figur 6

eine schematische Darstellung eines Axialschnittes einer verschiebbaren Walze mit einem erfindungsgemässen Antrieb.

The invention will be explained in more detail by means of exemplary embodiments in conjunction with the figures. The figures show:

FIG. 1

a schematic representation of the milling process of a roll mill according to the prior art;

FIG. 2

a perspective views of a roller mill with two drives according to the prior art;

FIG. 3

two rolls, each with a drive according to the prior art in a plan view;

FIG. 4

a propeller shaft with telescopic mechanism according to the prior art in a plan view;

FIG. 5

a schematic representation of an axial section of a sliding roller with a drive according to the prior art; and

FIG. 6

a schematic representation of an axial section of a displaceable roller with an inventive drive.

The reference numerals used in the drawings are summarized in the list of reference numerals. Basically, the same parts are provided with the same reference numerals.

WAYS FOR CARRYING OUT THE INVENTION

Fig. 6 shows a displaceable roller with a drive according to the invention. The displaceable roller 1 'has a radial bearing 11 and an axial bearing 12. An electric motor 2 has a rotor 21 and a stator 22. The rotor 21 is guided over a radial bearing 23 so that the rotor 21 is displaceable in the axial direction. A fixed shaft joint shaft during operation of the roller mill connects the displaceable shaft to the electric motor 2.

Optionally, it is possible for the axial bearing of the drive to be arranged on the propeller shaft or the rotor instead of on the displaceable roller. Optionally, it is possible that the drive has a gear, such as a planetary gear, wherein the gear between the propeller shaft and the displaceable roller is arranged. The transmission is supported so that there is no relative movement between the gear and the slidable roller and the transmission experiences the same movements orthogonal to the axial direction of the slidable roller as the slidable roller itself. Optionally, it is possible that the PTO shaft is out of position Operating the roller mill has an adjustable length, for example in the form of a telescopic mechanism with a locking screw.

LIST OF REFERENCE NUMBERS

1, 1 '

roller

11

Radial bearing of the roller

12

Thrust bearing of the roller

2

electric motor

21

rotor

22

stator

23

Radial bearing of the rotor

24

Thrust bearing of the rotor

3

propeller shaft

31

joint

32

spur

4

planetary gear

Claims (6)

Comprising roller mill
two parallel juxtaposed and counter-rotating rollers (1,1 '), wherein
one of the rollers (1 ') is displaceable orthogonal to the axial direction of this roller (1'), and wherein
the displaceable roller (1 ') is mounted in the axial and radial directions and
a drive comprises which drive
an electric motor (2) and
a propeller shaft (3), wherein the electric motor (2)
a rotor (21) and
a stationary stator (22), and wherein
the articulated shaft (3) is arranged between the rotor (21) and the displaceable roller (1 ') such that the articulated shaft (3) can transmit a rotational movement of the rotor (21) to the displaceable roller (1')
characterized in that
the rotor (21) is displaceably mounted in the axial direction and that
the propeller shaft (3) has an invariable during operation of the roller mill length. Roller mill according to claim 1, characterized in that the roller mill comprises a gear (4), which gear (4) between the displaceable roller (1 ') and the propeller shaft (3) is arranged and orthogonal to the axial direction of the sliding roller (1' ) is slidably mounted so that the transmission (3) relative to the displaceable roller (1 ') is stationary. Roll mill according to claim 2, characterized in that the transmission (4) is a planetary gear. Roll mill according to one of claims 1 to 3, characterized in that the radial bearing 23 of the rotor (21) has two plain bearings. Arrangement for driving a roller mill with
a displaceable roller (1 '), which displaceable roller (1') orthogonal to the axial direction of the displaceable roller (1 ') is displaceable, wherein the arrangement
an electric motor (2) and
a propeller shaft (3), wherein the electric motor (2)
a rotor (21) and
a stationary stator (22), and wherein
the articulated shaft (3) can be arranged between the rotor (21) and the displaceable roller (1 ') such that the articulated shaft (3) can transmit a rotational movement of the rotor (21) to the displaceable roller (1'), characterized that
the rotor (21) is displaceably mounted in the axial direction and
the propeller shaft (3) has a fixed length. Arrangement according to one of claims 5, characterized in that the radial bearing 23 of the rotor (21) has two plain bearings.

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