Twin roller crusher

Abstract

The invention relates to a dual-roller crusher (1) with rollers (2, 3) rotatably mounted in a crusher housing and are driven by a motor so as to counter-rotate synchronously about respective parallel center axes, crusher teeth (6, 7) being mounted on the outer surfaces of the rollers (2, 3), every crusher tooth (6, 7) of a roller (2, 3) of the pair of rollers being fittable into a respective pocket (8, 9) in the outer surface of the other roller (2, 3) of the pair of rollers such that, during rotation of the rollers (2, 3), each crusher tooth (6, 7) engages in the respective pocket (8, 9).

Claims

1. A dual-roller crusher comprising: a crusher housing; a pair of roller bodies rotatable about respective parallel axes, mounted in the crusher housing, and having respective outer cylindrical surfaces spaced apart by a clearance gap; a motor synchronously counter-rotating the roller bodies about the respective axes; and radially outwardly projecting crusher teeth mounted on the outer cylindrical surfaces of the pair of roller bodies, each crusher tooth of each roller body of the pair of rollers being paired with a pocket in the outer surface of the other roller body of the pair such that, during rotation of the pair of roller bodies, each crusher tooth can engage in the respective pocket of the other roller body, each crusher tooth projecting from the respective roller body by a radial tooth height greater than the clearance gap.

2. The dual-roller crusher according to claim 1, wherein a size and depth of each pocket is complementary to a shape and size of the respective crusher tooth.

3. The dual-roller crusher according to claim 1, wherein each pocket is dimensioned such that, during synchronous rotation of the pair of roller bodies, each crusher tooth is engaged in the respective pocket without touching a floor thereof.

4. The dual-roller crusher according to claim 1, further comprising: additional crushing projections on the outer surfaces of the pair of roller bodies and having radial heights smaller or the same as the clearance gap between the pair of roller bodies.

5. The dual-roller crusher according to claim 4, wherein the crusher teeth and the crushing projections are rowed along outer circumferential lines on the respective pair of roller bodies, and each roller body is provided with a plurality of the outer circumferential rows of crusher teeth and crushing projections spaced and parallel to each other.

6. The dual-roller crusher according to claim 5, wherein the circumferential lines are formed by annular elevations on an outer surface of the respective roller body carrying the crusher teeth and the crushing projections.

7. The dual-roller crusher according to claim 4, wherein the crusher teeth and the crushing projections of each roller body are axially offset on the surface thereof with respect to the crusher teeth and the crushing projections on the surface of the other roller body.

8. The dual-roller crusher according to claim 1, wherein each pocket is open only radially outwardly.

9. The dual-roller crusher defined in claim 1, wherein the clearance gap is measured perpendicular to the axes and on a plane including both of the axes.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) Embodiments of the invention are shown in the drawings and described in more detail below.

(2) FIG. 1 is a view of the essential components of a dual-roller crusher;

(3) FIG. 2 is the a same view, partly broken away;

(4) FIG. 3 is a top view;

(5) FIG. 4 is a section in a first operating position;

(6) FIGS. 5 and 6 are further sections in consecutive operating positions;

(7) FIG. 7 shows a variant in the view as in FIG. 1;

(8) FIG. 8 is a section through the variant.

FIELD OF THE INVENTION

(9) The drawings show the essential inventive elements of a dual-roller crusher 1. Such a dual-roller crusher comprises two rollers 2 and 3 rotatably mounted and driven by a motor so as to counter-rotate synchronously. Here, the rollers 2 and 3 have shaft stubs on their axial end faces that are mounted in a crusher housing and are driven so as to counter-rotate synchronously corresponding to the respective directional arrows 4 and 5 by a suitable motor drive. The central axes of the two rollers 2 and 3 are parallel to each other. Normally, such dual-roller crushers are outfitted with horizontally oriented rollers 2 and 3, and the material to be crushed is introduced from above and drawn into the nip between the rollers 2 and 3, while the material that has been crushed is discharged below.

(10) Crusher teeth 6 and 7 are mounted as a plurality of individual elements on the surface of the rollers 2 and 3 and project radially outward from the outer surface of the respective rollers 2 and 3. According to the invention, a corresponding number and arrangement of pockets 8 and 9 are provided in the rollers 2 and 3 so that during rotation of the rollers 2 and 3, the crusher teeth 6 or 7 of each roller each engage in a respective one of the pockets 8 and 9 of the other roller. The size and depth of the pockets 8 and 9 conforms to the shape and size of the respective crusher tooth 6 or 7, in particular in such a manner that each crusher teeth 6 and 7 of each roller does not contact the other during rotation of the rollers 2 and 3, but rather engages more or less without contact in the respective pocket 8 or 9, fits therein, and then withdraws therefrom.

(11) As can be seen for example in FIGS. 4 to 6, the pockets 8 and 9 and the crusher teeth 6 and 7 are adapted to each other in size and arrangement, so that during rotation of the rollers 2 and 3, a clearance gap is observed between the roller surfaces that is smaller than the height of the crusher teeth 6 and 7.

(12) Furthermore, additional crushing projections 10 and 11 formed on the surfaces of the rollers 2 and 3 have radial heights that are significantly smaller than the radial heights of the crusher teeth 6 and 7, and that do not mate with respective pockets. The height of these additional crushing projections 10 and 11 is slightly less than the width of the nip between the rollers 2 and 3, so that these may pass through the nip during operation of the dual-roller crusher without contacting the respectively opposite roller. These additional crushing projections are useful in order to further reduce the size of the material crushed by the crusher teeth 6 and 7 and the rollers 2 and 3, so that in the end result, a reduction in size to the final grain size can occur.

(13) As is apparent from the drawing, the crusher teeth 6 and 7 as well as the crushing projections 10 and 11 are arrayed in rows extending along respective annular circumferential lines, and each roller has a plurality of outer circumferential annular tooth rows that are parallel to one another and spaced apart from one another and that have the crusher teeth 6 and 7 and crushing projections 10 and 11. Such annular rows are formed in the embodiment of FIGS. 7 and 8 by annular ridges 12 and 13 on the surfaces of the rollers 2 and 3, these annular elevations 12, 13 carrying the crusher teeth 6 and 7 and the crushing projections 10 and 11. Between these annular ridges 12 and 13, the roller surface is smooth and recessed and formed with the pockets 8 and 9.

(14) As can be seen from the illustrated embodiments, the crusher teeth 6 and 7 and the crushing projections 10 and 11 of one roller are respectively axially offset on the surface thereof with respect to the crusher teeth and the crushing projections on the surface of the other roller.

(15) The invention is not limited to the illustrated embodiments, but rather the scope of the disclosure is variable in many ways.

(16) All singular or combined features disclosed in the specification and/or drawings are considered essential to the invention.