GB2036128A

GB2036128A - Mining Machine Shearer Drum

Info

Publication number: GB2036128A
Application number: GB7916425A
Authority: GB
Original assignee: Krampe and Co Fertigung in Bergbaubedarf GmbH; Krampe and Co
Current assignee: Krampe and Co Fertigung in Bergbaubedarf GmbH; Krampe and Co
Priority date: 1978-12-09
Filing date: 1979-05-11
Publication date: 1980-06-25
Also published as: DE2853249C2; BE875153A; DE2853249A1; GB2036128B

Abstract

A shearer drum for a mining machine comprising a tubular body (1), a part-conical annular end member (5) and at least one helical vane (2) extending around the tubular body (1), the end member (5) and vane (2) being provided with a plurality of bit holders for receiving shearing bits, at least the side wall (9) of the or each vane (2) which faces away from said end member being curved in the radial direction of the drum away from said end member (5). Transport of extracted mineral (10) is thus improved. <IMAGE>

Description

SPECIFICATION Shearer Drum for a Mining Machine The present invention relates to a shearer drum for a mining machine, in particular for underground mining of, for example, coal.

So-called single-thread and multi-thread shearer drums for underground mining machines are well known. Such shearer drums consist conventionally of a cylindrical, tubular housing on which a helically extending spiral vane is arranged, for example welded. Mounted at regular intervals on the outside of the vane are bit holders in which shearing bits are secured. The end side of the tubular housing adjacent the working face is closed by an end plate.

Also known are shearer drums of this type which are provided with a conical end ring. This end ring is connected fast to the end plate by welding. The conical end ring is provided at regular ntervals on its outer margin projecting towards the face likewise with bit holders in which there are exchangeably mounted shearing bits which project considerably beyond the outer marginal region of the conical end ring towards the face.

As a rule, the shearing bits are arranged so that their tips are enclosed by an imaginary common cylindrical envelope.

It has also been proposed in this connection to make the entire end plate in cross-section in the form of a truncated cone or alternatively partly in the form of a truncated cone and partly discshaped, the disc forming the radially inner part and being connected to the housing. Due to this conical form of construction, the frictional forces between the shearer drum and the working face are reduced. A better efficiency and a smaller development of dust during shearing are thereby obtained. It is also known in this connection that any deviation of the end plate from the radial arrangement leads to an improvement.

With known shearer drums, the helically extending spiral vanes run in a straight line in a radial section passing through the longitudinal axis of the drum. With an angle of the coal face and/or of the longitudinal axis of the shearer drum which deviates from the horizontal this leads to a reduction of the conveying effect of the spiral vane, since a part of the extracted mineral drops back over the upper edge of the vane. The mineral falling over the upper edges of the vane can reach, for example between the nozzle plate and the end plate of the shearer drum, where it not only disturbs the work, but can be pulverised into fine coal and dust, which is undesirable.

The object of the invention is to improve the conveyance of the mineral extracted by means of a shearer drum with an inclination of the coal face and/or the longitudinal axis of the shearer drum which is arbitrary per se and lies within practicable limits and to reduce the proportion of the fine coal produced during extraction by means of such shearer drums.

According to the invention, there is provided a shearer drum for a mining machine comprising a tubular body, a part-conical annular end member and at least one helical vane extending around the tubular body, the end member and vane being provided with a plurality of bit holders for receiving shearing bits, at least the side wall of the or each vane which faces away from said end member being curved in the radial direction of the drum away from said end member, over at least a part of its radial height.

Owing to the spiral vane having a curved face it is ensured that when the shearer drum axis is inclined to the coal face, the extracted mineral is transported to the conveying means better than hitherto. Tipping of the mineral over the upper edge of the spiral vane is largely prevented.

Rather, even with a large inclination of the longitudinal axis of the shearer drum the mineral drops back again into the spiral thread and is transported safely without falling between the shearer drum and the nozzle plate. The arrangement can be sudh that with any practicable inclination of the longitudinal axis of the shearer drum the tangent to an arbitrary point of the curved vane wall intersects the longitudinal axis of the shearer drum, starting from 900, at an angle becoming increasingly more acute towards the outer boundary of the respective vane wall.

The curve of the wall is preferably an exponential curve: The spiral may be three-dimensionally curved or formed like a plough share. In this case, very good conveying effect is obtained with an intensive tendency to keep the extracted mineral in the converying flow and not to let it fall outwardly from the vane or vanes.

The curve of the wall may be the arc of a circle or a plurality of arcs of different radii of curvature which merge into one another. The vanes can thereby be manufactured easily by stamping, for example pressing suitable sheet-metal strips or sheet-metal panels.

Both the inner and outer walls of the vanes may be curved, for example, parallel with each other.

The invention is illustrated by reference to an exemplary embodiment partly schematically in the drawings wherein: Figure 1 is a perspective view of a shearer drum, Figure 2 is a radial longitudinal section through the shearer drum shown in Figure 1.

As shown in the drawings, a shearer drum comprises a cylindrical tubular body 1 having a single spiral vane 2 mounted thereon extending along a helical line. This spiral vane 2 is made from a metal sheet welded on edge to the tubular body 1. The vane 2 is provided on its outer periphery with bit holders 3 arranged at regular intervals and connected fast to the vane by welding seams. Arranged conventionally in the bit holders are outwardly projecting shearing bits, also called picks, which are omitted in the drawings for the sake of simplicity.

Reference numeral 4 designates a closing cover, while 5 denotes an annular conical terminating body, a part of which extends radially to the longitudinal axis 6 of the shearer drum.

In the region of the free marginal region the conical terminating body 5 is provided with several bit holders 7 which are arranged over its outer periphery and which serve likewise to receive shearing bits or picks. The ends of the shearing bits arranged on the conical terminating body 5 and fastened to the respective vane 2 can each be enclosed by a separate or all by a common cylindrical envelope.

As shown especially clearly by Figure 2, the spiral vane 2 is biconvex in a section taken radially through the longitudinal axis 6 of the shearer drum, in such a way that its side walls 8 and 9 run convexly in the direction of the conical terminating body 5. The term "convexly" is not restricted to an arc of circle. All other suitable curve shapes, for example ellipses, hyperbolas or other exponential curves also come under consideration. The arrangement and form of the side walls 8 and 9 of the spiral 2 are such that the spiral has a ploughshare-like shape. This can be effected by corresponding forming, for example by pressing of a cold or heated sheet-metal strip.

Extracted mineral which is conveyed in the screw thread at 10 is in this way prevented from falling out over the upper edge 11 with an obliquely running working face or with relative inclination of the longitudinal axis 6 to the working face and from not being transported away.

Reference numeral 1 2 denotes a connecting flange to which a motor drive, not shown in detail, is coupled, optionally indirectly.

The features described in the description and in the patent claims and illustrated in the drawing may be material to the invention either individually or in any combinations.

Preferably, the tangent to said curved side wall intersects the longitudinal axis of the shearer drum at an increasingly acute angle, the further the point of tangency moves from the base of the vane situated in the region of the cylindrical tubular body towards the peripheral outer edge of the vane. More preferably this tangent intersects the longitudinal axis of the shearer drum at right angles in the region of the base of the vane. A particularly high efficiency is thus obtained, the force component holding the mineral in the screw threads of the shearer drum being especially large.

Claims

1. A shearer drum for a mining machine comprising a tubular body, a part-conical annular end member and at least one helical vane extending around the tubular body, the end member and vane being provided with a plurality of bit holders for receiving shearing bits, at least the side wall of the or each vane which faces away from said end member being curved in the radial direction of the drum away from said end member, over at least a part of its radial height.

2. Shearer drum according to claim 1, wherein the curve of the wall is an exponential curve.

3. Shearer drum according to claim 1 or 2, characterised in that the vane is curved or formed three-dimensionally like a ploughshare.

4. Shearer drum according to claim 1, wherein said curve is an arc of circle.

5. Shearer drum according to claim 1, wherein said curve consists of a plurality of arcs of different radii of curvature which merge into one another.

6. Shearer drum according to any preceding claim, wherein both the inner and outer walls of the vane are curved.

7. Shearer drum according to any preceding claim, wherein the tangent to said curved side wall intersects the longitudinal axis of the shearer drum at an increasingly acute angle, the further the point of tangency moves from the base of the vane situated in the region of the cylindrical tubular body towards the peripheral outer edge of the vane.

8. Shearer drum according to claim 7, wherein said tangent intersects the longitudinal axis of the shearer drum at right angles in the region of the base of the vane.

9. A shearer drum substantially as herein described with reference to the accompanying drawings.