GB2086964A - Improvements relating to shearer-loaders - Google Patents

Abstract

The support arm 21 of the shearer-loader has, between the frame 3 and the drum 11, a projecting part 26 which extends to a position in front of the goaf side drum end face 27, the height of the part 26 being less than the diameter of the drum 11. A journal 28, extending over most of the axial length of the drum 11, is rigidly secured to the part 26 and carries the rotating drum 11. Also mounted on the support arm 21, on the outside near the mineral face, is an output gear 37 connected to drive gearing and meshing with a tooth system 46 disposed on the drum periphery. The shearer drums can have a diameter which is only slightly greater than the height of the frame, and can discharge debris readily into the face conveyor past the projecting arm 26 of small dimensions. <IMAGE>

Description

SPECIFICATION Improvements relating to shearer-loaders The invention relates to a shearer-ioader. A shearer-loader which is of use particularly for working shallow seams, and will be disposed adjacent the face conveyor, may have overhung shearer drums disposed one at each end of its frame, each drum rotating around an axis extending parallel to the floor and perpendicularly to the mineral face and being so mounted on a pivoted support arm as to be vertically adjustable.

The transmission elements of each arm provides a driving connection between the drum and the driving motor disposed in the frame.

In such a machine the high speed output of the driving motor mounted in the frame is transmitted by way of the shearing head and of gearing inside the support arm to reduction gearing in the shearer drum and has its speed stepped down.

The speed and the torque determine the amount of driving power input to the shearer drum by way of the gearing in the support arm. Consequently, high speed running of the various gears of the gearing at a constant driving power always results in a correspondingly low torque which in turn results in reduced forces and therefore a reduced loading of the torque transmitting gears.

Consequently, if the speed reduction step is performed in the shearer drum, support arm dimensions, which depend upon the forces to be transmitted, remain reasonable. However, the diameter of the shearer drum cannot be less than a predetermined minimum if the reduction gearing is to be disposed inside the shearer drum.

Consequently, the shallowest seam which can be worked with a shearer-loader of this kind is determined more by the minimum possible shearer drum diameter than by the overall height of the machine. Also reducing the drum diameter by disposing the reduction gearing in the drum results in more obstructions to an unhindered discharge of debris into the face conveyor, since the support arm which carries the shearer drum and which is disposed near the face-side side wall of the conveyor disturbs the flow of debris because of its width, the same being determined by the gearing or transmission elements disposed in the support arm.

It is an object of this invention to provide a shearer-loader which is suited to working shallow seams and which can suitably deliver the debris to the face conveyor.

Accordingly, this invention provides a shearerloader having overhung shearer drums disposed one at each end of its frame, each drum rotating around an axis which will extend parallel to the floor and perpendicularly to the mineral face and being so mounted on a pivoted support arm as to be vertically adjustable, the transmission elements of such arm providing a driving connection between the drum and a driving motor disposed in the frame, the support arm being disposed between the frame and the shearer drum and having a projecting part which extends on the goaf side to a position in front of the drum end face, and has a journal which extends over most of the drum length and carries the drum, the support arm carrying on the outside of its wall near the mineral face an output gear which rotates about an axis parallel to the drum axis and meshes with a tooth system disposed in the periphery of the drum.

A machine of this kind in which the drum does not have any reduction gearing in it can have shearer drums of a diameter only a little greater than the height of the lowest frame. Although of reduced diameter, drums of this kind can deliver the debris laterally to the face conveyor since the support arm projection, which is devoid of gearing and which carries the drum, is of such small dimensions as to leave an adequate passage for the debris between its bottom edge and the top edge of the face conveyor.

Advantageously, pin teeth carried by the drum parallel to the drum axis form the tooth system of the drum. This kind of tooth system is very rugged and can deal satisfactorily with high tooth pressures such as occur in the transmission of the driving power required for the drum. More particularly, however, it is unaffected by soiling by the debris passing by the various pin teeth.

Conveniently, the tooth system is disposed near that third of the drum length which will be in the back of the cut. in this region the quantity of debris passing by way of the tooth system is relatively reduced; also, the support arm drive gear which extends into the shearer drum does not cause build-up of debris.

To improve debris delivery, near the periphery of the drum, the support arm, following the trajectory of the cutter picks, can widen like a clearing plough substantially over the height of the drum diameter. This plough-like widening of the support arm ideally has a skid which extends over the whole length of the bottom edge of such widening and which is pivotally mounted on a pivot extending parallel to the drum axis, for rubbing engagement with the floor. The skid or the like which closes the gap between the widening of the support arm and the floor can adapt itself to the shape of the seam because of its pivoted mounting and is protected against jamming.

In accordance with another feature of the invention, the plough-like widening of the support arm may be formed near the output gear with an aperture through which a segment of the output gear can extend. The aperture, which depends only on the width and height of the driving gear segment, substantially prevents debris from passing through near the output gear.

In order to enable the machine in accordance with the invention to be used in seams of differing thicknesses, the shearer drum bearings may be disposed on adjustable eccentric bushes of the journals which enable the distance between the bearing centres and the plough-like widening of the support arm to be varied so that the shearerloader can be fitted with shearer drums of different diameters.

Advantageously, the support arm has a part which widens like a casing, is disposed between the drum and the frame, receives the reduction gearing and has a goaf-side projecting part carrying the drum. This feature enables the support arm to be of the dimensions necessary to receive the reduction gearing in the region where the support arm does not impede the discharge of debris, whereas the projecting part of the support arm carrying the drum and devoid of transmission elements is of such reduced overall height as not to impede the discharge of debris.

Conveniently, each of the two support arms is disposed between two casing projections of the frame, one such projection, preferably the goafside one, receiving in its interior a train of gears which bridges the space between the support arm pivot and the motor shaft and whose pinion is disposed centrally of the support arm pivot and engages through the central pivot bore with reduction gearing disposed in the support. This feature enables the very wide casing-like support arm to be used to receive the entire reduction gearing and the high speed input thereto to be transmitted by relatively small gearing elements within the casing projection which connects the support arm to the frame.

For guidance and control the shearer-loader can have a gantry which bridges the face conveyor, is releasably connected to the frame, and engages with the goaf side guide rail of the face conveyor By means of two double acting pressure medium rams which form the connection between the guide rail and the gantry, the shearerloader, which is supported by a track on the mineral face side, can be pivoted around its longitudinal axis and whichever drum is cutting can be aligned parallel to the floor. Also, the gantry serves to receive the control elements, which are therefore readily accessible to the miner in the zone of movement.

The invention may be performed in various ways and a preferred embodiment thereof will now be described with reference to the accompanying drawings, in which: Figure 1 is a partial section through a shearerloader of this invention in plan view; Figure 2 is a front view of the shearer-loader without the gantry which extends over the face conveyor; and Figure 3 is a side view of the shearer-loader.

A shearer-loader 1 comprises a number of units and is disposed on the mineral face side adjacent a face conveyor 2. The frame 3 of the shearerloader 1, is releasably connected, for guidance and control, to a gantry 4 which extends over the face conveyor 2 and runs by way of skids or runners or the like 5 on a guide rail 6 (Figure 3) secured to the goaf side of the face conveyor 2. The machine 1 can be pivoted around its longitudinal axis under control of two double-acting pressure medium rams 7 which connect the skids 5 to the gantry 4.

Thus, by operating the rams 7 and by means of a runner 8 disposed in the back of the cut, the machine 1 can be so pivoted about its skids 10 bearing on the mineral face side wall 9 of face conveyor 2 that the overhung shearer drums 11 are aligned parallel to the floor. The machine control elements (not shown) are received on the goaf side of the gantry 4 and are therefore readily accessible to the miner in the zone of movement.

The two outer units of the frame 3 each receive a drum driving motor 12 and each have, on either side of the machine, two casing extensions 1 3, 14. The goaf side extension 14 receives a gear 1 5, which, together with gears 1 6, 1 7, connects the motor 12 to a shaft 18. The shaft 1 8 is disposed centrally of a support arm pivot shaft 19, and extends through a central bore 20 therein.

Two gears 23, 24 connect the shaft 18 to reduction gearing 22 disposed inside a support arm 21. That end of the support arm 21 which is near the frame 3 is disposed between the extensions 13 and 14 and the support arm 21 is retained in this region by a pin 25 which, together with the shaft 18, forms the support arm pivot shaft 1 9. A projecting part 26 of the support arm 21 extends on the goaf side to a position in front of the drum end face 27. The part 26 has a journal 28 which extends over most of the drum length and which is non-releasably mounted by way of a reduced diameter portion 29 in a bore in the part 26. The drum 11 is mounted via adjustable eccentric bushes 30 on the journal 28. The distance between the drum axis and the support arm 21 can be varied by means of the bushes 30 to enable the machine 1 to operate with drums 11 of differing diameters.

The reduction gearing 22 in the arm 21 mainly comprises planetary gearing 31 whose sun wheel 32 receives the drive of the motor 12 by way of the pinion gear stage 23, 24. From the output of the planetary gearing 31 the motion is transmitted by way of pinions 33 to 35 to a shaft 36 which has, on its end projecting from the arm 21 towards the mineral face, an output gear 37. Near the drum 11 the arm 21 extends over the whole width of the drum 11 and has in this region an end face 38 which follows, with radial clearance, the trajectory traced by the tops of the cutter picks. As can be seen from Figure 2, the end face of the arm 21 widens after the fashion of a clearing plough and is of substantially the same height as drum diameter. Disposed on the bottom edge of the widened part 38 is a skid runner or the like 39 which rubs on the floor and which is mounted for pivoting around a pivot 40 parallel to the drum axis. Pressure cylinders (not shown) are provided for vertical adjustment of the arm 21 and, therefore, of the drum 11. The latter cylinders and the rams 7 receive pressure liquid from a pump 41 which is disposed inside the arm 21 and which is drivingly connected by way of a shaft 42 and a pinion 43 to the gear 23 on the shaft 1 8.

In the back of the cut, the drum 11 has a conical closing ring 44 to ensure clearance. The drum 11 has helical bars or the like 45 for conveying the debris from the back of the cut towards the face conveyor 2. In that third of its length which is disposed in the back of the cut, the drum 11 has pin tooth gearing 46 whose pin teeth 47 extend parallel to the drum axis. The tooth system 46 is engaged by the output gear 37 on the face side of the arm 21 to drive the drum 11.

To this end, a projection 48 of the part 38, which extends beyond the width of the support arm, is formed with an aperture 49 through which the gear 37 can extend.

Claims (11)

1. A shearer-loader having overhung shearer drums disposed one at each end of its frame, each drum rotating around an axis which will extend parallel to the floor and perpendicularly to the mineral face and being so mounted on a pivoted support arm as to be vertically adjustable, the transmission elements of such arm providing a driving connection between the drum and a driving motor disposed in the frame, the support arm being disposed between the frame and the shearer drum and having a projecting part which extends on the goaf side to a position in front of the drum end face, and has a journal which extends over most of the drum length and carries the drum, the support arm carrying on the outside of its wall near the mineral face an output gear which rotates about an axis parallel to the drum axis and meshes with a tooth system disposed in the periphery of the drum.

2. A shearer-loader according to claim 1, wherein pin teeth carried by the drum parallel to the drum axis form the tooth system of the drum.

3. A shearer-loader according to claim 2, wherein the tooth system is disposed near that third of the drum length which is intended to be positioned in the back of the cut.

4. A shearer-loader according to any one of claims 1 to 3, wherein the support arm, near the periphery of the drum, widens like a clearing plough following the trajectory of the cutter picks substantially over the height of drum diameter.

5. A shearer-loader according to claim 4, wherein the plough-like widening of the support arm has a skid which extends over the whole length of the bottom edge of such widening and which is pivotally mounted on a pivot extending parallel to the drum axis, for rubbing engagement with the floor.

6. A shearer-loader according to claim 4 or claim 5, wherein the plough-like widening of the support arm is formed near the output gear with an aperture through which a segment of the output gear can extend.

7. A shearer-loader according to any one of claims 1 to 6, wherein eccentric bushes adjustably mount the drum bearings on the journal.

8. A shearer-loader according to any one of claims 1 to 7, wherein the support arm has a part which widens like a casing, is disposed between the drum and the frame, receives the reduction gearing and has a goaf side projecting part carrying the drum.

9. A shearer-loader according to claim 8, wherein the support arm has its casing-like widened part disposed between two casing projections of the frame, one such projection, preferably the goaf-side one, receiving in its interior a train of gears which bridges the space between the support arm pivot and the motor shaft and whose pinion is disposed centrally of the support arm pivot and engages through the central pivot bore with reduction gearing disposed in the support.

10. A shearer-loader according to any one of claims 1 to 9, wherein a gantry which bridges the face conveyor is releasably connected to the frame, and engages with the goaf side guide rail of the face conveyor.

11. A shearer-loader substantially as herein described with reference to the accompanying drawings.