GB2104574A - A mining machine - Google Patents

Abstract

A mining machine 1 comprises an elongate machine body 2 and at least one ranging arm 19 pivotally attached thereto about an axis 20 extending transversely of the machine body 2 and carrying a rotatable cutting head 21, and an electric motor 23 for powering the cutting head 21 through a transmission 25, 26, 27, 28 and 29, the axis of rotation 24 of the electric motor(s) 23 being co-incident with the arm pivot axis 20. <IMAGE>

Description

SPECIFICATION Mining machine This invention relates to a mining machine of the so-called shearer type comprising a machine body carrying a ranging arm which is pivotable with respect thereto under the control of a doubleacting control ram, the ranging arm in turn carrying a mineral cutting head rotatable about an axis extending transversely of the longitudinal axis of the machine body. Basically, such machines are either single-ended, with a ranging arm at one end, or double-ended, with a ranging arm at both ends, and they can be of the conveyor mounted type (usually for medium to thick mineral seams) or of the floor mounted, "in-web" type (usually for medium to thin mineral seams), but with either type, machine guidance is effected by sliding contact with the conveyor, which extends along the mineral face.

The machine body usually approximates in width to that of the conveyor e.g. 2 ft., but is of substantial length e.g. 20 ft. and power for both machine haulage and the cutting head(s) is conventionally effected from at least one electric motor mounted within the machine body via a suitable transmission comprising speed reduction/change gearing housed within a gearhead to which a ranging arm is pivotally attached. If the machine is double-ended with a single motor, there is also a need to accommodate a through shaft to transmit power from the motor to the remote gearhead. As the axis of rotation of the motor(s) is conventionally parallel to the longitudinal axis of the machine body, there is a need to transmit the drive through 900, which leads to a requirement inter alia for complex spiral bevel gear sets which are expensive from manufacture and maintenance viewpoints.

One attempt to alleviate this problem by mounting the electric motor(s) with its axis of rotation transversely of the longitudinal axis of the machine resulted in a design of double-ended machine in which each ranging arm carried its own electric motor rotatable about a transverse axis, speed reduction being via an epicyclic gearbox. However, because of this location, only motors of relatively small physical size could be employed, hence limiting the power available to the cutting heads. Furthermore, only a limited speed reduction was possible, which tended to make the cutting heads operate at higher than optimum speeds for strata conditions, dust suppression etc. This design also required the motors to be lifted with the arms hence requiring greater power from the double-acting control rams.Finally, the presence of a motor on a ranging arm results in a substantial projection from the arm which can be troublesome if, as is often the case with modern machines, there is also a requirement for the machine to perform the further dury of advancing the roadway which is conventionally provided at one or both ends of the mineral face.

According to the present invention, there is provided a mining machine comprising an elongate machine body and at least one ranging arm pivotally attached thereto about an axis extending transversely of the machine body and carrying a rotatable cutting head, and an electric motor for powering the cutting head(s) through a transmission, the axis of rotation of the electric motor(s) being co-incident with the arm pivot axis.

Thus, with the machine in accordance with the invention, the advantages of transverse motor mounting are attained without the disadvantages of having to carry the motor by its ranging arm.

For convenience, the term "motor" will hereinafter be used in the singular but this should not be taken as implying that only a single ended machine is involved, for a double ended machine (with components merely duplicated at both ends of the machine) could have its cutting heads powered by a common motor or an individual motor, as will be described in detail hereinafter.

It is also preferred for the axial dimension of the motor to be relatively small -- certainly within the lateral dimension of the machine body, but its diameter is not critical and indeed may, for an "inweb" machine, approach that of the cutting head(s) e.g. 36", or, for certain configurations of conveyor mounted machines, may even exceed the diameter of the cutting head(s), because the motor diameter, need not be confined to a size capable of fitting within the depth dimension selected for the machine body, e.g. 20".

It may be readily arranged for the cutting head motor to be removably clamped to the end of the machine body, which provides for ease of motor changing for maintenance/fault correction purposes. Thus, the end of the machine body may be forked, with clamping members securable across the fork arms.

In one construction, the or each arm may be provided with a trunnion by which it is pivotally carried, with interposed bearings, from the machine body. In another construction the or each ranging arm may be provided with a bifurcated end to embrace a cutting head motor, such end being suitably apertured to receive bearings.

A first stage speed reduction may be effected by having an output shaft of the cutting head motor drive an epicyclic reduction stage.

Conventionally, further speed reduction can if desired be attained by means of the geared transmission extending along the ranging arm to the cutting head. Also if required, a final stage speed reduction can be provided by an epicyclic stage within the cutting head, to attain the required speed, e.g. 20 r.p.m.

In the case of a conveyor mounted machine, the or each ranging arm is located at a face side of the machine with the cutting head(s) located to the face side of its arm. Hence the output shaft of the cutting head motor would also be located at the face side of the machine, and this provides the possibility of additional power take off at the goaf side of the machine for ancillary devices, such as a mineral breaker and/or for one or more hydraulic pumps. Thus, the power take off may include an output pinion engageable with an ancillary gear train(s) e.g. to power a hydraulic pump and/or a mineral crushing and breaking drum carried by a breaker arm hinged to the machine body about a transverse axis. If one or more hydraulic pumps are provided, these may be for primary power, e.y.

for providing hydraulic pressure fluid to hydraulic motors of a machine haulage unit, or for secondary power, e.g. to operate the control ram(s) of the ranging arm(s), roll steering rams of an "in-web" machine etc.

In the case of an "in-web" machine, the or each ranging arm is located at the goaf side of the machine, with the cutting head(s) located to the face side of its arm. In a one embodiment of double-ended, "in-web" machine a single motor powers both cutting heads, each ranging arm having a suitably bifurcated end for pivotal connection about a common axis co-incident with the axis of rotation of the motor.

The invention will now be described in greater detail, by way of examples, with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side elevation, looking from goaf to face, of a first embodiment of mining machine in accordance with the invention; Figure 2 is a plan view, partly in section, of the left-hand end of Figure 1 but to an enlarged scale; Figure 3 is an end elevation of Figures 1 and 2; Figure 4 is a view, to a larger scale, of the lefthand end of Figure 2; Figure 5 is a plan view of a second embodiment of mining machine; and Figure 6 is a plan view of a third embodiment of mining machine.

In all Figures, like reference numerals are employed for like components.

In Figures 1 to 4 is shown a mineral mining machine 1, comprising a machine body 2 supported by an underframe 3 from which extend four legs 4, each terminating in a slide shoe 5 for slidable engagement with the upper surfaces 6 of the face side and goaf side sidewalls 7 of a line pan 8 e.g. of standard 5 ft. length, a plurality of such pans being secured together, end-to-end, in articulated manner to form an armoured, scraper chain conveyor 9 of appropriate length, the conveyor 9 being seated on a mine floor 10 with a mineral face indicated at 11 and a mine roof indicated at 12, and hence the machine body 2 has a face side 13 (Figure 3) and a goaf side 14.

For clarity, the conventional drive and return ends of the conveyor 1 are omitted. The machine body 2 also carries haulage sprockets 1 5 engageable with a toothed rack 1 6 carried by the goaf side sidewall 7 of the conveyor 9.

The machine 1 is of the double-ended, ranging drum shearer type comprising, at each end 1 7 of the face side 13 of the machine body 2, a gearhead 1 8 which carries a trunnion mounted ranging arm 1 9. Each arm 1 9 is pivotable about an axis 20 extending transversely of the machine body 2, and carries a cutting head 21 rotatable about an axis 22. Associated with each ranging arm 1 9 is an electric motor 23 to provide power to rotate the associated cutting head 21 and, as will be described later, for possible ancillary purposes.

Considering the first embodiment shown in Figures 1 to 4, it will be observed, particularly in Figure 2, that the electric motor 23 is rotatable about an axis 24 which is co-incident with the pivot axis 21 of the associated ranging arm 1 9. In detail, an output shaft of the motor 23 drives an epicyclic, first stage speed reduction gearbox 25, an output shaft 26 of which is also co-incident with the axes 24 and 20 terminating in a drive pinion 27 to transmit power from the motor 23 along the ranging arm 19 via a gear train 28 located within the arm and which may also effect speed reduction, and an epicyclic, second stage speed reduction gearbox 29 located within the cutting head 21.

In the embodiment of Figure 5, a power take off includes a shaft 30 at the goaf side 14 of the machine body 2, and carries an output pinion 31 adapted to drive both a first ancillary gear train 32 extending for example to a hydraulic pump located within the machine body 2; and a second ancillary gear train 33 extending to a transverse drive shaft 34 and a further gear train 35, contained in a breaker arm 36 pivotable about a transverse axis 37, to power a mineral crushing and breaking drum 38 carried by the arm 36.

In the embodiment of Figure 6, the machine 1 is not of the conveyor mounted type of Figures 1 to 4, but on the contrary is mounted on the mine floor 10, being merely guided along the face 11 by the conveyor 9. The machine 1 is double-ended and has a single motor 23 rotatable about an axis 24 co-incident with the pivot axes 20 of a first, bifurcated ranging arm 19A, and a second bifurcated ranging arm 19B, each arm incorporating respectively gear trains 28A and 28B to convey power from the motor 23 to their respective cutting heads 21.

Claims (16)

1. A mining machine comprising an elongate machine body and at least one ranging arm pivotally attached thereto about an axis extending transversely of the machine body and carrying a rotatable cutting head, and an electric motor for powering the cutting head through a transmission, the axis of rotation of the electric motor(s) being co-incident with the arm pivot-axis.

2. A machine as claimed in Claim 1, provided with an individual motor for the or each ranging arm.

3. A machine as claimed in Claim 1, of the double-ended kind, provided with a common motor for the pair of ranging arms.

4. A machine as claimed in any preceding Claim, wherein the axial dimension of the motor is relatively small, being within the lateral dimension of the machine body.

5. A machine as claimed in any preceding Claim, wherein the motor is removably clamped to the end of the machine body.

6. A machine as claimed in any preceding Claim, wherein the or each ranging arm is provided with a trunnion by which it is pivotally carried, with interposed bearings, from the machine body.

7. A machine as claimed in any one of Claims 1 to 21, wherein the or each ranging arm is provided with a bifurcated end to embrace a motor, such end being suitably apertured to receive bearings.

8. A machine as claimed in any preceding Claim, wherein first stage speed reduction is effected by having the motor output shaft drive an epicyclic reduction stage.

9. A machine as claimed in any preceding Claim, wherein a greared transmission extends along the ranging arm to the cutting head.

10. A machine as claimed in any preceding Claim, wherein a final stage speed reduction is provided by an epicyclic stage within the cutting head.

11. A machine as claimed in any preceding Claim, wherein the or each ranging arm is located at a face side of the machine, and hence the cutting head motor output shaft is also located at the face side of the machine.

12. A machine as claimed in Claim 11, wherein a power take off from the motor is provided at the goaf side of the machine, for powering ancillary devices.

13. A machine as claimed in Claim 12, wherein, the power take off includes an output pinion.

14. A machine as claimed in Claim 12 or 13, comprising a mineral crusher pivotally attached to the machine body by a mounting arm and drivable by the power take off.

1 5. A machine as claimed in any one of Claims 1 to 13, of the floor mounted, "in-web" type, wherein the or each ranging arm is located along a goaf side of the machine.

16. A machine as claimed in Claim 15, when appendant to Claim 3, of the double-ended kind, wherein each ranging arm has a suitably bifurcated end for pivotal connection about a common axis co-incident with that of motor rotation.

1 7. A machine substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

1 8. A machine substantially as hereinbefore described with reference to Figure 5 of the accompanying drawings.

1 9. A machine substantially as hereinbefore described with reference to Figure 6 of the accompanying drawings.