GB1593362A

GB1593362A - Mining conveyors

Info

Publication number: GB1593362A
Application number: GB1740878A
Authority: GB
Original assignee: RICH SERVICES Inc ROY
Current assignee: RICH SERVICES Inc ROY
Priority date: 1978-05-03
Filing date: 1978-05-03
Publication date: 1981-07-15

Description

(54) IMPROVEMENTS RELATING TO MINING CONVEYORS (71) We, ROY RICH SERVICES Inc.

a Company organised under the laws of Panama and whose registered office address is 28, Irish Town, P.O. Box 15, Gibralter, do hereby declare the invention for which we pray that a Patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following- statement: This invention is concerned with improvements relating to mining conveyors.

In the mining process known as long wall mining a conveyor located in a gallery extends alongside and close to the mineral face. The conveyor comprises at least one driven sprocket assembly at one end of the conveyor (referred to hereinafter as the forward end) and an idle sprocket assembly at the opposite, far end. An endless conveyor belt extends between the two sprocket assemblies, upon which mineral cut from the face is deposited, and which conveys pieces of cut mineral from the gallery.

The conveyor also comprises a pair of parallel rail tracks extending lengthwise of, and which are mounted above, the belt. In a mining operation, a coal cutting machine is mounted on the rails, and is driven along the conveyor as a cutting head of the machine makes an elongate cut into the mineral face, the cut typically extending into the face a depth of 12 inches, and having a height equal to the diameter of the head, typically of 48 inches. Generally, the diameter of the cutting head will be selected in accordance with the height of the seam being mined, although for high seams it may be necessary for the cutting head to traverse the face twice.

The seam is taken out to floor level, and subsequently the conveyor is mechanically advanced to a position close to the newlyexposed mineral face.

Conventionally, the cutting machine comprises a drive housing, including a motor, mounted above the conveyor, and a drive shaft extending from the drive housing towards the mineral face, the cutting head being in the form of a shearer drum rigidly mounted on the drive shaft. Although therefore the shearer drum can take out the seam to one end of the conveyor (usually the far end), the shearer drum cannot be advanced sufficiently close to the forward end to take out that part of the seam in front of the driven sprocket assembly. Thus, there would be left an uncut part of the seam, known as the "stable hole", which it was necessary to take out manually, before the conveyor could be forepoled. During the operation of stable hole extraction, a mine worker could conveniently oil bearings of the driven sprocket assembly on the face side of the conveyor.

Recently long wall mining has adapted a cutting technique which eliminates the stable hole, by the use of a shearer drum carried on a ranging arm, which can be moved relative to the drive housing of the cutting machine to allow the stable hole to be cut out mechanically. Thus, the need for a mine worker to go to the face side of the conveyor is removed, and the elimination of the stable hole has allowed the use of a "prop-free front"- that is, where the roof of the gallery above the conveyor assembly is not supported. Thus, it is somewhat dangerous for a mine worker to go to the face side of the conveyor, and although routine service of the machinery specifically includes the regular application of oil to the face side bearings of the driven sprocket assembly, the tendancy is for this to be done less frequently than is necessary.The effect of this is that the driven sprocket assembly bearings will fail sooner than would otherwise be the case, and it has been discovered that the failure rate of the bearings of driven sprocket assemblies operating in mine workings in which the stable hole has been eliminated mechanically is statistically higher than in workings where manual extraction of the stable hole is necessary.

It will be appreciated that failure of the bearings of the driven sprocket assembly necessarily involves shutting down the whole of the face working, for the extended period of time involved in the dismantling of the equipment and providing a replacement bearing: the cost of this, taking into account lost production, and idle men and machinery, is usually substantial.

This invention provides a mining conveyor comprising a driven sprocket assembly and two spaced bearing assemblies betwecn which the driven sprocket assembly extends and on which the driven sprocket assembly is mounted for rotation, one of said bearing assemblies being on the goafside and the other being on the face-side of the conveyor, said bearings being operative between circumferentially exterior portions of the driven sprocket assembly and fixed housing elements of the conveyor, wherein the sprocket assembly comprises a hollow interior, inlet means whereby lubricating fluid may be introduced into the said hollow interior, and passage means through which lubricating fluid may flow from the hollow interior at least to the face-side bearing assembly.

This invention also provides a mining conveyor comprising a driven sprocket assembly and two spaced bearing assemblies between which the driven sprocket assembly extends and on which the driven sprocket assembly is mounted for rotation, one of said bearing assemblies being on the goafside and the other being on the face-side of the conveyor, wherein the sprocket assembly comprises a hollow interior, inlet means whereby lubricating fluid may be introduced into said hollow interior, and passage means through which lubricating fluid may flow from the hollow interior at least to the face-side bearing assembly, said passage means comprising a section extending generally radially outwardly towards the faceside bearing assembly.

Advantageously the passage-means comprises a first section extending generally in the radial direction relative to the sprocket assembly, and a second section provided at least in part by co-operation between the driven sprocket assembly and a cover plate secured to the face-side plate of the conveyor.

Advantageously further passage means are provided through which lubricating fluid may flow from the hollow interior at least to the goaf-side bearing assembly. Conveniently said bearing passage means comprises a section extending generally in a radial direction towards the goaf-side bearing assembly.

Preferably the inlet means is afforded by an inlet aperture located at a central, circumferential portion of the sprocket assembly.

Advantageously, the driven sprocket assembly comprises two outer portions, one being a goaf-side portion and the other being a face-side portion, each comprising a shaft section and a sprocket section, and a generally cylindrical central portion secured to and extending between the outer portions, said central portion affording the hollow interior of the driven sprocket assembly.

Alternatively, the driven sprocket assembly may comprise a drive shaft extending between the two bearing asemblies and two generally semi-cylindrical sprocket sections secured to the drive shaft.

Alternatively, the driven sprocket assembly may comprise goaf and face-side sprockets mounted on a drive shaft, a cylindrical spacer sleeve mounted on the drive shaft, and extending between said sprockets and axially operated locking means to cause the said sprockets and the sleeve to closely abut with one another in the axial direction of the drive-shaft.

There will now be given a detailed description, to be read with reference to the accompanying drawings, of a mining conveyor which is a preferred embodiment of this invention, which has been selected to illustrate this invention by way of example.

In the accompanying drawings: Figure 1 is a schematic plan view of the mining conveyor which is the preferred embodiment of this invention; Figure 2 is an end elevation, showing the conveyor, together with a coal-cutting machine, in an underground mine working; Figure 3 is an enlarged sectional view showing the driven sprocket assenibly of the preferred embodiment; and Figure 4 is an enlarged sectional view showing a modified form of driven sprocket assembly.

In the preferred embodiment of this invention, the conveyor comprises a driven sprocket assembly 6, and around this sprocket and a remote idle sprocket assembly (not shown) a conveyor belt 20 is mounted, the position of said conveyor belt being indicated in chain-dot lines in Figure 1.

The driven sprocket assembly 6 is connected through gearing 15 to a heavy-duty motor 16, so that by operation of the motor 16, the driven sprocket, assembly 6, and hence the endless conveyor belt 20, may be moved so as to convey pieces of mineral deposited on the conveyor belt in a direction lengthwise of the wall being cut.

Mounted above the conveyor belt, on rails 22, 22, is a drive motor 23 and upon a shaft 24 of said drive motor, which extends towards the wall being cut, a shearer drum 25 is mounted for axial rotation.

In use, starting at the far end of the conveyor, with the shearer drum located within a "sumped" cut (which extends into the seam being mined, at right angles to the long wall) the drive motor is driven along the rails towards the forward end of the conveyor, the shearer drum 25 taking a cut from the wall being mined the full height of the seam, and depositing cut material on the conveyor belt.

In the preferred embodiment, the shaft 24 is mounted on a ranging arm and when the drive motor has reached the position close to the forward end of the conveyor, the drive shaft moves on said ranging arm to take out the portion of the long wall alongside the forward end of the conveyor.

In the preferred embodiment, the driven sprocket assembly 6 extends between and is mounted for rotation in two bearing assemblies 8, 10, said bearing assembly 8 being on the face-side of the conveyor, and the bearing assembly 10 being on the goafside of the conveyor, said bearing assemblies being operative between circumferentially exterior portions of the driven sprocket assembly and fixed housing elements of the conveyor. Particularly, the bearing assembly 8 is mounted on a housing cavity 32 of the face-side plate 30 of the conveyor, and the bearing assembly 10 is mounted in a bearing housing cavity 14 of the gearing 15.

In the preferred embodiment, the driven sprocket assembly comprises two outer portions 36, 46, the outer portion 36 being a face-side portion and the outer portion 46 being a goaf-side portion. Each of the portion 36, 46 comprise a shaft section 38, 48 respectively, provided by a short stub shaft, and a sprocket section 39, 49 respectively keyed to its associated shaft section.

The driven sprocket assembly also comprises a generally cylindrical central portion 56 secured to and extending between the outer portions 36, 46, said central portion affording a hollow interior 58 which serves as an oil reservoir, an inlet aperture 60 being provided through which lubricating fluid such as oil may be introduced into the hollow interior 58.

The stub shaft of the face-side portion 36 is provided with a central, axial bore 42 which opens at the face-side end of the driven sprocket assembly, and a number of bores 44 extending parallel to the longitudinal axis, but spaced radially therefrom, said bores 44 also opening at the face-side end of the driven sprocket assembly.

The bores 42 and 44 provide the first section of passage means extending from the hollow interior 58 to the face-side bearing assembly 8. Secured to the face-side of the plate 30 over the exterior of the bearing housing cavity 32 is a cover plate 34, said cover plate cooperating with the face-side end of the stub shaft 38 to afford a second section of said passage means, extending from said first section to the bearing assembly 8.

Similarly, the stub shaft 48 of the goafside portion 46 is provided with a central axial bore 50, and a plurality of bores 52 extending parallel to the longitudinal axis of the stub shaft 48, but which are spaced radially from the said longitudinal axis.

These bores 50 and 52 provide the first section of further passage means, extending from the hollow interior 58, a second section of said passage means, extending from said first section to the bearing assembly 10, being afforded by a number of radial bores 54 extending generally outwardly from the bores 50 and 52.

Thus, in the use of the preferred embodiment, a reservoir of lubricating oil may be introduced into the hollow interior 58 of the driven sprocket assembly. This oil will be distributed outwardly, firstly in an axial direction, and subsequently in a radial direction, to the bearing assemblies, maintaining them lubricated. In use, when the hollow interior 58 is filled with oil, the bores 44 and 52 will be superfluous, but when only a small quantity of oil remains in the reservior, these bores 44 and 52 will conduct oil from the reservior towards the bearing assemblies.

In the modified form of driven sprocket assembly illustrated in Figure 4, a one-piece driven shaft 66 is keyed to the gearing 15, said driven shaft 66 having a circumferentially reduced central section 68, and bolted to the driven shaft 66 over said central section 68 is an assembly comprising two, generally semi-cylindrical sprocket sections 70, 72.

An axial bore 74 extends through the driven shaft 66 from the face-side end thereof, said bore 74 providing not only the hollow interior of the driven sprocket assembly which constitutes an oil reservior, but also providing the first sections of the passage means extending axially outwardly towards the face-side bearing assembly 8 and the goaf-side bearing assembly 10. As in the first embodiment, the second section of the passage means conducting lubricating oil to the bearing assembly 8 is afforded by the co-operation between the face-side end of the driven shaft 66 and a cover plate 34 extending over the outer side of the bearing housing cavity 32, and of the second section of the passage means through which lubricating oil is conducted to the bearing assembly 10 is provided by a plurality of radial bores 76.

Alternative to the mounting of semi cylindrical sprocket sections on the driven shaft 66, separate sprocket elements (particularly a goaf-side sprocket element and a face-side sprocket element) and an intermediate cylindrical spacer sleeve may be positioned on the driven shaft from one (conveniently the face-side) end thereof, an axially operating locking means being afforded to cause the said sprockets and the sleeve to closely abut with one another in the axial direction on the driven shaft.

WHAT WE CLAIM IS: 1. A mining conveyor comprising a driven sprocket assembly and two spaced bearing assemblies between which the driven sprocket assembly extends and on which the driven sprocket assembly is mounted for rotation, one of said bearing assemblies being on the goaf-side and the other being on the face-side of the conveyor, said bearing assemblies being operative between circumferentially exterior portions of the driven sprocket assembly and fixed housing elements of the conveyor, wherein the sprocket assembly comprises a hollow interior, inlet means whereby lubricating fluids may be introduced into said hollow interior, and passage means through which lubricating fluid may flow from the hollow interior at least to the face-side bearing assembly.

2. A mining conveyor comprising a driven sprocket assembly and two spaced bearing assemblies between which the driven sprocket assembly extends and on which the driven sprocket assembly is mounted for rotation, one of said bearing assemblies being on the goaf-side and the other being on the face-side of the conveyor, wherein the sprocket assembly comprises a hollow interior, inlet means whereby lubricating fluid may be introduced into said hollow interior, and passage means through which lubricating fluid may flow from the hollow interior at least to the face-side bearing assembly, said passage means comprising a section extending generally radially outwardly towards the ftce- side bearing assembly.

3. A mining conveyor according to claim 2 wherein the passage means comprises a first section extending generally in the axial direction relative to the sprocket assembly, and a second section provided at least in part by co-operation between the driven sprocket assembly and a cover plate secured to the face-side plate of the conveyor.

4. A mining conveyor according to claim 3 wherein the first section is provided by one or more bores extending through the driven sprocket assembly from said hollow interior in a direction extending parallel to the longitudinal axis of the driven sprocket assembly, and opening at the face-side end of the driven sprocket assembly, and the second section is provided by a passage provided by and extending between said face-side end with the cover plate partially enclosing said face-side end.

5. A mining conveyor according to any one of the preceding claims comprising further passage means through which lubricating fluid may flow from the hollow interior at least to the goaf-side bearing assembly.

6. A mining conveyor according to claim 5 wherein said further passage means comprises a section extending generally in a radial direction towards the goaf-side bearing assembly.

7. A mining conveyor according to any one of the preceding claims wherein the inlet means is afforded by an inlet aperture located at a central, circumferential portion of the sprocket assembly.

8. A mining conveyor according to any one of the preceding claims wherein the driven sprocket assembly comprises two outer portions, one being a goaf-side portion and the other being a face-side portion, each comprising a shaft section and a sprocket section, and a generally cylindrical central portion secured to and extending between the outer portions, said central portion affording the hollow interior of the driven sprocket assembly.

9. A mining conveyor according to claim 8 wherein each shaft section is provided by a stub shaft which is keyed onto its associated sprocket section.

10. A mining conveyor according to claim 9 wherein each stub shaft is provided with an axial bore constituting part of said passage means.

11. A mining conveyor according to one of claims 9 and 10 wherein each stub shaft is provided with one or more bores extending parallel to, but spaced from, the axis of the stub shaft. said bores constituting part of said passage means.

12. A mining conveyor according to one of claims 10 and 11 wherein the stub shaft of the outer, goaf-side section comprises one or more radial bores extending towards the goaf-side bearing assembly from the said bore or bores.

13. A mining conveyor according to any one of claims 1 to 7 wherein the driven sprocket assembly comprises a drive shaft extending between the two bearing assemblies and two generally semi-cylindrical sprocket sections secured to the drive shaft.

14. A mining conveyor according to claim 13 wherein the drive shaft comprises an axial bore affording the hollow interior of the driven sprocket assembly, and also affording part of said passage means.

15. A mining conveyor according to claim 14 wherein the axial bore extends into

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. cylindrical sprocket sections on the driven shaft 66, separate sprocket elements (particularly a goaf-side sprocket element and a face-side sprocket element) and an intermediate cylindrical spacer sleeve may be positioned on the driven shaft from one (conveniently the face-side) end thereof, an axially operating locking means being afforded to cause the said sprockets and the sleeve to closely abut with one another in the axial direction on the driven shaft. WHAT WE CLAIM IS:

1. A mining conveyor comprising a driven sprocket assembly and two spaced bearing assemblies between which the driven sprocket assembly extends and on which the driven sprocket assembly is mounted for rotation, one of said bearing assemblies being on the goaf-side and the other being on the face-side of the conveyor, said bearing assemblies being operative between circumferentially exterior portions of the driven sprocket assembly and fixed housing elements of the conveyor, wherein the sprocket assembly comprises a hollow interior, inlet means whereby lubricating fluids may be introduced into said hollow interior, and passage means through which lubricating fluid may flow from the hollow interior at least to the face-side bearing assembly.

15. A mining conveyor according to claim 14 wherein the axial bore extends into

the drive shaft from the face-side end, one or more radial bores being provided to conduct lubricating fluid from the axial bore to the goaf-side bearing assembly at least.

16. A mining conveyor according to any one of claims 1 to 7 wherein the driven sprocket assembly comprises goaf and faceside sprockets mounted on a drive shaft, a cylindrical spacer sleeve mounted on the drive shaft and extending between the said sprockets and axially-operated locking means to cause the said sprockets and the sleve to closely abut with one another in the axial direction of the drive shaft.

17. A mining conveyor comprising a driven sprocket assembly constructed and arranged substantially as hereinbefore described with reference (a) to Figures 1 and 3, or (b) to Figure 4 of the accompanying drawings.