GB2166469A - Fluid supply systems for rotary cutter heads mountable on mining machines - Google Patents

Abstract

A plurality of angularly spaced feed passages (5) extend along a rotary drive shaft (2) of a mining machine rotary cutter head (1), each feed passage being capable of feeding pressurised fluid to a bank of outlet nozzles arranged around a portion of the circumference of the cutter head. The supply of fluid to the feed passages is controlled by a plurality of slide valves 14, respectively. Operation of the slide valves is controlled by a valve operating arrangement (ie, a swashplate 20) mounted co-axial with the slide valves. <IMAGE>

Description

SPECIFICATION Fluid supply systems for rotary cutter heads mountable on mining machines This invention relates to fluid supply systems for rotary cutter heads mountable on mining machines, the fluid supply systems feeding fluid to outlet nozzles arranged to direct sprays outwardly from the rotating heads.

In particular, although not exclusively, the invention relates to a water supply system for a rotary cutter head which has cutter tools arranged around its circumference and which, in use, at any particular instant, can have only a portion of its circumference associated with the cutting zone and in engagement with the rock or mineral face. With such a rotary cutter head in order to try and reduce the total quantity of water discharged from the outlet nozzles it is known to provide water phasing arrangements on the cutter head so that only those outlet nozzles associated with the cutting zone are fed with water. Two forms of water phasing arrangements have been proposed.

One water phasing arrangement involved providing a fixed shaft extending through the rotary drive shaft for the rotary cutter head, a water phasing distribution being fixedly mounted on the fixed shaft. Unfortunately, such an arrangement encountered problems due to an efficient seal being required between the fixed and the rotating components.

In use, such seals were found to have relative short operational lives and tended to require time consuming replacement operations. Moreover, such seals tended not to be suitable for rotative high water pressures where water jets from the outlet nozzles were required to cut rock or mineral or to assist the cutter tools in cutting rock or mineral.

The second proposed water phasing arrangement required the cutting force on each cutter tool to urge the cutter tool against a resilient bias and, thereby, open a water feed valve. Unfortunately, no such an arrangement appears to have worked satisfactory over a relatively long period. Consequently, the second mentioned arrangement tends not to have been widely exploited. A further anticipated disadvantage of this latter arrangement is that with relatively high water pressure systems, the cutting force exerted on the cutter tool may be insufficient to urge open the water feed valve.

An object of the present invention is to provide an improved water supply system for a rotary cutter head which enables water phasing to be achieved and which tends to overcome or reduce the above mentioned problems.

According to the present invention a fluid supply system for a rotary cutter head mountable on a mining machine comprises a plurality of feed passages angularly spaced around and extending along a drive shaft for the rotary cutter head, in use, each passage leading to a number of outlet nozzle means provided on the rotary cutter head, an inlet supply passage for supplying pressure fluid to the plurality of passages, a plurality of slide valves associated with the plurality of passages, respectively, and each having an 'open' operational mode in which pressure fluid is fed from the inlet supply passage into the associated feed passage, and a 'closed' operational mode in which pressure fluid is not supplied to the associated feed passage, and a valve operating arrangement mountable co-axially with the rotary drive shaft and adapted to operatively engage the slide valves as the drum shaft rotates such that, in use, only those feed passages associated with the currently cutting portion of the cutter head are fed with pressure fluid.

Preferably, each slide valve comprises a reciprocal slide valve member and a plunger drivably attached to the slide valve member.

Advantageously, the valve operating arrangement comprises a component defining a working profile drivably engaging the plunger of each reciprocal slide valve member.

Conveniently, the component comprises a swashplate.

Alternatively, the component comprises a stepped plate arrangement.

Preferably, the component is rotatable relative to the rotary drive shaft to change the portion of the rotating cutter head supplied with pressure fluid.

Conveniently, the component is rotated under manual control.

Alternatively, the component is rotated under the control of control means controlling the cutting operation of the cutter head.

According to another aspect the present invention provides a rotary cutter head comprising a fluid supply system as defined above.

Further, the present invention provides a mining machine having a fluid supply system as defined above.

By way of example, two embodiments of the present invention will be described with reference to the accompanying drawings in which: Figure 1 is an incomplete diagrammatic longitudinal section of one embodiment of a fluid supply system constructed in accordance with the present invention; Figure 2 is an incomplete section taken along line ll-ll of Figure 1; Figure 3 is a longitudinal section of a detail of Figure 1, the detail being drawn on an enlarged scale; and Figure 4 is an incomplete diagrammatic longitudinal section of a second embodiment of a fluid supply system constructed in accordance with the present invention.

Figures 1 and 2 show details of a first em bodiment of a water supply system for a rotary cutter head 1 mountable on an output drive shaft 2 of a mining machine 3, (the rotary cutter head is not seen in Figure 1 and only a small portion of the mining machine 3 is shown in Figure 1). Only the machine end of the drive shaft remote from the working face is shown. The rotary drive shaft 2 is supported by a bearing 4 carried by the mining machine 3.

The water supply system comprises a plurality of feed passages 5 angularly spaced around and extending along the drive shaft 2.

Each feed passage 5 leads to a number of outlet nozzle means provided on the rotary cutter head. Each outlet nozzle means comprises a radially extending passage 6 and a bank of outlet nozzles 7 hydraulically connected to the passage 6 via branch passages 8, each bank of outlet nozzles being associated with a particular portion around the circumference of the cutter head. The water supply system also comprises an inlet supply passage 10 for supplying pressure fluid to the plurality of feed passages 5 via cross passages 11, the inlet supply passage extending axially along the rotary drive shaft 2. Pressure fluid is supplied to the inlet passage 10 from a mains feed 12 via a rotary seal assembly 13.

The flow of pressure fluid from the inlet supply passages 10, 11 to the plurality of feed passages 5 is controlled by a plurality of slide valves 14 associated with the feed passages 5, respectively. Each slide valve comprises (see particularly Figure 3) a reciprocal slide valve member 15 having a tapered end 16 for sealed engagement with a sealing 18 formed within the associated passage 5, and a plunger 19 having an axial stepped bore 17 slidably accommodating one end 24 of the slide valve member 15 and having a spherical end 25 drivably engaged by a swashplate 20 as will be explained later in the specification.

The plunger 19 is slidably mounted in an enlarged bore 21 co-axial with the associated passage 5. A coil spring 22 tends to urge the plunger 19 towards the mouth of the bore 21 and a seal 22 seals the plunger within the bore. A cover plate 28 retains the seals 23 in position; As mentioned previously, one end 24 of the slide valve member 15 is slidably accommodated in the axial bore 17, the slide member being urged out of the bore by a disc or coil spring 35. A stepped collar 26 engages a stop clip 27 to retain the slide member within the stepped bore 17.

In Figure 1 the relatively lower slide valve 14A is shown in a 'closed' operational mode with the tapered end 16 sealably engaging the valve seating 18 to cut off the supply of pressure fluid to the associated feed passage 5.

The relatively upper slide valve 143 is shown in an 'open' operational mode with the tapered end 16 disengaged from the valve seating 18 such that pressure fluid is fed from the inlet supply passage 10, 11 into the associated feed passage 5. It will be seen that as the plunger 19 is urged into the bore 17 the tapered end 16 of the slide member 15 first contacts the seating 18 to close the valve further movement of the plunger 19 into the bore 21 causes the slide member to move along the stepped bore 17 against the action of the spring 35, the collar 26 moving towards but not reaching an abutment shoulder 36 formed by the stepped bore. The slide member and plunger construction constitute a lost motion device.

The aforemention swashplate 20 (see particularly Figure 1) is provided on a valve operating arrangement having a hub 37 mountable on the rotary seal 13 co-axially with the rotary drive shaft 2. In Figure 1 a pad 38 is shown mounted on the swashplate 20 contacted by the plungers 19 of the valves 1 4B currently in the 'open' operational mode. The pad which is omitted from Figure 3 limits movement of the plungers out of the bore 21.

Thus, in operation as the drive shaft rotates relative to the valve operating arrangement the action of the swashplate drivably engaging the plungers 19 is to first urge the slide valves into the 'closed' operational mode 14A. Upon the valve plungers engaging a portion of the swashplate more remote from the drive shaft end face the plungers and slide valve members are urged by the action of the springs 22 until each valve is in its 'open' operational mode. As the drive shaft rotates each slide valve is repeatedly operated between its 'open' and 'closed' operational modes.

By suitably positioning the working profile of the swashplate 20 the fluid supply system ensures water is discharged only from those outlet nozzles associated with the cutting zone of the cutter head.

In order to permit the position of the swashplate to be changed, in order to change the portion of the rotating cutter head supplied with pressure fluid, a ring of gear teeth 40 are provided around the hub 37 of the valve operating arrangement, the gear teeth being drivably engaged by a gear wheel 41 mounted on the drive shaft 42 of a motor 43, as for example a stepped motor.

If the rotary cutter head is mounted on a roadway excavating machine having a boom arranged to traverse the cutter head repeatedly over the vertical working face the operation of the motor 43 may be controlled from the hydraulic system for traversing the boom.

Thus, as the position of boom is adjusted resulting in another portion of the circumference of the cutter head being presented to the working face, the motor 43 is operated to suitably adjust the position of the swashplate 20 thereby correspondingly adjusting the portion of the circumference fed with pressure fluid. With such a control the position of the swashplate is changed during cutting.

Alternatively, the motor 43 may be controlled from an electronic control as for example a micro processor. Alternatively, the motor may be manually controlled.

The water discharged from the outlet nozzles 7 on the cutter head 1 may be at high pressure suitable for cutting rock or mineral either with or without the aid of cutter tools mounted on the cutter head. Alternatively, the water discharged from the outlet nozzles 7 may be at a relatively lower pressure suitable for suppressing dust generated by the cutter tools during cutting and/or for cooling the cutter picks.

The fluid supply system according to the first embodiment of the invention is suitable for feeding water to a shearer type mine winning machine which traverses repeatedly to and fro along a longwall face. With such an installation it is only necessary to change the position of the swashplate 20 at each end of the longwall face when the machine is about to change its direction of traverse along the face. In such an installation the motor 43 may be manually controlled.

In other embodiments the swashplate may be replaced by a stepped plate having one working section mounted adjacent to the end face of the drive shaft 2 and another working section mounted more remote from the end face of the driven shaft. Thus, the valves having their plungers engaging said one working section would be in the 'closed' operational mode while valves having their plungers engaging the said another working section would be in the 'open' operational mode. In some embodiments the said another working section is dispensed with, outward movement of the plungers being limited by abutment means associated with the plunger.

Figure 4 shows a second embodiment of the invention in which the rotatable swashplate of the first described embodiment is replaced by a pivotally mounted swashplate 60 supported in a pivotal mounting 61 under the action of a hydraulic ram 62. Resilient or hydraulic centralised units 64, 65 may be provided.

Such an embodiment is suitable for use on the previously mentioned shearer type mine winning machines in which the position of the swashplate is only required when the cutting direction of the machine is reversed. Adjustment of the swashplate position switches the water discharge from one side of the cutter head to the diametrically opposite side of the cutter head.

Claims (11)

1. A fluid supply system for a rotary cutter head mountable on a mining machine, comprising a plurality of feed passages sngularly spaced around and extending along a drive shaft for the rotary cutter head, in use, each passage leading to a number of outlet nozzle means provided on the rotary cutter head, an inlet supply passage for supplying pressure fluid to the plurality of passages, a plurality of slide valves associated with the plurality of passages, respectively, and each having an 'open' operational mode in which pressure fluid is fed from the inlet supply passage into the associated feed passage, and a 'closed' operational mode in which pressure fluid is not supplied to the associated feed passage, and a valve operating arrangement mountable co-axially with the rotary drive shaft and adapted to operatively engage the slide valves as the drive shaft rotates such that, in use, only those feed passages associated with the currently cutting portion of the cutter head are fed with pressure fluid.

2. A system as claimed in claim 1, in which each slide valve comprises a reciprocal slide valve member and a plunger drivably attached to the slide valve member.

3. A system as claimed in claim 2, in which the valve operating arrangement comprises a component defining a working profile drivably engaging the plunger of each reciprocal slide valve member.

4. A system as claimed in claim 3, in which the component comprises a swashplate.

5. A system as claimed in claim 3, in which the component comprises a stepped plate arrangement.

6. A system as claimed in claim 3, 4 or 5, in which the component is rotatable relative to the rotary drive shaft to change the portion of the rotating cutter head supplied with pressure fluid.

7. A system as claimed in claim 6, in which the component is rotated under manual control.

8. A system as claimed in claim 6, in which the component is rotated under the control of control means controlling the cutting operation of the cutter head.

9. A fluid supply system for a rotary cutter head mountable on a mining machine, substantially as described above and substantially as shown in the accompanying drawings.

10. A rotary cutter head comprising a fluid supply system as claimed in any one of the preceding claims.

11. A mining machine comprising a fluid supply system as claimed in any one of the preceding claims 1 to 9.