GB2205881A

GB2205881A - Driving the cutting heads or rolls of an advancing or mining machine

Info

Publication number: GB2205881A
Application number: GB08814049A
Authority: GB
Inventors: Peter Kogler; Alfred Zitz
Original assignee: Voestalpine AG
Current assignee: Voestalpine AG
Priority date: 1987-06-17
Filing date: 1988-06-14
Publication date: 1988-12-21
Also published as: CN1007634B; ES2008545A6; DE3820264A1; ATA154587A; AT388024B; CN88103728A; IN168210B; DE3820264C2; GB8814049D0

Description

2205881 1.

Driving arrangement for the cutting heads or rolls of an advancing or mining machine The invention refers to a driving arrangement for the cutting heads or rolls of an advancing or mining machine, said cutting heads or rolls being rotatably supported on a cantilever arm at both sides thereof, noting that the driving shaft is rotatably supported within the interior of the cantilever arm.

In such known advancing or mining machines, the cutting heads or rolls are supported for rotation around axes crossing or intersecting the longitudinal axis of the cutting arm or cantilever arm, respectively. An arrangement of this type cant for example, be derived from AT-PS 359 453. On account of the high temperatures occurring at the bits during cutting work, cooling of the bits is of advantage at any rate. It has already been proposed also to cool the bits with water for the purpose of suppressing spark formation which is accompanied by the danger of explosions. For this purpose, it is known to arrange the water nozzles on the cutting head itself so that the water jet is immediately directed against the bits. Because the nozzles of such a bit cooling means are subjected to the action of the dust generated during cutting work, it is necessary to supply the water to the nozzles at a pressure as - 2 as high as possible and thus to prevent clogging of these nozzles. In the known constructions, the water is, on account of the rotating movement of the cutting heads, supplied to the cutting head via the carrier of the cutting head, i.e., as a rule, via the cutting arm. Sealing of water supply means is relatively complicated in case of high water pressure. From the already mentioned AT-PS 359 453 there is now known an arrangement, in which supply of the water to the nozzles is effected via a carrier being rigidly connected with the cutting arm and carrying the last stage of a stepdo%,,,n gearing, in particular a planetary gear. Subsequent to this carrier, supply of the water is effected via an axial passage till the outer side of the cutting head, and it had in particular to be prevented that water enters the space accommodating the gearing via any leaks, which would make ineffective the lubricating system. In these known constructions, there was arranged at both sides of the cutting head one gearing each comprising such planetary gears and there was provided a series of features for providing a high pressure sealing against cooling water tending to enter the gearing housing.

From the AT-PS 339 235 and the GB-PS 1 581 154 there have become known cutting machines, in which the last stage of the stepdown gearing is arranged within the respective interior of the cutting heads. Also in these known constructions, the supply conduits for supplying cooling medium to the bits must extend through part of the gearing, which requires complicated sealina means preventing cooling medium from entering into -1 0 1 the gearing in case of high pressures.

Beside the fact that the provision of two such stepdown gearings within the interior of hollow cutting heads or rolls represents a substantial constructional expenditure, there exists in such constructions still the risk that water enters through a leaking sealing and under high pressure into the lubricating circuit and the lubricant thus becomes spoiled and the gearing within the interior of the cutting heads may become destroyed.

The invention now aims at providing a driving arrangement of the initially mentioned type, which is of more simple construction and provides the possibility to reliably supply cooling agent under high pressure to the nozzles of the cutting heads or cutting rolls. For solvina this task, the driving arrangement according to the invention essentially consists in that the output shafts are supported in mutual coaxial relation at the free end of the cantilever arm and carry at their respective mutually facing inner ends a gear wheel being in meshing engagement within the interior of the cantilever arm with a common paraxial intermediate gear wheel, in that the mutually facing inner ends of the output shafts are supported on a common bearing support being stationary relative to the cantilever arm, in that the output shafts comprise a central cavity extending in axial direction and in that the output shafts are non-rotatably connected with the heads or rolls. In such a construction, the water supply passage need no more extent throuah a stage of the gearin t> but can be passed through the hollow output shaft, noting that the feature to support the mutually facing inner ends of the output shaft on a common bearing carrier being stationary relative to the cantilever arm provides in a simple manner the possibility to connect the water supply conduit to this bearing carrier. On account of the last intermediate gear wheel of the stepdown gearing being arranged within the cutting arm with its axis of rotation in parallel relation to the axis of rotation of the cutting heads or cutting rolls, the required sealing of the supply means for cooling agent is, in the following, substantially more simple also in case of high pressures of the cooling agent, because it is no more necessary to pass through a gearing stage. Furthermore, there can be used cutting rolls or cutting heads of relatively small space requirement. The provision of a stepdown gearing having its axes extending in essentially parallel relation to the axis of rotation of the heads or rolls, provides in a simple manner the possibility to install a single-part gearing housing, because the constructional parts required for this gearing may be inserted into the gearing housing via lateral openings, so that maintainance work is substantially facilitated. As a whole, the driving arrangement according to the invention allows a construction of the gearing which can easier be mounted and be attended to, and provides the additional essential advantage that supply oil cooling agent under high pressure is possible without any problems.

i d - Advatageously, the means for supplying cooling liquid is further developed such, that the bearing carrier extends through the axes of the output sh-afts and carries axial tubular protrusions extending through the cavity of the output shafts and that conduits for supplying cooling liquid under pressure are connected to the bearing carrier. The tubular protrusions on the bearing carrier are themselves again non-rotatably connected with the bearing carrier and thus with the cutting arm or, respectively, cantilever arm, so that the sealing surfaces of small diameter are only required far outside of the gearing. In this case, the bearing carrier may extend itself like a partition wall element between the ends of the output shaft and may preferably be designed as a partition wall element which extends essentially in the longitudinal axis of the cantilever arm and has its end located at a distance in front of the last intermediate gear wheel within the interior of the cantilever arm.

in a particularly simple manner, the bearing carrier can be designed to form one single piece with a housing wall, in particular with the front wall of the cantilever arm, which results in a simple assembling of the housing. Beside an advantageously one-piece design of the gearing housing within the area of the cutting arm, the output shafts may be embraced by housing shells which can be clamped together by means of the front wall element carrying the bearina carrier.

The bearing carrier provides, beside the adva,-,taceajs and sirD--".e supply of cooling liquid under pressure, also for a stable is 2 -:.

design of the bearings withstanding great forces. For the purpose of accommodating in a simple manner even bearings of large size, the construction is advantageously selected such that the output shafts comprise at their mutually facing ends carrying the external toothing of gears a recess for accommodating the bearings fixed to the bearing carrier. The bearing space provided in this manner may directly be supplied with the lubricant oil for the gearing, so that a construction reliably is obtained which is free of wear and needs only little mainte nance work.

In the following, the invention is further explained with reference to an example of embodiment schematically shown in the drawing.

In the drawing there is shown in an axial section a cutting arm together with the output shafts, the cutting heads or cutting rolls, respectively, connected to said output shafts being omitted.

In a cutting arm or cantilever arm 1, respectively, there are rotatably supported on the free end of the cantilever arm two output shafts 2 in mutually coaxial relation, said output shafts having on their mutually facing inner ends one external toothing of gears 3 each. This external toothing of gears 3 is in meshing engagement with a common intermediate gear wheel 4, which comprises a toothing 5 and has its axis 6 arranged in parallel relation to the axis 7 of said both output shafts 2. The intermediate gear whee! 4 represents the last sta-e oi a s-Le,.dovn gearing accommodated within a gearing- 1 1, 25 housing 8, said stepdown gearing comprising further gear wheels having their axes 6 and 7 extending in parallel relation to the axes 9 and 10. On account of such a construction of the gearing, it becomes possible to replace individual parts of the gearing through openings in the gearing housing 8, which openings are, for example, closed by covers 11 and 12.

Said both output shafts 2 are supported at their mutually facing inner ends via bearings 14 on a common bearing carrier 13 being stationary relative to the cantilever arm 1, noting that the bearing carrier 13 forms one single piece with the front wall 15 of the cantilever arm 1. In this case, the bearing carrier 13 is designed as a partition wall element extending substantially in direction of the longi- is tudinal axis 16 of the cantilever arm 1 and having its end located at a distance in front of the last intermediate gear wheel 4. The bearings 14, which are fixed to the bearing carrier 13 and support the output shafts, are housed within a recess 17 of the output shafts 2. The output shafts 2 are additionally supported on the cantilever arm 1 via bearings 18.

The output shafts 2 comprise each a central axial cavity 19 within which extend tubular protrusions 20 of the bearing carrier 13 for the purpose of supplying cooling liquid under pressure to nozzles of the cutting head. Supply of cooling liquid to the tubular protrusions 20 being rigidly connected with the bearing carrier 13 is, in this case, effected via conduits 21. For the purpose of preventing 1 C the pressurized cooling liquid from entering into the gearing housing, there are, in a simple manner, provided sealings 22, 23 within the area of the outlets of the tubular protrusions 20 and in proximity of the recesses 17 of the output shafts 2, noting that the sealing surfaces are only arranged at a location of small diameter and outside of the gearing, so that the provision. of sealings is substantially simplified and, in particularr penetration of pressurized fluid into the lubricant of the gearing can reliably be prevented.

Beside ease of assembling and ease of maintainance of the gearing on account of using gear wheels having their axes extending in parallel relation to the axis of the output shafts, ease of assembling and replacement of the output shafts 2 can be achieved if these output shafts are embraced by housing shells 24 which are clamped on the front wall element 15, carrying the bearing carrier 13, of the cantilever arm 1.

Claims

Claims:

1. Driving arrangement for the cutting heads or rolls of an advancing or mining machine, said cutting heads or rolls.being rotatably supported on a cantilever arm at both sides thereof, noting that the driving shaft is rotatably supported within the interior of the cantilever arm, characterized in that the output shafts (2) are supported in mutually coaxial relation at the free end of the cantilever arm (1) and carry at their respective mutually facing inner ends a gear wheel being in meshing engagement within the interior of the cantilever arm (1) with a common paraxial intermediate gear wheel (4), in that the mutually facing inner ends of the output shafts (2) are supported on a common bearing support (13) being stationary relative to the cantilever arm (1), in that the output shafts (2) comprise a central cavity (19) extending in axial relation and in that the output shafts (2) are non-rotatably connected with the heads or rolls.

2. Driving arrangement as claimed in claim 1, characterized in that the bearing carrier (13) extends through the axes (7) of the output shafts (2) and carries axial tubular protrusions (20) extending through the cavity (19) of the output shafts (2) and in that conduits (21) for supplying cooling liquid under pressure are connected to the bearing carrier (13).

3. Driving arrangement as claimed in claim 1 or 2, characterized in that the bearing carrier (13) forms one single piece with a housing wall, in particular with the front wall (15) of the cantilever arm (1).

4. Driving arrangement as claimed in claim 1, 2 or 3, characterized in that the bearing carrier(13) is designed as a partition wall element extending essentially in the longitudinal axis (16) of the cantilever arm (1) and ending at a distance in front of the last intermediate gear wheel (4) within the interior of the cantilever arm (1).

5. Driving arrangement as claimed in any of claims 1 to 4, characterized in that the output shafts (2) comprise at their mutually facing ends carrying the external toothing of gears (3) a recess (17) accommodating the bearings (14) fixed to the bearing carrier (13).

6. Driving arrangement substantially as described with reference to. and as shown in, the accompanying drawing.

j>uL,Iished 1988 a. The Patent Office. Slate House, 66 I High Filborn. Londor WC3 P. 4TP FLrtker c-nes mkv:)e obtained from The Patent Offi ce, Saes E-:,sr.ch. S,. Ma-%, C:,ay. Orpington Kent Br-.E 3RD PrinzeJ ty Multiplex teel=q'es ltd. S, Mary Crkv. Kenz. Con 1 87.