WO2017127009A1

WO2017127009A1 - Mining machine and method for operating a mining machine

Info

Publication number: WO2017127009A1
Application number: PCT/SE2017/050037
Authority: WO
Inventors: Gunnar Bergling; Emil OLOFSSON; Fredrik Saf; Sverker Hartwig
Original assignee: Atlas Copco Rock Drills Ab
Priority date: 2016-01-22
Filing date: 2017-01-17
Publication date: 2017-07-27
Also published as: EP3405648B1; SE1650078A1; EP3405648A4; EP3405648A1; ZA201803755B

Abstract

Mining machine (1) for driving tunnels, said mining machine (1) including: a cutting head (5) having rock engaging cutting elements (5´), a rotator (32) for driving said cutting head (5), means for forcing the cutting head against rock to be worked so as to disintegrate the rock, and means (7,7´) for transporting away released material. The cutting head is on an upper side is attached to a one-sided support unit. The mining machine includes a pressing unit arranged to press the cutting head (5) linearly against rock to be worked, and the rotator (32) is arranged to rotate the cutting head (5) in a first rotational direction during a cut where the cutting head is in a first side position and in a second rotational direction in a cut where the cutting head is in a second side position. The invention also relates to a method.

Description

MINING MACHINE AND METHOD FOR OPERATING A MINING MACHINE

FIELD OF THE INVENTION

The invention concerns a mining machine for driving tunnels, galleries or the like, said mining machine including: a rotational cutting head having a plurality of rock engaging cutting elements distributed on its periphery, a rotator for rotationally driving said cutting head, said cutting head having a rotation axis extending essentially vertically, when the mining machine is aligned on horizontal ground, a

positioning arrangement arranged to position the cutting head between cuts, said positioning arrangement being arranged to swing the cutting head horizontally from a first side to a second side to reach first side and second side positions respectively, means for forcing the cutting head against rock to be worked so as to disintegrate the rock, means for

transporting away released material. The invention also concerns a method for operating such a mining machine. BACKGROUND OF THE INVENTION

A process of mining and tunneling for extraction boring as well as a for the production of tunnels, galleries, shafts or the like is previously known.

For completing produced rooms and spaces, securing roof, floor, walls and possible surface treatment has to be included besides the drifting or tunnel driving itself.

In order to produce tunnels and galleries and for extraction boring it is previously known to use mining

machines having cutting heads such as cutter wheels that are brought to sweep a meeting rock surface to be worked as well as to linearly press a rotating cutting head with high force so as to disintegrate a rock. Tunnels and galleries in mines are ineffective spaces to the extent that they normally only comprise transport paths between sites where valuable ore is extracted. Production of tunnels and galleries is certainly time, labor and energy consuming and requires expensive equipment and is thereby expensive. For that reason it is problematic having bulky rigs requiring spacious tunnels for their transport since time, energy and resources are thus required to complete the

required transport spaces. In particular, it is important that disintegrated rock is removed effectively.

As examples of the background art can be mentioned

WO2011/029111 A2 and US 8950823 B2.

AIM AND MOST IMPORTANT FEATURES OF THE INVENTION

It is an aim of the present invention to provide a mining machine and a method which address the above problems and at least reduces these problems.

This is achieved in respect of a mining machine for driving tunnels, galleries or the like, in that the cutting head on an upper side is attached to a one-sided support unit such that the lower side of the cutting head is free from support means, that the mining machine includes a pressing unit arranged to press the cutting head linearly against rock to be worked, essentially in a longitudinal direction of the mining machine when aligned, and that the rotator is arranged to rotate the cutting head in a first rotational direction during a cut where the cutting head is in a first side

position and that the rotator is arranged to rotate the cutting head in a second rotational direction in a cut where the cutting head is in a second side position so that

disintegrated rock material is forced by the cutting head from the respective side to which the cutting head is swung to a more central part of an excavation site. The distinguishing features brings along important advantages. One major advantage is that the cutting head can be closed at its lower side making complicated seals between relatively movable part unnecessary. Seals on the upper side of the cutting head can be made easily accessible for

inspection and for service without having to dismount the cutting head from the one-sided support unit.

Also the rotator motor, the bearings and other components positioned inside the cutting head are advantageously easily accessible for inspection and for service through a removable inspection cover positioned at the top side of the cutting head holder.

The feature that the rotator is arranged to rotate the cutting head in different directions such that disintegrated rock material (muck) is forced by the cutting head from the respective side to which the cutting head is swung to a more central part of the excavation site makes muck handling

considerably more easy, since entry to the means for

transporting away released material (muck transport means) is typically placed centrally at the lower front of the mining machine. This feature allows using a more simple muck input feeder at the front of the machine.

The cutting head is advantageously formed as a rotating wheel having rock engaging and rock disintegrating elements distributed over its surface seen in a circumference direction as well as seen in an axial direction, in parallel with a rotation axis for the cutting head.

The cutting elements are also advantageously rotatable, at least part disc-shaped round elements that are brought to rotate and cut parallel grooves in the rock and thereby

disintegrate the rock when the rotating cutting head is pressed with high force against the rock during a cut. Said positioning arrangement is advantageously arranged to also swing the cutting head vertically up and down to reach upper and lower positions respectively.

In a particularly advantageous aspect of the invention the lower side of the cutting head is provided with a

plurality of drive protrusions having guide surfaces arranged to drive the disintegrated rock material. The drive

protrusions hereby force the muck being below the cutting head radially outwards from the rotation axis of the cutting head towards its periphery at the same time as they force the muck towards the center of the machine front. The muck is thereby imparted a combinatory movement out (from the rotation axis) - to the front center (of the mining machine), making it easy to collect by a muck transport input arrangement.

Said guide surfaces hereby suitably form an open, positive outward angle above 90° to a radius of the cutting head, which is a positive angle as seen in the prevailing rotational direction. This angle is suitably between 110° and 160° and preferably between 125° and 145°.

Since this arrangement works in both rotational

directions of the cutting head, at least a first selection of said drive protrusions are provided with guide surfaces arranged to be operative in the first rotational direction and at least a second selection of said drive protrusions is provided with guide surfaces arranged to be operative in the second rotational direction. "Selection" means in practice a number of drive protrusions being smaller than the total number of drive protrusions.

It is, however, preferred that all drive protrusions have guide surfaces operative in both rotational directions.

Furthermore, the drive protrusions are preferably

distributed on the lower side of the cutting head both

radially, so that different drive protrusions operate on different radial distances from the rotation axis (for

influencing muck at different radial distances from the rotation axis), and angularly, seen around the rotation axis, such that the drive protrusions are more or less evenly spread on the lower side.

Advantageously, the cutting head has a plurality of head scrapers, that are extending, seen in axial directions of the cutting head, at least partly past the cutting elements which contributes to removing partly loosened rock material from the rock face in an advantageous way.

It is preferred that a muck collecting apron is arranged at a front position of the mining machine below the cutting head. The muck collecting apron is preferably provided with muck discharge wheels for driving muck to a conveyer belt.

It is highly preferred that the rotator is enclosed inside said cutting head. This feature results in that rotator motor torque is easily transmitted to the cutting head and that complicated gearing can be avoided. This solution also is space saving, since the rotator occupies a normally empty space.

The support unit preferably includes a bearing support member arranged to enclose the rotator in an inside and to support cutting head bearings on an outside. The bearing support is preferably short and wide pipe-shaped with one end attached to the support unit. This solution gives a rigid and strong attachment with easy measures.

The rotator shaft is preferably directly connected to the cutting head. This is preferred since it is i.a. economic and space saving but it is not excluded that the connection is indirect over a gear transmission.

The free end of the cutting head being its lower side is defined by a torque transmitting web portion of the cutting head for strength and stability. The cutting head is suitably peripherally essentially cylindrical and has supports for the bearings on its inside.

The bearing support member is connected to a boom of the support unit in the form of a support boom through annular contact.

The bearing support member has at least one annular inside rotator support flange for mounting of the rotator.

The bearing support member is axially extending and essentially ring-shaped (pipe-shaped) .

The invention also relates to a method of driving tunnels, galleries or the like, with the aid of a mining machine including: a rotational cutting head having a

plurality of rock engaging cutting elements distributed on its periphery, the method including: rotationally driving said cutting head having a rotation axis extending essentially vertically, when the mining machine is aligned on horizontal ground, positioning the cutting head between cuts by swinging the cutting head horizontally from a first side to a second side, forcing the cutting head against rock to be worked so as to disintegrate the rock, and transporting away released material. The method is distinguished by pressing the cutting head linearly against rock to be worked, essentially in a longitudinal direction of the mining machine when aligned by forcing the cutting head with the aid of a one-sided support unit such that the lower side of the cutting head is free from support means, and rotating the cutting head in a first rotational direction during a cut where the cutting head is swung to the first side and rotating the cutting head in a second rotational direction in a cut where the cutting head is swung to the second side so that disintegrated rock material is forced by the cutting head from the respective side to which the cutting head is swung to a more central part of an excavation site. Advantages as above are achieved in respect of the inventive method.

The method preferably includes driving disintegrated rock material below the cutting head radially outwards, when rotating the cutting head, with the aid of a plurality of drive protrusions having guide surfaces arranged on the lower side of the cutting head.

The invention will now be described in greater detail with reference to the drawings.

BRIEF DESCRIPTION OF DRAWINGS

Fig. 1 shows a side view of a mining machine according to the invention,

Fig. 2 shows a top plan view of the mining machine in Fig. 1,

Fig. 3a and b show side views of the mining machine in Fig. 1 with the cutting head in different positions,

Fig. 4 shows a top plan view of the mining machine in Fig. 1 with the cutting head swung to a first side,

Fig. 5 shows a front part of the mining machine in larger scale in a perspective view,

Fig. 6 shows a front part of the mining machine in larger scale in a front view,

Fig. 7a, b and c show details of a lower side of

differently equipped cutting heads,

Fig. 8 shows a cutting head and a support unit of the mining machine in a vertical section, and

Fig. 9 shows diagrammatically an inventive method

sequence.

DESCRIPTION OF EMBODIMENTS Figs. 1 and 2 show a mining machine 1 including a front unit 2 and a rear unit 3, which are interconnected over a joint arrangement 4.

At the front of the front unit 2 there is shown a cutting head 5 which is formed basically as a rotating wheel having rock engaging and rock disintegrating elements distributed over its surface seen in a circumference direction (around the cutting head) as well as seen in an axial direction, in parallel with a rotation axis AROT for the cutting head. The rotation axis AROT is in the shown example included in a central plane C (see Fig. 2) extending essentially vertically when the mining machine is positioned on horizontal ground (and when the mining machine is aligned) .

The cutting head 5 is rotationally drivable through a rotator (see Fig. 8) being positioned inside the cutting head 5. The cutting head is supported by a cutting head holder 13 and is also swingable by the aid of a positioning arrangement including positioning cylinders (whereof upper positioning cylinders 12 ^'and 12^{' '} are shown) allowing for positioning the cutting head in vertical directions in order to cut higher cuts (see Fig. 3b) for forming a roof of a driven tunnel and lower cuts (see Fig. 3a) for forming floor or ground of said tunnel .

The arrangement for cutting head swing can be arranged in various ways and in the embodiment with upper positioning cylinders 12 ^'and 12^{' '}, the positioning arrangement 12 also includes (not shown) one or more lower positioning cylinder (- s) which is/are connected to a lower region of the cutting head holder 13.

If necessary, the cutting head can also be arranged to cut intermediate cuts between the higher cuts and the lower cuts . Fig. 2 also shows a removable inspection cover 37 positioned at the top side of the cutting head holder 13.

Seals, the rotator motor, the bearings and other components positioned inside the cutting head are advantageously easily accessible for inspection and for service through the

removable inspection cover.

As illustrated in Fig. 4, the cutting head 5 can also be swung laterally in order to perform drifting when extended width of the cut tunnel is required. The positioning

arrangement 12 is arranged also to position the cutting head 5 between cuts by swinging the cutting head horizontally to a first side position, which is represented in Fig. 4, or to a second side position (not shown) .

A pressing unit (not shown) is included in the front unit 2 which forces the rotating cutting head with its positioning arrangement linearly forward for performing the cutting, drifting, or driving face, wherein engaged rock is

disintegrated. The pressing unit can for example include powerful hydraulic actuator (-s) and/or a power linkage.

7 indicates means for collecting disintegrated material to be transported away from the cutting head 5.

Said means 7 includes a ground engaging scraper or apron having mechanical means in the form of rotational wheels with feeder arms (see Figs. 5 and 6) for collecting the

disintegrated rock material and to place it on a moveable transport band, which extends through the front unit and which connects to a similar transport band inside the rear unit all the way to a material discharge 7' for loading the material on a transport truck or the like.

The front unit 2 also exhibits crawler bands whereof one is shown and indicated with 6. In order to stabilize the mining machine during cuts in the drifting face, there are provided upper stabilizing units 10 for engagement with the tunnel roof and lower stabilizing units 11 for ground contact. These stabilizing units are forced against the meeting roof and ground respectively in order to secure the mining machine and counteract the considerable forces created during

performing the cuts in the drifting face.

Inside the rear unit 3 there is an operator^'s cabin being equipped with system interface for an operator for assistance or automatic control during the mining or drifting face as well as during tramming. A control unit is denoted CPU.

Furthermore, the rear unit 3 is provided with rear crawler bands 8 and drive means for the working equipment including drive motor means 22, transmission means 23 and pumps etc. 24 (only indicated in Fig.2) . In particular there are positioned one or more electric or diesel engines for power generation, a gear transmission and one or more

hydraulic pumps for supply of pressure fluid to various components such as the cutting head and the crawler bands.

At the rear part of the front unit 2 there are positioned two bolting equipment units 9 that are arranged for securing the roof more or less continuously during mining. The bolting equipment units 9 preferably work with self-drilling bolts for simplification of the equipment.

Swing cylinders together with a central swing axis ASWING provide means for swinging the front and rear units 2 and 3 of the mining machine relative to each other. This central joint arrangement exhibits an opening, through which the material band for disintegrated material is led for subsequently discharge .

Further to Figs. 1 and 2, the positioning arrangement for the cutting head 5 indicated with 12 actuates the cutting head holder 13 in the form of a support boom so as to be pivoted in a cutting head swing joint assembly 14 in respect of the remainder of the front unit 2 and to be controlled for lateral as well as vertical swinging through the upper and lower positioning cylinders. The cutting head swing joint assembly allows more or less universal (although limited) swing up and down as well as from side to side.

The pair of upper positioning cylinders (12 ^'and 12^{' '}) and the one or more lower positioning cylinder (-s) together with the cutting head swing joint assembly 14 provide such swing on the one hand since the respective upper and lower positioning cylinders are disposed in planes respectively above and below an essentially horizontal axis ALIFT for swinging the cutting head up and down around the cutting head swing joint assembly 14. Extending the upper positioning cylinders (and shortening the lower positioning cylinder (-s)) results in lowering the cutting head and extending the lower positioning cylinder (-s) (and shortening the upper positioning cylinders) results in lifting the cutting head. This is illustrated in Figs. 3a and 3b.

On the other hand, the pairs of lateral positioning cylinders are disposed laterally on each side of the cutting head swing joint assembly 14. Extending the positioning cylinder (-s) on one side and shortening the positioning cylinder (-s) on the other side results in side swinging the cutting head essentially around an axis AHEAD. Lifting/lowering and side swinging of the cutting head can of course be

combined.

Fig. 4 shows the cutting head swung into a first side position. Here the cutting head is arranged to rotate in a first rotational direction DRI during a cut. Hereby muck is forced by the cutting head from the first side, to which the cutting head is swung, of a part of a tunnel under

construction, to an area indicated with M being a more central area in a front central region of the mining machine so as to be more easily input to the means 7, 7^' for transporting away released muck.

When excavating at the other side of the tunnel, the rotator is arranged to rotate the cutting head in a second rotational direction in a cut where the cutting head is swung to a second side position (not shown) .

Fig. 5 is a perspective view of the mining machine 1 showing the cutting head 5 uplifted. The axis ALIFT is shown below a plane through the positioning cylinders 12 ^' and 12 ^' (only 12^{' '} shown) . 36 indicates head scrapers extending radially as well as axially at the outer periphery of the cutting head. The head scrapers aid in removal of rock being partly loosened because of the action of cutting elements 5'. At least a selection of the head scrapers preferably at least partly protrude axially past the cutting elements 5' and also contributes in feeding muck up on the apron 7.

Fig. 6 shows the cutting head 5 from the front. The cutting elements 5', which in this case are rotatable, at least part disc-shaped round elements that are brought to rotate and cut grooves in the rock when the rotating cutting head is pressed with high force during a cut for drifting, so as to produce parallel grooves and thereby disintegrate the rock. C indicates the central plane mentioned above.

The muck collecting scraper apron 7 is arranged slightly inclined at a front position below the cutting head 5. The apron is provided with rotational muck discharge wheels 15 for driving muck that is present on the apron to a conveyer belt 16. Also is shown the lower side of the cutting head 5 with a plurality of drive protrusions 17.

Fig. 7a shows diagrammatically the lower side of the cutting head 5 with drive protrusions in more detail. Drive protrusions 17^', 17^{' '} and 17^{' ' '} are here positioned with their top ends at three different radial distances, Ri, R2 and R3 respectively, from the rotation axis AROT SO as to be able to influence encountered muck at different radial levels. All drive protrusions 17^', 17^{' '} and 17^{' ' '} have guide surfaces 18 being operative in either rotational direction so as to be able to influence muck when the cutting head is rotating in both directions. All said shown guide surfaces 18 hereby form an open, positive outward angle a of about 135° to a radius of the cutting head, which is a positive angle as seen in the prevailing rotational direction.

Fig. 7b shows the lower side of a cutting head 5 with drive protrusions 17 (only two of a greater plurality shown) which are each provided with a guide surface 18 being

operative in one rotational direction only. Both drive

protrusions 17 have guide surfaces 18 being concavely curved. The two drive protrusions 17 in this embodiment together influence muck when the cutting head is rotating in both directions. It is evident that the cutting head in practice is provided with a plurality of pairs of drive protrusions 17 distributed around the rotation axis and radially from the rotation axis. Other shapes of drive protrusions 17 can be contemplated, for example more strip-shaped with more or less linear or curved or multi linear angled guide surfaces 18.

Fig. 7c shows the lower side of a cutting head 5 with eight drive protrusions 17 being strip-shaped or band-shaped and extending linearly along radiuses of the cutting head 5.

All eight drive protrusions 17 are active in either rotational direction of the cutting head and consequently exhibit linear guide surfaces 18 on either side.

The drive protrusions are dimensioned to protrude from the cutting head in order to fulfil the function to displace muck (or disintegrated rock) so as to force the muck being below the cutting head radially outwards from the rotation axis of the cutting head towards its periphery at the same time as they force the muck towards the center of the machine front .

For that purpose, the drive protrusions have to have a suitable extension in the axial (rotation axis) direction of the cutting head.

That extension is calculated based on firstly the

physical limitations that prevent said extension not to be too great because of interference with other components such as the muck collecting apron, the muck discharge wheels and the associated conveyer belt in a position where the cutting wheel is in a position closest to these components.

The dimensions also depend on character of rock or ore to displace, dimensions of the cutting head, cutters on the cutting head and expected size of particles and lumps of rock.

Given these considerations, a suitable axial extension from a side of the cutting wheel is about 10 - 80 mm. More preferred, the axial extension is from 25 to 65 mm and most preferred, the axial extension is from 35 to 55 mm.

The inventive mobile miner is subjected to great forces and torques required for its operation. This requires a driving arrangement and bearing support of the cutting head being sufficiently ridged and strong and yet small to maintain flexibility for allowing fast and effective rock working.

The rotational speed of the cutting head is relatively low, from about 10 revolutions per minute up to about 20 or 30 revolutions per minute. Given a certain effect this requires the torque to be great. The solution to the driving and

bearing support of the cutting head provides rigid and strong bearing support at a considerable distance from the rotation axis and preferably a direct drive hydraulic motor being very powerful with or without central reduction gear. The strong and rigid bearing support is essential since the support boom is one-sided meaning that the rotating cutting head is supported from one side only.

More in detail the rotator is preferably a direct drive hydraulic motor of radial piston type wherein the rotational speed of the rotator is the same as that of the cutting head.

It is, however, not excluded that a motor and a reduction gear in one or more steps is used, which, however, is a bulkier and more expensive solution. It is also possible to use an

electric synchronous motor or any other suitable motor having short building length together with a reduction gear.

When it comes to bearing support, it is preferred that a spherical radial roller bearing is used together with two axial bearings. Another embodiment can include a spherical roller bearing etc. The one-sided support boom has the

advantage that support of the cutting head on one side allows the cutting head to be placed closer to a tunnel floor of rock to be worked without any part of the support boom coming into contact with rock or equipment.

Fig. 8 illustrates this aspect of the invention, wherein a very large support bearing 19 is provided which is supported by a hollow, pipe-shaped bearing support member 20 which on a first end provides a large annular attachment surface 21 to the one-sided boom 13 (in this case constructed otherwise than what is shown in the previously discussed Figs) . This makes it easy, with reasonable dimensions and thickness of material of the bearing support member as well as of the inside of the cutting head 5, to transmit forces from rock contact to the boom 13 and vice versa.

The rotator 32 is fixed inside the hollow axis and preferably for example co-operates with an inside flange 33 of the bearing support member 20 so as to have the motor drive shaft 34 being directly connected to the radially extending lower side 35 of the cutting head 5, allowing the cutting head 5 to be closed and slim with said lower side 35 being the bottom of a "can-shape".

The support bearing 19 of the cutting head 5 is

positioned at the outside of the bearing support member 20.

Two of the plurality of drive protrusions having guide surfaces arranged to drive disintegrated rock material radially outwards in directions radially out from the rotation axis of the cutting head are exemplified at 17. These drive protrusions are advantageous to prevent muck from being accumulated below the cutting head and thereby obstructing downward movements and thus proper operation of the mining machine which requires positioning of the cutting head close to rock to be worked.

Fig. 9 shows diagrammatically an inventive method sequence.

Position 25 indicates the start of the sequence.

Position 26 indicates positioning and rotating a cutting head for drifting purposes.

Position 27 indicates forcing the cutting head linearly against rock to be worked.

Position 28 indicates rotating the cutting head in a first rotational direction during a cut where the cutting head is in a first side position.

Position 29 indicates driving disintegrated rock material below the cutting head radially outwards, when rotating the cutting head, with the aid of a plurality of drive

protrusions .

Position 30 indicates end of the sequence.

In practice, the measures related to the positions in Fig. 9 are initiated as required and in required order. Also other method steps are preferably taken as required.

The invention can be modified within the scope of the following claims. The cutting head can be equipped with stud-like, picklike or peg-like rock disintegrating elements that are rigidly positioned on the periphery of the cutting head.

Claims

CLAIMS :

1. Mining machine (1) for driving tunnels, galleries or the like, said mining machine (1) including:

- a rotational cutting head (5) having a plurality of rock engaging cutting elements (5^') distributed on its periphery,

- a rotator (32) for rotationally driving said cutting head (5) ,

- said cutting head (5) having a rotation axis extending essentially vertically, when the mining machine is aligned on horizontal ground,

- a positioning arrangement (12) arranged to position the cutting head (5) between cuts, said positioning arrangement (12) being arranged to swing the cutting head horizontally from a first side to a second side to reach first side and second side positions respectively,

- means for forcing the cutting head against rock to be worked so as to disintegrate the rock, and

- means (7,7^') for transporting away released material,

characterized in

- that the cutting head on an upper side is attached to a onesided support unit such that the lower side of the cutting head is free from support means,

- that the mining machine includes a pressing unit arranged to press the cutting head (5) linearly against rock to be worked, essentially in a longitudinal direction of the mining machine when aligned, and

- that the rotator (32) is arranged to rotate the cutting head (5) in a first rotational direction during a cut where the cutting head is in a first side position and that the rotator (32) is arranged to rotate the cutting head (5) in a second rotational direction in a cut where the cutting head is in a second side position so that disintegrated rock material is forced by the cutting head from the respective side to which the cutting head is swung to a more central part (M) of an excavation site.

2. Mining machine according to claim 1, characterized in that the cutting head (5) is formed as a rotating wheel having rock engaging and rock disintegrating elements distributed over its surface seen in a circumference direction as well as seen in an axial direction, in parallel with a rotation axis (AROT) for the cutting head.

3. Mining machine according to claim 1 or 2, characterized in that the cutting elements (5') are rotatable, at least part disc-shaped round elements, that are brought to rotate and cut parallel grooves in the rock and thereby disintegrate the rock when the rotating cutting head (5) is pressed with high force against the rock during a cut.

4. Mining machine according to any one of claims 1 - 3,

characterized in that said positioning arrangement (12) is also arranged to swing the cutting head (5) vertically up and down to reach upper and lower positions respectively.

5. Mining machine according to any one of claims 1 - 4,

characterized in that the lower side (35) of the cutting head (5) is provided with a plurality of drive protrusions (17) having guide surfaces (18) arranged to drive disintegrated rock material.

6. Mining machine according to 5, characterized in that said guide surfaces (18) form an open angle (a) to a radius of the cutting head.

7. Mining machine according to claim 5 or 6, characterized in that at least a first selection of said drive protrusions are provided with guide surfaces arranged to be operative in the first rotational direction and at least a second selection of said drive protrusions is provided with guide surfaces arranged to be operative in the second rotational direction.

8. Mining machine according to any one of claims 1 - 7,

characterized in that the rotator (32) is enclosed inside said cutting head (5) .

9. Mining machine according to any one of claims 1 - 8,

characterized in that a muck collecting apron (7) is arranged at a front position below the cutting head (5) .

10. Mining machine according to claim 9, characterized in that the muck collecting apron (7) is provided with muck discharge wheels (15) for driving muck to a conveyer belt (16) .

11. Mining machine according to any one of claims 1 - 10, characterized in that the support unit includes a bearing support member (20) arranged to enclose the rotator (32) in an inside and to support cutting head bearing or bearings (19) on an outside.

12. Mining machine according to claim 11, characterized in that the bearing support member (20) is axially extending and essentially pipe-shaped.

13. Method of driving tunnels, galleries or the like, with the aid of a mining machine (1) including:

- a rotational cutting head (5) having a plurality of rock engaging cutting elements (5^') distributed on its periphery, The method including:

- rotationally driving said cutting head (5) having a rotation axis extending essentially vertically, when the mining machine is aligned on horizontal ground,

- positioning the cutting head (5) between cuts by swinging the cutting head vertically up and down as well as

horizontally from a first side to a second side,

- forcing the cutting head against rock to be worked so as to disintegrate the rock, (in a cut) and

- transporting away released material,

characterized by

- pressing the cutting head (5) linearly against rock to be worked, essentially in a longitudinal direction of the mining machine when aligned by forcing the cutting head with the aid of a one-sided support unit such that the lower side of the cutting head is free from support means, and

- rotating the cutting head (5) in a first rotational

direction during a cut where the cutting head (5) is swung to the first side and rotating the cutting head in a second rotational direction in a cut where the cutting head is swung to the second side so that disintegrated rock material is forced by the cutting head from the respective side to which the cutting head is swung to a more central part of an

excavation site.

14. Method according to claim 13, characterized by driving disintegrated rock material below the cutting head (5) radially outwards, when rotating the cutting head, with the aid of a plurality of drive protrusions (17) having guide surfaces (18) arranged on the lower side of the cutting head (5) .