DRILL DRIVE FOR A DRILLING RIG

Abstract

The invention relates to a drill drive for a drilling rig with a motor, by which a drive shaft is rotationally driven which is supported in a rotatable manner in a housing with a bearing arrangement having at least a radial bearing, a first axial bearing and a second axial bearing, wherein on the first axial bearing a first force measuring device is arranged for determining a first axial force on the first axial bearing and on the second axial bearing a second force measuring device is arranged for determining a second axial force on the second axial bearing.

Furthermore, the invention relates to a drilling rig, in particular for oil or gas drilling, with a drill mast, along which a drill string with a drilling tool is arranged, wherein on the drill mast a drill drive according to the invention is supported in a displaceable manner for rotationally driving the drill string.

Claims

1. Drill drive (60) for a drilling rig, with a motor (61), by which a drive shaft (12) is rotationally driven which is supported in a rotatable manner in a housing (11) with a bearing arrangement (10) having at least a radial bearing (40), a first axial bearing (20) and a second axial bearing (30), wherein on the first axial bearing (20) a first force measuring device (50) is arranged for determining a first axial force on the first axial bearing (20) and on the second axial bearing (30) a second force measuring device (51) is arranged for determining a second axial force on the second axial bearing (30).

2. Drill drive according to claim 1, wherein the first axial bearing (20) is designed as a tapered roller bearing that carries an axial main load of the drive shaft (12).

3. Drill drive according to claim 2, wherein the radial bearing (40) is arranged at a lower end of the drill drive (60) in direction of a weight force acting on the drill drive (60) and wherein the second axial bearing (30) is arranged above the radial bearing (40) in direction of the weight force acting on the drill drive (60).

4. Drill drive according to claim 3, wherein the radial bearing is designed as a cylindrical bearing (40) and the second axial bearing (30) as a tapered roller bearing.

5. Drill drive according to claim 4, wherein the radial bearing (40) is designed as a non-locating bearing which is arranged in a movable manner parallel to an axis of rotation (15) of the drive shaft (12).

6. Drill drive according to claim 5, wherein the first axial bearing (20) is arranged between the radial bearing (40) and the second axial bearing (30).

7. Drill drive according to claim 6, wherein the first force measuring device (50) is arranged below the first axial bearing (20) and the second force measuring device (51) above the second axial bearing (30).

8. Drill drive according to claim 7, wherein a computer unit is provided which is connected to the first force measuring device (50) and the second force measuring device (51) and designed to calculate an axial force that acts on the drive shaft (12) below the bearing arrangement (10).

9. Drill drive according to claim 8, wherein the force measuring devices (50, 51) are arranged in a fixed manner and the computer unit is designed to compensate a load above the bearing arrangement (10), which acts in direction of the weight force and onto the drive shaft (12), compared to the load below the bearing arrangement (10), which is actually present on the drive shaft (12), in particular on the drill head.

10. Drill drive according to claim 9, wherein the first force measuring device (50) is arranged between the radial bearing (40) and the first axial bearing (20).

11. Drill drive according to claim 10, wherein on the drill drive (60) at least one temperature sensor (52) is arranged which is connected to the computer unit for determining a temperature-dependent bearing tensioning and designed to detect a temperature of the bearing arrangement (10).

12. Drilling rig, in particular for oil or gas drilling, with a drill mast, on which a drill string with a drilling tool is arranged, wherein on the drill mast a drill drive (60) for rotationally driving the drill string is supported in a displaceable manner which is designed according to one of claims 1 to 12.

Description

[0027] In the following the invention is described further by way of the drawings, wherein show:

[0028] FIG. 1 a bearing arrangement with supported drive shaft according to a preferred embodiment of the present invention;

[0029] FIG. 2 a drill drive with a bearing arrangement pursuant to the invention according to the preferred embodiment pursuant to FIG. 1.

[0030] In FIG. 1 a bearing arrangement 10 according to the invention is illustrated. The bearing arrangement 10 is arranged in a housing 11 that can surround a supported drive shaft 12 in the region of the bearing arrangement 10 in axial direction of the drive shaft 12. The drive shaft 12 has an axis of rotation 15, around which the bearing arrangement 10 is designed. In the bearing arrangement 10 the drive shaft 12 can have a first bearing surface 13. By means of the first bearing surface 13 the drive shaft 12 can be in direct or indirect contact with a first contact surface 21a, or respectively with a first bearing ring 21 of a first axial bearing 20. The first axial bearing 20 can in particular be designed to take up a force acting on the drive shaft 12 and to counteract the force that acts during drilling in the direction of a weight force, thus in downward direction towards the ground. This force can in particular be the weight force of the drive shaft 12 as well as an external load on the shaft 12. Hence, during a drilling operation the first axial bearing 20 can carry a main load of the applied load exerted onto the drive shaft 12. During extraction the first axial bearing 20 can be provided to take up the weight force of the drill string and/or drill head.

[0031] The first axial bearing 20 can in particular be designed as a roller bearing having several rolling elements 23 arranged circumferentially around the drive shaft 12. These can be arranged between the first bearing ring 21 and the second bearing ring 22 of the first axial bearing 20. The axes of rotation of the rolling elements 23 of the first axial bearing 20 can in particular be arranged at an angle to the axis of rotation 15 of the drive shaft 12, which differs from a right angle. In particular, the first axial bearing 20 can be designed as a tapered roller bearing, the rolling elements 23 of which have a smaller diameter on a first side facing towards the drive shaft 12 as compared to a second side facing away from the drive shaft 12.

[0032] In particular, the axis of rotation of the rolling elements 23 of the first axial bearing 20 can confine an angle with the drive shaft 12, which is smaller than 90° above the axis of rotation of the rolling elements 23 and larger than 90° below the axis of the rolling elements 23. By preference, the contact region of the first axial bearing 20 with the second contact surface 22 is designed orthogonally with respect to the axis of rotation 15 of the drive shaft 12, i.e. horizontally.

[0033] Furthermore, in an upper region of the bearing arrangement 10 the drive shaft 12 can have a second bearing surface 14, through which the drive shaft 12 can be in contact with a first contact surface 31 of a second axial bearing 30. In particular, the second axial bearing 30 can be arranged between the first contact surface 31 and a second contact surface 32 of the second axial bearing 30, which can be designed as bearing rings in particular.

[0034] The second axial bearing 30 which can also be of cylindrical design is preferably designed at an angle to the drive shaft 12. More particularly, the angle of the axes of rotation of rolling elements 33 of the second axial bearing 30 can differ from a 90° angle with respect to the axis 15 of the drive shaft 12. By preference, the axes of rotation of the rolling elements 33 of the second axial bearing 30 are aligned in such a manner in the bearing arrangement 10 that the second axial bearing 30 is able to take up at least a radial force component that preferably acts through the drive shaft onto the first axial bearing 20. By particular preference, the axis of rotation of at least one rolling element 23 of the first axial bearing 20 is arranged orthogonally to an axis of rotation of at least one rolling element 33 of the second axial bearing 30.

[0035] Along their axis of rotation the rolling elements 33 of the second axial bearing 30 can have an upper end that can be formed with a smaller diameter and a lower end that can be formed with a larger diameter. The upper end of the rolling elements of the second axial bearing 30 can in particular have a smaller distance to the drive shaft 12 than the lower end. In particular, the first axial bearing 20 and the second axial bearing 30 can be designed as locating bearings.

[0036] At a lower end of the bearing arrangement 10 a radial bearing 40 can be arranged which can be disposed between a first contact surface 41 of the radial bearing 40 and a second contact surface 42 of the radial bearing 40. The contact surfaces 41, 42 of the radial bearing 40 can in particular be designed as bearing rings. The radial bearing can be designed both as roller and plain bearing, in particular allowing an axial movement of the drive shaft 12 along its axis of rotation 15.

[0037] If the radial bearing 40 is designed as a roller bearing, rolling elements 44 of the radial bearing 40 can be arranged along a guide 43 that enables a movement of the rolling elements 44 in the axial direction of the axis of rotation of the drive shaft 12, thus a bearing clearance. Therefore, the radial bearing 40 can in particular be designed as a non-locating bearing. Furthermore, the radial bearing can in particular be designed to take up a radial force component of the drive shaft 12 and to guide the drive shaft 12 radially.

[0038] The first axial bearing 20 and the second axial bearing 30 can be formed with a radial component, in which case the bearing arrangement can be formed with a prestressing.

[0039] In the region of the first axial bearing 20 a force measuring device 50 can be arranged. This is preferably provided below the first axial bearing 20. In the region of the second axial bearing 30 a second force measuring device 51 can be provided. Preferably, the second force measuring device 51 is arranged above the second axial bearing 30. The first force measuring device 50 and the second force measuring device 51 are connected to a computer unit, not depicted, which is designed to compensate a main load above the bearing arrangement 10, which acts in the direction of the weight force onto the drive shaft 12, compared to the main load below the bearing arrangement 10, which is actually present on the drive shaft 12.

[0040] To determine a temperature of the bearing arrangement 10 at least one temperature sensor 52 can be provided that can be arranged in the region of the first axial bearing 20 for example. Furthermore, a temperature sensor 52 can be arranged in a region above the second axial bearing 30 for example, wherein the at least one temperature sensor 52 is provided to determine the temperature of the bearing arrangement 10 and the drive shaft 12 respectively. To determine a temperature-dependent bearing tensioning the at least one temperature sensor 52 can be connected to the computer unit which takes the temperature determined on the bearing arrangement 10 or on the shaft in the region of the bearing arrangement 10 into account when compensating the load.

[0041] In FIG. 2 a drill drive 60 is illustrated which has a bearing arrangement 10 according to the invention in the housing 11. To drive the drive shaft 12 provision is made for a motor 61 that can be provided at an upper end of the drill drive 60 above the bearing arrangement 10. The drive shaft 12 can in particular be driven electrically. As shown in FIG. 2, the drive shaft 12 protrudes at a lower end of the housing 11 from the bearing arrangement 10 and is designed to receive a drill string that preferably has a drill head. The drive shaft can also be designed to receive a drill flight or a different type of drilling tool. At a lower end of the drive shaft a suitable connecting device 63 is arranged. At least on two sides of the drill drive 60 a means 62 for guiding the drill drive, e.g. on a drill mast, can be arranged. By way of a suspension 64 located at an upper end of the drill drive, the said drill drive can be reliably delivered to the site of operation, wherein the drill drive, together with a drilling tool, as for example a drill string, can be pulled on the suspension 64 out of the borehole.