A PULLING TOOL FOR USE IN A WELLBORE AND/OR TUBING AND A PROPULSION MODULE OF A PULLING TOOL

Abstract

The invention relates to a pulling tool for use in a wellbore or tubing for pulling cable. The pulling tool comprises a propulsion module (64) having a main section (1) and a propulsion arm (2) hinged to the main section (1). The propulsion arm includes a propulsion wheel (6, 37) with a gear system. An electric motor (8) drives the propulsion wheel (6, 37) via the gear system. The gear system may include a harmonic gear or a compound split ring epicyclic gear. The invention further comprises a propulsion module (64) of a pulling tool including such a gear system.

Claims

1. A pulling tool for use in a wellbore or tubing for pulling cable, the pulling tool comprising a propulsion module having a main section and a propulsion arm hinged to the main section, the propulsion arm having a propulsion wheel with a gear system, the pulling tool further comprising an electric motor for driving the propulsion wheel via the gear system, wherein the gear system of the propulsion wheel comprises: a fixed internal gear rim; an internal gear rim inside the propulsion wheel; an input shaft coaxially positioned relative to the fixed internal gear rim and the internal gear rim of the propulsion wheel; at least one externally toothed body meshing with the fixed internal gear rim and the internal gear rim of the propulsion wheel; the fixed internal gear rim and the internal gear rim of the propulsion wheel having a different number of teeth; and the at least one externally toothed body being driven via the input shaft.

2. The pulling tool of claim 1 wherein the at least one externally toothed body is a flexible toothing supported by way of a flexible bearing against a wave generator driven by the input shaft, whereby the gear system of the propulsion wheel forms a harmonic gear.

3. The pulling tool of claim 1 wherein the at least one externally toothed body comprises planet wheels in a planet wheel carrier; the plan wheel carrier being able to rotate freely about its axis of rotation; the input shaft driving a sun wheel meshing with the planet wheels; and the planet wheel meshing with the fixed internal gear rim and the internal gear rim of the propulsion wheel; and whereby the gear system of the propulsion wheel forms a two-ring compound epicyclic split ring gear, of which one ring forms the fixed internal gear rim and the other ring forms the internal gear rim of the propulsion wheel.

4. The pulling tool of claim 3 wherein the planet wheels have an equal number of teeth along their entire width.

5. The pulling tool of claim 1 any one of the previous claims wherein the fixed internal gear rim and the internal gear rim of the propulsion wheel are of the same internal diameter.

6. The pulling tool of claim 1 any one of the previous claims wherein the electric motor includes a rotor having an anchor with an output shaft and a pinion fixed to the output shaft.

7. The pulling tool of claim 1 any one of the previous claims wherein the electric motor is a brushless motor having a longitudinal axis being perpendicular to a rotational axis of the propulsion wheel, the pulling tool further including a controller for the brushless motor.

8. The pulling tool of claim 1 wherein an electric actuator is provided between the main section and the hinged propulsion arm, whereby the hinged propulsion arm is configured for assuming a first retracted position inside the propulsion module and a second actuated position against a wellbore or tubing wall.

9. A propulsion module of a pulling tool for use in a wellbore and/or tubing, comprising a main section and a propulsion arm hinged to the main section, the propulsion arm having a propulsion wheel with a gear system, the propulsion module further comprising an electric motor for driving the propulsion wheel via the gear system, wherein the propulsion module comprises: a fixed internal gear rim; an internal gear rim inside the propulsion wheel; an input shaft coaxially positioned relative to the fixed internal gear rim and the internal gear rim of the propulsion wheel; at least one externally toothed body meshing with the fixed internal gear rim and the internal gear rim of the propulsion wheel; the fixed internal gear rim and the internal gear rim of the propulsion wheel having a different number of teeth; and the at least one externally toothed body being driven via the input shaft.

10. The propulsion module of claim 9 wherein the at least one externally toothed body is a flexible toothing supported by way of a flexible bearing against a wave generator driven by the input shaft, whereby the gear system of the propulsion wheel forms a harmonic gear.

11. The propulsion module of claim 9 wherein the at least one externally toothed body includes a planet wheel in a planet wheel carrier; the planet wheel carrier being able to rotate freely about its axis of rotation; the input shaft driving a sun wheel meshing with the planet wheel; and the planet wheel meshing with the fixed internal gear rim and the internal gear rim of the propulsion wheel; and whereby the gear system of the propulsion wheel forms a two-ring compound epicyclic split ring gear, of which one ring forms the fixed internal gear rim and the other ring forms the internal gear rim of the propulsion wheel.

12. The propulsion module of claim 11 wherein the planet wheels have an equal number of teeth along their entire width.

13. The propulsion module of claim 9 wherein the fixed internal gear rim and the internal gear rim of the propulsion wheel are of the same internal diameter.

14. The propulsion module of claim 9 wherein the electric motor includes a rotor having an anchor with an output shaft and a pinion fixed to the output shaft.

15. The propulsion module of claim 9 wherein the electric motor is a brushless motor having a longitudinal axis being perpendicular to a rotational axis of the propulsion wheel, the pulling tool further comprising a controller for the brushless motor.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 shows a perspective view of an embodiment of a propulsion module of a pulling assembly according to this invention;

[0050] FIG. 2 shows a perspective view of the propulsion arm;

[0051] FIG. 3 shows the drive mechanism of the propulsion arm;

[0052] FIG. 4 shows the propulsion wheel;

[0053] FIG. 5 shows a sectional view of the propulsion wheel with a compound split ring epicyclic gear;

[0054] FIG. 6 shows an exploded view of the wheel with the compound split ring epicyclic gear with all parts included;

[0055] FIG. 7 shows an exploded view of the wheel with the compound split ring epicyclic gear with all parts included;

[0056] FIG. 8 shows a sectional view of the propulsion wheel with a harmonic gear;

[0057] FIG. 9 shows an exploded view of the wheel with the harmonic gear with all parts included;

[0058] FIG. 10 shows an exploded view of the wheel with the harmonic gear with all parts included;

[0059] FIG. 11 shows an embodiment of a pulling tool having 4 propulsion modules.

[0060] The invention will now be explained in more detail when a compound split ring epicyclic gear is used, with reference to the drawings:

[0061] FIG. 1 shows a perspective view of an embodiment of a pulling assembly according to this invention. The pulling assembly comprises a main section 1 supporting a complete propulsion arm 2. Complete propulsion arm 2 is connected to main section 1 via a hinge joint 3 by way of which complete propulsion arm 2 can be tilted outwards.

[0062] FIG. 2 shows complete propulsion arm 2 comprising a rear arm body 4, a pivoting hole 5, the drive mechanism of FIG. 3, a complete propulsion wheel 6 and a front arm body 7.

[0063] FIG. 3 shows the drive mechanism comprising a motor 8, a straight gear 9 fixed to the drive shaft of the motor driving a straight gear 10. Straight gear 10 is connected to an angular gear 11 supported in front arm body 7 (FIG. 2) by way of a bearing 12. Angular gear 11 is connected to an angular gear 13 being part of the complete propulsion wheel 6.

[0064] The motor 8 rotates straight gear wheel 9, which transfers rotation to straight gear wheel 10 connected to angular gear 11, which transfers rotation to angular gear 13, which transfers rotation to the complete propulsion wheel 6.

[0065] Angular gear 13 is supported by way of a bearing 14 supported on a shaft 15, which is connected to angular gear 13, and of front arm body 7 (FIG. 2). Complete propulsion wheel 6 comprises a static component 16 fixed to front arm body 7 (shown in FIG. 2) by way of fixing screws 17.

[0066] FIGS. 4 and 5 show complete propulsion wheel 6 comprising a straight angular gear 13 including a straight-toothed sun wheel 18, a shaft section 19 supported by way of a bearing 20 in propulsion wheel 21. Angular gear 13 includes shaft 15, which is supported by way of bearing 14 in front arm body 7. Angular gear 13 is further axially supported by way of a bearing 22 in static component 16. Planet wheels 23 are supported by way of bearings 24 on planet carrier shafts 25. Planet holder shafts 25 are fixed to planet carrier flanges 26. Sun wheel 18 is connected to planet wheels 23, which is connected to an internal toothing 27 of static component 19 and an internal toothing 28 of propulsion wheel 21. Internal toothing 28 has a different number of teeth than internal toothing 27. When sun wheel 18 rotates planet wheels 23, which rotate against internal toothing 27, which is stationary, planet wheels 23 will rotate against internal toothing 28 at the same time so that propulsion wheel 21 rotates relative to static component 16. If the number of teeth of internal toothing 28 is greater than that of internal toothing 27 propulsion wheel 21 will rotate in the same direction as sun wheel 18. Similarly, if the number of teeth of internal toothing 27 is greater than that of internal toothing 28 propulsion wheel 21 will rotate in the opposite direction of sun wheel 18.

[0067] Propulsion wheel 21 is supported by way of a bearing 29, static component 16, and an outer propulsion wheel section 30 connected to propulsion wheel 21 by a thread 31.

[0068] Complete propulsion wheel 6 is fixed to front arm body 7 by way of bolts 17 (FIG. 3) in threaded holes 32.

[0069] FIGS. 6 and 7 show an exploded view of complete propulsion wheel 6. Angular gear 13 includes shaft 15, sun wheel 18, and shaft 19. Bearing 14 is mounted on shaft 15 and in upper arm body 7 (FIG. 3). Bearing 20 is mounted on propulsion wheel 21. Planet wheels 23 with bearings 24 are mounted on planet carrier shafts 25, which is in turn mounted to internal toothing 28 of propulsion wheel 21. Bearing 29 is mounted on static component 16, which is mounted between propulsion wheel 21 and outer propulsion wheel section 30 by way of thread 31. Angular gear 13 is mounted to static component 16 via bearing 22 where sun wheel is connected against planet wheel 23 and shaft 19 is mounted in bearing 20.

[0070] In another embodiment of the invention, a harmonic gear with a fixed outer wheel and a moving outer wheel may be used, with the moving outer wheel forming, or being directly connected to, the propulsion wheel of the pulling tool.

[0071] FIG. 8 shows a complete propulsion wheel 37 comprising an angular gear 38 fixed to a wave generator 39. Angular gear 38 is supported axially by way of a bearing 43 against a static component 44. Wave generator 39 is supported by way of a bearing 40 against a propulsion wheel 41 and by way of a bearing 42 against front arm body 7. A flexible toothing 45 is supported by way of a flexible bearing 46 against wave generatur 39. Flexible toothing 45 meshes with an internal toothing 47 of static component 44 and with an internal toothing 48 of propulsion wheel 41. Propulsion wheel 41 is supported by way of a bearing 49, static component 44, and an outer propulsion wheel part 50 connected to propulsion wheel 41 via a thread 51.

[0072] The number of teeth of flexible toothing 45 is lower than the number of teeth of internal toothing 47 so that when wave generator 39 rotates, flexible toothing 45 will also rotate, in the opposite direction. If there is one tooth less on flexible toothing 45 than on internal toothing 47 the flexible toothing will move around two teeth against internal toothing 47 for each turn of wave generator 39. If flexible toothing 45 and internal toothing 47 have an equal number of teeth, flexible toothing will not be rotated relative to internal toothing 47. However, for example, if internal toothing 48 has one more tooth than flexible toothing 45, then propulsion wheel will move around two teeth for each turn performed by wave generator 39 and in the same direction for wave generator 39.

[0073] FIGS. 9 and 10 show exploded views of complete propulsion wheel 37. Flexible bearing 46 is mounted on wave generator 39 and flexible toothing 45 is mounted on flexible bearing 46. Bearing 40 is mounted on wave generator 30 and in propulsion wheel 41 so that flexible toothing 46 meshes with internal toothing 48. Bearing 49 is mounted on static component 44, which is mounted together with propulsion wheel 41 and outer propulsion wheel 50 by way of thread 51 so that the flexible toothing meshes with internal toothing 47. Angular gear 38 is mounted on wave generator 39 together with a key 52 in keyways 53 and 54 (FIG. 8) and against static component 44 via bearing 43.

[0074] FIG. 11 shows a battery operated pulling tool comprising a cable transition 55, a battery module 56, an electronics module 57, four propulsion modules 58, and a nose connector 59.