WO2011010934A1

WO2011010934A1 - Internal conduit vehicle having a through passage

Info

Publication number: WO2011010934A1
Application number: PCT/NO2010/000278
Authority: WO
Inventors: Esben Beck
Original assignee: Helix Technologies As
Priority date: 2009-07-24
Filing date: 2010-07-09
Publication date: 2011-01-27

Abstract

An internal conduit vehicle (1) comprising a chassis (2) having a length axis, a first rotary wheel assembly (3a) mounted in a first end of said chassis, a second rotary wheel assembly (3b) mounted in a second end of said chassis, motors (4a,b) and power transfer means (5a,b; 6a,b; 7a,b) for powering said first and second wheel assemblies, The vehicle (1) is formed with a consistent through passage (10) from the back end to the front end of the chassis, preferably by arranging the motors and power transfer means eccentrically within the vehicle body.

Description

INTERNAL CONDUIT VEHICLE HAVING A THROUGH PASSAGE

Field of the invention

The present invention relates to an internal conduit vehicle, also called a pipeline, tractor, which is a device travelling inside a pipeline transporting measuring instruments and tools. Such devices are in particular in use in the oil and gas industry, but may also find use^'in other fields, such as for inspecting and cleaning water pipes, sewers or ventilation tubes.

Background

Several varieties of pipeline vehicles have been made in the past based on different technologies. Some use the fluid flowing in the pipeline for propulsion (pigs) or move along with worm-like movements. Others use wheels or belts for moving along the pipeline.

US patent 5,551,349 (Bodzin) describes a pipeline tractor comprising two coaxially aligned wheel assemblies mounted to each end of a chassis. Each wheel assembly includes a number of elongate rollers positioned at an angle around a hub. The rollers are suspended in both ends by a spring arrangement pressing the rollers against the pipeline wall. The rollers in each wheel assembly are angled in opposite directions, and are rotated by motors inside the chassis in opposite directions. This creates a translatory movement inside the pipeline.

Current pipeline tractors have a number of shortcomings: One is that they have a rather low traction force, mainly due to the small footprint of the wheels against the wall. This means that they may perform well in horizontal pipelines, but have a very limited ability of climbing steep pipelines. This also means that they may only carry very limited work loads, i.e. they cannot drag heavy tools or cables along a pipeline.

Another shortcoming is that existing design of pipeline vehicles comprising rotary wheel assemblies effectively prevents cable connection from the front part f the vehicle to the back part of the vehicle. The need for compact constructions has led to designs that effectively occupy all space between the rotary wheels by motor(s) and transmission gears arranged coaxially with the vehicle body. This means that even such pipeline vehicles are designed inter alia to pull cables through a pipeline; it is not possible to have cable connection from the entrance points to the front of the vehicle. One practical

consequence of this fact is the inability of cable transfer of power and information to and from the front end of the vehicle. |f there is a need to put a camera or a tool at he front end of the camera to inspect the pipeline in front of the vehicle, to remove obstacles in the pipeline or to perforin maintenance of the pipeline itself or of equipment arranged therein, such a camera or such tools must be battery operated and the vehicle provided with a battery that also needs to be mounted up front. This is also unfavourable since it requires additional space, adds to the weight and reduces the ability to pass bends in the pipeline. Furthermore, if there is a need for real-time transfer of the video signals from such a camera to the operator, the information must be transferred by radio waves or other cable-free means under conditions which may be unfavourable for transfer of such signals.

Objects of the invention

It is an object of the present invention to provide an internal conduit vehicle that allows cable transfer of power and information to the front end of the vehicle.

A further object is to provide a vehicle as mentioned above which may pass through sharp bends or pass T-bends without blocking.

Yet another object is to provide a vehicle that is able to travel fast and with a high degree of accuracy.

Furthermore it is desired that the vehicle, relative to its size, provides a high drag-force capacity and even provide features of interpolation.

The present invention

The above mentioned objects are achieved by the internal conduit vehicle according to the present invention as defined by claim 1.

The present invention comprises an internal conduit vehicle of the kind having rotary wheel assemblies at each end of the vehicle and which has a consistent through opening from front to back allowing cables to be drawn therebetween.

By "consistent through passage" in the context here used is understood that the passage is not obstructed at any time by any part of drive mechanism or other equipment that moves when the vehicle is powered, regardless of the type of vehicle movement performed, thus allowing cables or wires to be drawn through the passage and further backwards without coming in conflict with moving vehicle parts under any and all kinds of vehicle operations. A person skilled in the art understands that this allows power and information to be transported by means of cables though the vehicle when it is being operated in its natural environment.

By "rotary wheel assembly" is understood a wheel assembly with rotary wheel arms where the rotary plane is substantially perpendicular to the length axis of the chassis and the direction of movement.

By "power transfer means" is meant any means connected between a motor and the wheels (or a wheel assembly) transferring the motor power to a surface outside the vehicle. Brief description of the drawings

The invention will now be described in detail in reference to the appended drawings, in which:

Fig. IA is a perspective drawing showing internal elements of a pipeline tractor according to the present invention,

Fig. IB is a side view of the internal elements of Fig. IA,

Fig. 1C is an end view of the internal elements of Fig. IA

Fig. 2A is a perspective view similar to Fig. IA except that wheel assemblies are shown at each end of the vehicle,

Fig. 2B is an end view of the elements shown in Fig. 2A.

Detailed description

The drive lines for each wheel assembly are in the following description generally denoted A and B respectively. Thus an electric motor 4A is attached to a gearbox 5A which in turn is attached to a pinion 6A which is arranged in engagement with gear rim 7A at a first end of the conduit vehicle. Similarly an electric motor 4B is attached to a gearbox 5B which in turn is attached to a pinion 6B which is in engagement with gear rim 7B at a second end of the conduit vehicle.

As best seen from Fig. IB there is a clearance between the motor 4A and the gear rim 7B avoiding contact between the two and a corresponding clearance between the motor 4B and the gear rim 7A. Figure Ib also show part of the vehicle chassis 2.

As best seen from Fig. 1C the diameters of motor 4A, motor 4B, gearbox 5A₇ gearbox 5B, and pinions 6a, 6b are less than half the inner diameter of gear rim 7A and 7B. In Fig. IA-C both the motors and both the gear boxes have one common diameter, which it not mandatory for the invention. By using motors and gear boxes which such small diameters and arranged eccentrically in relation to the gear rims 7A and 7B and thereby away from the centre axis of the conduit vehicle, an open, longitudinal passage (10) is formed along the centre axis of the vehicle. In this open passage a tube (not shown) may be arranged to receive cables drawn through the passage, to make a rigid support for the cables and to physically protect the cables from the surrounding environment.

Figure 2A show how wheel assemblies 3A and 3B are attached to gear rims 7A and 7B respectively. Wheel assembly 3A comprises in addition to an attachment ring to be attached to the gear rim 7A, a number of wheels 8A attached to wheel arms 9A (best shown in Fig. 2B). The wheels 8A are shown mounted in pairs on each of four wheel arms. This arrangement of the wheels is not a requirement of the present invention and neither is the number of wheel arms. Thus there may be fewer or more wheel arms than four at each end of the vehicle and the wheels may be arranged in pairs or separately. The same is to be said about the wheel assembly 3B. Though the illustrations show only one motor + gearbox + pinion connected to each gear rim 7A (and 7B), there could be two or more, each of motors etc. in that case having correspondingly smaller diameter.

It should be noted that though we speak of a first end and a second end of the vehicle, we could as well speak of just one end and another end. Though one end is generally the front end of the vehicle for travelling into a tube or pipeline, for the sake of the discussion here, it is arbitrary which end is the "front" end and which is the "rear" end.

Though the powering transfer means illustrated are simple gear and pinion type means, a person skilled in the art know that other powering transfer means may be used as well, such as drive belts and pulleys, and drive chains and sprockets.

As an alternative embodiment to the one described above, all power transfer means may be concentrically arranged within the vehicle body and provided with a central bore.

Claims

C l a i m s

1. An internal conduit vehicle (1) comprising a chassis (2) having a length axis, a first rotary wheel assembly (3a) mounted in a first end of said chassis, a second rotary wheel assembly (3b) mounted in a second end of said chassis, motors (4a,b) and power transfer means (5a,b; 6a,b; 7a,b) for powering said first and second wheel assemblies, characterized in that the vehicle (1) is formed with a consistent through passage (10) from the back end to the front end of the chassis.

2. A vehicle as claimed in claim 1 wherein the power transfer means (5a,b; 6a,b; 7a,b) means in addition to a motor independently may include gear drives, drive belts and pulleys, and drive chains and sprockets.

3. A vehicle as claimed in claim 1 wherein the powering means at each end of the vehicle comprises at least one eccentrically arranged electric motor (4a,4b) and an eccentric drive assembly comprising a gearbox (5a, 5b) and holding a pinion (6a, 6b) that drives the wheel assembly (3A, 3B) via a gear rim (7A, 7B) with a central bore, said gear rim (7A, 7B) being concentric with the length axis of the vehicle.

4. A vehicle as claimed in claim 3 wherein the electric motors (4A, 4B) are mainly cylinder shaped with a length axis parallel to the vehicle (1) length axis and a diameter less than half the diameter of the vehicle chassis (2).

5. A vehicle as claimed in claim 3 wherein at least two electric motors are arranged to power each wheel assembly via a common second gear drive. .

6. A vehicle as claimed in claim 1 where any drive means is centrally arranged and has a central bore.