Patent Application
20160070080
The present invention relates to a power cable assembly device adapted to be arranged in the spaces between neighbouring power cores of a power cable, comprising a profiled body made of a polymer material and adapted to the cross-sectional shape and elongation of the power cable, said profiled body comprising a chamber and a slit to said chamber, said chamber being adapted to receive a fibre optic cable via said slit.
It also relates to a power cable comprising such a power cable assembly device.
When putting a power cable in the ground, or on the sea floor, it is often practical to add a fibre optic cable in a space between the power cores.
A power cable assembly device, a power cable and a tool is known from SE-C2-530 277, respectively. The known assembly device however suffers from a complicated access to the chamber containing a fibre optic cable.
The object is to provide a power cable assembly device having an improved design as regards access to the chamber of the profiled body.
This object has been achieved by the assembly device and the power cable, further comprising the feature that said profiled body is provided with a pair of transitions at least partly defining said slit and converging towards said chamber, said transitions being adapted to supportingly receive a fibre optic cable to be introduced through said slit.
Hereby is achieved a guided introduction of the fibre optic cable to the chamber.
In particular, the cross-section of the profiled body includes a first wall, a second wall and a third wall,
said first wall being convex and having first and second opposite end portions,
said second wall being concave and having third and fourth opposite end portions,
said third wall being concave and having fifth and sixth end portions,
the third end portion of said second wall being connected to said first end portion of said first wall,
the fifth end portion of said third wall being connected to said second end portion of the first wall,
said fourth end portion of the second wall forming said first angled transition,
said the sixth end portion of said third wall connecting to said second angled transition,
said slit extending in the elongation of the profile for allowing introduction of a fibre optic cable into said chamber.
Hereby, the profiled body is further defined.
Suitably, the cross-section of the chamber is substantially annular. Hereby, an optimal shape of the chamber is achieved. Of course, the annular chamber could be polygonal rather than circular.
Preferably, the diameter of the chamber (16) is in the range 11-25 mm, more preferably 12-23 mm.
Suitably, the slit is open in a mounted state, and the distance between the fourth end portion of the second wall and the sixth end portion of the third wall defining the slit is in the range 1 mm-13 mm, more preferably 3-11 mm, even more preferably 4-6 mm, most preferably 5 mm. Hereby the insertion of a fibre optic cable is made allowed to be performed readily and easily. The slit width should be chosen such that the diameter of the fibre optic cable including cover is 1-5 mm larger than the slit width.
Preferably, the wall thickness of either or all of the second wall, the third wall and a wall defining the chamber has a thickness in the range of 2-6 mm, more preferably 2,5-4 mm, most preferably 3 mm.
Suitably, the first wall is adapted to face a jacket of the power cable, said a second and a third walls being adapted to face a pair of neighbouring power cores.
In particular, the concavity of the outer surface of the second and third walls, respectively, is adapted to the number of power cores and the diameter of the power cores. Hereby, a tight fit will be achieved between the assembly profile and neighbouring power cores, and the power cores and the profiles will form a power cable with a substantially circular cross-section with high mechanical stability.
Furthermore, the convexity of the outer surface of the first wall is adapted to an imaginary circle between a peripheral point of each power core in relation to the diametrical centre point of the power cable. Hereby is achieved a power cable with large form stability when assembled, i.e. the cross-section of the assembled power cable with be substantially circular also at the high pressures on the bottom of sea bottom at large depths.
Preferably, said first angled transition connects to a first radial transition, said the sixth end portion of said third wall connecting to said second angled transition further connects to a second radial transition,
said first and second radial transitions being substantially parallel to one another, wherein the first radial transition of the fourth end portion of the second wall and the second radial transition of the sixth end portion of the third wall define together at least a part of said slit.
Suitably, said polymer material of the profiled body is PVC or PE. Hereby is achieved a profiled body with strong mechanical properties.
Suitably, the number of power cores is three and the number of power cable assembly devices is three. The diameter of each power core is in the range of 30-140 mm, more preferably 40-130 mm.
In the following, the invention will be described in more detail by reference to the enclosed drawings, in which
a-4d illustrate a tool for introduction of a fibre optic cable in a power cable assembly device shown in
The first wall 6 has a first end 6a and a second end 6b. Likewise, the second wall 8 has a first end 8a and a second end 8b, and the third wall 10 has a first end 10a and a second end 10b. The first end 6a of the first wall 6 is connected to the first end 8a of the second wall, while the second end 6b of the first wall 6 is connected to the first end 10a of the third wall 10.
The second end 8b of the second wall 8 continues to a first angled transition 12a and further to a first radial transition 14a. Likewise, the second end 10b of the third wall 10 continues to a second angled transition 12b and further to a second radial transition 14b.
The first and second angled transitions 12a, 12b are converging towards the first and second radial transitions 14a, 14b, the latter being substantially parallel to one another and thus substantially radial to the convex first wall 6.
According to this embodiment, the first and second radial transitions 14a, 14b are arranged at a distance from one another, defining an open slit 15.
Inside the profiled body 4, a chamber 16 defined by a substantially annular wall 18 is arranged. The annular wall 18 extends from the first radial transition 14a to the second radial transition 14b. A pair of reinforcement members 20a, 20b are arranged between the annular wall 18 and the first wall 6. Of course, the number of reinforcement members could be less than two, i.e. one or zero (i.e. leaving an open space between the annular wall 18 and the first wall 6), or more than two, i.e. three, four, five or even more, depending on the space available between the circumferential walls.
The assembly device 2 is made by extrusion of a polymer material, such as PE (e.g. MDPE or HDPE) or PVC and may have a length of several kilometres.
The first and second semi-conductive layers 25b, 25d form a smooth surface which controls the electric field strength. The swelling material 25e tightens against water in case the led screen 25f would start leaking.
Each power core 24a, 24b, 24c has a peripheral point 26a, 26b, 26c in relation to the diametrical centre 19 of the power cable 22, i.e. in the central space 27d. The three peripheral points 26a, 26b, 26c form together in relation to the centre point 19 an imaginary circle 26d.
The first and second power cores 24a, 24b touch one another at a contact point 23a and define a peripheral space 27a together with the imaginary circle 26d. Likewise, the second and third power cores 24b, 24c have a contact point 23b and define a second peripheral space 27b together with the imaginary circle 26d. Likewise, the third and first power cores 24c and 24a have a contact point 23c and define a third peripheral space 27c together with the imaginary circle. The first, second and third power cores 24a, 24b, 24c define between the contact points 23a, 23b, 23c a central space 27d.
In the peripheral space 27a, a first assembly device 2a is provided. Likewise, a second assembly device 2b is arranged in the second peripheral space 27b, and a third assembly device 2c is arranged in the third peripheral space 27c.
The power cable is provided with a jacket 28 to keep the power cores 24a, 24b, 24c and the assembly devices 2a, 2b, 2c together as one unit and to keep the circular cylindrical shape and mechanical protection. The jacket 28 comprises—from the periphery towards the centre point 19—two layers 29a of yarn made of polypropylene (PP), a first steel wire armour layer 29b, a first soft layer 29c of laying bands, a second steel wire armour layer 29d, a second soft layer 29e of laying bands.
As can be understood from
An elongated fibre optic cable 30 comprises a fibre optic wave conductor 31, i.e. a bundle of optical fibres inside a metal tubing 32a together with a mass 32b, such as a gel. The metal tubing 32a is covered with a layer of semi-conductive layer 33. The fibre optic cable 30 is put inside the chamber 16 of assembly device 2a.
Of course, this relates correspondingly to the case when a fibre optic cable is put inside the chamber of the assembly devices 2b and/or 2c.
Also in this embodiment, the first wall 6 of the profiled body 4 is convex and has first and second ends 6a, 6b; the second wall 8 is concave and has first and second ends 8a, 8b; and the third wall 10 is concave and has first and second ends 10a, 10b. The first, second and third walls are connected to one another as described in connection with
The second end 8b of the second wall 8 continues to a first angled transition 12a and further to a first radial transition 14a. Likewise, the second end 10b of the third wall 10 continues to a second angled transition 12b and further to a second radial transition 14b.
The first and second angled transitions 12a, 12b are converging towards the first and second radial transitions 14a, 14b, the latter being substantially parallel to one another and thus substantially radial to the convex first wall 6. Also in this embodiment the first and second radial transitions 14a, 14b are substantially parallel to one another and are thus substantially radial to the convex first wall 6.
However, according to this embodiment, the first and second radial transitions 14a, 14b are arranged without distance from one another, i.e. the slit 15 is closed at least when mounted, even though the slit for clarity reasons have been shown to be somewhat open.
Also in this embodiment, the annular wall 18 defining the chamber 16 extends from the first radial transition 14a to the second radial transition 14b. However, no further reinforcement members are needed. Instead, the annual wall 18 is partly constituted by the first wall 6.
Equalisation of the electric potential between the fibre optic cable 30 and metal parts of any one of the power cores 24a, 24b, 24c could be equalised either by providing the surfaces of the chamber 18, the radial transitions 14a, 14b, the angled transitions 12a, 12b and at least a part of the exterior concave walls 8, 10 with a semi-conductive layer. Alternatively, the walls could be provided with holes for allowing sea water to circulate inside the chamber 18.
The first and second radial transitions 14a, 14b have been shown in
Alternatively, the radial transitions 14a, 14b may be differently shaped, such as rounded.
a shows a tool 39 provided with support means 46 comprising four support members 48 in the form of double encapsulated ball-bearings 54. Each ball-bearing 54 is rotatably connected via an axle 72 to a U-shaped bearing support 73 across an axis through the aligned ball-bearings 54. The tool 39 is furthermore provided with guide means in the form of four pairs of guide wheels 41a, 41b of encapsulated needle bearings 55a, 55b, each rotatable about an axle 76, said axle 76 being parallel to the axles 72 of the ball-bearings 54.
In order to position the four ball-bearings 54 in relation to one another and in relation to the guide wheels, the tool 39 comprises a grid of parallel plates 75 of a first frame part 74a of an interconnection means 44 in the form of a frame 74, together forming a grid. Of course, the grid of parallel plates 75 could instead be constituted by a single plate.
The frame further comprises a pair of side walls 74b, 74c, connected perpendicularly to the first frame part 74a by screws 90. The side walls 74b, 74c are furthermore adjustably connected to a frame support 74f by screws 94 in a row of holes 96. In this manner, the first frame part 74a can be moved in a direction across the row of holes 96. Thus, the position of a plane through the axles 72 of the ball-bearings 54 can be adjusted in relation to the guide wheels 41a, 41b, depending on the thickness of the profiled body 4.
The frame support 74f is provided with an entrance opening 92 for introduction of the profiled body 4 into the tool 39. An access slot 93 in the frame support 74e allows for taking the tool 39 apart even if the profiled body 4 is still inside the tool 39.
The frame 74 further comprises a pair of plates 74d, 74e each connected to extension plates 74g, 74h. The plates 74d, 74e are each provided with a slot 97a, 97b in their opposing ends (the rear ends being hidden) for adjustable connection with screws 98a, 98b to a pair of rows of holes 99 in the frame support 74f. Hereby, the frame 74 is adjusted for the lateral dimension of the profiled body 4.
A pair of reinforcement members 74i, 74k are each provided with four sets of screws 80a. Each guide wheel 41a, 41b is independently movable in a slot 78 in the plates 74d, 74e towards a plane through the axles 72 of the ball-bearings 54, and is adjustable in the slot 78 by means of a corresponding set screw 80a. After performed adjustment, the position of the guide wheel 41a or 41b is fixed by means of a lock nut 80b.
The set of screws 80a and lock nuts 80b are adjusted in such a way that each guide wheel 41a, 41b is positioned at a predetermined distance relative to the support member 48. In this way, it is possible to adjust each pairs of guide wheels 41a, 41b relative to the other pairs of guide wheels 41a, 41b to bear against the edges of 5a, 5b of the profiled body 4. By said adjustment, the slit 15 will be widened and thus opened at a predetermined position between the first pair of wheels and the fourth pair of wheels.
In
In
In
First, the power cores 24a, 24b, 24c are held 120° in relation to one another by means of not shown equipment in the periphery of an imaginary circle 100.
Then, between the power cores 24a, 24b, 24c three tools 39a, 39b, 39c of the kind shown in
As explained above in connection with
In each tool 39a, 39b, 39c, a profiled body 4 is positioned between the four pairs of guide wheels 41a, 41b, starting from the level of frame support 74f (i.e. seen from the lower part in
The screws 80a of the first, second and third pairs of wheels 41a, 41b, counted from the frame support 74f, are adjusted such that the slit 15 of the profiled body 4 of
A fibre optic cable 30 is now introduced via the entrance opening 92 of the frame 74 (cf.
A guide beam 82 of the kind described above is then mounted.
Each profiled body 4 is collected together with the power cores 24a, 24b, 24c at a distance from the tools 39a, 39b, 39c (above the tools as seen in
During this movement, the slit 15 is opened by the support members 48 and the guide members 41, while fibre optic cables 30 are guided into the chamber by the guide beam 82.
It should also be noted that the tools 39a, 39b, 39c may be mounted for introduction of the fibre optic cable 30 through the entrance opening 92 of the frame 74 horizontally or vertically.
In case of high torsional stiffness of the profiled body 4, a higher pressure may have to be applied on one side 8 than the other 10 by the guide wheels 41a, 41b, or a pressure may even only be applied on one side 8 by one or more guide wheels 41a, while a lower or even no pressure may be applied on the other side 10 by one or more guide wheels 41b.
In
It should be noted that the guide beam 82 could instead be divided into three different items, corresponding to the sections 86a, 86b and 86c. Alternatively, the first and second sections 86b, 86c could instead be a pair of wheels with a peripheral shape corresponding to the cross-section of the first and second sections 86b, 86c, respectively.
It should be noted that the encapsulated ball-bearing 54 could be exchanged to an encapsulated roller bearing, having circular cylindrical rollers, or to plain bearings.
Likewise, the encapsulated needle-bearings could be exchanged to small ball-bearings or plain bearings. Of course the bearings could also be non-encapsulated.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/062819 | 6/19/2013 | WO | 00 |
