WO2005045253A1

WO2005045253A1 - Stabilising means for vibrationally stabilising a long shaft

Info

Publication number: WO2005045253A1
Application number: PCT/DK2004/000776
Authority: WO
Inventors: Lau Halkjaer
Original assignee: Hamworthy Svanehøj A/S
Priority date: 2003-11-10
Filing date: 2004-11-09
Publication date: 2005-05-19
Also published as: EP1692398A1; EP1692398B1; NO20062165L; JP2007510851A; KR20060111564A; NO339267B1; KR100847908B1; JP4713489B2

Abstract

The present invention relates to stabilising means for vibrationally stabilising a long shaft, the long shaft may surround a rotating shaft driving a submerged pump. The invention also relates to a method for manufacturing such stabilising means. The stabilising means, a so-called guide ring, comprises: at least two plate parts, in combination being adapted to fit at least substantially annularly around the long shaft and to substantially fix the long shaft in relation to at least one stabilising member. A minimum distance between the at least two plate parts and the long shaft is defined, and adjusting means for adjusting the minimum distance between the at least two plate parts and the long shaft are present. The two plate parts define a primary plane, and the longitudinal direction of the long shaft extends substantially normal to the primary plane when the stabilising means is mounted on the long shaft.

Description

STABILISING MEANS FOR VIBRATIONALLY STABILISING A LONG SHAFT

Field of the invention

The present invention relates to stabilising means for vibrationally stabilising a long shaft, preferably the long shaft comprises a rotating shaft driving a submerged pump. The invention also relates to a method for manufacturing such a stabilising means.

Background of the invention

Storing explosive media, e.g. gas or oil, in ships' tank is regulated by safety regulations such as those of the International Maritime Organisation (IMO) in order to minimise the risk of explosion during operation. Especially, it is presently not allowed to deploy electric motors within the tank for driving pumps etc. due to the risk of sparks igniting an explosion. Hydraulic motors have the drawback that accidental leaks will contaminate the content of the tank. Hydraulic systems also require a complicated supply of high pressure oil.

A common solution for driving a pump within the tank is to apply an electrical motor on top of the tank and mounting a long rotating shaft between the electrical motor and the pump inside the tank. Such pumps are known as deep well pumps. The rotating shafts can be up to 30 m long and require special considerations with regard to support and stabilisation.

Typically, the rotating shaft will be surrounded and supported by a concentric long support shaft. The support shaft is in turn fixed by intermediate support means, e.g. a pipe holder or clamp, to a parallel gas/oil pipe and/or a support tube surrounding both the support shaft and gas/oil pipe. Possibly, the support shaft can also be fixed to the walls of the tank. The support shaft needs to be fixed due to the vibrations induced by the rotating shaft. Movement of fluids in the tank known as sloshing may also generate forces that require the shaft to be fixed.

One way of fixing the intermediate support means onto the support shaft is to weld them together. However, this solution is highly inflexible when the system needs to be remounted for service or repair. Secondly, due the chemically aggressive environment the parts are usually manufactured in stainless steel, which is a troublesome material for welding.

Another solution for fixing the intermediate support means on the support shaft is to use flanges of the support shaft. The support shaft typically consists of smaller tube pieces joined by flanges. The flanges may additionally comprise means for fixing the intermediate support means. This solution limits the available fixation positions of the intermediate support means to the flanges and complicates design of the system.

Summary of the invention

It may be seen as an object of the present invention to provide means for overcoming the aforementioned problems with fixing of the support shaft by providing stabilising means for vibrationally stabilising the long support shaft and a method for manufacturing the stabilising means. It is a further object to provide stabilising means for vibrationally stabilising the long shaft in a flexible way for easy mounting and remounting for repair and service. It is yet a further object that the stabilising means can be quickly manufactured with relatively few steps of manufacturing.

This object and several other objects are obtained in a first aspect of the invention by a stabilising means for vibrationally stabilising a long shaft, the stabilising means comprising: at least two plate parts, in combination being adapted to fit at least substantially annularly around the long shaft and to substantially fix the long shaft in relation to at least one stabilising member, thereby defining a minimum distance between the at least two plate parts and the long shaft, and adjusting means for adjusting the minimum distance between the at least two plate parts and the long shaft,

wherein the at least two plate parts define a primary plane, and wherein the longitudinal direction of the long shaft extends substantially normal to said primary plane when the stabilising means is mounted on the long shaft.

During mounting and initial operation it is particularly advantageous to have stabilising means that are easily displaceable in the longitudinal direction of the long shaft. This is due to the fact that the optimal vertical positions for the stabilising means to dampen vibrations of the long shaft often may vary from estimates made beforehand. Thus, the possibility to easily displacing the stabilising means will increase the potential for damping the vibrations of the long shaft.

The stabilising means may be applied in off-shore and maritime applications, as well as in on-shore applications. In particular, the stabilising means may be applied in off-shore and maritime applications such as liquid gas tankers, chemical tankers, fuel production and storage off-shore facilities (FPSO) etc.

Preferably, the adjusting means is adapted to be in at least two positions, a first of said positions substantially fixing the stabilising means in a longitudinal direction of the long shaft, and a second of said positions allowing the stabilising means to slidably move along said longitudinal direction of the long shaft.

Preferably, the stabilising means further comprises at least one support element being mounted on at least one of the plate parts, the at least one support element being adapted to establish contact between the at least two plate parts and the long shaft. Even though the long shaft vibrates, the support elements can under practical conditions of operation be considered to be in contact with the long shaft. Typically, the force of the support elements on the long shaft will be considerable, e.g. assembling forces of 12 kN may be present. To obtain a sufficient suppression of the vibrations of the long shaft the assembling forces may be 2, preferably 5, possibly 10, times larger than the weight of the long shaft. The magnitude of the vibration forces may be around half the weight of the long shaft during typical operation with a submerged pump driven by a rotation shaft surrounded by a corresponding long shaft. Optionally, the stabilising means may be provided with dedicated vibration damping means, either active.or passive damping means.,.

Possibly, the stabilising means further comprises releasable fastening means, e.g. mounts with bolts and corresponding nuts, for releasably fitting the at least two plate parts around the long shaft for further joining the plate parts together.

Preferably, the stabilising means comprises at least one support element being mounted on at least one of the plate parts, the at least one support element being adapted to establish contact between the at least two plate parts and the long shaft, each of the at least one support element(s) defining a second plane, wherein, for each of the support element(s), said second plane is least substantially perpendicular to the primary plane defined by the at least two plate parts. Typically, the second plane of each support element substantially comprises the longitudinal symmetry axis of the long shaft for reasons of stability.

Preferably, at least one of the stabilising member(s) is a pipe extending in a direction being parallel to the longitudinal direction of the long shaft. Typically, the pipe is adapted to convey a fluid, e.g. gas or oil. This pipe is also known as the pressure pipe. More preferably, the at least two plate parts are further adapted to fit at least substantially annularly around the pipe, thereby defining a minimum distance between the at least two plate parts and the pipe, the stabilising means further comprising adjusting means for adjusting the minimum distance between the at least two plate parts and the pipe.

Alternatively or additionally, at least one of the stabilising member(s) is a pipe which at least substantially surrounds the long shaft. Thus, the surrounding pipe may comprise both the stabilising means, at least part of the long shaft and at least part of said pressure pipe, the stabilising means connecting the surrounding pipe with the long shaft and the pressure pipe. Preferably, at least one of the stabilising member(s) may be the inside walls of the tank, the walls having mounts adapted to fix the stabilising means.

Preferably, the stabilising means is in the form of a guide ring. A long shaft may be stabilised by more than one guide ring depending on the vibrations of the long shaft. Additionally, the one or more guide rings may be coupled together, preferably in a direction parallel to the long shaft. In such a configuration, the coupled guide-rings may mutually stabilise one another. Thus, for a single guide-ring the stabilising means function as a support whereas with a plurality of guide-rings the stabilising means may function as a fixing device.

Preferably, the long shaft comprises a rotating shaft adapted to mechanically transfer power from a drive means to a pump, the pump being submerged in a tank. The long shaft may support the rotating shaft by having bearings at appropriate intervals of the longitudinal length of the support shaft. Another advantage of the stabilising means is that the long shaft can be freed from the stabilising means, whereby the long shaft may be used for pulling up the submerged pump connected to the bottom end of the long shaft. Hence, for example pump service and repair is in turn also simplified by the more flexible stabilising means of the present invention. A problem encountered with a long shaft comprising a rotating shaft is that the rotating shaft may significantly raise the temperature of the long shaft over time. In turn, the stabilising means may also be exposed to a significant temperature raise over time during operation of the rotating shaft. This temperature problem may be at least partly solved by designing the plate parts to absorb and/or compensate for the raising temperature and/or by providing cooling as necessary.

The plate parts may be manufactured in stainless steel, typically a stainless and/or acid resistant steel e.g. AISI 316L, AISI 304, W. Nr. 1.4462 or similar, as the harsh environment of the tank will often necessitate a chemical inert material. Alternatively, the plate parts may be manufactured in aluminium or an alloy comprising aluminium. In particular, the plate parts may be manufactured in a material capable of withstanding prolonged exposure to vibrations and the associated wear, e.g. fretting wear. According to a second aspect of the invention there is provided a method for manufacturing a stabilising means for vibrationally stabilising a long shaft, the method comprising the steps of: providing at least two plate parts having a predetermined shape, adapted to releasably fit the at least two plate parts at least substantially annularly around the long shaft and to substantially fix the long shaft in relation to at least one stabilising member, and providing adjusting means being adapted to adjust a minimum distance between the at least two plate parts and the long shaft,

It is an advantage of the invention that the present invention facilitates a simple and fast manufacturing process for the stabilising means. Often, the stabilising means are manufactured in relative few numbers, thus costly manufacturing preparation are avoided due to the simplicity of the method for manufacturing the stabilising means.

Preferably, the method further comprises the steps of: a) providing at least one support element being adapted to establish contact between the at least two plate parts and the long shaft, and b) mounting the at least one support element on at least one of the plate parts. More preferably, the at least two plate parts define a primary plane and each of the at least one support element(s) define a second plane, and wherein the step of mounting the support element(s) on at least one of the plate parts is performed in such a way that, for each support element, said second plane is at least substantially perpendicular to the primary plane.

It is a particular advantage of the present invention that the at least two plate parts may be provided by means of a laser cutting method. Preferably, the at least two plate parts each has a thickness in the range of 2 mm to 20 mm, more preferably in the range of 4 mm to 16 mm, even more preferably in the range of 6 mm to 8 mm. All of these ranges are accessible to the present stage of commercially available laser cutting technology, e.g. Nitrogen lasers. However, principally there is no upper limit on the thickness of the plate parts except for limits imposed from a handle viewpoint and/or manufacturing view point. In particular, for an embodiment where the aforementioned support elements are not present it may be advantageous to increase the thickness of the plate part in order to enhance the area of contact between the plate parts and the long shaft to be stabilised. The method of manufacturing the stabilising means is particularly beneficial in that the manufacturing can be performed in just two steps; the aforementioned laser cutting step and a step of bending the plate parts into a predetermined shape. In that way welding can be completely avoided, which is advantageous because welding of stainless steel and aluminium alloys requires special care and/or special preparations.

The first and second aspect of the present invention may each be combined with the other aspect. These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

Brief description of the figures

While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.

Fig. 1 shows a side view of the surrounding environment of the stabilising means during operation,

Fig. 2 shows a cross sectional view along the line A-A of Fig. 1,

Fig. 3 shows a more detailed view of the stabilising means,

Fig. 4 shows a side view of the stabilising means,

Fig. 5 shows a main plate part of the stabilising means,

Fig. 6 shows different views of a minor plate part,

Fig. 7 shows a partial top view of the adjusting means of the invention,

Fig. 8 shows a support element of the invention,

Fig. 9 shows a side view of the stabilising means according to an alternative embodiment, and Fig. 10 shows a more detailed view of the stabilising means according to an alternative embodiment.

Detailed description of the invention

Fig. 1 shows a side view of the surrounding environment of the stabilising means during operation. An electrical motor 100 positioned on top of a tank drives a submerged pump 110 positioned on the bottom of the tank. A pipe 120 for conveying fluids is shown substantially parallel to a long shaft 130 comprising a rotating shaft 135 shown in Fig. 1. The wall 150 of the tank or other stable internal structure of the tank comprises mounts 140 for fixing the stabilising means 200.

Fig. 2 shows a cross sectional view along the line A-A of Fig. 1. In this cross sectional view, the rotating shaft 135 surrounded by the long shaft 130 is visible. It can also be seen that the wall 150 through the mount 140 and the stabilising member 200 is connected to the pipe 120 and the long shaft 130, and how the stabilising member 200 in turn in a substantially horizontal plane fits at least substantially around the long shaft 130 and the pipe 120.

Fig. 3 shows a more detailed view of a most preferred embodiment of the stabilising means 200. The stabilising means 200 comprises six plates grouped in three pairs of identical plates; two main plates 280, two first minor plates 291, and two second minor plates 284. When joined together by mounts 293 fastened by bolts 294, the two main plates 280 have an outer circular periphery for engaging with the mounts 140 shown in Fig. 2 (the top part of the upper main plate 280 is not shown to clarify Fig. 3). The two main plates 280 comprise suitable holes for securing the minor plates 291 and 284 by bolts 286. In this embodiment, the two main plates 280 exhibit a mirror symmetry around the axis B. The two first minor plates 291 are fastened onto the two main plates 280, each first minor plate 291 being mounted with a bolt and a corresponding nut in each main plate 280. The two first minor plates 291 fit substantially annularly around the long shaft 130. The first minor plates comprises four support elements 292 symmetrically arranged around the long shaft 130, the support elements 292 being designed for engaging and establishing contact with the long shaft 130. When the stabilising means 200 are in an engaged or fixed position relative to the long shaft 130 the two first minor plates 291 only have contact with the long shaft 130 in the vicinity of the support elements 292. The support elements 292 have a substantially triangular shape, the support elements 292 being substantially normal to a primary plane defined by the plates 280, 284, and 291. The support elements 292 will be described in more detail below. The two second minor plates 284 fit substantially annularly around the pipe 120 and comprise four support elements 300 similar to the support elements 292 of the first minor plates 291. The axis D intersects the axis B in a symmetry axis of the pipe 120. Upon 180 5 degree rotation around said symmetry axis of the pipe 120 the two second minor plates 284 can change position with each other, i.e. they have a rotational symmetry around the symmetry axis of the pipe 120. The two second minor plates 284 have two sets of adjusting means, i.e. respectively a nut 281 and a corresponding bolt 283, the bolt 283 being mounted in the abutting second minor plates 284 in a manner to be described in

10 more detail below. When the bolt 283 is tightened the support elements 300 (which are similar to the support elements 292) will reduce the distance to the pipe 120. In any given position of the adjusting means 281 and 283 a minimum distance between the pipe 120 and the support element 300 being closest to the pipe 120 can be defined. In the limit the minimum distance will be zero and the stabilising means 200 will be fixed onto the pipe

15 120. The two first minor plates 291 similarly comprise two sets of adjusting means 310 for adjusting and establishing contact between the support elements 292 and the long shaft 130.

In an alternative embodiment the minor plates 284 and 291 may not comprise support 20 elements 292 and 300. Instead, the inner periphery part of the minor plates 291 and 282 have a substantially half-circular shape with a radius of curvature approximately equal to the radius of long shaft 130 and the pipe 120, respectively. When the adjusting means 281, 283 and 310 are in a tightened position the minor plates 291 and 284 will be engaged with the long shaft 130 and the pipe 120, respectively, along at least a part of their said 25 inner periphery. For such an embodiment, the thickness of the minor plates 284 and 291 may be enhanced for improving the contact between the plates 284 and 291 and the long shaft 130.

Fig. 4 shows a side view of the stabilising means 200 showing how the plates 280, 284 and 30 291 are interconnected. It is to be noted how the plates 280, 284 and 291 define a primary plane substantially normal to the long shaft 130 and the pipe 120. It is also visible how the first minor plate 291 and the second plate 284 have a bent part substantially normal to said primary plane so as to engage their corresponding plate at the adjusting means 281, 283 and 310 with a substantially flat section seen from a side view. At the far 35 left and right mount 293, bolt 294 and nut 295 are shown for joining the two main plates 280. Furthermore, one of the bolts 286 for joining the minor plate 284 and the main plate 280 are shown in a cut out section behind the pipe 120. Fig. 5 shows a top view of a main plate 280 of the stabilising means 200 comprising appropriate holes 530 for joining the main plate 280 with another corresponding main plate 280 as shown in Fig. 3. Also shown are holes 520 for mounting of the first minor plates (not shown) and holes 510 for mounting of the second minor plates (not shown). 5 The main plate 280 also comprises additional holes 540 prepared for reducing material consumption without jeopardising strength and stability of the stabilising means 200. Furthermore, the holes 540 facilitate cleaning of the tank by automatic tank washing machines.

10 Fig. 6 shows three different views of the second minor plate 284; from the top A, and two side views, B and C respectively, B and C having a viewing angle normal to each other. The second minor plate 284 comprises holes 610 for joining the second minor plate 284 with appropriate fastening means, e.g. bolts and nuts or similar, to the main plates 280. The bolt 286 shown in Fig. 3 may thus penetrate a hole 510 shown in Fig. 5 and a hole 610

15 for joining the two said plates together. Additionally, the second minor plate 284 comprises receiving sections 620 for mounting of the support elements shown in Figs. 3 and 4 with reference numeral 292. The support elements 292 may be designed so that after insertion at the receiving sections 620 no dedicated fastening means are necessary during operation. The second minor plate 284 comprises a first part 284b, the first part 284b

20 comprises four projections 284d for fixation of the adjusting means (not shown) when the second minor plate 284 is assembled as a part of the stabilising means 200. Furthermore, the second minor plate 284 comprises two holes 284c that function as receiving holes for bolts (not shown) of the adjusting means. As it is apparent from especially Fig. 6, view B and C, that the second minor plate 284 also comprises a bent part 284a, the bent part

25 284a being substantially normal to remaining part of the second minor plate 284. The bent part 284a also comprises holes as seen in view C of Fig. 6 for receiving adjusting means 281 and 283 as well as the projections parts 284d when assembled as a part of the stabilising means 200. The first minor plates 291 will have a similar design to that shown in Fig. 6, but the first minor plate 291 is adapted to fit at least substantially annularly in

30 combination with another corresponding minor plate 291 around the long shaft 130.

Fig. 7 shows a partial top view of the adjusting means 281 and 283 of the invention when two second minor plates 284 are in abutting engagement as shown in Fig. 3. The bolts 283 are received in the holes 284c of the first part 284b of the second minor plate 284. The 35 projections 284d have also entered the corresponding holes of the bent part 284a. The nuts 281 are not in engagement with the bolts 283. It is an advantage of the invention that the receiving holes 284c can be dimensioned so that the bolts 283 do not fall out of the second minor plate 284 even though the corresponding nuts 281 are not engaged with the bolts 283. This is preferably done by manufacturing the holes 284c substantially equal to the size of the bolts 283 so that the bolts 283 after being pressed into the holes 284c will remain there also during remounting and service of the stabilising means 200.

Fig. 8 shows a support element 292 of the invention. The support element 292 has an A- 5 like shape with an open section 855 at the top in order to engage with the minor plates 280. The distance 820 is preferably slightly larger than the distance 810 in order to allow the minor plates to fit in when considering the given tolerances of the manufacturing process in question. When assembled, the parts 830 of the support element 292 will be engaged with the pipe (not shown) before the centre part 840 due to the small distance

10 850 of approximately 0,5 mm. When the pressure tension on the parts 830 is increased during operation the support element 292 (being manufactured in a relatively flexible material like stainless steel) will bend slightly upwards and the distance 810 will decrease, thus as the pressure tension is increased the support element 292 will press more and more onto the minor plate (not shown) positioned at 855. Therefore, the support element

15 292 needs no special fastening means as the above mentioned design inherently provides fastening during operation. The above remarks relating to the support elements 292 would apply equally to a similar description of the support elements 300 shown in Fig. 3.

Fig. 9 shows a side view of stabilising means 700 according to an alternative embodiment.

20 In this embodiment, the stabilising means 700 comprises two plate parts 600 that fit substantially annularly around the long shaft 130. The stabilising means 700 is mechanically connected to a stabilising member (not shown), e.g. a wall, a pipe parallel to the long shaft 130 etc. Support elements 292 similar to the previous embodiment are mounted on the plate parts 600 for establishing contact between the long shaft 130 and

25 the plate parts 600. As the support elements 292 are designed so as to provide self- fastening during operation no special fastening means are necessary resulting in a relatively simple design which is fast and cost-effective to manufacture and mount. The two plate parts 600 are joined by adjusting means, i.e. bolts 601 and nuts 603, mounted through a bent portion of the plate parts 600. This is also similar to the previous 0 embodiment, see e.g. Figs. 3 and 4 and the corresponding parts of the description. In Fig. 9, there is also shown in broken lines the mount 140 and the wall 150 similar to the Figs. 1 and 2.

Fig. 10 shows a more detailed view of the stabilising means 700. The two plate parts 600 35 are seen to have a rotational symmetry around the centre of the long shaft 130, said centre being coincident with the centre of the rotating shaft 135 as viewed in Fig. 10. Thus, the two plate parts 600 may be identical resulting in simple manufacturing process. The two plate parts 600 are joined by adjusting means, i.e. 601 and 603. In Fig. 10, it is seen that the support elements 292 are positioned relative to the long shaft 130 and the plates 600 so that there is little or no direct contact between the plate parts 600 and the long shaft 130 as illustrated by the tiny gap. This makes it easier to displace the stabilising means 700 in the longitudinal direction of the long shaft 130 when the adjusting means are slacken. The plate parts 600 comprise holes 540 to facilitate easy cleaning of the stabilising means 700 and the environment wherein the stabilising means 700 is positioned. Each of the plates 600 comprises two incisions or indents 620 in order to provide access for one or more auxiliary pipe(s) 800 within the abutting interface of the stabilising means 700 and the mount 140 (the latter not shown in Fig. 10). The auxiliary pipe 800 has a longitudinal extension substantially parallel to the long shaft 130, and the pipe 800 may contain cooling liquids, lubrication liquids, control wires, etc. for the lower lying pump 110 (not shown in Fig. 10).

Claims

1. A stabilising means for vibrationally stabilising a long shaft, the stabilising means comprising: at least two plate parts, in combination being adapted to fit at least substantially annularly around the long shaft and to substantially fix the long shaft in relation to at least one stabilising member, thereby defining a minimum distance between the at least two plate parts and the long shaft, and - adjusting means for adjusting the minimum distance between the at least two plate parts and the long shaft,

2. A stabilising means according to claim 1, wherein the adjusting means is adapted to be in at least two positions, a first of said positions substantially fixing the stabilising means in a longitudinal direction of the long shaft, and a second of said positions allowing the stabilising means to slidably move along said longitudinal direction of the long shaft.

3. A stabilising means according to claim 1 or 2, further comprising at least one support element being mounted on at least one of the plate parts, the at least one support element being adapted to establish contact between the at least two plate parts and the long shaft.

4. A stabilising means according to any of claims 1-3, the stabilising means further comprising releasable fastening means for releasably fitting the at least two plate parts around the long shaft.

5. A stabilising means according to claim 1, the stabilising means comprising at least one support element being mounted on at least one of the plate parts, the at least one support element being adapted to establish contact between the at least two plate parts and the long shaft, each of the at least one support element(s) defining a second plane, wherein, for each of the support element(s), said second plane is least substantially perpendicular to the primary plane defined by the at least two plate parts.

6. A stabilising means according to any of claims 1-5, wherein at least one of the stabilising member(s) is a pipe extending in a direction being parallel to the longitudinal direction of the long shaft.

7. A stabilising means according to claim 6, wherein the at least two plate parts are further adapted to fit at least substantially annularly around the pipe, thereby defining a minimum distance between the at least two plate parts and the pipe, the stabilising means further comprising adjusting means for adjusting the minimum distance between the at least two plate parts and the pipe.

8. A stabilising means according to claim 7, wherein the pipe is adapted to convey a fluid.

9. A stabilising means according to any of claims 1-8, wherein at least one of the stabilising member(s) is a pipe which at least substantially surrounds the long shaft.

10. A stabilising means according to any of claims 1-9, wherein the stabilising means is in the form of a guide ring.

11. A stabilising means according to any of claims 1-10, wherein the long shaft comprises a rotating shaft adapted to mechanically transfer power from a drive means to a pump.

12. A stabilising means according to any of claims 1-11, wherein the at least two plate parts have been provided by means of a laser cutting method.

13. A stabilising means according to any of claims 1-12, wherein the at least two plate parts each has a thickness in the range of 2 mm to 20 mm, more preferably in the range of 4 mm to 16 mm, even more preferably in the range of 6 mm to 8 mm.

14. A stabilising means according to claim 1, wherein at least one of the plate parts is manufactured in stainless steel.

15. A stabilising means according to claim 1, wherein at least one of the plate parts is manufactured in aluminium or an alloy comprising aluminium.

16. A method for manufacturing a stabilising means for vibrationally stabilising a long shaft, the method comprising the steps of:

- providing at least two plate parts having a predetermined shape, adapted to releasably fit the at least two plate parts at least substantially annularly around the long shaft and to substantially fix the long shaft in relation to at least one stabilising member, and providing adjusting means being adapted to adjust a minimum distance between the at least two plate parts and the long shaft, wherein the at least two plate parts define a primary plane, and wherein the longitudinal direction of the long shaft extends substantially normal to said primary plane when the stabilising means is mounted on the long shaft.

17. A method according to claim 16, further comprising the steps of: providing at least one support element being adapted to establish contact between the at least two plate parts and the long shaft, mounting the at least one support element on at least one of the plate parts.

10 18. A method according to claim 17, wherein the at least two plate parts define a primary plane and each of the at least one support element(s) define a second plane, and wherein the step of mounting the support element(s) on at least one of the plate parts is performed in such a way that, for each support element, said second plane is at least substantially

15 perpendicular to the primary plane.

19. A method according to any of claims 16-18, wherein the step of providing at least two plate parts comprises laser cutting the plate parts from a plate.

20 20. A method according to any of claims 16-19, wherein the step of providing at least two plate parts comprises providing at least two plate parts having a thickness in the range of 2 mm to 20 mm, more preferably in the range of 4 mm to 16 mm, even more preferably in the range of 6 mm to 8 mm.

25 21. A method according to any of claims 16-20, further comprising the step of bending at least one of the plate parts into a predetermined shape.

22. A method according to any of claims 16-21, wherein the step of providing the at least two plate parts having a predetermined shape, adapted to releasably fit the at least two 30 plate parts at least substantially annularly around the long shaft does not comprise any welding of the at least two plate parts.