Wound rotor

Description

[0001] The present invention relates to a method for manufacturing a Magnus rotor. The Magnus rotor is sometimes also referred to as a Flettner rotor. The principle of the Magnus rotor is based on the so-called Magnus effect, according to which a rotating body experiences a deflection force directed transversely to the flow direction due to suction and dynamic pressure forces.

[0002] The Magnus rotor typically consists of a vertical, tall, rotating cylinder made of sheet metal or a composite material. It features a so-called end plate at its free end, which keeps the flow along the tube and thus improves the rotor's efficiency. The Magnus rotor is rotated by an external drive, such as an electric drive, and its rotational speed is adjusted to the wind conditions. Magnus rotors can be used in various technical fields, with an important application being in the shipping sector. Here, Magnus rotors are often used as auxiliary propulsion systems and lead to a significant reduction in CO2 emissions.

[0003] GB 2,477,078 A discloses a Magnus rotor whose rotor body consists of a multitude of plastic and lightweight sections arranged one above the other along the rotor's longitudinal direction. This design, with individual sections arranged one above the other, simplifies the transport and installation of the Magnus rotor. In addition, a lightweight frame is provided inside the Magnus rotor, which includes cross braces and mounting plates. The rotor body is rotatably mounted on the free end of the frame.

[0004] GB 2,524,753 A discloses a method for manufacturing a rotor body for a Magnus rotor. The method involves assembling a plurality of curved panels into a circumferentially closed segment and arranging several segments one above the other to form the rotor body.

[0005] CN 103906680 A discloses a variable vertical sail system with multiple Magnus rotors for a ship. The Magnus rotors have an outer sail cylinder made of a lightweight shell, preferably aluminum. The shell is attached to frame elements made of steel or other material, which provide the cylindrical structure.

[0006] CN 1113130 ​​A describes a Magnus rotor in which at least two cylinder sections of the same diameter are connected via a connecting flange. These are then dynamically balanced.

[0007] From GB 2477078 A a Magnus rotor is known which has a support structure with several sections to which plate elements are attached.

[0008] From DE 20 2000 015 089 U1 a rotor device has become known which can be used as a side thruster on ships.

[0009] For the operation of the Magnus rotor, it is important that the rotating, upright cylinder is free of any imbalances. In general, imbalance occurs when a rotating body's (current) axis of rotation does not coincide with one of its principal axes of inertia. In this case, the imbalances lead to vibrations, which can lead to damage in rolling bearings, for example. In practice, static and dynamic imbalances are often relevant, although higher-order imbalances can also occur. With static imbalance, the body's axis of rotation does not coincide with its center of gravity. The center of gravity therefore moves in a circle around the current axis of rotation, causing vibrations in the rotor body. With dynamic imbalance, the axis of rotation does not coincide with a stable principal axis of inertia of the rotor body, but runs through the center of gravity.This causes a wobbling motion of the rotor body, which can also be referred to as flutter. Both effects can be reduced and sometimes completely eliminated by attaching weights to suitable positions on the rotor body. This process is generally very time-consuming for the Magnus rotor.

[0010] The invention is based on the object of providing a method for producing a Magnus rotor whose imbalance is as low as possible.

[0011] According to the invention, the object is achieved by a method having the features of claim 1. Advantageous embodiments form the subject matter of the subclaims.

[0012] According to the invention, this object is achieved by a method having the features of claim 1. The method according to the invention relates to the production of a Magnus rotor with at least one rotor body having a longitudinal axis. The method comprises the step of providing an internal model for the at least one rotor body. The internal model is mounted for coating with a fiber composite material, wherein for this purpose in particular the circumferential surface of the internal model is exposed in order to apply a fiber composite material. The internal model mounted for coating with the fiber composite material is wound with a fiber material and with the addition of a plastic material to produce the fiber composite material. The internal model functions as a winding mandrel. The winding process means that the fiber material is applied to the internal model in the circumferential direction in an at least partially continuous process.Finally, preferably after the fiber composite material has cured, the internal model is removed, leaving a wound body made of fiber-reinforced composite material. With regard to the technical task of the problem, the chosen manufacturing process is based on the realization that the winding process can achieve a very uniform material application in the circumferential direction, which avoids or at least significantly reduces imbalances in the rotor body. Static imbalances, for example, can be almost completely avoided with a uniform winding.

[0013] In a preferred embodiment of the method according to the invention, the Magnus rotor consists precisely of a wound rotor body. This means that the inner model extends longitudinally at least as long as the rotor body. By manufacturing the rotor body of the Magnus rotor in one piece as a wound rotor body, imbalances caused by assembling segments or sections of the rotor body can be avoided. Imbalances caused by assembling segments and sections often manifest themselves as dynamic imbalances, which are significantly more difficult to balance than static imbalances. The one-piece construction not only ensures a uniform structure in the circumferential direction through winding, but can also ensure the desired wall thickness in the longitudinal direction of the rotor.

[0014] With regard to winding the fiber material, two basic approaches can be distinguished. On the one hand, it is possible to apply winding layers and wind them evenly onto the inner model to form the rotor body. Alternatively, but also additionally, it is possible to wind individual fibers onto the inner model and bond them to the plastic material. Both approaches can also be combined. The winding process can generally be carried out by rotating the inner model relative to a device that applies the fiber material or by rotating the fiber material relative to the inner model. Both movements can also be used in combination for winding the fiber material.

[0015] In the method according to the invention, glass fibers, carbon fibers or aramid fibers can be used, whereby short and long fibers can be used when the fiber material is applied in winding layers, while continuous fibers can also be used when individual fibers are applied directly into the winding.

[0016] The plastic material used can be epoxy resin, vinyl ester resin and phenol formaldehyde resin or combinations of these.

[0017] In a preferred embodiment, the rotor body is wound as a cylindrical, preferably circular-cylindrical, tube. A uniform wall thickness can preferably be used. Although Magnus rotors are also known in which helical guide vanes are mounted along the circumference, the rotor body according to the invention preferably has a predominantly uniform outer contour.

[0018] For use of the rotor body in a Magnus rotor, a flange connection area is provided. The flange connection area is designed to hold an end plate of the Magnus rotor. According to the invention, the flange connection area is also wound and can, for example, accommodate a bore or a recess for a fastener for attaching the end plate.

[0019] In a preferred development, a greater wall thickness is provided in an area for a hub of the rotor body in order to absorb bearing forces of the Magnus rotor. The rotor body is mounted for its rotation on a drive shaft or other drive device. For this purpose, a connection is established between the drive and the rotor body to transmit the torque. This connection is made in the area of ​​the rotor bearing. Depending on the design of the rotor body, this area of ​​the rotor bearing can be located at one or more points along the longitudinal direction of the rotor body, whereby end-mounting of the rotor body is also possible.

[0020] In this bearing area, not only do forces generated by any imbalances act, but also the thrust forces caused by the Magnus effect, for example, are transferred to the ship. Therefore, depending on the selected wall thickness of the rotor body, it may be necessary to provide an increased wall thickness in the rotor bearing area for stability reasons.

[0021] In addition to the flange connection area and the rotor bearing area mentioned above, at least one end area of ​​the rotor body can also be designed with a greater winding thickness than a central area of ​​the rotor body. The reinforced end area increases the stability of the rotor body in the radial direction, which, for example, facilitates transport of the rotor body.

[0022] In addition to the above-mentioned areas of greater winding thickness, it is also possible to provide at least one structural area on the rotor body by varying the winding thickness. The structural area can run in a ring around the rotor body or be formed helically with a predetermined pitch on the rotor body. The structural areas can provide various aerodynamic or stability-generating advantages for the rotor body. With regard to rotational behavior, it must be taken into account that the rotor body and its axis of rotation move relative to the wind and thus to the acting forces, for example on a ship. This generates torques and forces corresponding to the moment of inertia of the rotor body, which must be absorbed and dissipated as evenly as possible. One or more structural areas can have an aerodynamic and / or mechanical stabilizing effect here.

[0023] In addition to varying the winding thickness, preformed parts can also be used to create the structure on the rotor body. The preformed parts can be inserted between two wound layers, similar to a sandwich construction. For this purpose, the winding process is interrupted after the first winding layer has been produced, the preformed part is positioned and, if necessary, secured, and the winding process can then be continued. In addition to wrapping the preformed part, it is also possible to position and secure the preformed parts on the inner model. The preformed parts can then be wrapped around it, for example to be separated from the cured fiber composite material after the inner model has been removed, or to be removed directly together with the inner model. The preformed parts allow the shape of the rotor body to be specifically adapted without having to vary the winding thickness.The use of molded parts offers the advantage that the parameters for producing the winding from fiber composite material do not have to be varied, but can be carried out uniformly.

[0024] In a further preferred embodiment, the rotor body is manufactured in at least some areas in a sandwich construction, in which at least one filler body is provided between the layers. In a particular embodiment, the entire rotor body is manufactured in a sandwich construction, so that a cylindrical filler body is provided between an inner layer of the fiber composite material and an outer layer of the fiber composite material. This cylindrical filler body can consist of shell-shaped elements that are arranged around a first applied layer of fiber composite material and then wrapped in the outer layer of the fiber composite material. The filler body of the sandwich construction can preferably be designed as a foam body that can bond well with the fiber-reinforced composite material.

[0025] In addition to the aforementioned design of a rotor body extending over the entire length, the Magnus rotor can also consist of several wound rotor bodies connected to each other longitudinally. The rotor bodies themselves are closed in the circumferential direction and therefore offer the advantages already mentioned with regard to static balancing. Wound, the rotor bodies have a uniform weight distribution in the circumferential direction.

[0026] The object of the invention is also achieved by a Magnus rotor having the features of claim 15.

[0027] The Magnus rotor according to the invention has at least one longitudinally extending rotor body made of a fiber composite material, which is designed as a wound fiber composite material. Wound fiber composite material is characterized by its circumferential, wrapped fiber structure. A wound rotor body has the advantage of a uniform mass distribution in the circumferential direction.

[0028] Preferably, the rotor body is designed in the form of a cylinder, in particular a circular cylinder, wherein at least one end plate is provided on the rotor body, which projects beyond the rotor body in the radial direction.

[0029] The Magnus rotor according to the invention is equipped with a rotor body with a bearing connection for a rotating shaft inside it. One or more bearing connections can be provided inside the rotor body. The bearing connection can be provided at the end of the rotor body; preferably, it is located centrally in the rotor body.

[0030] In a preferred embodiment, the Magnus rotor has exactly one wound rotor body which extends over the entire longitudinal direction.

[0031] The above invention is explained in more detail below using the following examples. They show: Fig. 1 a Magnus rotor with a one-piece rotor body having two end plates, Fig. 2 a wound rotor body with an end reinforcement and an inner flange for fastening the end plate, Fig. 3 a rotor body with wound, reinforced structural areas, Fig. 4 in a contrasting view a rotor body with a laminated foam part on the left side and a removable model part on the right side, Fig. 5 a rotor body in sandwich construction with a foam insert and Fig. 6 a rotor body consisting of several rotor bodies arranged one above the other.

[0032] Figure 1shows a Magnus rotor 10 having a rotor body 12. The rotor body 12 is circularly cylindrical and has a wall thickness along its longitudinal direction adapted to the loads. Furthermore, the rotor body 12 has an upper end disk 14 and a lower end disk 16, which, however, is not designed as a closed disk, but as an open disk ring. Both end disks 14, 16 protrude circumferentially beyond the rotor body 12. The Magnus rotor 10 is arranged on a base, which can be, for example, a ship's deck 18. A drive unit 20 is mounted on the deck 18 and extends into the interior of the rotor body. A drive shaft 24 is rotated by an electrically operated motor 22. The shaft 24 extends centrally within the rotor body 12 along its axis of rotation. An upper end of the rotor shaft 24 is connected to an upper hub 26.The upper hub 26 is designed as a frustoconical bearing part. However, it is also possible to design the hub with struts or spokes. The upper hub 26 has a hub ring that is connected to the outer ring(s) of an axial spherical roller bearing 29. The inner ring of the bearing is arranged on a vertical tube 25b. The drive shaft 24 is connected to the upper hub 26 in the area of ​​the upper bearing 29. For the connection between the hub 26 and the rotor body 12, the rotor body 12 has inwardly projecting bearing flanges 30, 32. The bearing flanges 30, 32 are arranged on the inside of the rotor body and are each connected to the upper or lower hub. As an alternative to a bearing flange 30, 32, the hub can also be held between two sections of the rotor body.

[0033] In the Figure 1In the illustrated embodiment, the upper hub 26 is connected to the drive shaft 24 via the upper bearing 29. The drive shaft 24 rotates the upper hub 26 with the outer ring of the upper rotor bearing 29. The hub tube 25a is guided externally around the stationary tube 25b and thus has a stabilizing function for the rotor body 12. The rotor body 12 is driven by the upper hub 26, which is connected to the outer hub tube 25a. The upper hub 26 is mounted on the stationary tube 25b via the rotor bearing 29.

[0034] The lower bearing 27 sits with its inner ring on the stationary tube 25b and with its outer ring on the outer hub tube 25a and on the lower hub 28. The upper bearing 29 sits with its outer ring in the upper hub 26, which is driven by the drive shaft 24 and connected to the hub tube 25a. The inner ring of the upper bearing 29 sits on the stationary tube 25b. Preferably, an oil bath is located between the stationary tubes 25b and the rotating hub tube 25a, which also includes the upper rotor bearing.

[0035] Figure 2a shows an overall view of a rotor body that was manufactured in one piece. In the end areas, Figure 2a a circumferential thickening 34. Accordingly, a circumferential thickening 36 is provided at the opposite end. Figure 2bshows a detailed view of the thickening. The thickening 34 increases towards the outside. This means that the inner diameter of the rotor body has a constant value over its length. In a first section 38 of the thickening 36, the wall thickness of the rotor body increases. Figure 2ba linear increase in wall thickness is shown in section 38. Section 38 with increasing wall thickness transitions into a second section 40 with constant wall thickness. In addition to the increase in wall thickness in sections 38 and 40, an inwardly projecting flange 42 is also provided, which is also circumferential and partially closes off the rotor body. The inwardly projecting flange 42 is provided with a bore 44, which is intended to fasten an end plate to the rotor body 12. The inwardly projecting flange 42 can be wound or manufactured in some other way. For example, the flange 42 can be inserted into the internal model used for winding the rotor body, so that the wound fiber composite material is wound onto the already prepared flange. However, subsequent winding of the inwardly projecting flange 42 is also possible.

[0036] Figure 3shows a structural region 46 for a rotor body 12" produced via a laminate. The structural region 46 consists of a region 48 of constant maximum wall thickness, to which two sections 50a, 50b with increasing wall thickness belong. The sections 50a, 50b with increasing wall thickness show a linearly increasing wall thickness in the illustrated embodiment. However, other forms of wall thickness increase are also possible. The structural regions 46 form the illustrated embodiment of the Figure 3 Ribs arranged at equal distances along the rotor body. The end region 34 is also as in the embodiment of Figure 2 thickened, however, the outer radius of the end regions does not approach the maximum outer radius of the structural region 48. The structural regions 46 are therefore more pronounced than the thickened end regions 34.

[0037] Figure 4shows two shapes of the rotor body with which a structure can be formed. A foam part 52 is shown on the left side of the Figure 4 Laminated. Laminated refers to an inner layer of fiber composite material 54 and an outer layer of fiber composite material 56. The foam part 52, which determines the outer contour of the rotor body, is arranged between these layers.

[0038] The right side of Figure 4shows another embodiment for creating an outer contour in the rotor body. Here, a model part 58 is provided, which is arranged on the inner model of the rotor body and is completely wrapped with the fiber composite material 60. If the inner model 62 on the rotor body is removed, the model part 58 can also be removed and the cured fiber composite material remains in the shape imprinted by the model part. Both the laminated foam part 52 and the subsequently removable model part 58 serve to create a structure for the rotor body. What differs about the two approaches is that the foam part 52 remains in the rotor body while the model part is removed, so that only the fiber-reinforced composite material is present.

[0039] Figure 5shows a rotor body manufactured in a sandwich construction. An inner wound layer 64 alternates with a foam insert 66, which in turn is wrapped by an outer layer 68. The foam insert 66 can be applied to the wound inner layer in the form of individual curved components. The parts adjoin one another, thus forming a cylindrically closed foam insert, which is subsequently held by the outer wound layer 68 of the fiber composite material.

[0040] Figure 6shows an alternative design of the rotor body, in which wound rotor bodies 70, 72, 74 are arranged one above the other in the longitudinal direction. Each of the rotor bodies 70, 72, 74 has an inner flange 76, 78 at both ends, each provided with a bore 80. By placing two wound rotor bodies 72, 70 or 74, 72 one above the other in the longitudinal direction, they can be connected to one another by screw-bolt connections 82. A particular advantage here is that each of the rotor bodies is already wound rotationally symmetrically and therefore has a uniform mass distribution. In addition, the inwardly projecting fastening flanges with their bolt connections provide sufficient opportunity to produce weights for effective balancing of the entire rotor body.

[0041] The entire rotor body is preferably designed as a cylinder and has a diameter of 0.1 m to 5 m or more. For use as a Magnus rotor, its length is typically one to ten times the diameter. The rotor body is mounted to rotate around a vertical axis and is usually mechanically or electrically driven and set in rotation. When wind flows against the rotating rotor cylinder, the rotation generates lift, which is used as additional thrust for the ship.

[0042] The rotor body according to the invention is made of a glass fiber reinforced plastic (GRP) or a carbon fiber reinforced plastic (CFRP). Fiber reinforcements such as aramid can also be provided. A model for the inner diameter of the rotor is produced. This model is usually mounted so that it can rotate about its horizontal axis. While the inner model rotates, a resin-impregnated fiber tape is wound around the model. The winding can be carried out in such a way that the desired phase direction of the individual winding layers relative to one another is created. The result is a cylindrical, fiber-reinforced tube whose wall thickness is determined by the number of winding layers. Depending on the design of the inner model, flanges can be wound onto the end of the wound cylinder. These flanges are shaped inwards or outwards and serve for the later attachment of the end plates.To reinforce transitions from the outer wall to the flanges or to reinforce cylindrical areas, several layers are partially wound on top of each other (see . Figure 2 ).

[0043] Using the technique of wrapping several layers on top of each other on the outside, the cylinder can be partially reinforced and also provided with a larger surface (compare Figure 3 ).

[0044] It can be advantageous to apply rings or molded parts to the cylindrical model structure, which allow the cylinder to be wound in a certain waviness (compare Figure 4). Such additional model parts can be manufactured in such a way that they can be removed after the entire cylinder has been formed. Alternatively or additionally, foam models can be produced which are applied to the basic model as a rotational part. These foam models can remain inside the cylinder for later reinforcement purposes and reinforce the designs from the inside. It is also possible to wind a cylinder from several material structures. For example, a first GRP layer can be wound, followed by a foam layer or a mat layer with hollow bodies and then another GRP layer, creating a sandwich structure. The sandwich structure can also be achieved by placing two wound tubes of different diameters inside each other and filling the space between them with foam or other filling material.

[0045] After the resin has hardened, the wound cylinder can remain on its wound model and the surface can be sanded and / or painted to achieve different surface structures.

[0046] Once the cylinder has hardened, it is removed from the winding form. It can be advantageous if the winding form has the option of reducing its support diameter to limit the extraction forces. The cylinder is then available for further removal work or for the installation of reinforcements or holding points. List of reference symbols

[0047] 10 Magnus Rotor 12 Rotor Body 12" Rotor Body 14 Upper End Plate 16 Lower End Plate 18 Base 20 Drive Unit 22 Motor 24 Drive Shaft 25 Double Tube Construction 25a Outer Hub Tube 25b Fixed Axle 26 Upper Hub 27 Lower Bearing 28 Lower Hub 29 Upper Bearing 30 Flange 32 Flange 34 Thickening 36 Thickening 38 Section 40 Section 42 Flange 44 Bore 46 Structural Area 48 Area of ​​Constant Maximum Wall Thickness 50a Section 50b Section 52 Foam Part 54 Inner Fiber Composite Material 56 Outer Fiber Composite Material 58 Model Part 60 Fiber Composite Material 62 Inner Model 64 Inner Wound Layer 66 Foam Insert 68Outer wound layer 70Rotor body 72Rotor body 74Rotor body 76Inner flange 78Inner flange 80Bore 82Screw-bolt connection

Claims

1. A method of manufacturing a Magnus rotor (10) having at least one rotor body (12) which has a longitudinal axis, comprising the following method steps: - Providing an internal model (62) for the at least one rotor body (12), - Bearing of the inner model (62) for coating with a fibre composite material (60), - Wrapping the beared inner model (62) with a fibre material and supplying a plastic material for producing the fibre composite material (60), and - Removal of the inner model (62), whereby - a greater winding thickness is provided in a region of a hub (26, 28) of the rotor body (12) in order to absorb the bearing forces of the Magnus rotor (10), and - at least one flange connection area is wound on the rotor body (12), which is intended to hold an end disc (14, 16) for the Magnus rotor (10).

2. Method according to claim 1, characterised in that the Magnus rotor (10) has exactly one wound rotor body (12) or the Magnus rotor (10) has several wound rotor bodies which are connected to one another in the longitudinal direction.

3. Method according to claim 1 or 2, characterised in that the fibre material is wound around the inner model (62) in the form of winding layers.

4. Method according to one of claims 1 to 3, characterised in that the fibre material is fed in the form of individual fibres to a winding around the inner model (62).

5. Method according to one of claims 1 to 4, characterised in that the rotor body (12) is wound as a cylindrical, preferably as a circular cylindrical tube.

6. Method according to one of claims 1 to 5, characterised in that at least one end region with a greater winding thickness than a central region of the rotor body (12) and / or at least one structural region on the rotor body (12) is provided in which the winding thickness varies.

7. Method according to one of claims 1 to 6, characterised in that the at least one moulded part is wrapped in the wound composite material or is arranged between the composite material and the inner model (62) to form the mould.

8. Method according to one of claims 1 to 7, characterised in that the rotor body (12) is constructed in a sandwich design with a filler body between the layers.

9. Magnus rotor (10) with at least one longitudinally extending rotor body made of a fibre composite material, wherein the at least one rotor body is wound, wherein a greater winding thickness is provided in a region of a hub (26, 28) of the rotor body (12) in order to absorb the bearing forces of the Magnus rotor (10), wherein at least one flange connection region is wound on the rotor body (12), which is provided to hold an end disc (14, 16) for the Magnus rotor (10).

10. Magnus rotor (10) according to claim 9, characterised in that the rotor body has the shape of a cylinder, in particular a circular cylinder.

11. Magnus rotor (10) according to claim 9 or 10, characterised in that the rotor body has at least one end disc which projects beyond the rotor body in the radial direction.

12. Magnus rotor (10) according to one of claims 9 to 11, characterised in that the rotor body has at least one bearing connection for a rotating shaft in its interior.

13. Magnus rotor (10) according to one of claims 9 to 12, characterised in that exactly one wound rotor body is provided or has a plurality of wound rotor bodies which are connected to one another in the longitudinal direction.