Underwater turbine

Abstract

The invention relates to an underwater turbine (100), in particular an underwater turbine (100) of a tidal power plant, having at least one rotor shaft (8), wherein: one end of the rotor shaft (8) can be connected, for conjoint rotation, to a rotatable rotor hub (4) which bears rotor blades (6), and the other end of the rotor shaft extends into a stationary housing of the underwater turbine (100), in particular a nacelle (2) of the tidal power plant; the underwater turbine (100) has a positive-engagement rotor rotation lock (20) in an interior of the stationary housing of the underwater turbine; the rotor rotation lock (20) has at least one translatable locking element (28), which can be brought from a free position, in which the rotor rotation lock (20) does not act, into a locking position, in which the locking element (28) prevents rotation of the rotor shaft (8), and at least one receptacle (26), which is designed such that, in the locking position, the at least one receptacle is engaged with the at least one locking element (28) in order to prevent rotation of the rotor shaft (8).

Description

[0001] 2024P00088DE

[0002] Underwater turbine

[0003] The present invention relates to an underwater turbine, in particular an underwater turbine of a tidal power plant, and a rotor shaft bearing unit for such an underwater turbine.

[0004] Underwater turbines require regular maintenance. This often necessitates retrieving the turbines from the water, such as the ocean, and carrying them ashore for repair or maintenance. To enable maintenance underwater or at the surface, in addition to access to the nacelle, it is also essential that the rotating components, particularly the drive train, can be shut down. This is typically achieved using a braking system equipped with a brake disc that uses high friction to prevent further rotation of the drive train.

[0005] However, such braking systems can only be used effectively with underwater turbines that have a gearbox, as the torques upstream of the gearbox are too high for such a braking system. The gearbox translates the slow rotation of the rotor shaft into a fast rotation of the gearbox output shaft, which in turn drives a generator rotor to produce electricity.

[0006] One disadvantage of such systems is that the brake discs are subject to high wear and often need to be replaced, thus requiring further maintenance. Another disadvantage is that no maintenance is possible if the brake system fails. Furthermore, no maintenance work can be carried out on the gearbox itself, and in the event of a gearbox failure, there is no way to stop the rotor. 2024P00088DE

[0007] Furthermore, to service the rotor shaft or perform other maintenance tasks inside the nacelle, it must be ensured that the drive train is stationary to prevent injury to maintenance personnel. Particularly during offshore maintenance work, it is a well-known problem that wave motion and other environmental factors pose a significant health risk to maintenance personnel if the rotor or rotor shaft moves even minimally. The locking effect of a purely friction-based braking unit is therefore often insufficient.

[0008] It is known to connect the rotor hub to the nacelle in a rotationally fixed manner using a mechanical locking bolt, or to provide additional locking elements on the braking system, with the locking bolts engaging in correspondingly provided receptacles. A problem with the known systems is that unavoidable rotational inaccuracies or imbalances of the rotor shaft can lead to a slight misalignment of the locking bolts and receptacles. Furthermore, for example, heavy seas can cause radial and / or axial displacements of the rotor blade shaft, which can also lead to misalignment of the locking bolts and receptacles. This, in turn, can damage the locking device, cause it to jam, or lead to the failure of the entire locking device.

[0009] The object of the present invention is therefore to provide an underwater turbine that can be serviced easily and safely even underwater.

[0010] This problem is solved by an underwater turbine according to claim 1.

[0011] The following describes an underwater turbine, in particular an underwater turbine of a tidal power plant, wherein the underwater turbine has at least one rotor shaft which is rotatably connected at one end to a rotatable rotor hub carrying rotor blades and extends at its other end into a stationary housing of the underwater turbine, in particular a nacelle of the tidal power plant.

[0012] Furthermore, the rotor shaft is rotatably mounted in the stationary housing by means of a rotor shaft bearing assembly, wherein the rotor shaft bearing assembly is received in a bearing housing that can be connected to the stationary housing of the underwater turbine or that forms part of the stationary housing of the underwater turbine. 2024P00088DE

[0013] To enable on-site maintenance of the underwater turbine, i.e., underwater or at the water's surface, and to allow maintenance of all drivetrain components, while ensuring that this is possible even under adverse maintenance conditions, an underwater turbine is proposed in which the turbine incorporates a positive-locking rotor rotation lock within its stationary casing. The rotor rotation lock comprises a rotatable element, a stationary element, and at least one locking element interacting with a receptacle. The locking element can be moved from a locked position, in which it engages with the receptacle and prevents rotation of the rotor shaft, to a free position, in which it engages with the receptacle and allows rotation of the rotor shaft.

[0014] In other words, the interaction between the locking element and its receptacle creates a positive locking mechanism that prevents the rotor shaft from rotating. This positive engagement ensures that the rotor shaft, and therefore the rotor itself, comes to a complete standstill. This allows the rotor rotation lock to be used not only to ensure safe working conditions but also to hold the rotor in specific positions, preventing collisions between the rotor blades and other objects such as the seabed, floating ice floes, or passing ships. Furthermore, it allows for maintenance on an optional gearbox.

[0015] Furthermore, the rotor shaft bearing arrangement is secured in its axial position by means of a retaining ring which is non-rotatably connected to the rotor shaft, and the rotatable element is designed as a radially extending support element which is non-rotatably connected radially inside to the retaining ring.

[0016] This ensures that even minor misalignments of the locking bolts and their receptacles cannot occur in the event of unavoidable rotational inaccuracies or imbalances of the rotor shaft. Furthermore, the retaining ring prevents radial and / or axial displacements of the rotor blade shaft, which can also lead to misalignment of the locking bolts and receptacles, for example, in heavy seas. 2024P00088DE

[0017] Recordings would be made. This, in turn, ensures that the locking device is not damaged, jammed, or fails completely.

[0018] According to a further advantageous embodiment, the retaining ring is designed to apply a preload force to the rotor shaft bearing assembly. This eliminates the need for an additional element for preloading the rotor shaft bearing assembly. Furthermore, the retaining ring acts directly on the rotor shaft bearing assembly, preventing radial and / or axial displacement of the rotor blade shaft, for example, in heavy seas.

[0019] Furthermore, an exemplary embodiment is advantageous in which the rotor shaft bearing arrangement comprises at least a first bearing unit facing the rotor hub and a second bearing unit facing the nacelle, each bearing unit comprising an inner ring and an outer ring, and the retaining ring being in contact with the inner ring of the second bearing unit. Such a design allows adjustment of the clamping force applied by the retaining ring to the rotor shaft bearing arrangement even after the underwater turbine has been in operation, since the retaining ring is accessible from the nacelle. This allows fine adjustments to be made after the bearing units have run in, or wear-related changes in clearance to be compensated for.

[0020] According to a further advantageous embodiment, the rotor shaft bearing arrangement comprises a first, single-row tapered roller bearing unit facing the rotor hub and a second, single-row tapered roller bearing unit facing the nacelle, arranged in an O-arrangement. Tapered roller bearings can withstand high forces but must be precisely preloaded for optimal operation. Such preloading can be achieved directly with the aid of the retaining ring without the need for any additional components.

[0021] Of course, it would also be possible to provide an additional preload ring.

[0022] The design of the rotor shaft bearing arrangement as two tapered roller bearing units also enables the shaft to be supported with virtually no radial or axial runout, which ensures that no or only minimal movements occur on the shaft, especially under adverse weather conditions. Furthermore, the choice of the type of rotor shaft bearing arrangement 2024P00088DE ensures that the locking elements can be precisely aligned with each other, which in turn prevents damage or jamming of the rotor rotation lock.

[0023] It is particularly advantageous if the tapered roller bearing units are designed as two single-row tapered roller bearings in an O-arrangement. The O-arrangement allows the tapered roller bearing units to absorb not only high radial loads but also axial forces from both directions, thus minimizing radial and / or axial runout of the rotor shaft. This results in exceptionally stable rotor shaft support under all operating and environmental conditions, which in turn ensures trouble-free operation of the rotor rotation lock.

[0024] According to a further advantageous embodiment, the retaining ring has a radially extending section and an axially extending section, the axially extending section being designed to axially secure the rotor shaft bearing assembly. The radial section, on the other hand, provides a mounting option for components of the rotor rotation lock. Due to the angled design of the retaining ring, it can be adapted to various rotor shaft bearing arrangements and preload conditions. This allows the entire rotor rotation lock concept and design to be adapted to different bearing types and sizes. Furthermore, if necessary, a simple replacement of the retaining ring allows, for example, wear-related preload changes to be compensated for without replacing the entire rotor shaft bearing assembly.

[0025] It is particularly advantageous if the rotor shaft has a step at which it reduces from a first rotor blade-side diameter to a nacelle-side diameter. Preferably, the mounting ring is arranged at this step and extends radially inwards with its radial section. This allows the mounting ring to be attached directly to the rotor shaft, in particular by screwing it on.

[0026] This design also allows the support element to be attached to the mounting ring on a different diameter, which simplifies the fastening itself and also distributes the force on the mounting ring to different points.

[0027] According to a further preferred embodiment, the radially extending support element has at least one receptacle on its radial outer side, which can be engaged with the locking element. By arranging the receptacles radially outward, it can be ensured that the support element can decelerate and support even large torques without being excessively large.

[0028] In particular, the positive-locking design of the rotor rotation lock allows the rotor rotation lock to be attached directly to the rotor shaft via the carrier element or to the mounting ring, since the positive-locking engagement between the locking element and the mounting is also suitable for absorbing the high torque forces of the slowly rotating rotor shaft.

[0029] Furthermore, the radially extending support element can also have an axial extension to bridge a gap between the stationary (bearing housing) and the rotating (support element) part. A dished shape can be chosen for this purpose.

[0030] Furthermore, an embodiment is preferred in which the radially extending support element is designed in the shape of an annular disk.

[0031] The ring-shaped design allows for particularly good torque absorption and at the same time the formation of evenly distributed mounting points around the circumference, so that the rotor shaft can be fixed at certain preset positions.

[0032] With locking elements / receptacles evenly distributed around the circumference, the force can be distributed evenly across the locking elements, resulting in a uniform shear force. The geometric arrangement of the locking elements can be, for example, symmetrical at 90 degrees when using 4 locking elements / receptacles, or at 60 degrees when using 6 locking elements. As mentioned above, the locking elements are preferably evenly distributed around the circumference, resulting in a symmetrical design of the support element with equal mass proportions and low imbalance during rotation. The support element can have the same number of receptacles and locking elements, or it can be equipped with more receptacles than locking elements.

[0033] Furthermore, the locking elements can also be distributed unevenly around the circumference. In this case, it is preferable to provide additional balancing weights on the support element to counteract the imbalance.

[0034] Furthermore, it is advantageous if the radially extending support element has at least one recess designed to allow access to an adjacent component of the underwater turbine. With an annular disk-shaped design of the support element, a component located behind or adjacent to it is largely covered. The recesses are provided to nevertheless allow access to this component or parts thereof. Instead of an annular disk shape, the support element can, of course, also have an oval or rectangular shape. Preferably, a central feature, for example an opening, is provided for attaching the support element to the rotor shaft. Another embodiment shows that the support element can also be designed with multiple parts.

[0035] The support element preferably has a cross shape, which, in the case of a two-bladed rotor, allows for vertical and / or horizontal mounting of the rotor blades. In the case of a three-bladed rotor, the support element can have six support arms, each spaced 60° apart.

[0036] According to a further preferred embodiment, the receptacle cooperating with the locking element is equipped with a centering disc which is attached to the element forming the receptacle by means of fastening elements.

[0037] The centering disc preferably has a central bore, with the aid of which a preferably vertical or horizontal rotor blade locking is achieved.

[0038] Providing a centering disc has the further advantage that one or more or all of the centering discs can easily be replaced with a centering disc that has an eccentric bore instead of a central one. 2024P00088DE

[0039] This allows a rotor blade locking mechanism to be shifted by + / - 2 degrees relative to the aforementioned vertical or horizontal orientation. This variant has the advantage of enabling different angular positions within a small angular range for specific assembly, repair work, or transport.

[0040] Of course, it is also possible to design the entire mounting as a central or eccentric bore. In this case, an additional centering washer is not required.

[0041] Furthermore, a preferred embodiment is one in which the locking element is arranged on or formed by the stationary element of the underwater turbine. Naturally, the receptacle could also be formed on the stationary element. In this case, the stationary element is attached to or within the stationary housing of the underwater turbine, or is formed by the stationary housing itself or a part thereof. The use of an existing stationary element, either attached to or formed by the stationary housing, enables a solution that can withstand the high torques without requiring the introduction of additional heavy-duty elements into the underwater turbine design.

[0042] It is particularly advantageous if the stationary element is formed by the bearing housing that accommodates the rotor shaft bearing assembly. The bearing housing is usually connectable to the stationary housing of the underwater turbine or is directly formed as part of the stationary housing.

[0043] Alternatively or additionally, the stationary element can also be formed by a gearbox housing of an optional gearbox present in the underwater turbine. Typically, an underwater turbine has a gearbox with at least one gearbox input shaft and one gearbox output shaft, which are enclosed in a gearbox housing to translate the slow rotation of the rotor shaft into a fast rotation of the gearbox output shaft, which in turn drives a generator rotor to produce electricity. Both housings, the bearing housing as well as the gearbox housing or the nacelle itself, have sufficient rigidity to support the high torques that must be absorbed by the rotor rotation lock.

[0044] The bearing housing itself can be designed as a separate component that can be connected to the stationary housing of the underwater turbine in a rotationally fixed manner. This allows the rotor shaft bearing assembly to be provided as a prefabricated element, which is then installed in the nacelle together with the rotor shaft. This enables bearing settings to be adjusted before installation, significantly simplifying assembly.

[0045] Alternatively, the bearing housing can also be integrally formed with the stationary housing of the underwater turbine. This allows for a particularly watertight underwater turbine, as there are no connection points between the bearing housing and the nacelle that need to be sealed against water ingress.

[0046] According to a further preferred embodiment, the stationary element, e.g., the bearing housing or the gearbox housing, has at least one recess in which the at least one locking element is slidably arranged. This allows actuating mechanisms that move the locking element to be easily arranged in the stationary element without the need for rotary feedthroughs or similar components to supply an actuating mechanism with, for example, electricity or a pressurized fluid. Furthermore, arranging the locking element in the stationary element provides a solution that can withstand high torques without requiring the inclusion of additional heavy-duty components in the underwater turbine design.

[0047] The locking element itself is preferably an electromechanically or hydraulically actuated bolt that is axially displaceable within the receptacle. Manual insertion and retraction of the bolt by hand, crank mechanism, or the like is also conceivable.

[0048] It is particularly advantageous if the locking element and the receptacle are designed to be complementary to each other. This allows for a particularly good fit of the locking element in the receptacle. It is especially preferred if the locking element and / or the receptacle have a conical shape. This ensures that even with slight misalignments of the locking element relative to the receptacle, the locking element can still be guided into the receptacle.

[0049] Naturally, the locking element and / or the receptacle can also have a cylindrical shape. This prevents any axial force from being exerted on the components during either retraction or locking.

[0050] According to a further preferred embodiment, several locking elements and / or receptacles are provided, wherein the locking elements and / or receptacles are evenly distributed. This allows the force exerted by the rotor shaft on the support element or the retaining ring during locking to be evenly distributed over the support element or the retaining ring.

[0051] According to a further advantageous embodiment, the rotation lock is designed to fix the rotor in one or more predetermined positions. For this purpose, several locking elements and / or several receptacles can be provided distributed around the circumference, defining corresponding angular positions at which the rotor can be fixed. It is also possible to provide a different number of locking elements and receptacles. For example, only two receptacles but four locking elements can be provided, so that the rotor can be fixed in an arrangement offset by 90° to each other. Of course, this can also be achieved with four receptacles and four locking elements, or with another configuration.

[0052] According to a further advantageous embodiment, the rotor rotation lock is further equipped with at least one sensor designed to detect the relative position between the locking element and the receptacle. This ensures that the locking element and the receptacle are correctly positioned relative to each other before the locking element is actuated and the receptacle is engaged. The sensor can, for example, be a position monitoring device, such as a camera. Another embodiment shows that the position monitoring device is designed using an angle position sensor, such as an encoder. 2024P00088DE

[0053] Furthermore, sensors may be present that detect the end position of the locking element, for example, whether the locking element is fully retracted into the receptacle. The sensor can be, for example, a limit switch or a proximity switch.

[0054] It is also advantageous if at least one speed monitoring device is provided, for example an encoder disk, designed to monitor the rotational speed of the rotor shaft and / or a gearbox input shaft and / or a gearbox output shaft and / or a generator rotor shaft. This ensures that the rotor rotation locking system is not activated when the rotor is rotating.

[0055] According to a further advantageous embodiment, in order to enable the locking element to engage in the receptacle, it is further provided that the rotor is slowed down in its rotational movement. This can be achieved, for example, by adjusting the rotor blades so that the flow cannot exert a rotational force on the rotor blades. Alternatively, in addition to the rotor rotation lock (rotor blades in the feathered position), a braking system can be provided in the underwater turbine that can slow the rotation of the rotor shaft to a standstill. Preferably, the braking system interacts with the rotor shaft (8), a gearbox input shaft, a gearbox output shaft, or a generator rotor shaft. The braking system can be designed as a separate braking system, such as a brake disc, or the generator can be operated in such a way that it slows the rotation of the rotor shaft to a standstill.With the help of all these braking systems, it can also be ensured that the mounting and the locking elements are aligned. This is particularly advantageous when a specific parking position of the rotor needs to be achieved, for example, to prevent damage from the seabed, ice floes, or passing ships.

[0056] Further advantages and advantageous embodiments are specified in the description, the drawings, and the claims. In particular, the combinations of features specified in the description and the drawings are purely exemplary, so that the features may also exist individually or in different combinations. 2024P00088DE

[0057] The invention will now be described in more detail with reference to exemplary embodiments illustrated in the drawings. These exemplary embodiments and the combinations shown in them are purely illustrative and do not define the scope of protection of the invention. The scope of protection is defined solely by the pending claims.

[0058] They show:

[0059] Fig. 1: a schematic sectional view through an underwater turbine according to a preferred embodiment;

[0060] Fig. 2: a schematic sectional view through another preferred embodiment;

[0061] Fig. 3: a schematic perspective view of an exemplary embodiment;

[0062] Fig. 4: a schematic top view of a detail of Fig. 2 or 3;

[0063] Fig. 5a, b: schematic sectional views through another preferred embodiment;

[0064] Fig. 6: a schematic sectional view through an underwater turbine according to a further preferred embodiment; and

[0065] Fig. 7a, b: schematic sectional views through another preferred embodiment.

[0066] In the following, identical or functionally equivalent elements are marked with the same reference symbols.

[0067] Figure 1 schematically shows a preferred embodiment of an underwater turbine 100 with a nacelle 2, a rotor hub 4, and rotor blades 6 pivotally attached thereto. The rotor hub 4 is non-rotatably connected to a rotor shaft 8, which extends into the nacelle 2. The rotor shaft 8 is rotatably supported by a rotor shaft bearing unit 10, the bearing unit 10 being received by a bearing housing 12. The bearing housing 12 is usually non-rotatably attached to the nacelle 2, but can also be integrally formed with the nacelle 2. Figure 1 also shows that further elements, such as a gearbox 14 and a generator 16, can be provided in the nacelle 2. The gearbox 14 serves to translate the slow rotation of the rotor shaft 8 into a high-speed rotation of a gearbox output shaft, which drives the rotor of the generator 16 to generate electricity.

[0068] Alternatively, a slow-running ring generator can be used. In this case, a gearbox 14 can be omitted.

[0069] A coupling 18 connects one end of the rotor shaft 8 to the gearbox 14, or in the case of a slow-running ring generator, the rotor shaft 8 is directly connected to the slow-running ring generator 16.

[0070] Figure 1 further shows that a rotor rotation lock 20 is provided in the housing 2. The rotor rotation lock 20 has a radially extending support element 22, which is fixedly attached to the rotor shaft 8. For this purpose, the support element 22 is fastened to a mounting ring 50 by means of fastening elements 54. The mounting ring 50 surrounds the rotor shaft 8 and also secures and preloads the rotor shaft bearing unit 10. At its radially outer edge, the support element 22 also has receptacles 26 that can engage with locking elements 28 to fix the rotor shaft 8 in a specific position. The locking elements 28 are supported by the bearing housing 12, so that the rotor rotation lock 20 interacts with the bearing housing 12 to prevent rotation of the rotor shaft 8.

[0071] Alternatively, the rotor rotation lock 20, as shown in Figures 6 and 7, can also interact with a gearbox housing 30 of the gearbox 14. In this embodiment, the locking elements 28 are supported by a gearbox housing 30 and engage with the support element 22 from the gearbox side.

[0072] Figures 2 to 5 show sectional views through and perspective views, respectively, of embodiments in which the rotation lock 20 interacts with the bearing housing 12. Figure 2 shows a sectional view through and Figure 3 a perspective view of the bearing housing 12 and the rotor shaft bearing unit 10, which is designed as a tapered roller bearing. Figure 4 shows a top view of a detail from Figures 2 and 3. 2024P00088DE

[0073] Fig. 5 shows in particular the operation of the locking elements 28, with subfigure 5a showing a situation in which the rotor shaft 8 is rotatable, while subfigure 5b shows the locked position.

[0074] All features of the views can also be implemented additionally or alternatively in the embodiments shown in the respective other views. Figures 6 and 7 each show embodiments in which the rotation lock interacts not with the bearing housing 12, but with the gearbox housing 30. Partial figure 7a shows a situation in which the rotor shaft 8 is rotatable, while partial figure 7b shows the locked position.

[0075] The sectional view of Figures 2 and 3 and the perspective view of Fig. 4 show a rotation lock 20 which, as shown in Figure 1, interacts with the bearing housing 12, while the sectional view of Fig. 6 shows a rotation lock which interacts with the gearbox housing.

[0076] As can be seen in Figures 2 to 5, the bearing housing 12 is sealed and rotationally fixed to the stationary housing 2 and has the bearing unit 10 on its radially inner side to rotatably support the rotor shaft 8. The rotor shaft 8 extends through the bearing housing 12 into the nacelle 2 and is rotationally fixed at its end, which is received in the gearbox housing 30, to a gearbox input shaft 32 or, in the case of a slow-running ring generator without a gearbox 14, to a rotor shaft of the ring generator. The gearbox 14 and the generator 16 are not shown further.

[0077] Figures 2 to 5 further show that the disc-shaped support 22 is fixed to the rotor shaft 8, more precisely to a coupling element 18 that is non-rotatably connected to it. This non-rotatable connection can, for example, be achieved via a toothed connection. The figures also show that the support element 22 has receptacles 26 which interact with locking elements 28.

[0078] The rotor shaft 8 itself is, as can be seen in Fig. 2, supported by means of two tapered roller bearing units 10-1, 10-2, wherein the tapered roller bearing units 10-1, 10-2 are in O- 2024P00088DE

[0079] The arrangement is shown in Fig. 2. Furthermore, Fig. 2 shows that the tapered roller bearing units 10-1, 10-2 are designed as a single-row tapered roller bearing unit 10.

[0080] The tapered roller bearing units 10 are preloaded by means of a retaining ring 50, which is attached to the rotor shaft 8 by screws 52. This ensures that the bearing units 10 have virtually no radial or axial runout at the rotor shaft end 8. This, in turn, guarantees the functionality of the rotor rotation lock even under adverse conditions, allowing the locking elements 28 to engage in the receptacles 26. The retaining ring 50 further comprises a radially extending section 56 and an axially extending section 58, the axially extending section 58 being designed to axially secure the rotor shaft bearing assembly 10. The angled design of the retaining ring 50 allows it to be adapted to various rotor shaft bearing arrangements and preload conditions.This allows the entire rotor rotation locking concept and design to be adapted to different bearing types and sizes. Uniformity can be achieved, if necessary, by simply replacing the retaining ring 50, so that, for example, a wear-related change in preload can be compensated for via the retaining ring without replacing the entire rotor shaft bearing.

[0081] The support element 22 is attached to the mounting ring 50 by means of fasteners 54, as shown in Fig. 2. The mounting ring 50 prevents radial and / or axial displacements of the rotor blade shaft 8, for example in heavy seas, which would lead to misalignment of the locking elements 28 with respect to the receptacles 26. Thus, mounting the support element 22 to the mounting ring 50 ensures that the rotor rotation lock 20 is not damaged, that the locking elements 28 do not jam, and that the entire rotor rotation lock 20 does not fail.

[0082] In the illustrated embodiment of Fig. 2, the receptacles 26 are equipped with or formed over centering discs 60, which can be inserted into corresponding openings on the support element 22. The centering disc 60 can have a central bore 62, as shown in Figs. 2 and 3; however, it is also possible for the centering disc 60 to have eccentric bores 64, as can be seen in the detail view of Fig. 4. The centering disc 60 can also be fastened to the support element 22 by means of screws 66, as shown in Fig. 2024P00088DE; however, other fastening options are also conceivable.

[0083] The receptacle 26 provided by the centering disc 60 is preferably conical, as shown in Fig. 2. This allows for a uniform distribution of force on the locking elements when the locking element 28 is inserted into the conical receptacle of the support element 22, which in turn results in a uniform shear force being exerted on them, thus increasing their service life.

[0084] Furthermore, the conical receptacle 26 allows the locking elements 28 to engage even with a slight misalignment of the angular position of the shaft 8, since the locking elements 28, the receptacle 26 and the centering disc 60 align themselves to each other via the conical shape.

[0085] The geometric arrangement of the locking elements 28 can be, for example, symmetrical at 90 degrees when using 4 locking elements, as shown in Fig. 3. Alternatively, a 60-degree arrangement, for example when using 6 locking elements 28, can also be advantageous. The locking elements 28 are preferably evenly distributed around the circumference, resulting in a symmetrical construction of the support element 22 with equal mass proportions and low imbalance during rotation. However, the locking elements 28 can also be unevenly distributed around the circumference if the installation situation and operation require it. In this case, it is advantageous to provide additional balancing weights to avoid mass imbalance.

[0086] As mentioned above, the centering disc 60 can have eccentric bores 64 instead of a central bore 62. The eccentric bores 64 allow for an exceptional rotor blade locking mechanism, which is, for example, offset by + / - 2 degrees relative to the aforementioned vertical or horizontal orientation. This variant serves to enable different angular positions within a small angular distance for special assembly, repair work, or transport.

[0087] In the embodiments shown in Figures 2 to 7, the locking elements 28 are equipped as hydraulically actuated bolts 36, wherein the bolts 36 can be moved from a retracted position (see Figures 5a and 7a) to an extended position (see Figures 5b and 7b). For this purpose, for example, as shown in Figures 5 and 7, a working chamber 38 can be pressurized with hydraulic fluid to move the bolt 36 into its extended position. In its extended position, the locking position, the bolt 36 engages in the receptacle 26 and thus prevents rotation of the rotor shaft 8.

[0088] Furthermore, as can be seen from the embodiments shown in Figures 2 to 7, the bolt 36 has a conical shape, thus facilitating easier insertion into the recess 26. Likewise, even if, as shown in the embodiment of Figure 5, no centering disc 60 is provided, the receptacle 26 can also be slightly conical, thereby also enabling easy insertion of the bolt 36 into the receptacle.

[0089] In all embodiments, sensors and actuators 40; 42, which may be provided on the locking system, can be used to detect the position between bolt 36 and receptacle 26 and to ensure that receptacle 26 and bolt 36 are aligned before the bolt 36 is moved. Furthermore, the sensors and actuators can be used to detect whether and to what extent a bolt 36 is received in the receptacle 26. For example, sensor 42 can be used to detect a respective end position of the bolt 36 in the receptacle 26, wherein a first end position allows free rotation of the rotor shaft 8, while the second end position defines a locking of the rotor shaft 8.

[0090] Furthermore, the embodiment shown in Figures 2 to 5 shows that additional recesses 44 are provided in the support element 22. These recesses 44 serve as maintenance openings, for example to replace and / or maintain elements of the bearing 10 arranged below, such as a seal or another component.

[0091] To enable the locking elements 28 to engage with the receptacle 26, a braking system 46 (see Figure 1) is preferably provided, which serves to decelerate the gearbox output shaft. This braking system 46 can also be used to set a specific position between the receptacle 26 and the locking element 28. Similarly, by rotating the rotor blades 6 using a rotor blade tilting system 48 (see Figure 1), it is possible to prevent the flow from exerting torque on the rotor shaft 8. This also allows for positioning between the receptacle 26 and the locking element 28. It is also possible to use the generator 16 as a corresponding actuating element.

[0092] Precise alignment between the receptacles 26 and the locking elements 28 is necessary because the force with which the bolts 36 engage in the receptacles 26 is very high in order to withstand the large forces acting on the rotor rotation lock 20. Only when precise alignment is achieved can the locking element 28 be engaged in the receptacle 26 without causing damage.

[0093] In the illustrated embodiments, the rotor rotation lock 20 has two receptacles 26 and two locking elements 28. Of course, it is also possible, as shown in the embodiment of Fig. 4, for four locking elements 28 and four receptacles 26 to be provided on the bearing housing 12 or on the support element 22. Thus, the support element 22 forms a support column, which has the receptacles 26 on its support arms, which are also equipped with centering discs 60.

[0094] However, it is also possible to provide several widely distributed locking elements 28, while the support element, for example, as shown in the embodiments of Figures 1 and 6, has only two receptacles, so that the rotor can be stopped at several angular positions. For example, the bearing housing 12 can have four, six, or eight locking elements 28, each of which can interact with two receptacles of the support element 22. Alternatively, it is of course also possible to design the support element 22 as a circular disk with several receptacles at its outer edges into which the locking elements can engage.

[0095] As an alternative to the embodiments shown here, it is of course also possible for the support element 22 to carry the locking elements 28, which in turn engage with receptacles on the bearing housing 12 and / or a gearbox housing. It is also conceivable that not only one rotor rotation lock 20 can be provided, but several; for example, one rotation lock could interact with the bearing housing 12 and another rotation lock with the gearbox housing.

[0096] If a gearbox or generator change should later become necessary during the offshore operation of a floating tidal turbine, the main components can be removed from "aft" - i.e. from the stern, for example via a vertical lift with an offshore ship crane, due to the arrangement of the rotor rotation lock 20 directly on the rotor shaft 8.

[0097] The rotor shaft bearing unit 10, comprising rotor shaft 8, rotor hub 4, and rotor blades 6, can remain permanently installed in the underwater turbine 100. The rotor shaft 8 remains securely locked to the support element 22 with the locking element 28 and does not rotate. In the illustrated embodiment of Fig. 1, the support element 22 is firmly connected to the mounting ring 50 by means of circumferential screws 52 (see Fig. 2).

[0098] When the locking elements 28 are actuated during repairs, the rotor shaft 8 remains locked, the clutch 18 can be released, and the gearbox 14 or generator 16 can be axially detached and slid backwards as a first step. The removal of the main components is therefore safe, and rotating gearbox parts or a mechanical brake 46, i.e., a high-speed shaft with a brake disc, pose no danger to the technician.

[0099] Replacing the gearbox via the nacelle's rear extension is therefore possible and fundamentally similar to replacing the gearbox of a wind turbine. This saves the costs and effort of a complex bow-side (front) removal on land or in a ship's dry dock.

[0100] Overall, the rotor rotation lock 20 shown here for an underwater turbine 100 enables the rotor shaft 8 to be securely and reliably locked in a specific position. This allows, firstly, for safe maintenance inside the underwater turbine 100 and, secondly, for the secure and predetermined locking of the rotor blades 6 in a predetermined position. Furthermore, the rotor rotation lock 20 presented here also allows maintenance on other components, such as the gearbox 14, the generator 16, or the brake 46. 2024P00088DE

[0101] Reference symbol list

[0102] 100 underwater turbines

[0103] 2 gondolas, housing

[0104] 4 Rotor hub

[0105] 6 rotor blades

[0106] 8 Rotor shaft

[0107] 10 Rotor shaft bearing unit

[0108] 12 bearing housings

[0109] 14 gearboxes

[0110] 16 Generator

[0111] 18 Clutch

[0112] 20 Rotor rotation lock

[0113] 22 Support element

[0114] 26 recordings

[0115] 28 locking elements

[0116] 30 Gearbox housings

[0117] 32 Gearbox input shaft

[0118] 36 bolts

[0119] 38 workroom

[0120] 40; 42 Sensors and actuators

[0121] 44 cutouts

[0122] 46 Braking system

[0123] 48 Rotor blade swivel system

[0124] 50 fastening rings

[0125] 52 Fasteners

[0126] 54 Fasteners

[0127] 56 radial section of the mounting ring

[0128] 58 axial section of the mounting ring

[0129] 60 Centering disc

[0130] 62 centric bore

[0131] 64 eccentric bore

[0132] 66 screws

Claims

2024P00088DE P a t e n t a n s p r ü c h e Unterwasserturbine 1. Underwater turbine (100), in particular an underwater turbine (100) of a tidal power plant, with at least one rotor shaft (8), wherein the rotor shaft (8) is rotatably connected at one end to a rotatable rotor hub (4) supporting rotor blades (6) and extends at its other end into a stationary housing of the underwater turbine (100), in particular a nacelle (2) of the tidal power plant, wherein the rotor shaft (8) is rotatably mounted in the stationary housing by means of a rotor shaft bearing arrangement (10), and wherein the rotor shaft bearing arrangement is received in a bearing housing (12) which is connectable to the stationary housing of the underwater turbine (100) or which forms part of the stationary housing of the underwater turbine (100), characterized in that the underwater turbine (100) has a positive-locking rotor rotation lock (20) inside its stationary housing, wherein the rotor rotation lock (20) rotatable element,a stationary element, and at least one locking element (28) cooperating with a receptacle, wherein the locking element (28) can be moved from a locking position in which the locking element (28) engages with the receptacle and prevents rotation of the rotor shaft (8) to a free position in which the locking element disengages from the receptacle and allows rotation of the rotor shaft (8), wherein the rotor shaft bearing arrangement is further secured in its axial position by means of a retaining ring (50) which is rotationally fixed to the rotor shaft (8), and wherein the rotatable element is designed as a radially extending support element (22) which is radially internally rotationally fixed to the retaining ring (50).

2. Underwater turbine (100) according to claim 1, wherein the retaining ring (50) is designed to apply a preload force to the rotor shaft bearing arrangement. 2024P00088DE 3. Underwater turbine (100) according to claim 1 or 2, wherein the rotor shaft bearing arrangement (10) comprises at least a first bearing unit facing the rotor hub and a second bearing unit facing the nacelle, wherein each bearing unit comprises an inner ring and an outer ring, and wherein the retaining ring (50) is in contact with the inner ring of the second bearing unit.

4. Underwater turbine (100) according to one of the preceding claims, wherein the rotor shaft bearing arrangement (10) comprises a first single-row tapered roller bearing unit facing the rotor hub and a second single-row tapered roller bearing unit facing the nacelle, arranged in an O-arrangement.

5. Underwater turbine (100) according to one of the preceding claims, wherein the retaining ring (50) has a radially extending section (56) and an axially extending section (58), wherein the axially extending section (58) is designed to axially secure the rotor shaft bearing arrangement (10).

6. Underwater turbine (100) according to one of the preceding claims, wherein the radially extending support element (22) has at least one receptacle (26) radially outside which can be engaged with the locking element (28).

7. Underwater turbine (100) according to one of the preceding claims, wherein the radially extending support element (22) is designed in an annular disk shape and has at least one recess (44) designed to allow access to an adjacent component of the underwater turbine (100).

8. Underwater turbine according to one of the preceding claims, wherein the receptacle (26) cooperating with the locking element (28) is equipped with a centering disk (60) which is attached to the element forming the receptacle by means of fastening elements (66).

9. Underwater turbine (100) according to one of the preceding claims, wherein the receptacle (26) and / or the centering disk (60) has a central or an eccentric bore (62; 64).

10. Underwater turbine (100) according to one of the preceding claims, wherein the at least one locking element (28) is arranged on the stationary element, the stationary element being the bearing housing (12) or a gearbox housing (30). 2024P00088DE 11. Underwater turbine (100) according to one of the preceding claims, wherein the locking element (28) and the receptacle (26) are shaped complementarily to each other, wherein in particular the locking element (28) and / or the receptacle (26) have a conical and / or a cylindrical shape.

12. Underwater turbine (100) according to one of the preceding claims, wherein one or more sensor(s) (40; 42), in particular a position monitoring device, is further provided, which is designed to monitor a position of the locking element (28) and / or the receptacle (26), and / or one or more speed monitoring device(s), in particular an encoder, is provided, which is designed to monitor a rotational speed of the rotor shaft (8) and / or a gearbox input shaft (32) and / or a gearbox output shaft (18) and / or a rotor shaft of a generator (16).

13. Underwater turbine (100) according to one of the preceding claims, wherein a braking system (46) is further provided which is designed to slow down the rotation of the rotor shaft (8), wherein the braking system (46) preferably interacts with the rotor shaft (8) or a transmission input shaft (32) or a transmission output shaft or a rotor shaft of a generator (16).

Images