FIN STABILIZER, A VIBRATION DAMPING ELEMENT AND A WATERCRAFT

Abstract

A fin stabilizer is provided for roll stabilization of a watercraft. The fin stabilizer includes a drive unit connected in a vibration-damping manner to a ship's structure. Specifically, a vibration damping element is provided between the drive unit and the hull of the watercraft wall such that a mounting portion of the drive unit is spaced from an attachment portion of the hull wall.

Claims

1. A fin stabilizer for roll stabilization of a watercraft, the watercraft having a hull wall with an attachment portion, the fin stabilizer comprising: a rotatably mounted stabilizer fin; a drive unit for changing an angle of attack of the stabilizer fin and having a mounting portion fastenable to the attachment portion on the hull wall; and at least one vibration damping element arranged between the mounting portion of the drive unit and the attachment portion of the hull wall such that the mounting portion is spaced from the attachment portion.

2. The fin stabilizer according to claim 1, wherein the at least one vibration damping element includes a plurality of vibration damping elements.

3. The fin stabilizer according to claim 2, wherein each one of the plurality of vibration damping elements has an outer part releasably connected to the mounting portion of the drive unit and an inner part connected to the attachment portion of the hull wall.

4. The fin stabilizer according to claim 3, wherein the outer part of each vibration damping element is formed of a material having a greater hardness than a material of the inner part.

5. The fin stabilizer according to claim 2, wherein the mounting portion of the drive unit has a plurality of apertures and each one the plurality of vibration damping elements is inserted through a separate one of the plurality of the apertures of the mounting portion.

6. The fin stabilizer according to claim 2, wherein each one of the plurality of vibration damping elements is individually removable while the mounting portion of the drive unit is mounted to the attachment portion of the hull wall.

7. The fin stabilizer according to claim 6, wherein the outer part of each one of the plurality of vibration damping elements has a rotationally asymmetrical outer contour and each one of the plurality of apertures has a rotationally asymmetrical inner contour.

8. The fin stabilizer according to claim 2, wherein a separate one of a plurality of fastening screws extends through each one of the plurality of vibration damping elements and is engaged with a separate one of a plurality of threaded holes of the attachment portion of the hull wall.

9. A vibration damping element for a fin stabilizer according to claim 1, wherein the vibration damping element has an outer part for attachment to the mounting portion of the drive unit and an inner part for attachment to an attachment portion of the hull wall, wherein the inner part of the vibration damping element or the outer part of the vibration damping element has vibration-damping properties.

10. A watercraft having a fin stabilizer according to claim 1.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0018] Preferred exemplary embodiments of the fin stabilizer according to the invention are explained in greater detail below with reference to greatly simplified figures. More specifically:

[0019] FIG. 1 is a partial longitudinal cross-section through a fin stabilizer according to the invention for a watercraft;

[0020] FIG. 2 is a perspective front sectional view of a first exemplary embodiment of the fin stabilizer;

[0021] FIG. 3 is a perspective rear sectional view of a first exemplary embodiment of the fin stabilizer; and

[0022] FIG. 4 is a schematic illustration of a partial overlap between an inserted vibration damping element and a mounting portion receiving it in a second exemplary embodiment of the fin stabilizer.

DETAILED DESCRIPTION OF THE INVENTION

[0023] FIG. 1 shows a partial region of a fin stabilizer 1 according to the present invention, shown in longitudinal section. The fin stabilizer 1 is used for the roll stabilization of a watercraft, such as a freighter or a yacht, both underway or at anchor.

[0024] The fin stabilizer 1 includes a stabilizer fin 2 with a fin shaft 4 and a drive unit 6. In addition, the fin stabilizer 1 has a coupling (not shown), a fixing device for securing the stabilizer fin 2 at an angle of attack and an open-loop and closed-loop control device (not shown).

[0025] The stabilizer fin 2 is connected positively, non-positively and/or frictionally to a driven shaft of the drive unit 6 by the fin shaft 4 and the coupling. The coupling is, for example, a clamp coupling, a steel multi-plate clutch, etc., and the driven shaft in the example shown here is a transmission output shaft of a transmission 8 of the drive unit 6. A drive of the drive unit 6 can be of hydraulic or purely electric design, for example, being designed as an electric motor. The transmission 8 is interposed in the drive. However, it is also conceivable to dispense entirely with the transmission 8, for example if the electric motor is embodied as a high-torque synchronous motor with a large number of poles.

[0026] The fin shaft 4 extends through a holder tube 10 and is mounted rotatably about a longitudinal axis through the tube 10 by means of bearing assemblies (not shown). For example, the bearing assembly may include a rolling bearing assembly and a water-tight sliding seal assembly. The rolling bearing assembly is, for example, a two-row self-aligning barrel roller bearing and is arranged remote from the water, namely proximal to the coupling. The sliding seal is arranged close to the water, namely remote from the coupling. As such, the seal prevents penetration of seawater into an annular space (not indicated) between the holder tube 10 and the fin shaft 4 and thus protects the rolling bearing from the water.

[0027] The holder tube 10 itself is guided axially by a carrier tube 12, which extends through a section of an external skin or a hull wall 14 on the water side and is firmly connected in a manner secure against rotation, preferably welded, to the hull wall 14. With its end within the hull, the carrier tube 12 forms a flange 16, to which the holder tube 10 is attached, e.g. screwed, by means of its outer shoulder 18.

[0028] To attach the drive unit 6, in this case the transmission 8, to the holder tube 10 so as to be mounted in a manner secure against rotation, the holder tube 10 has an attachment flange or attachment portion 20 at its end within the hull. The transmission 8 has a corresponding mounting flange or mounting portion 22. Attachment of the transmission 8 to the holder tube 10 is accomplished by means of a multiplicity or plurality of two-part screwed joints.

[0029] According to the present invention, the mounting portion 22 and the attachment portion 20 are not in direct physical contact but are instead in contact by means of a plurality of vibration damping elements 24 arranged between the mounting portion 22 and the attachment portion 20 in the manner of spacers. Preferably, each screwed joint is assigned or includes one vibration damping element 24.

[0030] Exemplary vibration damping elements 24, including the screwed joints, are shown in FIGS. 2 and 3.

[0031] The vibration damping elements 24 are preferably of identical design or identically formed. The vibration damping elements 24 each have an outer part 26 which rests from a rear against the mounting flange 22 (i.e., the first screwed joint part), and an inner part 28, which extends axially through apertures 30 (preferably each formed as circular hole) in the mounting flange 22 and is penetrated by an axial fastening screw 32. Each fastening screw 32 engages in a corresponding internally threaded hole 34 in the attachment flange 20 (i.e., the second screwed joint part). In the screwed state, each vibration damping element 24 is clamped by means of the threaded engagement between the hull-side attachment flange 20 and a respective screw head 36, with the result that the end of the respective inner part 28 of the vibration damping elements 24 is pressed against the attachment portion 20. For uniform introduction of a screwing force, washers (not shown) are preferably arranged under the screw heads 36, the washers completely covering the ends of the inner parts 28.

[0032] In the exemplary embodiment shown in FIGS. 2 and 3, the respective outer part 26 is an annular flange, which rests against the rear of the mounting flange 22 by means of a multiplicity or plurality of screws (none shown). The outer part 26 preferably consists of (i.e., is formed of) a relatively harder material than a material of the inner part 28. Examples of such relatively harder materials of the outer part 26 are metals or metal alloys and the inner part 28 may be formed of an elastomeric material, as described below.

[0033] When viewed in a direction from the front to the rear (from the mounting portion 22 in the direction of the attachment flange 20), the respective inner part 28 has a conically widening or tapering shape. Each outer part 26 is arranged on a radially widest location of the inner part 28. The outer parts 26 each extend around and are integrally connected with the inner part 28, for example, by being adhesively bonded to or cast or molded to the inner part 28. Each inner part 28 consists of, or is formed of, a material that is relatively softer or less hard than the material of each outer part 26. The material of the inner part 28 provides a damping effect and may be, for example, a rubber-type material or an elastomer such as natural or synthetic rubber.

[0034] In order to enable the vibration damping elements 24 to be screwed to the mounting flange 22, the respective outer part 26 (annular flange) thereof has an outside diameter which is larger than an inside diameter of the circular apertures 30. For the removal of individual vibration damping elements 24 of the exemplary embodiment shown in FIGS. 2 and 3, e.g. in order to conduct an inspection, the entire mounting flange 22, and thus the entire transmission 8, must be removed. That is, in order to remove one vibration damping element 24, all the vibration damping elements 24 have to be removed.

[0035] In another exemplary embodiment shown in FIG. 4, the vibration damping elements 24 are removed and mounted individually from the front with the mounting portion 22 mounted on the transmission 8.

[0036] In this case, apertures 30 in the mounting portion 22 and outer parts 26 of the vibration damping elements 24 do not have a rotationally symmetrical contour as with the exemplary embodiment according to FIGS. 2 and 3, but instead have asymmetrical contours such that the outer part 26 can only be passed or inserted axially through each aperture 30 in a specific first alignment with respect thereto, and can only be placed or positioned into rear-side contact with the mounting flange 22 in a specific second alignment, which is different from the first alignment. In other words, after each outer part 26 passes through an aperture 30, the outer vibration damping element 24 must be rotated about its longitudinal axis in order to achieve the overlap between the outer part 26 and the mounting portion 22 to enable screw fastening in the region of overlapping body portions. In the depicted exemplary embodiment, the apertures 30 each have an oval inner contour and the outer parts 26 each have a corresponding oval outer contour. Illustrative alternative contours are diamond-like contours.

[0037] A disclosure is made herein of a fin stabilizer for roll stabilization of a watercraft, the drive unit of which is connected in a vibration-damping manner to a ship's structure, a vibration damping element and a watercraft.

[0038] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention.

[0039] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0040] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter. The invention is not restricted to the above-described embodiments, and may be varied within the scope of the following claims.

LIST OF REFERENCE SIGNS

[0041] 1 fin stabilizer [0042] 2 stabilizer fin [0043] 4 fin shaft [0044] 6 drive unit [0045] 8 transmission [0046] 10 holder tube [0047] 12 carrier tube [0048] 14 hull wall [0049] 16 flange (holder tube) [0050] 18 outer shoulder (carrier tube) [0051] 20 attachment flange/portion (hull-side) [0052] 22 mounting flange/portion (drive-side) [0053] 24 vibration damping element [0054] 26 outer part [0055] 28 inner part [0056] 30 aperture [0057] 32 fastening screw [0058] 34 internally threaded hole [0059] 36 screw head