FIN STABILIZER

Abstract

A fin stabilizer is for the roll-stabilizing of a watercraft in motion, at anchor, or at zero speed, including a shaft on which a stabilizing fin is disposed. The shaft is drivable by a drive unit for changing at least one angle of attack of the stabilizing fin in the water. A cross-sectional geometry of the stabilizing fin is changeable by at least one actuator, and the stabilizing fin forms a closed surface geometry. Due to the hydraulically effective cross-sectional geometry of the stabilizing fin, which cross-sectional geometry is largely changeable by at least one actuator, a significantly increased energy efficiency of the fin stabilizer results with a simultaneously improved stabilizing effect of the fin stabilizer, in particular with respect to suppressing rolling movements of the watercraft.

Claims

1. A fin stabilizer for the roll-stabilizing of a watercraft in motion, at anchor, or at zero speed, the fin stabilizer comprising: a shaft, a stabilizing fin disposed on the shaft and forming a closed surface geometry, a drive unit for driving the shaft and for changing at least one angle of attack of the stabilizing fin in the water, and at least one actuator configured to change a cross-sectional geometry of the stabilizing fin.

2. The fin stabilizer according to claim 1, wherein the stabilizing fin includes an inflow body and an outflow body arranged at a distance from the inflow body, the inflow body and the outflow body are being fixedly connected to each other by a connecting body disposed therebetween.

3. The fin stabilizer according to claim 2, wherein the connecting body is formed by at least one elastic deformation body.

4. The fin stabilizer according to claim 3, wherein the connecting body includes at least one support element having a bending stiffness significantly higher than a bending stiffness of the at least one elastic deformation body of the connecting body.

5. The fin stabilizer according to claim 2, wherein in an undeformed base state of the connecting body, a central plane of the inflow body, a central plane of the outflow body, and a central plane of the connecting body extend essentially in one base plane.

6. The fin stabilizer according to claim 5, wherein the inflow body and the outflow body are connected to each other by the connecting body such that in a deformation state of the connecting body, an outflow angle is defined between the central plane of the outflow body and the central plane of the inflow body.

7. The fin stabilizer according to claim 2, wherein the at least one actuator is integrated into the inflow body.

8. The fin stabilizer according to claim 7, wherein the at least one actuator is connected to the outflow body by at least one coupling link.

9. The fin stabilizer according to claim 8, wherein a first end of the coupling link is connected to the at least one actuator and a second end of the coupling link is connected to the outflow body outside the central plane of the outflow body.

10. The fin stabilizer according to claim 2, wherein the at least one actuator is configured to change at least one outflow angle between a central plane of the outflow body and a central plane of the inflow body.

11. The fin stabilizer according to claim 1, wherein the at least one actuator is controllable by a control and/or regulating unit so at to provide an increase of the energy efficiency and/or an increase of the stabilizing effect of the fin stabilizer.

Description

[0017] In the following a preferred exemplary embodiment of the invention is explained in more detail with reference to schematic Figures.

[0018] FIG. 1 shows a schematic depiction of the fin stabilizer, including a stabilizing fin in an undeformed base state of the stabilizing fin, and

[0019] FIG. 2 shows the stabilizing fin of the fin stabilizer of FIG. 1 in a deformation state.

[0020] FIG. 1 shows a schematic depiction of the fin stabilizer, including a stabilizing fin in an undeformed base state of the stabilizing fin. A fin stabilizer 100 for preferred roll stabilizing of a not-depicted watercraft, such as a ship or pontoon, comprises inter alia a fin carrying shaft 110 on which a stabilizing fin 116 is attached. Using a drive unit 120 graphically indicated only by a dotted line, the shaft 110 is rotatable about a longitudinal 10 central axis 122 by an angle of attack α. The angle of attack α can fall, for example, in a range of ±45°. The stabilizing fin 116 is located completely in the water that acts upon the stabilizing fin 116 in a preferred flow direction 124.

[0021] Using an actuator, a cross-sectional geometry 130 of the stabilizing fin 116 is changeable largely steplessly, wherein independent of the configured change the cross-sectional geometry 130 of the stabilizing fin 116 always forms a closed surface geometry 136, i.e., a self-contained peripheral contour. In the context of the present description, the term “self-contained surface geometry” defines a surface that is free of points of discontinuity, such as steps, shoulders, recesses, grooves, notches, channels, gaps, holes, bores, etc.

[0022] Here by way of example the stabilizing fin 116 includes an inflow body 140 and an outflow body 148 arranged at a distance therefrom, which inflow body 140 and outflow body 148 are connected to each other by a connecting body 144 disposed therebetween. Here the inflow body 140 includes a cross-sectional geometry symmetric with respect to an associated central plane 142, which cross-sectional geometry essentially corresponds to that of a rectangle, wherein a semioval directed against the flow direction 124 is upstream of the rectangle. In the undeformed base state, by way of example the connecting body 144 has a cross-sectional geometry that corresponds to a trapezoid symmetric with respect to an associated central plane 146, and a cross-sectional shape of the outflow body 148 essentially follows the shape of an isosceles triangle that is also configured symmetrically with respect to an associated central plane 150. As a result, the cross-sectional geometry 130 of the stabilizing fin 116 has an almost optimal hydrodynamic design for the inflowing water.

[0023] In the undeformed base state, shown here by way of example, of the stabilizing fin 116, the central planes 142, 146, and 150 lie in a common base plane 156. The water preferably flowing from the flow direction 124 first impacts against the inflow body 140, passes the connecting body 144, and finally flows off over the outflow body 148 of the stabilizing fin 116.

[0024] The connecting body 144 is formed by at least one elastic deformation body 160 into which at least one support element 162 is integrated whose bending stiffness is preferably significantly higher than that of the deformation body 160. For example, the deformation body 160 can be formed by an elastomer, such as, for example, silicone, rubber, or the like.

[0025] The support element 162 can be realized, for example, by a fiber composite plastic, a resilient metal, etc. The changing of the cross-sectional geometry 130 of the stabilizing fin 116 is effected solely by a corresponding elastic deformation of the connecting body 144.

[0026] Since the inflow body 140 generally has the largest usable installation space, at least one actuator 170 is preferably integrated into the inflow body 140. The at least one actuator 170 is controllable by a control and/or regulating unit 172. The control and/or regulating unit 172 preferably simultaneously serves for controlling, by the drive unit 120, an angle of attack α of the stabilizing fin 116 with respect to the surrounding water. Here the actuator 170 is flexibly connected to the outflow body 148 by a coupling link 178 configured in the manner of a thrust rod. A first end 180 of the coupling link 178 is linked to a rotatable pivot arm 182 of the actuator 170, while a second end 184 of the coupling link 178 is flexibly connected to the outflow body 150 outside the central plane 150 of the outflow body 148. Instead of the eccentric drive, shown here merely by way of example, for the mechanical coupling of actuator 170 and outflow body 148, using a not-indicated linear actuator or using an alternative transmission design, the outflow body 148 can be, for example, directly coupled using the at least one actuator 170. Furthermore, a deformation of the deformation body 160 and of the support element 162 of the connecting body 144 is possible using an actuator, for example, integrated therein.

[0027] In the undeformed base state shown here of the stabilizing fin 116, an outflow angle β between the central plane 142 of the inflow body 140 and the central plane 150 of the outflow body 148 is 0°, since in the undeformed base state both central planes 142, 150 lie in the base plane 156 of the stabilizing fin 160. The same applies to the central plane 146 of the deformation body 144.

[0028] The inflow body 140 and the outflow body 148 are elastically connected to each other by the connecting body 144 such that in a deformation state, depicted in FIG. 2, of the stabilizing fin 116, due to an elastic deformation of the deformation body 160 and of the support element 162 of the connecting body 144, with the operation of the actuator 170 there is at least one outflow angle β different from 0° between the central plane 142 of the inflow body 140 and the central plane 150 of the outflow body 148.

[0029] Using the control and/or regulating unit 172, the at least one actuator 170 is controllable here such that due to the changing of the cross-sectional geometry 130 of the stabilizing fin 116, an increase of the energy efficiency results and/or an increase of the stabilizing effect of the fin stabilizer 100 results with energy consumption remaining constant.

[0030] FIG. 2 illustrates the stabilizing fin of the fin stabilizer of FIG. 1 in a deformation state. The fin stabilizer 100 in turn comprises the fin carrying shaft 110 including the stabilizing fin 116 attached thereto, wherein the shaft 110 is drivable in a pivoting manner about the longitudinal central axis 122 by the drive unit 120 under the control of the control and/or regulating unit 172. The stabilizing fin 116 acted upon by water in the preferred flow direction 124 is in turn divided into the inflow body 140, the elastic connecting body 144 including the elastic deformation body 160 having the support element 162 integrated therein, and the outflow body 148, wherein the inflow body 140, the connecting body 144, and the outflow body 148 are connected to each other to provide a compact unit. Using the coupling link 178, the pivot arm 182 of the actuator 170 controlled by the control and/or regulating unit 172 is hinged to the outflow body 148 of the stabilizing fin 116. In comparison to the depiction of FIG. 1, the inflow body 140 is located unchanged in a symmetric position with respect to the base plane 156.

[0031] Due to the operating of the actuator, which operating is controlled by the control and/or regulating unit 172, the pivot arm 182 of the actuator 170 is rotated from the rest position of FIG. 1 by the pivot angle γ, whereby the outflow angle β between the central plane 150 of the outflow body 148 and the base plane 156 is increased to a value different from zero, and the deformation state of the stabilizing fin 116 is achieved. In the course of this deformation the support element 162 is bent upward in the manner of a cantilever, and the elastic deformation body 160 of the connecting body 144 is deformed approximately into a general quadrilateral. During this process the cross-sectional geometry 130 or the peripheral contour of the stabilizing fin 116 changes such that the stabilizing fin 116 has, in comparison to the base state of FIG. 1, altered hydrodynamic properties, and the stabilizing fin 116 is optimally adaptable to changed operating conditions of the fin stabilizer 100. However, due to the elastically formed connecting body 144, the surface geometry 136 or the upper or enveloping surface of the stabilizing fin 116 remains free of any points of discontinuity that would lead to eddies, and thus concomitantly to a non-laminar flow around the stabilizing fin 116, and thus as a result to an increase of the hydraulic flow resistance of the stabilizing fin 116.

[0032] However, if the pivot arm 182 of the actuator 170 is rotated by the same pivot angle γ in the opposite direction, then a complementary cross-sectional geometry 132 of the stabilizing fin 116 indicated by dotted lines results. Here the two cross-sectional geometries 130, 132 are mirror-symmetric with respect to the base plane 156 of the stabilizing fin 116.

[0033] Between the base state of the stabilizing fin 116, illustrated in FIG. 1, and the deformation state of the stabilizing fin 116, depicted in FIG. 2, a plurality of (intermediate) deformation states are represented by correspondingly less rotating of the pivot arm 182 of the actuator 170 under the control of the control and/or regulating unit 172.

[0034] Since the cross-sectional geometry 130, 132 of the stabilizing fin 116 can be adapted to the respective current operating conditions in the water, optimally and nearly in real time, a considerable increase of the energy efficiency of the fin stabilizer 100 is realizable with a simultaneous optimization of the stabilizing effect of the fin stabilizer 100.

[0035] The invention relates to a fin stabilizer 100 for the roll-stabilizing of a watercraft in motion, at anchor, or at zero speed, including a shaft 110 on which a stabilizing fin 116 is disposed, wherein the shaft 110 is drivable by a drive unit 120 for changing at least one angle of attack α of the stabilizing fin 116 in the water. According to the invention it is provided that a cross-sectional geometry 130 of the stabilizing fin 116 is changeable by at least one actuator 170, and the stabilizing fin 116 forms a closed surface geometry 136. Due to the hydraulically effective cross-sectional geometry 130 of the stabilizing fin 116, which cross-sectional geometry 130 is largely changeable by at least one actuator 170, a significantly increased energy efficiency of the fin stabilizer 100 results with a simultaneously improved stabilizing effect of the fin stabilizer 100, in particular with respect to suppressing rolling movements of the watercraft.

REFERENCE NUMBER LIST

[0036] 100 Fin stabilizer
110 Fin carrying shaft

116 Stabilizing fin

[0037] 120 Drive unit
122 Longitudinal central axis (fin carrying shaft)
124 Flow direction (water)
130 Cross-sectional geometry (stabilizing fin)
132 Complementary cross-sectional geometry (stabilizing fin)
136 Surface geometry (stabilizing fin)
140 Inflow body
142 Central plane
144 Connecting body
146 Central plane
148 Outflow body
150 Central plane
156 Base plane (undeformed base state)
160 Elastic deformation body
162 Support element

170 Actuator

[0038] 172 Control and/or regulating unit
178 Coupling link (coupling rod)
180 First end (coupling link)
182 Pivot arm (actuator)
184 Second end (coupling link)
α Angle of attack (fin carrying shaft)
β Outflow angle (outflow body, base plane)
γ Pivot angle (pivot arm actuator)