Abstract: An electrically driven hydrofoil for fastening to a board in order to lift the board out of the water during travel operation, comprises at least one drive module, which as an autonomous unit is fastened to a portion of the hydrofoil that remains submerged in the water during travel operation, an electric battery, and an electrically operated propulsion device supplied with power by the battery. It is thus possible to equip a conventional hydrofoil and a corresponding hydrofoil board with an electric drive, without the need for modifications to the board or to the hydrofoil. The battery can be arranged in the drive module so that there will be no need to provide external electrical connection between the propulsion device and the battery. The drive module may thus form an autonomous unit that may be attached to the hydrofoil as required, but otherwise is separate from the hydrofoil.

Abstract: A hydrofoil for a watercraft has at least one wing and one connecting rod for attaching the at least one wing to a mast. A conically tapered projection is provided on the connecting rod and a conical recess is provided on the wing which engage in one another. The wedge angle of the conical recess is greater than the wedge angle of the conically tapered projection in order to allow angular adjustment between the connecting rod and the wing. By means of a fixing device, the connecting rod can be braced against a portion of the conical recess and/or the wing can be braced against a portion of the conically tapered projection.

Abstract: A hydrofoil for a watercraft comprises a mast as well as a front wing and a rear wing, which are arranged, based on the forward travel direction, one behind the other at a free end portion of the mast. The rear wing is designed as an annular wing and, in addition, includes at least one tubular portion, which is oriented to the forward travel direction in such a way that water is able to flow through said tubular portion counter to the forward direction of travel.

Abstract: An electrically driven hydrofoil for fastening to a board in order to lift the board out of the water during travel operation, comprises at least one drive module, which as an autonomous unit is fastened to a portion of the hydrofoil that remains submerged in the water during travel operation, an electric battery, and an electrically operated propulsion device supplied with power by the battery. It is thus possible to equip a conventional hydrofoil and a corresponding hydrofoil board with an electric drive, without the need for modifications to the board or to the hydrofoil. The battery can be arranged in the drive module so that there will be no need to provide external electrical connection between the propulsion device and the battery. The drive module may thus form an autonomous unit that may be attached to the hydrofoil as required, but otherwise is separate from the hydrofoil.

Abstract: A torsional vibration damper comprises an outer housing, an inner part concentric relative to the outer housing, a plurality of chambers formed between the outer housing and the inner part and being filled with a damping medium, a plurality of leaf spring assemblies joining the outer housing and the inner part in a torsionally flexible manner, wherein each of the leaf spring assemblies is arranged in one of said chambers and separates the corresponding chamber into sub-chambers, a plurality piston chambers formed separately in the outer housing, wherein each piston chamber is connected with the sub-chambers of one of the chambers, and a plurality of pistons adjustably arranged in the piston chambers, respectively, for controlling the flow of damper medium between the sub-chambers of a chamber. The damping properties of this torsional vibration damper can be adjusted easily.

Abstract: A device for absorbing structure-borne sound comprises at least one torque transmitting flange having two or more layers of materials of different damping capacity and stiffness stacked on each other. At least a portion of the flange has a radially jagged cross-sectional profile including two or more flanks consecutively arranged in radial direction and alternately inclined to the radial direction. The consecutive flanks merge into each other by forming corners, respectively. This structure-borne sound absorber reduces the propagation of vibrations at acoustically relevant frequencies via rotating machine parts. Combination with a compensation coupling results in a high-elasticity coupling preventing noise radiation.

Abstract: A hydrofoil, suitable for kite surfing and jet skiing, comprises a keel fin having a first end portion for fastening to a board; and a front wing and a rear wing which are arranged one behind the other in the travel direction and are connected to a second end portion of the keel fin; wherein a connecting rod is situated on the second end portion of the keel fin and detachably connects the wings to the keel fin; and wherein a plate is situated on an outer side of the keel fin and on an outer side of at least one of the wings, and via detachable fastening means is braced to the connecting rod so as to detachably fasten at least one of the wings to the keel fin.

Abstract: A displacement compensating coupling comprises a first coupling member, a second coupling member and connecting elements for connecting the coupling members. The coupling members are each made in one piece from composite material and have a first flange portion for attachment to one of the drive elements, a diaphragm portion that extends radially outwardly from the first flange portion, a second flange portion and a tube portion extending from an outer circumference of the diaphragm portion to the second flange portion. Each of the tube portions has two or more recesses that are spaced from each other in circumferential direction. In a first relative position of the coupling members, the recesses of the first coupling member face the recesses of the second coupling member, and in a second relative position the recesses of the first coupling member and of the second coupling member are offset in circumferential direction.

Abstract: A hydrofoil fin for attachment to a board for kiteboarding or jet skiing comprises a core portion having a plurality of torsion boxes and outer shell made of a multi-layer fiber composite material and encapsulating the torsion boxes of the core portion. The hydrofoil fin provides a very rigid support of bending and torsional forces acting on the same and on the wings and against the board. This has an advantageous effect on the riding performance of during kite surfing and jet skiing.

Abstract: A hydrofoil fin for attachment to a board for kiteboarding or jet skiing comprises a core portion having a plurality of torsion boxes and outer shell made of a multi-layer fiber composite material and encapsulating the torsion boxes of the core portion. The hydrofoil fin provides a very rigid support of bending and torsional forces acting on the same and on the wings and against the board. This has an advantageous effect on the riding performance of during kite surfing and jet skiing.

Abstract: A torsional vibration damper comprises an outer housing, an inner part concentric relative to the outer housing, a plurality of chambers formed between the outer housing and the inner part and being filled with a damping medium, a plurality of leaf spring assemblies joining the outer housing and the inner part in a torsionally flexible manner, wherein each of the leaf spring assemblies is arranged in one of said chambers and separates the corresponding chamber into sub-chambers, a plurality piston chambers formed separately in the outer housing, wherein each piston chamber is connected with the sub-chambers of one of the chambers, and a plurality of pistons adjustably arranged in the piston chambers, respectively, for controlling the flow of damper medium between the sub-chambers of a chamber. The damping properties of this torsional vibration damper can be adjusted easily.

Abstract: A device for absorbing structure-borne sound comprises at least one torque transmitting flange having two or more layers of materials of different damping capacity and stiffness stacked on each other. At least a portion of the flange has a radially jagged cross-sectional profile including two or more flanks consecutively arranged in radial direction and alternately inclined to the radial direction. The consecutive flanks merge into each other by forming corners, respectively. This structure-borne sound absorber reduces the propagation of vibrations at acoustically relevant frequencies via rotating machine parts. Combination with a compensation coupling results in a high-elasticity coupling preventing noise radiation.

Abstract: A displacement compensating coupling comprises a first coupling member, a second coupling member and connecting elements for connecting the coupling members. The coupling members are each made in one piece from composite material and have a first flange portion for attachment to one of the drive elements, a diaphragm portion that extends radially outwardly from the first flange portion, a second flange portion and a tube portion extending from an outer circumference of the diaphragm portion to the second flange portion. Each of the tube portions has two or more recesses that are spaced from each other in circumferential direction. In a first relative position of the coupling members, the recesses of the first coupling member face the recesses of the second coupling member, and in a second relative position the recesses of the first coupling member and of the second coupling member are offset in circumferential direction.

Abstract: A hydrofoil, suitable for kite surfing and jet skiing, comprises a keel fin having a first end portion for fastening to a board; and a front wing and a rear wing which are arranged one behind the other in the travel direction and are connected to a second end portion of the keel fin; wherein a connecting rod is situated on the second end portion of the keel fin and detachably connects the wings to the keel fin; and wherein a plate is situated on an outer side of the keel fin and on an outer side of at least one of the wings, and via detachable fastening means is braced to the connecting rod so as to detachably fasten at least one of the wings to the keel fin.

Abstract: A torsionally flexible coupling comprises an inner part having a rotating shaft, an outer part extending around the inner part and arranged coaxially thereto, and spring elements or spring packs arranged between the inner part and the outer part and spaced in circumferential direction, wherein each spring element or spring pack is clamped at a radially outer end in a clamping support on the outer part, and a radially inner end is flexibly engaged with a corresponding groove on the inner part. In position of rest the spring elements or spring packs are angled relative to a radial direction passing through the respective clamping support and are inclined against the main direction of rotation of the coupling. Such an inclined position of the spring elements or spring packs allows a reduction of the portion of damping caused by friction so that damping can become predominantly hydraulic.

Abstract: A torsional vibration damper or rotationally elastic coupling comprises: an outer housing including a flange; an inner part arranged within and rotatable relative to the outer housing; a plurality of intermediate pieces arranged around the inner part and spaced apart from each other in circumferential direction so as to form a plurality of chambers filled with a damping medium; a plurality of leaf spring assemblies having one or more leaf springs, said leaf spring assemblies being arranged in said chambers and having outer end portions engaging with receptacles formed between neighboring intermediate pieces and inner end portions engaging with the inner part; and a clamping ring extending around the intermediate pieces and the leaf spring assemblies for securing the leaf spring assemblies between the intermediate pieces.

Abstract: For a method for manufacturing a hollow shaft with at least one integral flange made of fiber composite, a plurality of intersecting windings of fiber material are applied onto a core. Moreover, the core has, for each flange, a radial spreader ring with an axial bearing surface. The windings are laid over an outer circumferential portion of the respective spreader ring and fixed. One or several inserts made of fiber material are inserted in the area of the spreader ring between the windings. The fixing of the wound fiber material is released, but is first still held on the spreader ring. Portions of the windings are then pulled off from the outer circumferential portion of the spreader ring and brought to rest on the axial bearing surface of the spreader ring in order to form a partial portion of a flange.

Abstract: A force-fitting clamping connection includes a first metal clamping surface, a second metal clamping surface, and a clamping element for clamping the clamping surfaces against one another. The first clamping surface forms a hardened fine surface structure with microreliefs and microdepressions. The second clamping surface has a lower hardness than the first clamping surface. Preferably, the first clamping surface is surface-treated by sand-blasting, shot-blasting or embossing before the hardening operation. This allows permanently high friction coefficient values between the clamping surfaces. A flange connection includes such a clamping connection for transmitting high torques.

Abstract: A torsionally flexible coupling comprises an inner part having a rotating shaft, an outer part extending around the inner part and arranged coaxially thereto, and spring elements or spring packs arranged between the inner part and the outer part and spaced in circumferential direction, wherein each spring element or spring pack is clamped at a radially outer end in a clamping support on the outer part, and a radially inner end is flexibly engaged with a corresponding groove on the inner part. In position of rest the spring elements or spring packs are angled relative to a radial direction passing through the respective clamping support and are inclined against the main direction of rotation of the coupling. Such an inclined position of the spring elements or spring packs allows a reduction of the portion of damping caused by friction so that damping can become predominantly hydraulic.

Abstract: A torsional vibration damper comprises an outer housing, an inner part that is concentric relative to the outer housing, a plurality of chambers formed between the outer housing and the inner part, which are filled with a damping medium and are connected to one another through overflow channels, and a plurality of leaf spring assemblies that are arranged in the chambers and join the outer housing and the inner part with one another in a torsionally flexible manner. The leaf spring assemblies have machining-induced deflections. Two leaf springs with substantially similar deflections are each arranged within a chamber. The leaf spring pairs may be arranged in a mirror-image array or in parallel to one another. Thus, the manufacturing cost of a torsional vibration damper can be reduced, while its compact outer dimensions can be maintained.