Deutsche Forschungsanstalt Fur Luft-und Raumfahrt E.v.

Deutsches Zentrum Fur Luft-und Raumfahrt E.v.

Deutsche Forschungs- Und Versuchsanstalt Fur Luft- Und Raumfahrt E.v.

Eras Gmbh

Elmar J Breitbach

Andreas Buter

Thilo Bein

Ernst-August Dehne

Ulf-Carsten Ehlert

Torsten Grutzmacher

In a thin-walled profile with profile variation using anisotropisms due to the material or the structure, the anisotropisms due to the material or the structure are arranged locally in the profile to produce specific changes in the contour.

Profile

An engine mount (1) is disclosed which is particularly suitable for a propeller-driven aircraft. The engine mount (1) comprises a tubular frame structure (3) for the attachment of an engine (4) to a supporting structure, particularly to a cowling box (2). The frame structure (3) comprises a multitude of point-shape connected and braced members (8), (11), (12), (13), (15), and is part surrounding the engine (4). The engine (4) is bolted to mounts at one end of the tubular frame structure (3) in the direction (5) of drive, and, at its other end in the direction (5) of drive, the tubular frame structure (3) is, in turn, bolted to mounts on the supporting structure. According to the invention at least one member of the tubular frame structure (3) is an active member (12) the length of which can be changed under control.

Engine mount, particularly for a propeller-driven aircraft, comprising a

In the case of a profile edge of an aerodynamic profile the profile edge (1, 20) comprises multifunctional material on its outside (3, 23) and/or inside (2, 22) or within its structure (11).

Profile edge of an aerodynamic profile

An actuator (1) having at least one triggerable element (4,5) of variable lengths made of a multifunctional material (6) for large regulating distances is disclosed. The multifunctional material is arranged in layers on a deformable platform carrier structure 93), the carrier structure and the multifunctional material being disposed symmetrically about a longitudinal center plane (7) of the actuator. The carrier structure includes at least a pair of arcuate sections formed on both sides of the longitudinal center plane of the actuator, each such arcuate section describing an arc of at least 180.degree.. The triggerable elements of variable lengths may be actuated with heat supplied by a separate heat source, or by electricity provided from a separate source of electricity so that the triggerable elements either expand or contract, thus moving a stringer (26) formed as a part of the carrier for performing the desired actuation function.

Actuator with a triggerable element of variable length made of a

An interface (3) for vibration reduction in structural-dynamic systems comprises a base-side construction element (8) and a structure-side construction element (9) and at least one actuator (14), for example a piezoelectric or a magnetostrictive actuator. The actuator (14) has a main direction (17), and the extension of the actuator (14) in its main direction (17) between a first engagement point (15) on the base-side construction element (8) and a second engagement point (16) on the structure-side construction element (9) can be voluntarily changed by means of a drive signal. Therein, the actuator (14) is under pressure prestress between the first engagement point (15) and the second engagement point (16), and at least one elastic element (18) is arranged in parallel to the actuator (14) between the base-side construction element (8) and the structure-side construction element (9), the elastic element (18) having a longitudinal stiffness parallel to the main direction (17) of the actuator (14) which is as low as possible, and a transversal stiffness perpendicular to the main direction (17) of the actuator (14) which is as high as possible.

Interface for vibration reduction in structural-dynamic systems

A pivot drive for quick and precisely positioned rotational movements around a limited angle value comprises one or more rods with a cross-section which is not warping-free and one or more actuators for the introduction of longitudinal forces into the rods. The longitudinal forces generate warping in the rods so that the rod ends rotate relative to one another. Each rod is constructed in the form of a tube and has a continuous slot arranged in its longitudinal direction.

Pivot drive

A current collector (15) is provided for transmitting energy between a contact wire (2) and a motor coach. The current collector comprises at least one collector shoe (1) and a support arm (11) constructed and arranged to lift the collector shoe, and to apply a contact force in which the collector shoe lies below and against the contact wire. The support arm is rotatably connected to the motor coach about a horizontal axis (17) and raiseable about the axis by a lifting device (3). The lifting device includes a fast actuator (23) which is constructed and arranged to be controlled by a control device (22) in dependence on a signal (20, 21) of at least one displacement sensor, force sensor (18), or acceleration sensor (19) located on the current collector to maintain the contact force of the collector shoe against the contact wire.

Current collector for transmitting energy between a contact wire and a

A current collector for transmitting energy between a contact wire and a motor coach having at least one collector shoe (1) and at least one suspension spring (16) with a positive stiffness, the suspension spring supporting the collector shoe which lies with a contact force from below and against the contact wire. The suspension spring (16) is arranged in parallel with a correction spring (17), the correction spring having a negative stiffness in a zero-crossing of its spring characteristic curve, which coincides with the spring travel of the suspension spring (16), which spring travel corresponds to the desired contact force.

A current collector is provided for transmitting energy between a contact wire and a motor coach. The current collector has a first support am (11) connected to the motor coach and being raisable about a first horizontal axis (28); and a pair of second support arms (8 and 18) connected to the free end of the first support arm rotatably about a second horizontal axis (28). The pair of the second support arms (8 and 18) is connected to an extension element (14) protruding over the second horizontal axis (28). Further, the current collector has a guide bar (13) rotatably connected with the motor coach and the extension element (14); and at least one collector shoe which is supported on the free end of the pair of the second support arms (8 and 18). The extension element (14) is connected to each of the two second support arms (8 and 18) via a torsional actuator (16 and 17, respectively) being arranged on the second horizontal axis (28). A control device (25) is provided which controls the two torsional actuators (16 and 17) dependent on the signal (21, 22) of at least one displacement, acceleration or force sensor arranged on the current collector.

A spring-system, used for the suspension of motor-vehicles, comprises a manical, pneumatic, or hydro-pneumatic suspension-spring inserted between the sprung and the unsprung masses of the motor-vehicle. The suspension-spring is linear and possesses relatively high positive rigidity with only short spring-travel. Arranged in parallel with the suspension-spring is a correcting spring having negative rigidity and zero-crossover in the region of negative rigidity. The correcting spring comprises two parts each equipped with permanent magnets, one of these parts being connected to the sprung mass and the other to the unsprung mass. Each of the parts of the correcting spring comprises a plurality of permanent magnets arranged one behind the other in the direction of movement, with pieces of soft iron arranged therebetween, like poles of adjacent permanent magnets adjoining the soft-iron intermediate pieces, and the magnetizing axes of the permanent magnets being arranged in parallel with the direction of movement. The arrangement is such that the magnetic flux, deflected by the soft-iron intermediate pieces perpendicularly to the direction of movement, produces, in both parts, like poles facing each other and repelling each other in unstable equilibrium at the same height in relation to the direction of movement.

Spring-system for motor vehicles

In a semi-active system for suppressing external load-carrying wing flutter in aircraft, the carrying wing (1) is provided with one or more external loads (2), and the suspension of the external load (2) on the carrying wing (1) about an axis is arranged at right angles to the plane of symmetry of the aircraft. The external load (2) is mounted to pivot about the axis (3). A spring is provided between the carrying wing (1) and the external load (2); however, it is constructed, to take up the stationary and quasi-stationary moments, as a linear spring (7) with relatively great stiffness and permitting only small spring excursions. A further spring (8) is arranged in parallel with spring (7) and is constructed to be nonlinear and also to have negative stiffness and passage through zero in the region of the negative stiffness. The springs (7 and 8) form a spring system of small stiffness in and about the operating point defined by the passage through zero of the nonlinear spring (8) and the stationary moments. The operating point of the nonlinear spring (8) is slaved in each equilibrium position between the carrying wing (1) and external load (2).

Process and apparatus for suppressing external load carrying wing

A resiliently suspended mass varies the resistance of a pair of ohmic resors located in a magnetic field by changing the magnetic field by changing position in response to acceleration. The mass may be made of soft iron or contain a magnet to affect the change in the magnetic field.

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Gottingen, Germany

Elmar J Breitbach