Abstract: Disclosed is a rotor system for an aircraft including a rotor having multiple rotor blades disposed about an axis of rotation of the rotor substantially radially. A plane perpendicular to the axis of rotation, which extends through the rotor blades in a radial direction, forms a rotor plane. A rotor shroud surrounds the rotor circumferentially with regard to the axis of rotation, confines an air duct of the rotor extending in an axial direction of the axis of rotation, and forms a hollow structure extending circumferentially with regard to the axis of rotation. The hollow structure has on its circumferential face facing the rotor in the radial direction an area permeable to gas. The rotor plane intersects the area, and the hollow structure is configured to at least partially absorb acoustic waves of at least one frequency penetrating through the area.

Abstract: A rotorcraft having an electric drive for driving a main rotor of a rotorcraft, more particularly a helicopter, the electric drive comprising: a coupler for coupling the electric drive to a rotor mast, which can be coupled for conjoint rotation with a drive unit of a helicopter rotor transmission, for coupling for conjoint rotation with the main rotor or tail rotor. A rotorcraft with an electric drive is provided with which the space requirement is reduced, the construction is simplified and the maintenance requirement is reduced. This problem is solved in that the electric drive is designed as an electric ring motor, with the electric ring motor being arranged and attached coaxially with the rotor mast.

Abstract: Disclosed is a rotor system for an aircraft including a rotor having multiple rotor blades disposed about an axis of rotation of the rotor substantially radially. A plane perpendicular to the axis of rotation, which extends through the rotor blades in a radial direction, forms a rotor plane. A rotor shroud surrounds the rotor circumferentially with regard to the axis of rotation, confines an air duct of the rotor extending in an axial direction of the axis of rotation, and forms a hollow structure extending circumferentially with regard to the axis of rotation. The hollow structure has on its circumferential face facing the rotor in the radial direction an area permeable to gas. The rotor plane intersects the area, and the hollow structure is configured to at least partially absorb acoustic waves of at least one frequency penetrating through the area.

Abstract: A drive unit, particularly for the main rotor of a rotary wing aircraft, comprises: a planetary gear mechanism including a plurality of planetary gears. Each planetary gear has at least one planet wheel with toothing and the planetary gears are arranged concentrically to a central axis inside the planetary gear mechanism so that a rotatable shaft, in particular a rotor shaft of the rotary wing aircraft, can be driven by the planetary gears or the sun wheel. A compact and simplified drive unit can be provided in a very wide range of fields of use, particularly for driving a main rotor of a rotary wing aircraft. This can be achieved in that a first drive, particularly an electric drive, is integrated into at least one planetary gear, comprising a planet wheel and a planet wheel carrier, to form a first drive unit, so that the shaft can be set rotating by the first drive.

Abstract: A rotorcraft having an electric drive for driving a main rotor of a rotorcraft, more particularly a helicopter, the electric drive comprising: a coupler for coupling the electric drive to a rotor mast, which can be coupled for conjoint rotation with a drive unit of a helicopter rotor transmission, for coupling for conjoint rotation with the main rotor or tail rotor. A rotorcraft with an electric drive is provided with which the space requirement is reduced, the construction is simplified and the maintenance requirement is reduced. This problem is solved in that the electric drive is designed as an electric ring motor, with the electric ring motor being arranged and attached coaxially with the rotor mast.