Abstract: An actuating device for actuating a valve element of an exhaust gas turbocharger includes a pressure chamber which is delimited in part by a first housing element and in part by a diaphragm formed separately from the first housing element. A fluid is introducible into the pressure chamber. The diaphragm is reversibly deformable in order to actuate the valve element and the diaphragm is held on the first housing element by a first cooling ring in which sodium is accommodated.

Abstract: The invention relates to a rotor (4) for an air supply unit (1) of a fuel cell unit, which rotor is to be rotatably mounted in a housing (5) of the air supply unit (1) by means of foil-air bearings (15, 16). According to the invention, at least portions of the rotor (4) are formed of a carbon graphite material or of a synthetic-resin-bonded carbon fiber material or coated therewith. The invention also relates to an air supply unit (1) having a rotor (4) of this type.

Abstract: An actuating device for actuating a valve element of an exhaust gas turbocharger includes a pressure chamber which is delimited in part by a first housing element and in part by a diaphragm formed separately from the first housing element. A fluid is introducible into the pressure chamber. The diaphragm is reversibly deformable in order to actuate the valve element and the diaphragm is held on the first housing element by a first cooling ring in which sodium is accommodated.

Abstract: In a valve drive arrangement of an internal combustion engine, having a first camshaft unit which comprises an outer shaft and primary cams connected to the outer shaft, a second camshaft unit which comprises an inner shaft disposed in the outer shaft, secondary cams connected to the inner shaft and disposed on the outer shaft and an adjusting unit for adjusting the two camshaft units relative to each other an adjusting unit provides for an at least two stage sequential valve stroke wherein, in a switching process, two shaft elements of a camshaft unit are displaced sequentially one after the other.

Abstract: In a valve drive arrangement of an internal combustion engine, having a first camshaft unit which comprises an outer shaft and primary cams connected to the outer shaft, a second camshaft unit which comprises an inner shaft disposed in the outer shaft, secondary cams connected to the inner shaft and disposed on the outer shaft and an adjusting unit for adjusting the two camshaft units relative to each other an adjusting unit provides for an at least two stage sequential valve stroke wherein, in a switching process, two shaft elements of a camshaft unit are displaced sequentially one after the other.