Abstract: An electrical machine, e.g. water turbine or bow propeller, includes a ring shaped stator ring and inside it a rotatable rotor ring with to it mounted blades flown around by the fluid. Magnetic elements generate axial directed magnetic forces between rotor and stator. Stabilizing elements keep the rotor during operation in an axial stable position. A magnetic preload is active in the machine and the amount of this magnetic preload is set by the mechanical bearing of the rotor ring, such that merely variation is required in a dimension of the mechanical bearing to optimize a for the rest identical machine for different nominal flow speeds of the fluid through the machine.

Abstract: An electrical machine, e.g. water turbine or bow propeller includes a ring shaped stator ring and inside it a rotatable rotor ring with to it mounted blades flown around by the fluid. Magnetic elements generate axial directed magnetic forces between rotor and stator. Stabilizing elements keep the rotor during operation in an axial stable position. The magnetic elements include permanent magnets to generate an axial directed magnetic preload which is oppositely directed to the force exerted by the water to the rotor ring such that the axial force to be exerted by the stabilization means is smaller. The magnetic elements include the stator and rotor of the generator/motor, wherein the stator and rotor are behind each other, relative to the axial direction.

Abstract: The invention relates to a high-pressure device (1) having a cylindrical high-pressure vessel (3) and prestressing means in order to exert an axial pressure on the vessel. The vessel (3) can have been formed from a number of layers of composite material, such as glass, carbon or aramide fibers which are oriented in the peripheral direction and are embedded in a matrix of epoxy resin or polyurethane. By applying the axial prestress to the pressure vessel (3), the tangential stress is distributed more uniformly over the wall thickness of the high-pressure vessel (3), the stress decreasing at the inside of the wall and increasing at the outside thereof. As a result, the innermost fibers of a high-pressure vessel (3) made of composite material are subjected to appreciably less stress, which has a beneficial effect on the life of the high-pressure vessel (3), and all fibers of the wall are utilized effectively.