Abstract: For improving a drill, in particular a spiral drill, comprising a base body extending substantially longitudinally in a direction axial to a drill axis, said base body comprising a drilling portion, wherein a radially inward core region in relation to the drill axis and a radially outer region are provided in the base body in the drilling portion, and the drilling portion comprises a plurality of spiral-shaped recesses in the outer region, and arranged between each two spiral-shaped recesses is a wall part, it is proposed that the drill comprises at least four main cutting edges, in particular exactly four main cutting edge and/or the drill comprises at least three central cutting edge portions.

Abstract: For improving a drill, in particular a spiral drill, comprising a base body extending substantially longitudinally in a direction axial to a drill axis, said base body comprising a drilling portion, wherein a radially inward core region in relation to the drill axis and a radially outer region are provided in the base body in the drilling portion, and the drilling portion comprises a plurality of spiral-shaped recesses in the outer region, and arranged between each two spiral-shaped recesses is a wall part, it is proposed that the drill comprises at least four main cutting edges, in particular exactly four main cutting edge and/or the drill comprises at least three central cutting edge portions.

Abstract: In a turbo-machine having a rotor member movable relative to a stationary housing member there is provided a substantially ring-shaped or annular seal between both of these members and serves to seal pressurized water from an external space or region. One of both of these members possesses a sealing surface against which there is pressed a sealing body of the seal which is inserted into the other member, the sealing body being for instance constituted by a lip seal. Improved lubrication, reduced friction and enhanced service life of the seal is attained in that, the sealing surface has fed thereto a friction-reducing liquid, for instance by means of radial grooves provided in the sealing surface or by means of bores opening into the sealing surface.

Abstract: A tidal power plant and method of operating the same are disclosed. In tidal power plants the turbines are arranged in channels between the sea and a storage reservoir. Heretofore known constructions of tidal power plants included relatively complex mechanisms for maintaining the turbine or turbines operating for the maximum amount of time, but generally they have failed to exceed a high overall operating efficiency. The present invention seeks to improve upon prior installations by designing a tidal power plant in which the or each turbine is disposed in a main channel between the sea and the storage reservoir. A connection channel is arranged above the main channel containing the turbine. A shutoff device is located at the reservoir side of the turbine and the connection channel to control and direct the flow of water.

Abstract: The disclosure concerns a radial bearing arrangement for a large diameter rotor wherein the rotor carries an annular surface in a peripheral region spaced radially from the axis which cooperates with a series of bearing devices mounted in a foundation. The bearing devices provide reactions in a limited number of main supporting directions and act collectively to restrain the rotor against movement in all radial directions. Not more than two of the bearing devices provide positive, non-yielding restraint in those main directions, whereas the other bearing devices have radially displaceable bearing shoes and furnish yielding holding forces. The arrangement may include one type of yielding bearing device which furnishes a reaction which varies with displacement and affords a centering action, and/or a second type which furnishes a constant reaction during slow displacements and an increased reaction during rapid displacement, and thus affords damping action.

Abstract: The disclosure concerns a hydroelectric machine set in which the electrical machine is in the form of a rim which surrounds a service water duct containing the bladed wheel of a hydraulic machine, and wherein the blades of said wheel are joined to the rotor of the electrical machine by torque-transmitting connections which allow free radial movement of the blades relatively to the rotor. Preferably, those connections also permit pivoting movement of the blades relatively to the rotor.

Abstract: The disclosure concerns a Francis-type hydraulic machine, i.e., a turbine, pump-turbine or pump, having a bladed wheel of large diameter, and in which bearing apparatus for supporting the rotor is arranged in a peripheral region of the bladed wheel spaced radially from the axis.

Abstract: The invention relates to gloss-stable modacrylic fibres and filaments comprising 50 to 84% of acrylonitrile, 15 to 48% of vinylidene chloride and 2 to 5% of an olefinically unsaturated sulphonic acid or salt thereof, all percentages being by weight, having a shrinkage in boiling water of at most 0.3%, a reduction in density on treatment with boiling water of no more than 0.015 g/cc and a scattered light component after boiling of at most 35 units compared with a BaSO.sub.4 standard of 1000 units, the increase brought about by treatment with boiling water amounting to no more than 30 units as well as to a process for their production.

Abstract: The disclosure concerns a hydroelectric machine including a tube-type hydraulic machine having a bladed wheel which rotates about a horizontal axis and is provided with fixed blades which are encircled by, and connected with, a rim to which the rotor of a surrounding electrical machine is attached. The wheel, rim and rotor form a single rotating unit which is supported in the radial direction without physical contact by at least two hydrostatic centering supporting devices and at least one hydrostatic damping device. At least one hydrostatic load-beaing device may be included for accepting without physical contact a constant portion of the weight of the rotating unit. In addition, the machine may include hydrostatic supporting devices, of the centering type or of both the centering and the damping type, for accepting without physical contact the axial thrusts imposed on the rotating unit.

Abstract: The pressure chamber located in the sealing member is sub-divided by webs into a plurality of individual sub-chambers with restrictors between each sub-chamber and the barrier medium supply in order to obtain a uniform adjustment over the entire periphery of the gap between the sealing member and rotating part. Various types of means such as pressure-filled tubes are used to bias the sealing member from within a groove in the stationary part towards the rotatable part.

Abstract: A supporting device for a mobile part which is subjected to dynamic forces relieves the normal support bearings of the necessity of handling these unusual loads. The device comprises a support element which adjoins the mobile part, and a hydraulic control which causes that element to supply a constant, relatively small supporting reaction under normal conditions, which may produce slow displacements of the mobile part, and to supply an increased or decreased reaction, depending upon the direction of movement, when the mobile part is displaced rapidly by the dynamic forces.

Abstract: Hydrostatic supporting apparatus which supports, without physical contact, a mobile part which moves relatively to a load-bearing part. The apparatus comprises a supporting piston which has at least one hydrostatic bearing pocket which provides a pressure cushion through which the mobile part is supported, and which is urged toward the mobile part by a controlled pressure which increases and decreases, respectively, as the piston moves toward and away from the load-bearing part. Preferably, pressure control is effected by a throttle valve interposed either in a supply path leading from a source of pressure medium to the pressure chamber of a hydraulic supporting motor, or in a feed passage leading from that pressure chamber to the bearing pocket.

Abstract: Hydrostatic apparatus for supporting a mobile part which moves relatively to a foundation comprises a bearing shoe having a bearing face containing a pressure pocket, and a hydraulic servomotor which exerts on the shoe a force urging it toward the mobile part. A support element connected with the shoe and the foundation positively holds the shoe against movement in at least one direction along its supporting axis, and its restraint is so correlated with the pressure forces acting on the shoe that the latter is rendered non-displaceable. Depending upon the relative magnitudes of the forces developed by the servomotor and by the pressure acting on the bearing face, the support element may normally be unloaded, loaded in tension or loaded in compression. In the first case, the support element prevents movement of the shoe in opposite directions along the support axis, whereas in the second and third cases it may permit movement of the shoe toward and away from the foundation, respectively.

Abstract: The disclosure concerns a hydroelectric machine including a tube-type hydraulic machine having a bladed wheel which carries adjustable blades, rotates about a horizontal axis and is connected with a shaft which extends into a guide blade lattice hub, and an electrical machine which surrounds the bladed wheel and has a rotor secured to an annular rim in which the external ends of the adjustable wheel blades are pivotably mounted. The rotating set is provided with three radial bearing arrangements, one being associated with the rotating unit formed by the rotor and the rim, providing sole radial support for that unit, and consisting exclusively of hydrostatic devices which support without physical contact. The other bearing arrangements are associated with the shaft at its free and bladed wheel ends, respectively.