Abstract: A frictional revolving joint for joining a hub to a shaft has a tapered ring arrangement with two tapered ring sections with conical outer surfaces that have a V-shaped cross-section and a clamping ring made of two clamping ring elements that enclose the tapered ring arrangement.The ring shaped pressure chamber formed by the front surfaces of both clamping ring elements may be put under pressure by a hydraulic fluid, causing the clamping ring elements to slide outwards on the V-shaped tapered ring sections.The ring-shaped pressure chamber (57) is sealed itself by sealing rings (55a, 55b,; 63) that engage the clamping ring elements (53a, 53b) in all positions of the latter. The ring-shaped pressure chamber (57) is thus hermetically sealed and hydraulic fluid cannot escape outwards.

Abstract: A hydraulically actuatable shrinking disc, especially for a force transmitting connection of a hub having a cylindrical outer surface with a shaft comprises an inner ring arranged to be located on a cylindrical outer surface of a hub and having a double-conical outer peripheral surface, two pressure rings which are arranged axially opposite to one another in a displaceable and clampable manner on the inner ring and have inner conical surfaces which corresponds to the outer peripheral surface of the inner ring, the pressure rings forming therebetween a pressure chamber for a pressure fluid, the pressure rings being mirror-symmetrical in their cross-section and each formed with a cylindrical outer peripheral surface, the pressure rings being provided with openings which serve as pressure medium passages, a clamping ring which serves as an abutment for the pressure rings and surrounds the latter, the clamping ring having an outer peripheral surface which is provided with a connecting opening for the pressure flu