Patent ID: 7806618

Claim:
A rotary connecting means based on frictional engagement, comprising: a hollow shaft ( 2 ) to be placed on a shaft, and a tapered ring ( 3 ) placed on the hollow shaft ( 2 ) and including at least one tapered ring section ( 4 a ) having an inner surface abutting the hollow shaft ( 2 ), and having an oblique outer surface ( 5 a ); at least one tensioning ring element ( 6 a ) placed on the tapered ring ( 3 ) and having an oblique inner surface, wherein the tensioning ring element ( 6 a ) slides between a starting position and a tensioning position along the oblique outer surface ( 5 a ) of the tapered ring section ( 4 a ); and tensioning means comprising a pressure ring chamber ( 15 ) and an annular piston ( 7 ) within the pressure chamber ( 15 ) for moving the tensioning ring element ( 6 a ) into the tensioning position, wherein: in addition to the tensioning means there is provided at least one separate retaining element ( 8 ) for securing the tensioning ring element ( 6 a ) in the tensioning position, which retaining element ( 8 ) is arranged to move and be guided in a radial direction with respect to the hollow shaft ( 2 ), independent of the tensioning means, from a free position into a clamping position in which the retaining element ( 8 ) axially blocks the tensioning ring element ( 6 a ) in the tensioning position, wherein the piston ( 7 ) defines a receptacle ( 16 ) for the retaining element ( 8 ) in the free position and a guide ( 17 a , 17 b ) for the retaining element ( 8 ) during movement of the retaining element ( 8 ).