Abstract: The invention relates to a clamping device for a rod which moves in an axial translatory or rotating manner. Said clamping device comprises a housing, a clamping sleeve which is axially fixed therein, a tensioning piston which can be displaced in the housing embodied as a cylinder, and a spring device for pre-tensioning the piston in the direction of the clamping sleeve in the locking state. Said spring device includes at least one helical plate spring which, in the event of a fracture, maintains the holding force and the dynamic course of the same. In one embodiment, the at least one helical plate spring is coaxially arranged in relation to the rod. In another embodiment, a plurality of helical plate springs are arranged on the circumference of the rod such that they are parallel with the axis thereof, for distribution of a pre-tensioning force acting on the spring device.

Abstract: A low-friction seal comprising a quasi dimensionally stable sealing ring (44) that is accommodated with radial and axial clearance in a groove (30; 76) of one of two surface, whereby said surfaces are sealed off from each other and can move in a relative position to each other, and the peripheral section of the sealing ring protruding from the groove (30? 76) is placed opposite the other surface that is to be sealed. Means are provided between the side wall (34; 80, 82) of the groove on the side of the pressure-chamber and the sealing ring (44) in order to prevent pressure from spreading to the bottom (37, 78) of the groove, whereby radial deformation of the sealing ring in the direction of the surface that is to be sealed is avoided.