Abstract: Air flows are produced in a sliding bearing between the bearing surfaces (L) sliding relative to one another of a movable body (1, 3) and a stationary body (2). Compressed air is expanded through nozzles (4) between the bearing surfaces (L) to atmospheric pressure. As a result of these air flows, the static pressure between the bearing surfaces (L) is reduced so that compressive forces acting between the moving and the stationary body are produced. The bearing surfaces (L) and air flows are so matched to one another that the movable body (1, 3) is in a force-free state of equilibrium on assuming a position in which the bearing surfaces (L) of the movable body (1, 3) are not in contact with the bearing surfaces (L) of the stationary body (2). In order to ensure a clearly defined equilibrium position, the clearance between the movable body (1, 3) and the stationary body (2) is chosen so that any possible change of the spacings between the bearing surfaces brings about an opposing change of the pressure ratios.

Abstract: For increasing the tensile force on the draw rod (4) of a tool spindle clamping device, in addition to a first, pretensioned spring assembly (8) between the draw rod (4) and sleeve (1) is a second spring assembly (15), which is coupled in pretension with a fastener (17, 18) between the proximal end of the sleeve (1) and the proximal end of the draw rod (4). In operation, the two spring assemblies (8, 15) act in parallel and lead to a tensile force of approximately 18,000 to 20,000 N with which the cone (7) of a tool (6) fixed to the draw rod (4) is drawn into an internal cone (2) of the sleeve (1). For ejecting the tool (6), the second spring assembly (15) is uncoupled from the draw rod (4) and the draw rod is moved against the distal end of the sleeve (1). For uncoupling the second spring assembly (15) from the draw rod, a hydraulically operated piston (20) is provided at the proximal end of the clamping device.