Abstract: The invention relates to a dry-running piston rod sealing arrangement (1) for sealing a piston rod (2) mounted in a longitudinally displaceable manner. The sealing arrangement comprises at least one sealing ring (5) having a sealing surface (5a), an actuator (7), a sensor (8), and a chamber ring (3) containing the sealing ring (5). The actuator (7) comprises an active connection in relation to the sealing ring (5), such that the sealing surface (5a) can be radially displaced in relation to the piston rod (2). The actuator (7) can be controlled according to a measuring value detected by the sensor (8).

Abstract: The invention relates to a dry-running piston rod sealing arrangement (1) for sealing a piston rod (2) mounted in a longitudinally displaceable manner. Said sealing arrangement comprises at least one sealing ring (5) having a sealing surface (5a), an actuator (7), a sensor (8), and a chamber ring (3) containing the sealing ring (5). The actuator (7) comprises an active connection in relation to the sealing ring (5), such that the sealing surface (5a) can be radially displaced in relation to the piston rod (2). The actuator (7) can be controlled according to a measuring value detected by the sensor (8).

Abstract: Method for the stepless regulation of the delivery of a suction valve of the plate-type of construction, comprising a valve plate which is actuated by an electromagnet arranged in a valve catcher, wherein the electromagnet is so controlled that, in a first control phase (11a), the valve plate (3) firmly contacts the valve catcher (6), or a damper plate (4) arranged between the valve catcher (6) and the valve plate (3) and is blocked, and that, in a second control phase, the electromagnet (9) is controlled by a decaying alternating current, in order to demagnetise the valve plate (3), so that the valve plate is released.