Abstract: A drive unit (10) for a foldable safety barrier boom (100) having a drive motor (12), in particular a drive motor (12) with a brake; a threaded spindle (16) which is coupled with the drive motor (12) such that the rotational movement of the output of the drive motor (12) is transmitted to the threaded spindle (16), and which is coupled with a spindle nut (18), such that it linearly moves along a slide guide (21) arranged in parallel to the threaded spindle (16) upon rotation of the threaded spindle (16); a slide (20) which is fixedly coupled with the spindle nut (18); and a coupling joint (27), in particular in the form of a coupling rod (27), which is jointly provided at the slide (20) for jointly coupling the slide (20) to a barrier arm (110) of the safety barrier boom (100).

Abstract: A hydrostatic system has a pressure source and a hydraulic motor or a consumer. An additional hydraulic motor/pump unit is furnished for controlling the volumetric flow for the consumer or the power output of the hydraulic motor.

Abstract: A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.

Abstract: A hydrodynamic machine for producing a braking torque, the hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and a hydraulic system including an open loop and closed loop control unit, a working medium accumulator, a line system, a pump operable to produce a volume flow circulation of a working medium through the line system and the toroidal working chamber, a heat exchanger, and a pressure control valve operable to control or adjust the baking performance or the braking torque.

Abstract: A hydrodynamic machine for producing a braking torque, the hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and a hydraulic system including an open loop and closed loop control unit, a working medium accumulator, a line system, a pump operable to produce a volume flow circulation of a working medium through the line system and the toroidal working chamber, a heat exchanger, and a pressure control valve operable to control or adjust the baking performance or the braking torque.

Abstract: A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.