Abstract: The invention concerns a pressure-limiting valve to limit the pressure of hydraulic oil which can be admitted through two intakes, consisting of a control rod in a cylindrical housing equipped with the two intakes, which can be moved against spring force, which, when one intake is exposed to oil under high pressure, connects the other intake supplied with oil kept under low pressure to an outlet leading to the pressure-limiting valve. A pressure-limiting valve of simple construction, which easily installed, is achieved through the fact that the control rod is provided with an axial hole in which a second control rod can be moved against the force of at least one limiting spring adjusted to the pressure to be limited, and that the first control rod, depending on which of the two intakes is subjected to the high pressure, is pushed into a position in which the second control rod connects the intake that is under low pressure to an outlet opening, while overcoming the force of the limiting spring.

Abstract: A hydrostatic axial piston machine has a drum-like cylinder block which is supported in a manner fixed against rotation on a driving or output shaft and is provided concentrically and parallel to its center line with cylinder boreholes in which axially displaccable pistons are arranged which are supported via spherical heads on a slanting disk which is fixed to the housing and preferably adjustable in its slanting angle. The cylinder openings opposite the slanting disk sweep over roughly kidney-shaped low pressure and high pressure control openings of a control body, between which reversing regions with additional boreholes are located. To control the additional boreholes, which influence the pressure increase or the pressure drop on the passing of the cylinder openings over the reversing regions, in dependence on the operating states, a borehole opens at least in a reversing region of the control body which is connected to the high pressure side or the high pressure control opening by a line.

Abstract: The invention concerns a pressure-limiting valve to limit the pressure of hydraulic oil which can be admitted through two intakes, consisting of a control rod in a cylindrical housing equipped with the two intakes, which can be moved against spring force, which, when one intake is exposed to oil under high pressure, connects the other intake supplied with oil kept under low pressure to an outlet leading to the pressure-limiting valve.

Abstract: A hydrostatic axial piston machine has a drum-like cylinder block which is supported in a manner fixed against rotation on a driving or output shaft and is provided concentrically and parallel to its center line with cylinder boreholes in which axially displaccable pistons are arranged which are supported via spherical heads on a slanting disk which is fixed to the housing and preferably adjustable in its slanting angle. The cylinder openings opposite the slanting disk sweep over roughly kidney-shaped low pressure and high pressure control openings of a control body, between which reversing regions with additional boreholes are located. To control the additional boreholes, which influence the pressure increase or the pressure drop on the passing of the cylinder openings over the reversing regions, in dependence on the operating states, a borehole opens at least in a reversing region of the control body which is connected to the high pressure side or the high pressure control opening by a line.

Abstract: Vehicles with differential speed steering are provided having a hydrostatic transmission on each side for driving the drive wheels on that side, a spring-loaded servo piston operating a final control element of each transmission, at least one control pressure pick-off connected to the operating cylinders for controlling forward and backward travel, a pair of second control pressure pick-offs connected with the operating cylinders for controlling turning, a manually controlled pilot valve in a connection between the second control pick-offs and the operating cylinder and a control pressure reducing valve acting on the second control pressure pick-offs reducing the pressure to prescribed characteristics independently of the incoming pressure with respect to the actuation path.

Abstract: Control for a continuously adjustable drive, equipped with a signal transmitter arbitrarily actuatable by a manipulation element, in which the conversion setting imposed on the drive is influenced by the position of the manipulation element, in which case an additional r.p.m.-dependent signal is superimposed on the signal emitted by the signal transmitter, at least at excessively small drive r.p.m.'s, where the arbitrarily adjustable signal transmitter preferably is a pressure-regulating valve to which the pressure impounded in front of a restrictor in the delivery line of a constant pump is fed.

Abstract: A regulating device is provided for an aggregate of several pumps driven by a primary source at least one of which is adjustable and with a constant volume auxiliary control pressure pump driven by the same primary source in the delivery line of which a restrictor is located with the pressure gradient in front of and following the restrictor acting on the control pressures of an hydraulically regulated discharge valve in a drain line connected to the delivery line of the auxiliary pump, the drain line being connected in front of the restrictor, adjusting means connected to each adjustable pump and a control pressure line to which all adjusting means are connected, branching off from the drain line ahead of the discharge valve.