Linde Material Handling Gmbh

Burkhard Sturmer

Martin Steigerwald

A hydrostatic pump () with a variable displacement volume can be operated in a closed circuit and is driven by a drive engine (), in particular by an internal combustion engine. To control the displacement of the pump (), a control device () is provided which can be actuated as a function of the speed-dependent control pressure which is a function of the speed of the drive engine (). To improve the control characteristics of the pump, a switchover device () is provided, by which the pump () can be switched between a speed-dependent displacement control by the speed-dependent control pressure and a volume flow-dependent delivery control, in which the control device () of the pump () can be controlled as a function of the actuation of an actuator mechanism ().

Hydrostatic pump

A hydrostatic pump () has a mechanical displacement volume control with a mechanical control element (), which for generation of an actuator pressure that acts on a positioning piston () which is functionally connected with a displacement setting device (), has a position-controlled control valve () functionally connected with a control lever () and with the displacement setting device () of the pump (). A pump with a mechanical displacement volume control with a pressure limiting function can be accomplished by mechanically decoupling the control lever () from the displacement setting device () whereby a pressure cutoff function is provided, with which, by respective pilot valves (), a pressure signal can be generated from a delivery line () of the pump (), which signal is transmitted via the control valve () to the positioning piston () and counteracts the control pressure.

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Kleinostheim, Germany

Burkhard Sturmer