Linde Hydraulics Gmbh & Co. Kg

Rolf Lasaar

Lukas Krittian

Markus Jung

Alfred Langen

Thomas Loeffler

Thomas LÖFFLER

Günter Hofmann

A hydrostatic variable displacement pump () has a displacement volume set by an electro-hydraulic control device () provided with a safety function. In a fault scenario, the variable displacement pump () is set to a neutral position. The electro-hydraulic control device () has a single electro-hydraulic setpoint encoder () to specify the setpoint of the displacement volume of the variable displacement pump () and an electrically actuatable valve device () connected in series downstream of the setpoint encoder (), by which the direction of displacement of the variable displacement pump () is controlled and which is provided with the safety function.

Hydrostatic variable displacement pump which can be set in either direction of displacement

A hydrostatic power unit () comprises a variable displacement machine with a continuously variable displacement volume and is operated as a pump and motor and is in a drive connection with an internal combustion engine (). When operated as a pump, the power unit sucks hydraulic fluid out of a tank () and delivers into a delivery side (P), and, when operated as a motor, functions as a hydraulic starter to start the internal combustion engine (). When operated as a motor, the power unit is supplied with hydraulic fluid from a hydraulic accumulator (). The displacement volume of the power unit () is set by a displacement volume control device () actuated by a positioning piston device () supplied with hydraulic fluid from a charging pressure circuit (). The power unit () includes a supplemental positioning piston device () in an operative connection with the displacement volume control device () and which is actuated directly by the pressure present in the hydraulic accumulator (). By means of a connection of the supplemental positioning piston device () with the hydraulic accumulator, the power unit () can be adjusted to increase the displacement volume to start the internal combustion engine ().

Hydrostatic power unit

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Grossostheim, Germany

Rolf Lasaar