Jungheinrich Aktiengesellschaft

Michael Knieriem

Thomas Stolten

Frank Hörmann

Nils-Peter Hansen

Benjamin Jonas

Olaf Lenz

Ulf Bergmann

Rüdiger Schwarz

Volkmar Schlüter

An industrial truck () with a lift mast (), a hydraulic system (), and a method for operating a hydraulic system (). The lift mast () of the industrial truck () is driven by a mast lift cylinder () and includes at least one mast lift stage (). A free lift stage is present that is driven by a free lift cylinder () with which a load receiving means () can be displaced along the lift mast (). The industrial truck () includes a hydraulic system () for supplying the at least one mast lift cylinder () and the at least one free lift cylinder () with a hydraulic fluid (). The hydraulic system () is configured to at least at times simultaneously actuate the at least one mast lift cylinder () and the at least one free lift cylinder () in load lifting operation and/or in load lowering operation.

Industrial truck, hydraulic system for an industrial truck and method for operating a hydraulic system

The invention relates to an industrial truck () with a lift mast (), a hydraulic system () as well as a method for operating a hydraulic system (). The lift mast () of the industrial truck () is driven by a mast lift cylinder () and comprises at least one mast lift stage (). Furthermore, a free lift stage is present that is driven by a free lift cylinder () with which a load receiving means () can be displaced along the lift mast (). The industrial truck () comprises a hydraulic system () for supplying the at least one mast lift cylinder () and the at least one free lift cylinder () with a hydraulic fluid (), wherein the hydraulic system () is configured to at least at times simultaneously actuate the at least one mast lift cylinder () and the at least one free lift cylinder () in load lifting operation and/or in load lowering operation.

Driving system with converter control for low voltage three-phase motors, which is provided with a power unit containing transistors and capacitors, a triggering unit for the transistors and a control unit as well as connections for direct and alternating current, the units being disposed in a common casing made of a heat-conductive material, characterised by the following features: the power unit is provided with a first printed circuit board () made of fairly heat-conductive material, which is disposed on the fairly heat-conductive bottom of the casing () in a plane fitting arrangement, a second printed circuit board () contains the triggering unit, the second printed circuit board () being electrically and mechanically connected to the first printed circuit board () in a spacing to it with the aid of contact pins () of metallic material attached on the first printed circuit board () by soldering, and terminal pins () are connected with contact points () of the first printed circuit board () and lead through openings in the second printed circuit board () as well as in the cover () in an insulated manner.

Driving system with converter control for low-voltage three-phase motors

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Norderstedt, Germany

Michael Knieriem