Deere + Company

Karsten Oberst

Marcus Bitter

Hendrik Nordhoff

Harald Winkelmann

A hydraulic system for an agricultural vehicle is proposed. The hydraulic system comprises a main hydraulic circuit, which is fed with hydraulic fluid by a main hydraulic pump, a variable displacement charge pump which supplies charge pressure to the main hydraulic pump, and a lubricating hydraulic circuits. In order to keep efficiency losses on the vehicle to a minimum, particularly at high engine speeds, part of the hydraulic fluid delivered by the charge pump can be diverted to the lubricating hydraulic circuit.

Hydraulic system

A two-stage brake valve includes a valve housing. The valve housing contains a chamber, one side of which serves as an equalizing reservoir which is connected directly or indirectly with at least one brake cylinder bore which is formed in the valve housing. The other side of the chamber forms an emergency steering volume for a hydrostatic steering circuit. A return line of the hydrostatic steering circuit opens into the chamber and an overflow opening communicates an upper region of the chamber through a channel to a fluid reservoir. To prevent foaming brake fluid from reaching the brake circuit, an intermediate wall separates the equalizing reservoir from the emergency steering volume. The equalizing reservoir and the emergency steering volume are connected to each other via an equalizing opening.

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Ludwigshafen, Germany

Karsten Oberst