Robert Boschgmbh

Heiko Witte

Martin Behm

A hydrostatic transmission for a traction drive of a mobile working machine includes a variable-displacement pump and one or more motors connected to one another in a closed hydraulic circuit. An electronic control unit of the hydrostatic transmission is configured to initiate and to end a braking operation by the hydrostatic transmission if a traveling speed of the mobile working machine reaches a threshold value. The threshold value is adjustable by the electronic control unit automatically or in a manner dependent on a driver demand. The braking torque is also adjustable.

Hydrostatic transmission and method for braking using the same

A hydrostatic transmission for a traction drive includes a variable-displacement pump and one or more motors coupled to one another in a closed hydraulic circuit. A braking operation by means of the transmission can be initiated in the traction drive by an electronic control unit if there is a risk of overspeeding of an associated internal combustion engine. The braking operation is initiated if at least two activation thresholds are overshot, of which a first activation threshold is variable whereas the further activation threshold is fixed or variable.

Hydrostatic transmission with overspeed protection facility

A hydrostatic transmission for a traction drive includes a variable-displacement pump and one or more motors coupled to one another in a closed hydraulic circuit. A braking operation is introduced into the traction drive via the hydrostatic transmission, and is controlled in closed-loop fashion by an electronic control unit. A braking torque is controlled in closed-loop fashion indirectly by a swept volume of the secondary unit, for which purpose one or two closed-loop controllers are provided.

A hydrostatic transmission with which a braking operation is realized in which at least one traction motor which acts as a pump is supported via a closed circuit on an adjustable axial piston pump which acts as a motor, and which in turn is supported on an internal combustion engine. Since overspeeding of the latter should be avoided, pilot control is performed with a rotational speed that is subcritical for the internal combustion engine, and thereafter closed-loop control is performed with a closed-loop controller which outputs a corrective value in a manner dependent on the rotational speed deviation between the present rotational speed and the maximum and thus ideal rotational speed of the internal combustion engine.

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Ulm, Germany

Heiko Witte