Modules with functional safety for hydrostatic travel drives

: Released: 17.02.2016; Last updated: 06.09.2022; Hits: 6045

Vehicle manufacturers achieve significantly less effort for the integration and application of hydrostatic travel drives in construction machinery with function modules from Bosch Rexroth. They combine innovative functions with safety that has already been analyzed and standardized in accordance with the Machinery Directive. In addition, the developers have examined all components and their interactions with one another and further improved the robustness of the function modules.

For a whole series of function modules, the risk analyzes of the Machinery Directive were already carried out in accordance with the standards and from this the required performance levels b and c were determined according to the C standards applicable to the application. The standard configuration of the function modules fulfills these performance levels in hardware and software. In addition, the developers have shown the causal relationships in the system on the basis of FMEA considerations. On the basis of real measured load collectives in numerous applications, the system loads were determined and the components matched to it.

Bosch News: State-of-the-art semiconductor factory opened in Dresden

The control of the hydrostatic travel drives with the standard safety functions is integrated in the driveline software DRC. With a low engineering effort, vehicle manufacturers can equip their wheel loaders or telehandlers with these drive solutions. The traction module 2 + 1 ensures up to 20% lower fuel consumption and traction-free driving. The diesel engine, which is powerful up to 130 kW, drives an adjusting motor and a constant motor via an axial piston pump. The driving range is changed automatically and driving speeds up to 40 km / h can be achieved. The software integrated in the control unit prevents traction interruptions and noticeably increases operator comfort. This functional module is suitable for construction and agricultural machinery between 6 and 16 t Operating weight and tensile forces up to 120 kN.

The Shift on Fly function also fulfills the functional safety requirements of DIN EN ISO 13849 and controls both manual and automatic switching. The software has an optimized shift strategy, which enables safe shifting in different driving situations. Short, synchronized shifts increase comfort. In addition, it provides additional driving and comfort functions tailored to the system. The functional module with hydraulic pump, hydraulic motor, control unit with software and a gearbox offers increased efficiency of the overall drive. Both 2 + 1 and Shift on Fly cover a large performance variance by a variety of combinations of different pumps and engine sizes.

Housing bearing replacement saves significant TCO

In addition, Rexroth supports manufacturers of compact construction equipment and wheel loaders with the Hydraulic Start-Stop HSS to reduce exhaust and noise emissions. The function module switches off the diesel engine automatically in standstill phases and starts it automatically with previously stored hydraulic energy if necessary. The required torque is immediately available. The solution consists of a Axialkolbenverstellpumpe, a valve block, a compact memory and a Bodas controller with pre-programmed software.