PI 008-16 Lohr am Main, 2016-01-20

Simple parameterization of the fan speed control

Fast engineering: the predefined BODAS software AFC30 from Rexroth requires only the input of individual parameters for the fan speed control to produce the optimum cooling performance as and when it

Control solution for hydrostatic fan drives evaluates up to six different temperature signals

Today's exhaust gas emission regulations increase the demands on cooling capacity in combustion engines in on-highway and off-highway vehicles by up to 40 percent. Hydrostatic fan drives from Rexroth supply this additional performance on demand while saving installation space. The newly developed AFC30 control solution from the BODAS electronic modular system by Rexroth requires only a simple parameterization. The fan speed control, which works on demand, reduces fuel consumption by up to five percent.

The fan speed control from Rexroth is based upon the controller RC4-5/30 that is in large-scale production and the AFC30 standard application software from the BODAS modular system. The software is simple to parameterize and it controls the fan power according to individual setpoint specifications, independent of the combustion engine speed. It also records up to six different temperature signals digitally via CAN bus or via connected analog sensors and adjusts the power accordingly. The software takes external fan requirements into consideration, i.e. a retarder signal and additionally supports other functions such as a fan rotation limit as overspeed protection or an after-run function for a controlled switch off. Thanks to the modular layout of the software, other functions can also be easily implemented. The control communicates with the engine, gears and retarder control units via the SAE J1939 CAN bus record. Diagnosis and parameterization take place via the PC software BODAS-service or—if it is available—via the new BODAS DI4 display. The system independently monitors for cable breaks and short circuits. Vehicle manufacturers connect optional operating elements either directly with the controller or via CAN bus.

During day-to-day work, mobile working machines regularly suffer from contamination of the cooler fins by dust and dirt, which reduces the cooling performance. The control remedies this with a cleaning reversing function. The fan changes its direction of rotation either on manual demand or at defined time intervals, and blows the dirt outwards. During the start phase and at very low ambient temperatures, the "fan standstill" option for the fan wheel switches off the rotation completely, thus reducing exhaust emissions under these unfavorable operating conditions. In total, the fan speed control, which works on demand, reduces fuel consumption by up to five percent.

AFC30 is designed for the control of hydrostatic fan drives in open circuits. It supports various hydraulic configurations with variable and constant pumps, as well as with fixed motors to drive the fan wheel. Designers place the hydraulic pumps, pipes, control elements as well as the cooler and the fan wheel wherever there is space in the construction machine. Thanks to its high flexibility with regard to space, the modular system of the hydraulics fulfills the increased requirements of the cooling capacity.

Economical, precise, safe, and energy efficient: drive and control technology from Bosch Rexroth moves machines and systems of any size. The company bundles global application experience in the market segments of Mobile Applications, Machinery Applications and Engineering, and Factory Automation to develop innovative components as well as tailored system solutions and services. Bosch Rexroth offers its customers hydraulics, electric drives and controls, gear technology, and linear motion and assembly technology all from one source. With locations in over 80 countries, more than 33,700 associates generated sales revenue of approximately 5.6 billion euros in 2014.

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The Bosch Group is a leading global supplier of technology and services. It employs roughly 360,000 associates worldwide (as per April 1, 2015). The company generated sales of 49 billion euros in 2014.* Its operations are divided into four business sectors: Mobility Solutions, Industrial Technology, Consumer Goods, and Energy and Building Technology. The Bosch Group comprises Robert Bosch GmbH and its roughly 440 subsidiary and regional companies in some 60 countries. Including its sales and service partners, Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for further growth. In 2014, Bosch applied for some 4,600 patents worldwide. The Bosch Group’s strategic objective is to create solutions for a connected life. Bosch improves quality of life worldwide with products and services that are innovative and spark enthusiasm. In short, Bosch creates technology that is “Invented for life.”

Additional information is available online at , and

*The sales figure disclosed for 2014 does not include the former joint ventures BSH Bosch und Siemens Hausgeräte GmbH (now BSH Hausgeräte GmbH) and ZF Lenksysteme GmbH (now Robert Bosch Automotive Steering GmbH), which have since been taken over completely.


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Susanne Herzlieb
Maria-Theresien-Straße 23
97816 Lohr am Main
Phone: +49 9352 18-1573

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