PI 035-15 Lohr am Main, 2015-09-14

New hitch control valve EHR12 for compact open center control block by Rexroth

The new EHR12 valve from Rexroth (front) supplements the proven SM12 control block for smaller tractors with the Electrohydraulic Hitch Control EHC function.

Electrohydraulic hitch control now also available for lower mid-size tractors

Rexroth now offers a compact solution for the Electrohydraulic Hitch Control EHC on lower mid-size tractors using open center technology with the new EHR12 valve. It is optimally harmonized to the modular control block SM12 from Rexroth, and the EHC function increases its appeal while simultaneously optimizing the installation space. With the proven SM12 block, tractor manufacturers can control up to ten consumers and realize all tractor-relevant functions: from pulling and alternating plows to free-moving front loaders with locking and kickout function.

Gear pumps and open center technology are widely used among tractors in the power class of between 37 to 88 kW (50 to 120 hp). In these vehicles, there is often very little installation space available for mobile hydraulics. This is why many manufacturers previously had to go without the Electrohydraulic Hitch Control EHC, even though the demand for this function has risen significantly in this class. With the newly developed EHR12 valve, Rexroth therefore offers a very compact and flexible solution for the lower mid-size range, specially designed for combination with the proven and popular control block SM12. Design engineers can install the component as a sandwich valve, pipeline valve, or end valve, as well as directly onto the tractor transmission with an additional flange. The end valve variant replaces the normally required end plate of the SM12 and thus further increases the compactness. The leak-free EHR12 with a flow rate of up to 60 l/min is based on Rexroth's 35 years of experience with the Electrohydraulic Hitch Control EHC. Rexroth also offers all the components required for a complete solution to fit the new valve: an electronic control unit with preprogrammed software, control panels and the necessary sensors.

The control block SM12 with the EHR12 hitch control valve offers a high degree of design freedom for the realization of all tractor-relevant functions, such as four positions or a free-moving front loader with locking function, in a compact package.

EHC regulates the penetration depth of the plow evenly in single and double action, even at differing resistances. The function thus allows for a sensitive tracing of the contours of the ground for optimal harvest yield. The integrated slip control of the drive wheels prevents the vehicle from becoming stuck and guarantees a gentle working of the soil. Vibration damping prevents the tractor from pitching while transporting heavy attachments or loads. This improves driving safety at higher speeds. Furthermore, practical experience has shown that EHC has a positive effect on fuel consumption compared to a mechanical control.

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, Factory Automation, and Renewable Energies 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.

To learn more, please visit

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.


Search press releases


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

Related Articles

Press Information

Pulsation halved – Noise reduced

By integrating an additional compression volume, Bosch Rexroth has cut the pressure pulsation of mobile hydraulic systems in the Rexroth A10 medium pressure pumps. This technical solution reduces the noise emissions of agricultural and forestry machinery and improves the controllability of hydraulically operated vehicle functions.

Press Information

Greater availability of agricultural and forestry machinery thanks to smart servicing

As part of the electronification of mobile hydraulics, Bosch Rexroth is developing new, data-based services for all aspects of mobile working machines. The PredictDrivetrain service from Bosch Rexroth detects wear using operating and sensor data and is able to determine the remaining service life. Thus, downtimes for tractors, combine harvesters and other agricultural and forestry machinery in the field can be avoided without the conventional, pre-scheduled preventive maintenance intervals. The lean determination of operating data also serves as a basis for the application-oriented design of mechanical components using the NextGenSpec app without the danger of undersizing or oversizing. For the assembly of new vehicles, CalibrateHydraulics significantly reduces the commissioning effort with the online transfer of test bench data for components to the OEM.