007-13 Elchingen, 2013-01-29

Strong and effective – Optimal application with Rexroth 4EE

A1VO axial variable displacement pump

Small, strong, and efficient: the A1VO axial variable displacement pump presents an attractive opportunity to switch to a variable fan drive system.

The A1VO axial variable displacement pump improves fan drives in construction machinery

  • Solutions for reducing emissions
  • Energy efficiency considered from the start

Bosch Rexroth aims to optimize machines and systems to ensure the best possible productivity with the lowest possible energy consumption. The comprehensive Rexroth 4EE (Rexroth for Energy Efficiency) approach helps manufacturers use their construction machinery in an optimal manner at the best possible level of energy efficiency. Thanks to flexible solutions and advisory services, manufacturers can optimize their current vehicle lines and develop new models that meet the TIER 4 final standard, for instance. At BAUMA 2013 in Munich, Bosch Rexroth is showing how this aim can be achieved with the A1VO axial variable displacement pump.

With its 4EE concept, Bosch Rexroth has developed an approach that makes it possible to develop new machine concepts and optimize existing systems and devices. The concept applies four levers to significantly improve the energy efficiency of machines and systems throughout their life cycle. First, energy system design focuses on energy efficiency in the early development phases of new solutions and optimization. Second, the aim of efficient components is to ensure that energy is used in the most efficient manner possible by applying energy-efficient products and systems. Third, energy recovery aims to use hydraulic accumulator charging circuits and electric drives with feedback capability to store unused energy that can be used at a later date. And finally, energy on demand focuses on managing energy needs and achieving high energy savings, for instance by switching off unneeded components.

The 4EE system offers effective solutions for the construction machinery market, particularly with regard to reducing emissions, which has become an important issue for manufacturers and operators. The TIER 4 norm in the United States and Europe’s off-highway Stage IV have set new standards for major markets in Europe, North America, and Japan Without doubt, the new norms will have an impact on global markets. In recent years, regions around the world have tended to adopt new emissions standards in the years following legislation in the industrialized nations.

Manufacturers are meeting these challenges primarily with the latest generation of diesel engines. Depending on engine performance, exhaust gas treatment systems play an important role. In addition to other challenges, the requirements of the temperature management system also become more complex. Increasingly, these requirements exceed the technical limitations of fixed systems, for which fan speed is often directly related to diesel engine speed.

With the A1VO axial variable displacement pump, Bosch Rexroth provides an attractive opportunity for switching to a variable fan drive system that provides exactly the amount of cooling needed in an energy-efficient manner. The attractiveness of the A1VO lies on the one hand in its cost effectiveness. Compared with other axial piston variable displacement pumps, the price difference to the fixed gear pumps that are generally applied is significantly smaller. On the other hand, the size of this Rexroth development is comparable to that of gear pumps, which makes it even easier for manufacturers to switch technologies.

The A1VO is an alternative for many hydraulic systems that have been equipped with fixed pumps until now. For instance, it has already been successfully applied in small tractors. With a peak pressure of 315 bar and output of up to 105 liters per minute, the A1VO’s performance is unprecedented, with nearly 90 percent efficiency. For a tractor typical of this market segment with a 90 horsepower diesel engine, the A1VO reduces fuel consumption by between 10 and 15 percent per hour. This represents fuel savings of 10,000 liters over an operating period of 6,000 hours.

Bosch Rexroth AG is one of the world’s leading specialists in the field of drive and control technologies. Under the brand name of Rexroth, the company supplies more than 500,000 customers with tailored solutions for driving, controlling, and moving. Bosch Rexroth is a partner for mobile and machinery applications, engineering, factory automation as well as renewable energies. The company covers the requirements and special needs of each of these markets. As The Drive & Control Company, Bosch Rexroth develops, produces and sells components and systems in more than 80 countries. In 2011, Bosch Rexroth, part of the Bosch Group, achieved sales of around 6.4 billion euros with 38,400 employees.

For more information, please visit

The Bosch Group is a leading global supplier of technology and services. In the areas of automotive and industrial technology, consumer goods, and building technology, over 300,000 associates generated sales of 51.5 billion euros in fiscal 2011. The Bosch Group comprises Robert Bosch GmbH and its around 350 subsidiaries and regional companies in over 60 countries. If its sales and service partners are included, then Bosch is represented in roughly 150 countries. This worldwide development, manufacturing, and sales network is the foundation for further growth. In 2011, Bosch spent approximately 4.2 billion euros on research and development and applied for over 4,100 patents. With all its products and services, Bosch enhances the quality of life by providing solutions which are both innovative and beneficial.

For more information please visit: ,


Search press releases


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