024-11 Lohr, 2011-04-04

Silent Machines release Operators

For many applications, the external gear pump SILENCE PLUS from Rexroth eliminates the need for seco

For many applications, the external gear pump SILENCE PLUS from Rexroth eliminates the need for secondary noise reduction measures.

External gear pump SILENCE PLUS from Rexroth lowers noise levels by an average of 15 dB(A)

Throughout the entire pressure range of up to 280 bar, Rexroth's new external gear pump SILENCE PLUS reduces noise emissions by an average of 15 dB(A) compared to conventional external gear pumps. In lower pressure ranges of under 50 bar used in coolant, filter and lubricant cycles, it runs almost without noise. For many applications, this eliminates the need for secondary noise reduction measures. In addition, Rexroth also moved the measurably reduced noise into a lower frequency range.

Field tests have shown that at lower pressure ranges, the increase in noise emission from the electric motor caused by the pump is barely noticeable. At a working pressure of 10 bar, airborne noise increases by only 3dB(A) from 52db(A) to 55dB(A). In addition, by moving the noise into a 35 percent lower frequency range, its pitch is close to that of the electric motor. The result: A low-pitched ambient working noise that is much more pleasant compared to other external gear pumps.

The design prevents oil from getting trapped between the tooth flanks, and reduces pressure pulsation in the system by around 75 percent. This reduces body-borne noise throughout the entire hydraulic cycle. The new pump seamlessly complements Rexroth's broad spectrum of pumps. Having identical mounting dimensions, it is fully compatible with the other pump models of Rexroth's standard and SILENCE series, and therefore enables users to exchange pumps without having to make any design changes.

The high-precision external gear pump ensures full-surface zero-clearance dual-flank contact in all areas of the gears. The pump's helical gearing with a non-involute tooth profile creates a closed line of contact in the form of the figure 8. The first variant includes nominal sizes with a performance range of 12 to 28 cm³/revolution.

The extremely quiet hydraulic pump is especially well-suited for use in tool and paper-cutting machines, passenger elevators and car lifts as well as material handling or waste presses in residential areas. Depending on the application, the SILENCE PLUS pumps also complement the range of pumps used in Rexroth's variable-speed pump drives which reduce the energy consumption of hydraulic power units by up to 80 percent.

Further details are available on the Internet at

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 industrial applications and factory automation, mobile applications and using renewable energies. As The Drive & Control Company, Bosch Rexroth develops, produces and sells components and systems in more than 80 countries. In 2009 Bosch Rexroth part of the Bosch Group, achieved sales of around 4.1 billion Euro with 34,200 employees.

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The Bosch Group is a leading global supplier of technology and services. According to preliminary figures, some 283,500 associates generated sales of 47.3 billion euros in the areas of automotive and industrial technology, consumer goods, and building technology in fiscal 2010. The Bosch Group comprises Robert Bosch GmbH and its more than 300 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. Bosch spent some four billion euros for research and development in 2010, and applied for over 3,800 patents worldwide. With all its products and services, Bosch enhances the quality of life by providing solutions which are both innovative and beneficial.

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