Rexroth opens up new fields of applications with planetary screw assemblies with new sizes. The drive elements with screw diameters up to 75 mm and leads up to 20 mm achieve static load capacities up to 1,496 kN while featuring a compact design. They are ideal for use in medium sized and heavy-duty machinery such as presses, plastic injection molding machines and machine tools.

All electric presses and injection molding machines are reaching increasingly higher performance classes. This places more exacting demands on mechanical axis systems, which have to transmit exponentially higher forces. Rexroth now meets these requirements with planetary screw assemblies that feature diameters of 60 and 75 mm as well as leads of 10 and 20 mm each. Moreover, screw diameters of 20, 30, 39 and 48 mm with leads of 5 and 10 mm are available. The new sizes cover dynamic load capacities up to 544 kN and static load capacities up to 1,496 kN within a minimum of installation space. The drive units represent robust drive solutions for use in high force applications, such as process or plastic injection molding machines. The design principle of planetary screw assemblies allows a high load capacity in relation to the installation dimensions. The planets rotate with a defined contact profile in a nut around a screw in parallel to the axis. This ensures very smooth running and reduces noise emission. Numerous contact faces result in high axial stiffness and load capacities, thus allowing for a long service life.

These screw assemblies feature a high positioning accuracy and repeatability, also with minimal travel movements. Planetary screw assemblies can reach travel speeds of up to 1.5 m/s (90 m/min), thereby meeting increased dynamic requirements for shorter machine cycles. When combined with a servomotor and drive controller, the user gets a mechatronic unit from a single source, which moves large forces within a minimum of installation space. Compact cylindrical single nuts, flange single nuts and split flange single nuts for all tolerance classes offer the designer a high degree of freedom. For applications with more demanding precision requirements, all nut types are available preloaded. This allows backlash-free operation in tolerance classes T7 and T5.

Rexroth’s innovative sealing technology in planetary screw assemblies results in long lubrication intervals. This reduces maintenance costs and spares the environment due to a lower consumption of lubricants. In manufacturing the screws, Rexroth benefits from its experience in the efficient roll-forming process. This technology, which has proven successful in large series production, achieves the same accuracy levels as the more expensive grinding process. Rexroth supplies the planetary screw assemblies ready-to-install with machined ends.

High-performance cylinder drive from Bosch Rexroth optimizes mold oscillation. The electro-hydraulic high-performance linear drive from Bosch Rexroth makes it possible to control all oscillation parameters while casting. Thanks to this flexibility in terms of control, various curve shapes can be implemented in order to optimize the oscillation. Both the stroke amplitude and the oscillation frequency can be varied during the casting process along with the casting speed. If no radial forces come into play, users can opt for Rexroth’s cost-effective
high-performance cylinders. The high-performance series of cylinders are of modular design. The modular system comprises of five force levels from 16 to 250 kN with two predefined styles of mounting, those being “trunnion” or “head flange”. The equal effective areas of the cylinder ensure good controllability, even with highly dynamic applications up to a maximum frequency of 50 Hz. The basic version of the high-performance cylinder is fitted with a connection block, associated valves, pressure accumulator, damper accumulator and measuring points. An integrated magnetostrictive position measurement system for position sensing is available as an option.

The recently expanded Fountain Inn, South Carolina campus, operating since 1989, specializes in manufacturing hydraulic pumps and has additional training, R&D and shipping capabilities.

In November 2014, Bosch Rexroth celebrated the 25th anniversary of its Fountain Inn, SC hydraulics production facility. After undergoing an expansion in 2013, the location is home to the company’s largest hydraulics manufacturing facility in the Americas.

Opened in 1989, the facility was originally made up of a single 250,000 sq. ft. building and specialized in manufacturing hydraulic pumps.

Now, the Fountain Inn facility is more than double its original size in order to better serve its customers in the region and beyond. Rexroth last year converted an existing industrial warehouse into a state-of-the-art manufacturing and assembly facility, bringing the whole campus to a total of 510,000 sq. ft. The plant occupies more than 100 acres of land and employs more than 700 associates.

The expansion was done as part of Bosch Rexroth’s ongoing “local for local” strategy. Rexroth believes in focusing on localized business growth opportunities like Fountain Inn so it can more directly foster relationships with local and regional customers and supply fast domestic shipping to customers.

The expanded Fountain Inn space enabled Bosch Rexroth to similarly broaden the site’s capabilities. With the expanded campus, the company not only manufactures but also assembles its industry-leading hydraulic pumps and motors, and large hydraulic vane motors – used in mobile and industrial hydraulic systems. Specifically, the Fountain Inn campus has full-scale production and assembly capabilities for the following Rexroth products:

• A22VG, A24VG Axial Piston Variable Double Pump
• A10VO/31, A10VO/52 Variable Displacement Pumps
• A4VG/32, A10VG Variable Pumps
• Rineer High Torque Vane Motors

Over the past 25 years the company has added product engineering and research and development resources, as well as a hands-on apprentice shop for the company’s trainees. It also supports the mobile aftermarket, offering remanufacturing, spare parts and repairs.

“Bosch Rexroth has always emphasized quality, domestically manufactured products and customer satisfaction,” said Mike McCormick, vice president and technical plant manager at Bosch Rexroth. “Our Fountain Inn plant has exemplified these priorities for the past 25 years. We’re pleased that our facility also provides value-added services including R&D, training and faster delivery.”

The additional resources at Fountain Inn have grown Rexroth’s shipping capabilities in North America. The Drive & Control Company has enhanced its GoTo Focused Delivery Program, expanding its capacity to quickly deliver high-demand products like the A10VO hydraulic pump to customers in the region.

The Fountain Inn campus is one of four Rexroth manufacturing facilities in the United States. With additional locations in Illinois, Pennsylvania and North Carolina, Rexroth continues to serve its broad customer base throughout the region.

The trend toward increased machine safety has significant effects for OEMs. Starting in the EU, the number of standards and norms has increased exponentially since the 1990s. Also, regional and national safety standards now apply more frequently in addition to international standards. OEMs with an international focus must implement the regulations of every target market in order to be able to market their products there.

Simultaneously, the content needs of state-of-the-art safety technology also has increased significantly. A complex system analysis of automation for the evaluation of machine safety has become the norm in nearly all markets. Control systems and software are central components in overlapping technologies. Bosch Rexroth, a worldwide leading manufacturer of drive and control technologies, established a network of safety specialists within its global organization. They capture the requirements of the respective market and develop regionally adapted solutions. Rexroth makes this expertise available to OEMs and end users and therefore improves their chance for success on global markets. “Specifically smaller and mid-sized manufacturers like to take advantage of our services for machine safety,” says Michael Jochem, who is responsible for coordinating machine safety activities at Bosch Rexroth on an international level. This ranges from ready-to-install modules to complete engineering of safety solutions which includes extensive documentation.

“For many years we have noted the increase of machine safety regulations globally,” says Michael Jochem. “We see very different approaches to this in significant markets, some of which grew historically, but often also have industrial-political motivations.” This rule applies: the more international standards that apply in a market, the more open it is with greater machinery engineering export opportunities. The EU, China, and even Turkey have significantly reduced their share of national regulations over the past years.

This overview will show the wide variety of standards regarding machine safety in significant markets:

European Union: Pioneer for system approach
With the Machinery Directive 2006/42/EC, the European Union not only harmonized a plethora of national standards, it also introduced a new system that is a global role model. Since the end of 2009, only machines that comply with the Machinery Directive may be marketed within the EU. OEMs are responsible for this. They must document the functional safety of every machine and must include the documentation in the delivery.

“The Machinery Directive harmonized the system across all industries and applications,” says Wouter Leusden, Safety Specialist at Bosch Rexroth in BENELUX. “Whether machine tools, packaging lines, or movable bridges: design engineers must always perform a risk assessment, define the required performance level for functional safety, and offer reliable realization with the respective system solutions.” In the handbook “10 Steps to Performance Level,” Bosch Rexroth has divided this complex process into practical work packages. “Engineers often have difficulties understanding the current standards,” explains Wouter Leusden. “Our handbook was written by experts for experts, and customers frequently confirm that the handbook has helped them.” The brochure “10 Steps to Performance Level,” which can be downloaded free of charge at www.boschrexroth.com/safety, offers a first overview of the handbook.

“Approximately 50 percent of safety-relevant standards and norms are globally valid IEC or ISO standards,” estimates Frederic Harmand, coordinating the Safety Specialists in France. “The other half comes from European institutions, for example the European Committee for Standardization (CEN) and the European Committee for Electro-Technical Standardization.“ In the process, the status of the European environment for standards has stabilized over the past five years. “This offers reliable framework conditions for OEMs,” says Frederic Harmand.

USA: On the way to harmonization
The environment for standards in the US has grown historically and is very diverse. The number of standards and norms has increased significantly since the turn of the millennium. The absolute number of standards is even higher than in Europe. “This is primarily because the US has a plethora of state agencies on a national level and for each individual state, in addition to independent organizations, which issue standards,” explains Angela Patterson, Safety Specialist at Bosch Rexroth in the US. Her colleague Gary Thrall adds: “We clearly see a trend toward harmonizing American standards with European standards.”

Today, 70 percent of relevant regulations in the US already correspond to international or European standards. “Our customers in the US can profit from our extensive experience with European requirements,” explains Gary Thrall. But there are still standards specific to America. “We also support European OEMs in complying with these American regulations in order to be on the safe side,” says Angela Patterson.

China and Turkey: All focused on international standards
International standards simplify market access for all OEMs globally, while a high proportion of international standards favors the export opportunities of domestic OEMs. The basic concept of every machine or facility already takes these standards into consideration. This significantly reduces the adaptation requirement for other markets. Specifically, export-oriented nations like China or Turkey take this route.

“The topic of machine safety becomes more and more important for Chinese OEMs and they have quickly adjusted to international standards,” says Guihua Ying, Safety Specialist at Bosch Rexroth in China. “While many manufacturers initially focused on Asian and African markets, they now focus on the European and American markets that are highly regulated by standards.” This is where Chinese safety specialists can support compliance with additional, regional regulations.

“Atilla Yavuz describes the initial situation: “When it comes to machine safety, Turkey focuses almost exclusively on European and international standards.” In this, Engineering Department Manager at Bosch Rexroth in Turkey sees significant advantages for machinery construction. “Machinery construction is, after all, the second largest industry sector among Turkish exports,” says Atilla Yavuz. “The international harmonization of the standards environment reduces adaptation requirements for exports into other counties. With success: after all, Turkey’s five largest OEMs export into more than one hundred countries.”

Other major markets like India are only starting this journey and are currently developing guidelines for machine safety.

Brazil: Regulations capture even installed machines
Brazil, as one of the BRICS states, has made great progress in terms of industrialization and is one of the most significant markets for machinery construction. “The number of standards for machine safety has doubled in the past five years, but Brazil focuses chiefly on international and European standards,” says Fernando Lopes. The Safety Specialist at Bosch Rexroth in Brazil points out that the standard NR12, which was revised in 2010, is closely related to the European Machinery Directive. Yet there is one important difference, emphasizes his colleague Makoto Yokoyama: “NR12 also applies to machines and facilities that are already installed. Old facilities can be re-sold only if they comply with NR12.” Bosch Rexroth therefore retrofitted already more than 400 installed presses based on the new safety requirements.

“We work closely with European and American OEMs to develop standard-compliant machine concepts for the Brazilian market,” says Fernando Lopes of his daily work. “At the same time, we are the established contact person for end users when it comes to retrofitting their installed facilities, because Rexroth develops and implements standard-compliant, cross-technology solutions.”