In many ways, green fluid power technology is just starting to hit its stride. Twenty years ago, a green, efficiency-minded design was little more than a feather in the cap of a fluid power system. If the fluid power industry wasn’t actively fueling its dirty technology reputation, it wasn’t working too hard to fix it either. That’s no longer the case as of the last few years. Those considering fluid power design solutions won’t have it any other way.
For a technology that treads with such a heavy industrial and environmental footprint, it’s easy to assume high-level oversight would be the norm. But it isn’t. The choice to design smaller, more efficient fluid power systems has largely been left to the will of manufacturers. For the moment at least, even Tier IV and Tier V emissions standards are having little impact on design concerns. The legislative push that nudged other industries to design green has not been nearly as strong in fluid power. It’s as if industry outsiders view fluid power as so technologically crude already, improvements would not make much of a difference. Fluid power professionals know that’s not true, but the idea is fairly common. Kevin Gingerich, manager, Communications and eBusiness at Bosch Rexroth, said that hydraulic power is far from the power source relic that it’s often viewed as.
“People seem to think of hydraulic technology as a technology from the past: Not intelligent, not precise, capable of brute force only, but today’s hydraulic drive systems are precise, compact and intelligent,” he said.
Gingerich also explained that hydraulic drive systems can position axes to a few micrometers. They can also be situated in smaller spaces because they introduce less heat into a system. “Really, the more you know about modern hydraulics, the more you realize just how modern, capable and relevant this amazing technology is,” he said.
While regulatory bodies may be silent on the need to increase fluid power’s friendliness to the environment, fluid power end users are not. Frank Langro, director of marketing and product management for Festo, said consumers began sending consistent feedback for smaller, more efficient designs about five years ago.
“The bigger, well-known companies were in the lead on this; dollars and cents drove the demand,” Langro said. “All companies want to be consumer friendly. They want to take steps to create more sustainability and protect the environment as well.”
Langro added an example, stating that if you save three cents on every widget you produce, and you’re producing millions of widgets, well, that’s quite a bit of money.
Gingerich also echoed this idea of increased consumer expectations. “Twenty years ago, nobody was asking for increases in efficiency at the level that customers are asking now.” He also said the competition for design improvements has gone global.
“Green energy needs have created an innovation revolution that is seeing new technologies being developed all the time,” Gingerich said. “It has also created a much higher level of expectation among customers, especially in Europe where energy costs are much higher.”
Out of the West, China is also heavily involved with research and development. Back from a recent Asia trip, Dr. Monika Ivantysynova, director of the Maha Fluid Power Research Center at Purdue University, said students overseas are looking to innovate and make a big impact on the industry.
“You know what is going to help green engineering in fluid power? Competition. I just returned from China and I gave talks there in front of graduate students,” Ivantysynova said. “I think the global competition will help make faster progress. We need new engineering. We need a new set of architectures for all kinds of fluid power systems that are different, but not too much different. I personally think fluid power has a bright future but we can do much better.”
Langro spoke about the NFPA’s decision a few years ago to take a hard look at the challenges fluid power would be facing in the future. The NFPA’s road mapping process lead to a predictable destination: efficiency.
“It was pretty much unanimous that you saw efficiency as the leader. Compact and intelligent products that are easy to use, intelligent, plug-and-play applicable and more diagnostic, were needed,” he said. One of the initial hurdles though, was that end user demands had not reached the fever pitch needed to spark action.
“OEMs weren’t always on board,” Langro said. “Producing the lowest cost machine and adding new developments that could create a more efficient machine just wasn’t their priority.”
Some companies were thinking long term regardless of demand. Nic Copley, VP, Technology and Innovation for Parker Hannifin, said, “The general awareness of the need to be more conscious of green issues has been going on for quite a few years. I first noticed it back in the ‘90s when there was a big push to start moving away from systems that had oil lubrication in them. A lot of work around development materials was done just to make sure that you could develop pneumatic systems that would run oil-free or lubrication-free for the lifetime of the product. I think it’s been a long, incremental, step-by-step pathway, but probably the last five to eight years has been much more focused.”
Copley went on to remind us that people have been forecasting the demise of fluid power’s relevance for years. But we haven’t seen that happen. The technologies that were supposed to put fluid power out to pasture are now working with it. Copley said he expects hybrid technology to be influential in solving future fluid power efficiency issues.
“I expect we will see a lot more combining of technology. I think that in the fluid power world, we’ll probably see a lot more merging between the electro-pneumatic and the hydraulic worlds,” he said. “We’ll see the benefits of all the technologies converging to make sure we have far more effective and efficient systems in the future.”
For pneumatics in particular, the efficiency of electrical input power to compressed air outlet power continues to keep compressed air costs up. Vicki Gonzalez of Nexmatix noted that the pneumatics industry has been around for more than a century, but many of the fundamental products, like directional control valves, were designed in a time when companies did not think about the cost of energy to compress air.
“A great example is the directional control, which is designed to exhaust air during every stroke,” she said. “The DOE estimates that manufacturers today spend $8.8 billion on electricity to compress air and these pneumatic systems have efficiencies of less than 20%. That’s over $6 billion dollars we could save if we started designing for efficiency.”
As for hydraulics, leakage remains public enemy number one. Leakage poses environmental, safety and efficiency threats. The primary solution is preventative maintenance—creating smarter, more efficiency-minded products. At Rexroth, for example, it has even become a company-wide initiative.
“We call it 4EE, or Rexroth for Energy Efficiency. It serves as the basis for our energy advice for industrial companies and for the development of energy-efficient solutions in optimizing our own operations. It’s a systematic initiative to create energy efficiency across all drive and control technologies, with four levers that cover the spectrum of opportunities in efficiency: Energy System Design, Efficient Components, Energy Recovery and Energy on Demand,” said Gingerich.
Overall, in industrial production, companies are optimizing machines and processes by taking advantage of a diversity of technologies. The focus of which is mostly the reduction of power consumption and the increase of operating efficiencies. The focus of how this is done varies from company to company but most of the talk revolves around a few concepts. The creation of lightweight components, for example, is popular for creating cleaner and more efficient operation and a transition toward hybrid technologies.
Mike Tuohey, sales and marketing communications manager at Piab, also said this hybridization is crucial in most companies’ green engineering strategy. “For example, as a design focus, now electronics and pneumatics are both improving operating efficiencies. This addresses many of the concepts of green engineering.”
Additionally, companies are designing electronic controls that are better than ever at monitoring a system and allocating energy on an as-needed basis. Integrated sensor technology is the focal point of predictive maintenance. Langro said that this type of technology allows for the monitoring of pressure flow and hazardous system abnormalities.
“We released a product that is part of our MS series of air supply units and it is an energy efficiency module. It’s an intelligent on-off valve with a flow sensor and pressure sensor. If the unit notices that the machine is in an idle state, the on-off valve adjusts accordingly,” Langro said. “This way there is no unnecessary air consumption through leaks or any other losses in the machine.”
LEADING THE WAY
There are several new concepts leading the way in green fluid power. For example, Rexroth’s Sytronix system is, again, another development focusing on the “energy on demand” concept. It provides power to a hydraulic pump only during active cycles—as opposed to constant pressure, which requires a constant energy supply. With conventional hydraulic systems found on many industrial machines, an electric motor typically runs at a constant speed to power the hydraulic unit, regardless of whether pressure is needed at that moment. Therefore, the motor is always running and consuming energy even if the machine is idle. The Sytronix pump drive regulates the speed and consequently, the energy consumption of the electric motor according to machine demands. Depending on a machine’s cycle characteristics and power rating, the pump drives achieve a 30 to 80% energy savings.
Nexmatix’s valve technology is helping engineers in pneumatic applications. The valves use designs that act as plug-and-play replacements for standard off-the-shelf valves. These plug-and-play alternatives typically recycle 30% of the compressed air used in pneumatic actuator applications without compromising actuator function. The reduced compressed air usage directly correlates to less energy cost. This valve technology can also be applied to the majority of 5-port/3-position and 5-port/2-position valve lines with little cost difference.
As one might expect, Industry 4.0 advances are also on the horizon in fluid power. Festo plans to build on its valve manifold system by integrating OPC UA into the platform.
Piab has noticed the Big Data trend in fluid power as well. “Adding data measuring capabilities at the component level is important now. Now there is the need for tapping into the Internet of Things and Big Data revolution. We’re seeing the need to provide the ability to monitor components and develop data to support improved production and efficiency,” said Tuohey.
Companies are continuing to zoom-in on fluid power efficiency at the component level. Now, that focus has translated into a global shift in how we think about fluid power designs. Langro noted, “The saying is if you don’t measure it, nobody will pay any attention.” The green energy trend has clearly gained the attention of fluid power component manufacturers. Not only are they paying attention, they are working harder than ever to bring noticeable change to the industry. Designing for efficiency is good for both the green of eco-friendly technology and the green of collective company coffers. Regardless of motive, fluid power reaps the benefits.