Are the hydraulic components on the right track to be moved?

In short :

  • Mitch Eicher, Business Development Manager at Parker Hannifin, is a mechanical engineer with a passion for bringing hydraulic valve application designs to market. He shares the ideas of his field.
  • With the advantages of high power density, large output force and easy to actualize linear motions, hydraulic transmission systems are widely used in industrial hydraulics and for mobile hydraulic machinery.
  • Along with the shift from purely mechanical to electro-hydraulic components, higher levels of performance, accuracy and scalability are expected.

The current boom and expected growth in the integration of electronics with hydraulics reveals a change in direction. It forces manufacturers to review their competitive positioning to identify the simplest, safest, most economical systems that are both scalable and easy to maintain. But does this also mean that traditional hydraulics are about to be permanently displaced?

With investments moving towards renewable energy and over time, new technologies related to high pressure hydraulic systems become more applicable. Electro-hydraulic pumps, for example, are known to be up to 80% more efficient than their traditional counterparts.

Mitch Eicher, business development manager at Parker Hannifin, says traditional hydraulic components will remain critical to systems where flow, pressure or actuators need to be controlled. Based solely on the force, speed required and energy consumed, he argued, it would be expensive in size and cost to drive all components directly using electromechanical solutions.

“These very high-force, high-demand applications are still largely performed by hydraulic valves,” Eicher said. “You can get what you pay for, it’s a very dense solution.”

On the whole, hydraulics experts tend to agree that the combination of high power density, high force output, and the ease with which motion can be actualized makes the hydraulic transmission stands head above shoulders in industrial and mobile hydraulic machinery.

“Hydraulic power operation gives you great value for your money – it’s a very dense solution in a small space,” pointed out Eichler, a mechanical engineer specializing in hydraulic valve applications.

Building Interdependencies

A debate over hydraulics or one or the other supports a way of thinking that is more academic than practical, Eichler said. Within Parker Hannifin’s Motion Systems Group, different divisions work together. “It’s not as long as you opt for hydraulics, pneumatics or electromechanics anymore,” he explained. “We see them as a system solution. Our manufacturing division focuses on hydraulic valves, but with the advent of electrification, these valves are getting smarter and smarter. In some applications, they can become more electromechanical for their control or for certain components. »

Parker’s next generation of DFplus control valves are a prime example of future design. As Parker’s highest dynamic valve, it has been around for 20 years and is designed for the most demanding applications such as general presses, machine tools and blow molding. The next generation FP valve will have multiple communication protocols including IO-Link. The range of functions includes actual value (spool position), temperature, operating hours and various error messages.

In this example, the focus is less on developing completely new hydraulic valve technology and more on bringing new communication capabilities into existing hydraulic systems, including valve programming via NFC (Field Communication). near) with your phone, with your table or with your computer, and do it wirelessly or via different bus protocols. “That’s really what we see as the future,” Eichler said.

Manage complexity

Does the introduction of new technologies simplify or complicate design features? To some extent, the industry is witnessing a bit of both. “From the late 1980s to the early 2000s, when electrohydraulics started to become much more prevalent, valve control was largely mechanical,” Eichler explained.

“I usually compare it to a Swiss watch,” he added. “All the sensing and logic was done by coils and different springs and orifices and lots of mechanical artifices that did the job. And that was the only way to do it. But now that we’re seeing systems getting more advanced , they also become simpler.Instead of having all these different orifices, spools and mechanical sensing elements, you can reduce the number of parts and the complexity of the valve by closing the loop around the spool.

Instead of having compensators that will always give you a fixed pressure drop (“to give a certain flow out of the valve and therefore a certain speed of the system”), you can achieve this more simply with a valve that has electronics advanced on board and this can ensure that you achieve this throughput. “And, if you need to open the valve further, it will, instead of relying on internal mechanical parts to achieve it through traditional hydraulic control,” Eichler said.

Oriented towards Industry 4.0

As valve design evolves with the integration of electronics, so does the understanding of how machines operate. Industries want to get smarter, more efficient and lower costs, and they want to be able to do more predictive maintenance, Eichler pointed out.

The synergistic integration of digital and mechatronic technologies means that industrial valves are better equipped to monitor and perform online diagnostics and to provide more efficient control. This also applies to off-road/on-road equipment types.

Consider the efficiency of an automated side-loading waste disposal truck, where a driver controls a mechanical arm from the side of the truck. Older trucks rely on lever directional control valve actuation. Newer machines, on the other hand, use sequence valves or may have on-board electronics and advanced sensing built into the hydraulic system that complete the action at the touch of a button or lever. “You walk away from a lot of pipes and mechanical connections, and you run wires, and you press a button,” Eichler said.

The new compact design and productivity gains also come with health and safety benefits. Automation takes the physical strain out of manual work routines and puts operators out of harm’s way, Eichler said.

If “smart” is the end goal, technologies that support hydraulic functions are anything but lagging behind. “If manufacturers are trying to do it all and make every valve capable of sensing everything we can imagine, then it’s probably never going to be a competitive solution for the end user,” he said.

Instead, the preference is to work with OEMs and their end users on a case-by-case basis and understand what their data collection process is. Eichler suggests asking troubleshooting questions: “What will they use it for? How will they use it? And how valuable is it? per hour, day by day?” Depending on the application, all of these types of modifications can be integrated into different valves.

“We want to make sure we’re not just assembling toys for engineers,” Eichler joked. “The more whistles and bells a valve has, the more great it is. Sometimes you need that built into the valve because it warns you to follow something you didn’t think was important and teaches you something about your machine. But it comes down to size and cost and that total value proposition.

This article originally appeared in Power & Motion.

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