The Future of Fluid Power
By Mike McLeod
Fluid Power hydraulics pneumaticsResearch from U.S.-based fluid power center could realize significant gains in efficiency and help the industry find new markets.
On a different front, Monika Ivantysynova of Purdue University is looking at improving the power management of multi-actuator mobile hydraulic machines. Her research is focused on replacing the traditional single hydraulic pump controlled by directional valves with multiple smaller control pumps paired with each actuator, thereby reducing system pressure-drop and allowing for energy regeneration.
Her work is at the heart of a high efficiency excavator, one of four technology test beds the Center has in active development. Stelson says that, through a number of different CCEFP research efforts, a reasonable target would be a decrease of 50 percent in energy consumption in heavy equipment—a number that could have implications for more than only the mining and construction industries.
“The fact is we don’t know how much energy goes into fluid power, nationally,” he says. “My guess is that it’s about 4 percent of the U.S.’s total energy production. If we could save 2 percent of that energy by making everything 50 percent more efficient, it would mean saving about $40 billion in imported crude oil.”
The CCEFP’s other test bed projects could show similar energy saving benefits, Stelson adds. For example, the Center’s hydraulic hybrid project—through a combination of regenerative breaking, optimum engine loading and engine downsizing—has the potential to double passenger car fuel efficiency.
“The rule of thumb in the automotive industry is that if you save one unit of mass somewhere in the car, then overall savings are three times as much,” he says. “Since fluid power has the highest power to weight ratio of any technology, it is clearly superior if you need high power in a mobile package.”
While Stelson admits that the CCEFP’s efforts may not be able to reverse the tend away from fluid power in some manufacturing sectors, he says its research is opening the way to non-traditional markets, ranging from new diagnostic medicine techniques to replacing the inefficient and often unreliable gear boxes with hydrostatic bearings in wind turbines.
“The reason we are able to realize these improvements, I’m sorry to say, is that fluid power is so primitive—the controls haven’t been improved in decades,” Stelson adds. “But it is because of this that the CCEFP has a possibility to make huge improvements.” DE
