Gary Kurtz estimates that using water instead of petroleum fluids in
hydraulic systems could save 500 million gallons of gasoline in the U.S. alone.
Saving fuel is one reason the professor of agricultural engineering and his
students at Purdue University built a lawn mower that is propelled and steered
with a water hydraulics system.
They are demonstrating that water's lower viscosity boosts the mower's energy
efficiency. They also hope to show that the technology may be practical for
agricultural, construction, mining, and forestry equipment.
Viscosity is a measure of how fast liquids flow. Water's lower viscosity
means less energy is required for pushing it through the hydraulic system. Kurtz
estimates that the cost of building a water hydraulic system for his mower is
approximately twice that of a comparable petroleum-based system. However, Kurtz
points out that the cost of stainless steels and ceramics needed
for producing water hydraulic systems are dropping, which would help make
water hydraulic more affordable.
"We have a proposal in to a golf course association now," says Kurtz. "They
like the idea because oil now leaked from the hydraulic systems in lawnmowers
kills the grass on golf course greens." Danfoss, Fairchild Manufacturing,
Indianapolis Valve and Fitting, Parker-Hannifin, and Swagelok provide equipment
for the project. Jacobson, a division of Textron, donated the mower retrofitted
with the water hydraulic system.
For more information e-mail Kurtz at firstname.lastname@example.org.