Truck & Off-Highway Engineering - February 2020 - 37

Q&A
Parker takes electro-hydrostatic approach
for electric machines
Off-highway industrial machines require multi-function impleelectro-hydrostatic actuation enables energy recovery and it
ment operation with dynamic duty cycles. In many cases, macan be accomplished fairly easily in applications where it
chine implements demand short bursts of full engine power
makes sense. Energy can be recovered and used right away or
and brake dynamic loads requiring 50% or more of energy
stored in the battery.
consumed. Many next-generation machines reduce energy
loss and improve productivity by incorporating hybrid-electric
What might industry folks not know about EHA?
approaches with energy storage. An efficient implement soluIn general, I think that the benefits of electro-hydrostatic actuation enabling the hybrid-electric approach is essential to
tion are understood in the industry. However, I don't think that the
achieve maximum improvement potential.
flexibility of the approach is well understood. It does not have to
At the upcoming IFPE 2020 show in Las
be an all-or-nothing type of decision. There isn't
Vegas (www.ifpe.com), education sessions ofa need to add complexity and cost to have a
fered to attendees will address this challenge
dedicated motor pump for every possible funcand other issues facing the fluid power and motion. It is important to take advantage of the
tion control industries. A session titled
system's flexibility and target electro-hydrostatic
"Fundamentals of Hydraulic Systems" will inactuation to a function where it makes sense.
clude speakers from Ultra Clean Technologies
Corp., Atos North America, Parker Hannifin, and
What are some frequently asked questions
Hallite Seals Americas. Show organizer AEM
you hear from manufacturers concerning EHA?
Performance and cost are the two main areas of
(Association of Equipment Manufacturers)
concern from manufacturers. The benefits of the
spoke with presenter Dale Vanderlaan, R&D
engineering manager at Parker Hannifin, to distechnology need to be greater than the cost,
and that really comes down to targeting a solucuss electro-hydrostatic actuation (EHA), its
tion and picking the right technology for an apbenefits, and how electrification will impact
next-generation hydraulic systems.
plication. First and foremost, manufacturers
Dale Vanderlaan, R&D engineering
want to be sure that the performance and remanager at Parker Hannifin.
What are some benefits of EHA compared to
sponse of a traditional approach are not deother technologies?
graded. I believe that you can get similar perforElectro-hydrostatic actuation is an extremely
mance for mobile applications and often better
flexible solution, focused on improving hyperformance. The key is to understand what the
draulic system efficiencies. Next-generation
requirements are and work to select the right
off-road mobile machines will be electrically
technology to accomplish the goals. There are
powered. Simply powering an existing pump
usually questions related to noise, as well. When
and hydraulic system with a battery does not
vehicles are powered with batteries, they operaddress the efficiency of the hydraulic system
ate with less noise. Manufacturers want to unand will require a large battery, which takes up
derstand the impact on noise reductions.
a lot of space and can be costly. By taking an
electro-hydrostatic approach to improve sysWhat knowledge will session attendees take
tem efficiency, existing cylinders and system
away and be able to implement at their own
infrastructure can be used. Electromechanical
companies?
types of systems are not practical, so we know that hydraulic
Electrification is happening at all sorts of levels and adoption
cylinders will not be replaced anytime soon. Not having to
rates. It's about getting ready for it, since it's a matter of
change cylinder technology is a significant benefit.
when, not if. Smaller machines are already battery-powered.
Addressing valve loss within a system is also key to improvAs battery technology improves, it will be an enabler to move
ing efficiency. Changing the traditional hydraulic distribution
to the ultimate goal of battery-operated large off-road mamethod with a power-on-demand approach can be very benchines. Because of this, it is important to move into this nexteficial with certain functions. Electro-hydrostatic actuation
generation hydraulic system approach. We are seeing one
does not require a control valve to control the actuator, which
motor driving existing pump and system, but the real benefits
eliminates the valve loss for a particular function. If applied to
are to be gained by making hydraulic systems more efficient.
more than one function, additional valve loss can be eliminatThere are significant improvements when electro-hydraulic
ed. Being able to apply [electro-hydrostatic actuation] to the
actuation is implemented.
right need within an application is a key benefit. And finally,
AEM contributed this Q&A for TOHE's IFPE pre-show coverage.

PARKER HANNIFIN

"Simply powering
an existing pump
and hydraulic
system with a
battery does
not address the
efficiency of the
hydraulic system."

TRUCK & OFF-HIGHWAY ENGINEERING

February 2020 37

http://www.ifpe.com

Truck & Off-Highway Engineering - February 2020

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