March 02, 2003
Hydraulic Energy Storage Hybrid Engine Developed For Trucks

The business case for electric hybrid cars is pretty weak because so many heavy batteries are required and replacing them when they wear out is expensive. Another approach to energy storage is compressed air. Ford is taking this idea and pursuing compressed air hybrids. Still yet another approach uses hydraulic fluid compression to store energy.

Chandler noted that, "This smaller, lighter version of Permo-Drive's Regenerative Drive System (RDS) offers significant fuel savings, reduced emissions and improves brake life to the trucking industry and major fleet operators, including the U.S. military."

A U.S. Army vehicle equipped with the Permo-Drive system recently underwent three weeks of intensive testing. Preliminary results show a 27 percent improvement in fuel economy, a 36 percent jump in rapid-acceleration or "dash" capability and a 60 percent improvement in deceleration when comparing hydraulic-system deceleration rates to engine-braking.

Dennis J. Wend, executive director of the U.S. Army National Automotive Center, recently noted that, "In our modeling and simulation work to date, parallel hybrid-hydraulic systems show the potential to provide significant fuel-economy savings for future generations of trucks."

The US Army has a greater incentive than private industry to boost fuel efficiency of its vehicles because of the logistical cost and enormous difficulty of delivering fuel to remote battlefields. Therefore it is not surprising that the Army would be testing this technology.

Chandler pointed out that the company's hybrid hydraulic system also has been tested on commercial vehicles in Australia, where it achieved fuel economy gains of 33 percent or more. Permo-Drive's system captures normally wasted energy generated during braking, then releases it back into the vehicle's driveline when additional power is needed.

RDS technology can be applied to new or existing trucks. Key design features include an innovative inline axial-piston pump/motor, high-pressure accumulator energy-storage devices that utilize special composite materials, ultra-light-weight metals and advanced hydraulic and electronic engineering. The Permo-Drive system integrates vehicle dynamics, hydraulics, mechanical engineering, accumulator technology, material science, computer telemetry and electronics.

Computer control advances combined with materials advances are probably both essential enabling technologies that are making designs based on this type of hybrid technology possible.

The Permo-Drive RDS storage system includes two hydraulic fluid "accumulators" -- a high-pressure tank (up to 5,000 PSI) and a low-pressure reservoir. As braking takes place, energy is captured with the flow of oil from the low-pressure tank to the high-pressure accumulator. A central processor later controls the release of the oil during acceleration to enhance overall fuel economy and reduce emissions.

Technologies that capture braking energy would useful as a way to decrease fuel usage even in vehicles powered by fuel cells or batteries.

Share |      Randall Parker, 2003 March 02 11:25 PM  Energy Transportation

rassol said at May 6, 2003 10:45 AM:

how work hybrid cars

Nikhil N. Birajdar said at June 3, 2004 6:56 AM:

hi,myself nikhil from india.i wanted to know about the hydraulic energy for improvement of engine characteristics.i am doing my bachlor course in mechanical engineering.So i am impressed after reading your webpage.but i need to know more technical specifications & to see how it works i request you to please tell me what to do? also i wanted to do research on it enthusiastically.

okoye celestine said at June 8, 2004 5:49 PM:

Dear sir,
I wish to commend your research effort and development on this field and would like to request your assistance on my Phd. research project titled "Hydraulic pressure fluid storage (problems and break throughs)". Thanks for your anticipated co-operation

Sincerely yours

Okoye celestine.

manoranjan kumar said at February 18, 2005 7:21 AM:

dear sir,
myself manoranjan from india i am doing my undergraduate in mechanical engineering sir, i want to know how can i manage the shaft gear arrengement in hybrid vehicle when i will be using the electricc motor to run at slow speed as well as idelling time with the same battery for some minute.

John Newell said at July 16, 2006 11:09 AM:

In the late seventies, a friend of mine, Ralph Di Cossimo, a body shop owner, developed the idea for a car that combined electrical storage, wind power and hydraulics as described here to design a car that would essentially run on no fuel. The wind turned the turbine, the turbine charged the battery to start the car, forward or backward motion generated electricity to keep the battery charged and the activity of braking charged and maintained the hydraulic systems. He built a small model of the car less the hydraulics to demonstrate how wind and electricity could be combined to keep the system functional and provide enough power to get the car reliably in motion. He didn't have the drafting expertise to draw the hydraulics as he pictured them in his mind. The model used to run up and down our street in Scarborough, Ontario using no power at all beyond wind. It was crude. There were no on board devices for remote control since at the time neither of us had any extra cash, both of us being newly divorced. But regardless, it is possible to build a functional car or truck that uses no "fuel" and does not need to be charged or recharged at an electrical receptacle.

Nick said at December 30, 2007 4:40 PM:

It is possible to create power with compressed gases with very little energy use. Compressed gases can produce 150psi or greater at 85 degree. There is a lose of gases during prduction. Although lose is controllable and could possibly be reduced to zero. Alternative energy of the future?

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