The Conservative Cave

Interests => Around the House & In the Garage => Topic started by: Chris_ on May 21, 2008, 06:21:54 PM

Title: Hydraulic Hybrid Cars: No Batteries Required
Post by: Chris_ on May 21, 2008, 06:21:54 PM
What if there was a hybrid vehicle technology that could at least double the gas mileage of passenger cars, SUVs and light trucks? What if it could slash emissions by 50 percent or more? And what if it could challenge our usual mileage expectations by offering better fuel consumption in the city than on the highway?

In many ways, these hydraulic hybrids conceptually resemble their electric hybrid cousins. Only in this case, energy storage takes place not in a battery but in high-pressure hydraulic accumulators usually charged in excess of 3,000 psi. The best of these accumulators have power densities of roughly 500 kW/kg, according to Jim O’Brien, founder and chief technology officer for Hybra Drive Systems, a start-up focusing on the development of hydraulic power trains. Bosch Rexroth's Hybrid Regenerative Braking System Design News' Video Library

Design concepts for hydraulic hybrids vary, but typically the car’s diesel or gas engine powers a hydraulic pump motor, which charges that high-pressure accumulator. The accumulator, in turn, drives one or more additional pump motors connected to the wheels. A second lower pressure accumulator typically completes the hydraulic circuit. Depending on the design, there may be one pump motor to drive a pair of wheels through a differential or one pump motor per wheel for an all-wheel-drive version with independent torque control. During braking, the pump motors on the wheels reverse themselves, re-charging the accumulator and capturing energy that would otherwise be lost to heat.

Lately, the EPA has been focusing on hydraulic hybrid delivery trucks, but Kargul says the lab has also built and tested smaller vehicles, too, including one based on a Ford Taurus. Speaking at the recent IFPE Show, Kargul says this 3,800 lb diesel-powered hybrid vehicle chalked up a gas mileage of 85 mpg. Another consumer-sized vehicle, this one based on a Ford Expedition SUV, chalked up an 82 percent improvement in combined city and highway gas mileage. The city cycle was a 130 percent better, Kargul says.

http://www.designnews.com/article/CA6549294.html

(http://i237.photobucket.com/albums/ff68/kayaktn/CA6549294_B.jpg)  (http://i237.photobucket.com/albums/ff68/kayaktn/CA6549294_C.jpg)

Fascinating :popcorn:
Title: Re: Hydraulic Hybrid Cars: No Batteries Required
Post by: Chris_ on May 21, 2008, 06:22:53 PM
Ford F-150 to debut hydraulic hybrid system by 2008? (http://www.autoblog.com/2006/02/14/ford-f-150-to-debut-with-hydraulic-hybrid-system/)

Autoblog reader Brent drew our attention to a web site, called New Tech Spy, that claims Ford's F-150 will soon come with the Hydraulic Launch Assist system first seen on the Mighty F-350 Tonka introduced at the 2002 North American International Auto Show. And while it was likely always Ford's hope to put the system on its F-series trucks, this is the first outside confirmation that we've been privy to.

At an alleged 60 mpg, Hybrid Launch Assist would not only reinvent the pickup truck market, it'd likely turn the industry on its ear altogether
Title: Re: Hydraulic Hybrid Cars: No Batteries Required
Post by: Chris_ on May 21, 2008, 06:25:39 PM
Other than an animation showing the hydraulic system in motion, there isn't much to this video.  It's all I could find on YouTube.  :p

[youtube=425,350]95Ebjoca7Fo[/youtube]
Title: Re: Hydraulic Hybrid Cars: No Batteries Required
Post by: RobJohnson on May 21, 2008, 11:40:01 PM
This is very interesting.
Title: Re: Hydraulic Hybrid Cars: No Batteries Required
Post by: Thor on May 22, 2008, 10:23:41 PM
Yeah, all is fine and dandy until the accumulators start leaking down, which they WILL. I can't tell you just how many times I had to pump up the accumulator on a Phrog from the pre-charge of 1500 psi to 3000 psi just to fire up the APU.      :banghead:
Title: Re: Hydraulic Hybrid Cars: No Batteries Required
Post by: Rebel on May 22, 2008, 10:33:37 PM
Yeah, all is fine and dandy until the accumulators start leaking down, which they WILL. I can't tell you just how many times I had to pump up the accumulator on a Phrog from the pre-charge of 1500 psi to 3000 psi just to fire up the APU.      :banghead:

Funny should mention that. I made a post about it here:

http://ncaabbs.com/showthread.php?tid=299398&pid=3322693#pid3322693