I read an article on hydraulic hybrids. It's an interesting technology to increase mainly city mileage on a vehicle by recovering braking energy into a hydaulic system then using that on the next acceleration. The claim is that they can recover 70% of the energy as opposed to 20% for an electric hybrid. In addition, there's no batteries to replace in 10 years, just hydraulic fluid or gas, I suppose.

http://www.seedmagazine.com/news/200...at_the_epa.php
http://www.epa.gov/OMS/technology/#hydraulic
(Lower down on that page they also announced a diesel that does not need catalytic converters to lower the NOx emmisions.)

From what I read, it seems like this could possibly be adapted to a vehicle. In fact, it seems that the EPA has already done it with a Ford Expedition. Any thoughts, comments? Is anyone doing this?

-Jim

 

Here's a guy that made a 68 Beetle into a hydraulic hybrid using a 6.5HP B&S lawnmower engine to pump the hydraulics. He's ramping it up to make a delivery truck.

http://www.hybridcars.com/hydraulic-hybrids.html
http://www.automationalley.com/autoa...Hybradrive.htm
http://www.Hybra-Drive.com

A Google search of "hydraulic hybrid f-150" also seems to reveal some rumors that there will be an HH F-150 by 2008. If you believe these rumors it would be rated 60 MPG. It would be interesting to track down the root source.

-Jim

 

Apparently, Ford also had a hydraulic system on their F-350 Tonka concept in 2002.

http://www.designnews.com/article/CA220671.html

SPEECH: FORD F-350 TONKA CONCEPT REVEAL, NAIAS, JANUARY 6, 2002

Eaton is making a Hydraulic Launch Assist system, probably targeted for larger commercial trucks. Still it would be interesting with their experience in the supercharger aftermarket to see if they'll bring out a retrofit kit for smaller applications.
Embracing the Strengths of Hydraulic Technology

-Jim

 

The real interest in this technology is for the refuse collection and city bus systems. There have been recent articles in Popular Mechanics/Science magazines as well as articles for a long time in engineering magazines.

 

I agree, as heavy stop-and-go is where this technology shows it's best advantage. I know, however, that I have a very stop-and-go commute like many people, so an alternative to electric hybrids that could pay back more quickly and with little or no future cost (ie battery replacement in an electric hybrid) would be pretty cool to see.

-Jim

 

Found some more links on Hydraulic Hybrids:

An Australian company that makes an add-on kit for medium and heavy duty military and commercial trucks:
Permo-Drive

Pretty slick looking installation. It looks like it just cuts the driveshaft with their pump and the accumulators.

They are teamed up with Dana to provide this system to the US Army for FMTV's:
Dana Corporation, Permo-Drive Technologies Ltd. Sign Agreement For Fuel-Saving Hybrid Vehicle System

I'm guessing that they feel that they can protect the accumulators adequately enough from hostile fire to justify the gains in fuel economy and added acceleration.

-Jim