Archives

http://www.cleanmpg.com/photos/data/2/AmericanFlag.jpg "The hydraulic hybrid is able to recover and reuse about 70% of the energy that otherwise would have been wasted during the braking process." (http://fleetowner.com/green/freightliner-hydraulic-hybrid-0304/)

http://www.cleanmpg.com/photos/data/501/Freightliner_MT-55.jpgDavid Cullen - FleetOwner (fleetowner.com) - Mar. 4, 2009

Another valuable addition where it is needed most! --Ed.

CHICAGO. Freightliner Custom Chassis Corp. (FCCC) rolled out a pilot model of a hydraulic-hybrid version of its MT-55 walk-in van chassis here at the Work Truck Show and 45th annual convention of the National Truck Equipment Assn. Powered by a 200-hp Cummins ISB 2007, the FCCC hydraulic hybrid chassis does not require a transmission and uses a Parker hydraulic-propulsion system.

The hydraulic hybrid chassis was designed and engineered in partnership with Parker Hannifin Corp. to address environmental and cost-savings concerns, according to FCCC, which said it would both improve fuel economy and reduce brake wear due to its regenerative braking system.

"The hydraulic hybrid chassis not only offers a reduction in operating costs, it also decreases exhaust emissions, providing a substantial environmental benefit," said Jonathan Randall, director of sales and
marketing for FCCC. "As the first chassis manufacturer to launch hybrids into the walk-in van market, we are very proud to continue that tradition by introducing our hydraulic hybrid as another option for customers."

Randall said that predictions based on preliminary testing have shown that the hydraulic hybrid improves fuel economy “between... http://fleetowner.com/green/freightliner-hydraulic-hybrid-0304/

Very Cool. Nice to see that both Fedex and UPS have test vehicles. I'm intriqued by the 70% regenerative braking recovery, bettering the typical 25% of electric /gas hybrids. Makes me wonder if it would be worth someone putting a hydraulic hybrid drive train in a car...

I think the classical argument against hydraulics in a passenger car is that the system is too bulky and heavy.

Hopefully as the technology develops we will see lighter system being developed. I suspect we could see it in heavy consumer trucks in another 5+ years. However even if it was 100% efficient, the amount of "charge" is limited, so you can't really do a hydrolic version of PHEV, so as they tech matures, it will push away hydrolic's advantage where ever it can be used.

However even if it was 100% efficient, the amount of "charge" is limited, so you can't really do a hydrolic version of PHEV, so as they tech matures, it will push away hydrolic's advantage where ever it can be used.

Agreed. Though I'm hoping for faster implementation.
The systems really do not add much for weight. In large vehicle applications an automatic trans can weigh 1000 lbs, so when replaced with a pump and accumulator their is no net gain.

Hydraulic works because it can capture energy (braking) at a higher rate than electric can. And it can deliver more immediate power. But electric can store power longer. Thus- hydraulic for heavy, stop/start applications; electric for light, longer distance applications.

Keith

In other articles about hydraulic hybrids that I've read they noted that another advantage vs. gas-electric hybrids is that the system is so much simpler both mechanically and electronically and less expensive while claiming more efficient energy recovery. One even suggested that existing vehicles could be retrofitted with such a system without much trouble. That's intriguing.