New Hybrid Type???

[trebuchet03]

Coolness A few years ago there was a hydraulic drive train human powered vehicle at the ASME event. Bugger that we weren't allowed storage devices - it'd be super simple with their vehicle

I wonder what the working fluid is....

[bryn]

i was reading that the made a hummer system, that worked well and even managed to fit the system in a VW passat wagon, still got better mpg than the regular diesel

[Formula413]

Sounds like a brilliant idea, and delivery trucks are a perfect platform for it.

The fact that it was seen on the back of a flatbed might seem to suggest there are some bugs to be worked out.

[knowbodies]

Let me get this straight. They're hauling a highly fuel efficient vehicle around on a flatbed truck. Wouldn't it be more efficient to just drive the truck?

[Doofus McFancypants]

The initial release of the truch was Chicago..
Maybe they were relocating it to another city to test it out further?
it was going south on I75 into Atlanta.. could have been heading here - or on its way down to Miami?

Maybe the design is more focused on Stop and GO than it is on Long Highway Runs..

Steve

[MetroMPG]

FYI: Green Car Congress: UPS to Purchase 7 Hydraulic Series Hybrid Vans; Prototype Showed 45-50% Improvement in Fuel Economy

After two years of road-testing of a prototype, UPS has placed its first order for hydraulic diesel series hybrid delivery vehicles (HHV), becoming the first in its industry to do so.

Disclosing the results of its road testing on Detroit routes for the first time, UPS and the US Environmental Protection Agency (EPA) said the prototype vehicle had achieved a 45-50% improvement in fuel economy compared to conventional diesel delivery trucks. UPS believes similar fuel economy improvements and a 30% reduction in CO2 are achievable in daily, real-world use.


The hydraulic series hybrid, originally developed in a laboratory of the US Environmental Protection Agency (EPA), uses a diesel engine/pump to pressurize and transfer hydraulic fluid to the rear drive pump/motor and/or high pressure accumulator. The hydraulic drivetrain replaces the conventional drivetrain and eliminates the need for a conventional transmission.

Full story

[MazdaMatt]

very cool. The application in garbage trucks and shuttles and city busses seems perfect for this.

[Formula413]

Wait, so the engine doesn't actually drive the wheels? I thought the hydraulics were used to supplement the engine, being pressurized through regenerative braking and providing the power to get the truck moving, similar to a Prius but with hydraulics instead of electricity. Why sacrifice the power lost in converting the engine's rotational force into hydraulic pressure?

[Sideblinder]

Jet aircraft have variable output hydraulic pumps on their engines directly connected to hydraulic motors to turn their generators at a perfectly constant speed. They're called constant speed drives. You could take one of these and essentially turn it backwards to get a constant input, variable output transmission. This allows the engine to run in it's most efficient profile for load, and I wouldn't be surprised if it ended up being close to the efficiency of a conventional transmission. Now you can easily reverse the function of your variable output hydraulic motor into an adjustable hydraulic pump for braking, add a couple of valves and an accumulator and your done. In my opinion it's the system for those who refuse for whatever reason to support electrics, or when an electric is simply not suitable.

[TestDrive]

Very short stop and go, city delivery trucks often have an automatic transmission.