Ford pickup hydraulic hybrid (univ of idaho project)
 

Searching here I didn't see this one listed so i'm sharing it...

https://seniordesign.engr.uidaho.edu...%20may2005.pdf

Apparently about a decade ago, some university of idaho engineering students turned a 1988 Ford F350 into a hydraulic hybrid, gaining both improved acceleration and apparently 25% fuel mileage increases as well as reduced wear expected on the brakes and such.

I scanread the above and don't understand it all but i'm intrigued. I would be curious how hard it would be to replicate such a project just on a smaller vehicle. I would like to use secondhand parts (maybe forklift parts which I thought used accumulators?) as much as possible to keep the budget down even cheaper... apparently one potential benefit of hydraulics vs electrics is much lower cost even brand new (I see this quoted elsewhere but I don't have any offhand examples).

It could also be possible for a 'hydraulic hybrid' to charge the accumulator while maintaining a steady speed, then engine-off-coast while bleeding off pressure to maintain some speed I should think... giving a constant speed pulse and glide effect.

From what i've read elsewhere electrics cant recover more than 30-40% of the energy of regenerative braking end-to-end, but hydraulics are much more efficient at it. (though they lack the power density, storing seconds of energy not minutes) With no battery pack to die 100,000 miles in it's possible the overall total cost savings would be superior as well, what do you think?

If it stores seconds of energy then its only going to give that 25% boost in city driving. Then be limited exactly like electric hybrids on the highway with both likely see reduced fuel economy.

If it stores seconds of energy it would make a good postal delivery vehicle hybrid system.

Used hydraulics are cheap if you can find what you need but used electronics are widely available and dirt cheap.

How much do you know about hydraulics?
I find hydraulics to be incredibly expensive new and what you do find out there used is very limited and often leaky warn out junk. Just maintaining the hydraulic systems I work with is usually fairly difficult.
To get any amount of useable fluid quickly moved from an accumulator to a hydraulic motor you are going to need pretty large lines.
Anyone referring to hydraulics as being cheap or easy, well that is just an alien concept to me.

Also a hydraulic hybrid sounds like it would need a good amount of electronic controls and instrumentation to make it all cooperate as any kind of useable system. That is a whole entire other ball game. So now you have fluid power systems plus electronics If some one could put something like this together, chances are they wouldn't know squat about how to install and program all the controls with associated instrumentation. To me that would be the hard part.

I don't really see how hydraulics could be that much cheaper new. A hydrostatic motor about the size you would want to use to move a full size vehicle with any useable quickness would start at several thousand dollars. The ones I have experience with were diesel engine driven and moved munitions handling trucks weighing between 3600 to 8000 pounds empty, both used the same hydrostatic drive and these hydrostatic motors just by them selves cost over $5,000.

I think the University proved that building a hydraulic hybrid makes for a great academic exercise and not much else.
That is why you don't see all kinds of hobbies and experimenters building them, they almost all go electric.

There are actually a number of real-world HH vehicles out there. UPS has a number of delivery trucks, Waste Management has garbage trucks, Caterpillar makes a hydraulic hybrid excavator, &c. As noted, most of them are in applications where there's frequent start/stop cycles,

Ford once presented a hydraulic hybrid F-350 prototype in 2001 or 2002, Chrysler announced in 2007 that it would release some hydraulic hybrid setup for its minivans, Peugeot did some experiences with hydraulic hybrid setups for the Peugeot 208 and the Citroën C3 but, apart from trucks, buses and special machinery, the only vehicles commercially-available with a hydraulic hybrid setup were some Yamaha motorcycles with an auxiliary hydrostatic drive for the front wheel.

They are waiting for my patent to expire.

regards
mech

;)

Aside from (likely) UPS , all these vehicles already use hydraulics extensively ... so they are already one step closer to using it for energy recovery .
If you need to add an hydraulic system and all its additional cost, weight, complexity, just for energy recovery you're likely not going to gain very much.

AFAIK, the HH system in the trucks is entirely separate from the trash loading/compacting. I think the HH system is designed to replace the normal transmission on a truck chassis, which would then have the trash apparatus (or whatever) added on. So it could be used on any truck, it's just that the very frequent start/stop cycle of garbage trucks (or UPS delivery trucks) makes them the low-hanging fruit.

In many urban operations, that kinetic energy recovery is actually worth the cost, complexity and weight.

Yes I agree. The more extreme, pervasive and continuous the stop, start routine the more a hydraulic hybrid makes sense.
A garbage collection truck would be perfect.