Moody Diesel

[Frank Lee]

Originally Posted by Old Mechanic

Non-electric Ford F-150 hydraulic hybrid could get 40 mpg

Maybe not wasted after all Frank. How about that full sized truck getting 40 MPG. Imagine what a Corolla sized vehicle would do.

regards
Mech

Did PNGV figure it all out for them? Looks like they're still developing it, and I don't see anything like it for sale anywhere:

The CCEFP is a network of seven universities and 55 industrial partners researching hydraulic and pneumatic technologies. It's funded by the National Science Foundation.

[rmay635703]

Originally Posted by Frank Lee

Did PNGV figure it all out for them? Looks like they're still developing it, and I don't see anything like it for sale anywhere:

They figured it out 50 or 60 years ago, they just can't find a package that fits in their little box of what they feel americans want or accept.

Also there was a mandate that the prototypes be produced, sadly the date was after the change of presidents and thus got shelved.

maybe says something of our ineffectively political machine as well.

Not sure how you would ever get a singular dream/purpose in Americans like the japanese where we would work collectively to solve problems facing everyone.

Alas I digress

[ron]

I still think HYDRASRICS as we use to call it, is too heavy and would be costly to service & maintain and were pushing toward the 30s in mpg now,it seems.

[user removed]

Ron read page 2 of this article, and if your next criticism is leaks, then consider the new hydraulic fluids are biodegradable and you could actually drink them. "I can hold a 500 HP hydraulic motor in my hand, and I am not a big person" quote from Charles Gray on the second page. How big is your 500 HP electric motor?

How about the 15% loss of power in charging the Nissan Leaf's battery (source Consumer Reports testing).

Parker Hannifin has held a chain less challenge for students to design hydraulic hybrid bicycles. Human powered hydraulic hybrids (not saying they are more efficient than a regular bike).

That fairly addresses the size issue, and carbon fiber tanks addresses the weight issue.
Lots of old biases against HH designs, all of them wrong.

You could even put a simple launch assist in the rear axle of Nissan Leaf and extend it's range by recovering 80% of braking energy instead of the 30% of an electric vehicle.
Kind of hard to cram 600 HP seconds of energy into a chemical battery in 20 revolutions of the wheels (60-0 fast stop and no electric solution except maybe adding capacitors).

You could even use hydraulics as a load leveler to increase the recharge efficiency of an electric car (stored in the accumulator in 4 seconds released over a minute to charge the battery more efficiently).

I find the it's my way or the highway tunnel vision of advocates of different solutions to be disturbing. It should be an open minded solution oriented perspective that includes every pathway to success.

regards
Mech

[ron]

looks like youve done a lot of reading on the subject. Ill look up that article on hyd vehicles asap, one thing I find hard to understand is how big of an I.C.engine/pump combo does it take to make a 500 hp hydraulic motor turn and how fast. (Criticism) No Just stating what I know to be true Hydraulics are Expensive,Heavy,&yes they will eventually leak. Now, what they do have is a hydraulic fluid based on coconuts yes its biodegradeable but I wouldnt drink it . "old hydraulic mens tolls never rust they just get harder to hold on to"

[user removed]

Remember the 500 HP is more like an electric motor (compared to an IC engine) and the torque would tear most vehicles to pieces. Its more of an example of how compact the power can actually be.

I have been around body shops most of my life and in spite of that have seen very few hydraulic leaks, even when you focus enough energy on a vehicle to twist an F350 frame up like a pretzel

All done with an air compressor which should answer your issue of how big an engine do you need. A pressure washer 5 HP at 3k PSI can charge an accumulator (it would take some time) and the energy concentrated in the accumulator could provide acceleration of sufficient g force to make you black out in a 2k pound vehicle. With a 5 HP pressure washer pump and engine. The real question is how much is your average power requirement and how steep are the grades your vehicle must climb.

All of that is not really relevant if the engine is of a larger size it just runs for a lower percentage of time when the vehicle is in motion. Smaller engine higher percentage. Overall the same amount of fuel consumed as long as the engines are in the same bsfc range.

I was reading today about the Nissan Leaf that made the Pikes Peak hill climb in 14 minutes and some seconds. I wonder how much of the battery capacity it took, probably close to all that was available.

Think of the accumulator as an energy shock absorber with a capacity of 600 horsepower seconds, available instantly. The same energy as you see being absorbed in a 60 MPH into a solid barrier collision that destroys a car completely. You will never be able to put that kind of energy back into a chemical battery in that short a time period, unless you add a very expensive capacitor to your already very expensive battery. Even then the conversion stages and individual losses will stop you from ever coming close to 80% recovery AND reapplication, not even close.

regards
Mech

[ron]

so ok now ill tell you that I Love Hydraulics It was as I call it my Glamour job from 73 to 90 worked on everything from the presses that made the tiles for the space shuttle the glomar explorer H. Hughes ship that picked up the russian sub circa 68or9 and so much more stories for hours, yep. I love hydraulics. They are just heavy im sure you remember how heavy the port-a-power cyl weighed on that frame machine, It pulled like he-- nice and slow Yes? Id love to see a hyd powered car but I dont think I ever will. Mabe a hyd assisted vehicle . remember hyd stores a lot of power for a short amount of time in an accumulator,but a battery stores its energy/power and can give it out over hours without recharge. apples and oranges, Im not here to argue Im here to learn . Ron

[user removed]

The new direct injection systems in IC engines work at pressures of close to 3000 PSI. Combustion pressures in iC engines peak at about 1500 PSI. Not sure about the hydraulic brakes. Engine lubrication systems, cooling systems, AC systems, power steering and the others previously mentioned demonstrate that modern vehicles have numerous "hydraulic systems" with numerous potential leak sources. Yet my 13 year old Maxima with 140 k miles leaves no trace of any failure in those systems on the floor of the garage.
You are absolutely correct about weight. A 4 ton portable hydraulic jack is a heavy machine, but it is very efficient at converting the pressure into useful work, and has survived the test of time for many decades. The drive I conceived will work with 1/8th inch wall thickness high tensile steel up to 3k PSI, more if you use an accumulator of higher pressure capacity. Modern racing sailboats work with pressures of 12 PSI, which would require double the wall thickness of the pistons and cylinders in a drive motor.
Containment of the high pressure portion of the circuit in the return low pressure vessel uses the same type system that an engine uses for lubrication, of course at much higher pressures.
Low pressure containment vessels also allow individual seals to be eliminated, with a designed in fluid loss of 1-2% to act as lubrication and cooling, with a filter in the low pressure return circuit and a radiator for heat dissipation. None of this is new technology except the drive itself. The rest is ancient technology, most of it dating back to the replacement of seals with rubber and synthetics going back to pre WW2.
While the battery point is certainly valid, the counterpoint is the first gen Honda Insight, which only had enough battery capacity to move the vehicle about a mile on battery alone. In the early Insight the battery was supplemental to the engine and acted as an energy damper in precisely the same way I see a hydraulic system operating, with the exception that the engine was directly connected to the motor, instead of being capable of independent operation. With what many would consider serious design flaws, the first gen Insight is still the mileage champ among production vehicles, with a 48 pound battery in a 2 k pound car. It would be interesting to convert one of those Insights into a hydraulic hybrid with a 100 pound accumulator system and drives in each front wheel, eliminating the transmission axles and brakes, as well as the engines induction control systems would be very close to weight neutral, while providing blistering acceleration and pulse a glide capability in the accumulator while maintaining a constant speed.
Anyway that is what I am trying to get built today. Maybe in a year it will be finished but it won't be an early Insight conversion in the first prototype, maybe the second if things sort out well.
Appreciate the interest.

regards
Mech

[ron]

wow lost every thing I was writing so Ill try again. the concept of hyd assist is gerat. I hope that you look into the 3000 psi . wall thickness of 1/8 to 1/4 may be a little thin as you know hyd equip is 4 times rated for safety, decompression is going to play a part when you release the stored fluid . I hooked up a system for aarp years ago and it took 3 ten gallon accumulators to start a CAT and the nitrogen precharge was 4500 psi,and it hammered like he-- ,it also cranked and carry the engine to 1800 rpm in as i recall .025 sec so the sign wave of electric power wouldnt drop so they wouldnt loose computer data input if a power failure happened. just design first so t&m isnt wasted, If it dont work on paper get another sheet . hope this helps food for thought. Ron hyho off to work i go

[drmiller100]

a simple hydraulic system which does not seem to leak includes brake systems on cars installed for about 100 years now.

it seems to me a pair of hydraulic pumps/motors are needed. A very large capacity (40 cubic inch?) for braking and a smaller one (10 cubic inch?) for acceleration.

Air might be another good hydraulic fluid.