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10-22-2008, 07:49 PM
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#1
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Join Date: Apr 2008
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Country: United States
Location: up nawth
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Trip to Va Tech #2
Mid semester report from the senior students on my hydraulic in wheel drive design.
I won't be back until Saturday afternoon. I will fill you all in on their findings. They have focused on designing a system that could be used in a Dodge Sprinter van. Each in wheel drive motor should be capable of about 60 HP energy conversion and brake energy recovery.
They have also decided to make the prototype capable of adjustment of the stroke position which is a key component of a functional unit. Previously they had thought they would produce a fixed stroke position design to test.
Talk with yall Saturday.
regards
gary
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10-28-2008, 09:26 AM
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#2
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how did it go?
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10-28-2008, 09:52 AM
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#3
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Yes, keep us informed. I'd love to see how this worked out for ya'll.
I'm doing something similar for the BUV club here at UC, but am going to power a driveshaft on a small pickup's rear clip. Getting hydraulic steering and switchable 3x3 vs 2x3 with only a 10hp input is the interesting part right now.
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10-28-2008, 10:31 AM
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#4
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Yea, I am real interested in this as I am sure others are also. A buddy has a diesel powered Dodge Sprinter van used in his business.
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Dave
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10-28-2008, 11:52 AM
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#5
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Both meetings went very well. The students prepared a 40 page document where they studied various configurations. They are planning to build a 1.5 HP portable test prototype that will use 110 volt power to store energy in an accumulator then release it to see how much they can recover.
The meeting in DC was more related to the financial strategy and the ability to acqquire federal funding for further development.
In general I think both meetings lived up to my expectations, and the second meeting could be summed up with the statement that I should not spend any more money on this, because funding should be available.
Attached is a document that explains my overall goals which is to achieve the mileage figures at the bottom of the chart for the vehicle in the description. 66.7 MPG city and 58.1 highway for a class 2 truck.
It requires a system efficiency of 80% for regeneration. It also requires a dramatic change in engine design, and overall reductions in weight, wth improvements in aerodynamics.
The core of the package where my design applies is in the drive system, using either an accumulator or a flywheel, with consideration to both especially with cost as a factor.
Bottom line is a small Corolla sized sedan with 80 highway and 100 city mileage figures. Those could rise easily if CD could be made to be .19 or lower.
regards
gary
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10-28-2008, 11:56 AM
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#6
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The mileage projection chart.
Gary
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10-28-2008, 12:52 PM
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#7
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just to clarify
class 2 truck?
is that an s-10 or a silverado (I just used chevy as an example)?
I would assume a small compact truck like an s-10. even at that, those numbers are unbelievable. if you could make it into a new vehicle with minimal cost. if you could keep it around the 20k range or even have a retrofit that would go on existing vehicles (that would take some work)
all in all, if you can pull this off, you could be in the runnings for the automotive X-prize. the idea is great.
*edit* I think you attached the wrong pic to the first post (the first of the second) it is a pic of your old car (I think it was a 34 ford, I might be wrong)
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10-28-2008, 02:22 PM
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#8
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Sorry Beef look at the weight. These are EPA estimates, not my figures. Base mileage is 15 and 21 (not including fractions)
Class 2 trucks 9000 LBS assuming that is gross, but it drops to 7600.
They are predicting an engine efficiency of 42% current diesels approach 41%powertrain at 85%, and regeneration at 80 %.
The real advantage of my design is simplicity and low manufacturing cost, as well as much lower per vehicle parts count.
Moving the transmission to each wheel at the same weight as the brake components you are replacing, while eliminating the rest of the powertrain components.
My original flywheel-enigne design should be able to actually beat their 42% projection and actually approach 58% like some of the free piston HCCI engines, while providing flywheel storage to eliminate the need for any accumulator. This function is incorporated into the engines transformation into a flywheel.
Pancaked on the other side of the engine is the transmission which directly provides fluid pressure to each wheel motor, but also serves to store energy in every regeneration event.
The engine either runs at max BSFC, or destrokes itself (almost instantly) into a free spining flywheel, or an accumulator can be used with any conventional engine (but accumulators are expensive).
First step
Take a conventional FWD car like my VX, replace the rear hubs with my design and use the rear wheels to regenerate deceleration forces, as well as allowing the engine to cycle on and off at max BSFC when cruising. Now you have a vehicle that hypermiles itself. Flywheel or accumulator for storage in rear spare tire well. Run flat tires.
75 MPG average
Second step
Dedicated (minus conventional powertrain) flywheel (or accumulator) storage that separates the engine from the powertrain. All drive energy comes from storage with supplemental storage energy replenishment from cycling engine on and off. Acceleration times now rival braking distances and times. 0-60 in 6seconds or less and less than 130 feet to achieve 60 MPH on stored energy alone, but only for one event. Totally reversible process.
100 MPG average
Third step
Dedicated flywheel-engine (either one or the other, but always a flywheel). Engine placed horizontally in an enlarged front corssmember that also serves as a scattershield in case of catastrophic engine failure. Engine has no cooling or induction system, operates in HCCI mode with open throttle, and multi fuel compression ignition capability, approaching or exceeding free piston designs rated in the mid 50% ranges.
130 MPG average
As the design progresses the weight of the vehicle will drop as it does in the graph due to elimination of heavy powertrain and cooling system components, also indiction system components. Final evolution should weight about 75% or first config.
Mileage claims could actually improve with dedicated efforts at reducing aero drag to the minimum possible. Hydraulic drive systeam also have capability to reduce vehicle gorund clearance on highways at higher speeds, while increasing it significantly in adverse enviornments like deep snow. mud, etc.
In the event electric drives become practical or desirable for local in city type 0 emissions operation, modules could be interchangeable from combustion power storage repleneshment or dedicated electric replenishment.
regards gary
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10-28-2008, 03:09 PM
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#9
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Quote:
Originally Posted by R.I.D.E.
First step
Take a conventional FWD car like my VX, replace the rear hubs with my design and use the rear wheels to regenerate deceleration forces, as well as allowing the engine to cycle on and off at max BSFC when cruising. Now you have a vehicle that hypermiles itself. Flywheel or accumulator for storage in rear spare tire well. Run flat tires.
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Will the rear wheels have enough braking traction for the amount of regeneration you're talking about? Would it make sense to use a RWD vehicle and your system uses the front wheels? This probably makes it much more difficult to make/use hubs for the purpose, but what about accepting some drivetrain loss and using a 4wd-style front axle with off-the-shelf hubs?
You could use a compact pickup. You could start with a RWD truck and use the axle from the 4wd version, or start with a 4wd truck and remove the transfer case and front driveshaft. Then hook your regen up in place of the front driveshaft. You might be able to house the vx-spare-tire-sized flywheel/accumulator in some of the space freed up where the T-case was...but if not, and if you can't find a decent place to put it, there's always the truck bed... but Ford managed to fit 65 miles worth of batteries under the Ranger EV.
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10-28-2008, 08:02 PM
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#10
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Cow, the idea is to keep his original drive wheels and use the rears as a proof of concept. If you use a motor that's fine with bi directional fluid flow, it will become a pump when the vehicle is coming to a stop (read: he's 'engine' braking with the hydraulic motors attached to his wheels). This goes to an accumulator/resivior of some kind, which is then released on demand.
By using a bypass valve he can drop the system pressure to nill after the initial acceleration uses up the pressure in the system, so the motor is free wheeling, and when he goes to stop the bypass valve closes and the motors start pumping fluid into the resivior. On acceleration the fluid is allowed to flow again, but going from the resivior to the motor, thus helping to power the vehicle.
That's one of the awesome things about hydraulic transmissions and drives - the power unit can also be an extremely effective brake and storage devise
There's a decent amount of math involved. Right now I'm prepared to murder my team mates.
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