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10-29-2008, 04:18 PM
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#21
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I see the point now, but I still think that there is far more energy available to be recovered from the front.
-Jay
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10-29-2008, 04:56 PM
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#22
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Quote:
Originally Posted by theholycow
Ah, that is precisely what I was missing. I thought he was looking to regenerate a lot more energy.
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Not on the concept. If he gets it going the way he's describing, he'll have 4 wheel regenerational braking.
Hydraulics make a heck of a parking brake to boot
The only issue I think he'll run across is finding the pump(s) and motors. They're going to be very very very heavy duty custom builds, which won't be anywhere near cheap.
For my project a few years down the road I'm working on making my Saturn RWD with a 6 speed that's hydraulically powered from the factory 4 banger engine.
Not as nifty as 4 wheel hydrostatic driven wheels, but it'll be a lot more fun to tear through the gears
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10-29-2008, 08:44 PM
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#23
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Join Date: Apr 2008
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The regenerative braking efficiency is listed on the chart at 80-85%.
Gas electric hybrids get about 30% back, just a little more than 1/3 of the hydraulic system.
The new component is the in wheel IVT (infinitely variable) pump-motor. Its cost when in mass production will be almost identical to the brake components you no longer need, and you will never wear out your brakes again.
Moving the drive directly to each wheel (the second stage of development) means you can now design the system to apply the exact amount of power to each wheel that is necessary to reach the limit of the tires traction with the ground.
Remember I said 0-60 in 130 feet. How many cars do you know of that can do that? And that is on accumulated storage alone. You can do that rate of acceleration ONCE without the engine even running, not even idling (which it will never do anyway). You don't need it more than once, so why add weight and cost to do it more than once.
Try this, drive your car using only the emergency brake for stopping. We drive conservatively as hypermilers anyway. I guarantee you I can drive my daily trip using only the emergency brake on my Honda. Tiny little drums are all I need because I try not to use my brakes at all. My design eliminates brakes altogether (in the conventional sense), with the exception of an emergency brake in case of a catastrophic system failure.
Remember the key to this stage of evolution. By retrofitting this system to a car like my VX, you are only progressing to stage 1, which is Launch assist. Focus on the assist definition. The system will be engineered to only provide and recover the power to the rear wheels that they can handle as far as traction is concerned. If you want to accelerate faster than that lmit you use the engine and the front wheels to accelerate faster, but in doing so you waste a lot more fuel.
When cruising at a constant speed the rear wheels (in the VX example) would be more than adequate to maintain any reasonable speed. If you need to accelerate uphill on an interstate on ramp with a full load of passengers, in heavy traffic, you would have to add engine power to do so safely.
Sure the system could be retrofitted to almost any vehicle, but if you try to do so through the existing powertrain you must run the drive pump-motors at much higher RPMs which is where the current designs loose a significant amount of efficiency, from 94 down to 75 %. That eliminates that configuration as a reasonable solution. In wheel motor speeds of 1000 RPM would mean vehicle speeds in excess of 80 MPH. Splitting the power requirements to all 4 wheels individually makes a lot more sense when you consider that each wheel only has to provide 1/4 of the acceleration forces.
You have also eliminated the necessity of a power teansmission components to carry all of the engines power to the wheels. Thats hundreds of parts no longer needed.
In our cars we reduce the propshaft RPM through the differential. By moving the transmissions work to the wheels themselves you have low RPMs (much more efficient) as well as 4 wheel regeneration. This is in the 2nd evolution, when the engines connection to the wheels is completely eliminated.
The difference between stage 1 and stage 2 is 40% stage one mileage improvement, and 80% stage 2 improvement.
Launch assist could be available by the end of 2009 (stage 1) with stage 2 within 18 months after that.
The whole concept is based on the potential for low risk implementation and positive cash flow from sales, to finance stage 2 and 3. This makes the system especially attractive to manufacturers, which is crucial to them accepting the design and producing it in huge quantities.
Stage two is 4 wheel drive, as well as regeneration, something few if any hybrids offer. Regeneration can continue to 0 vehicle speed at all 4 wheels, once you have progressed to stage two. In stage two you are still using a conventional engine for power, but like the Prius, you are running the engine only in its sweet spot (best BSFC range), because it no longer has anything to do with the power applied to the wheels.
The engine replaces lost pressure in the accumulator, if you are using accumulator storage, or spins up the flywheel, if you are using flywheel storage. The choice depends on cost comparisons of flywheels or accumulators. I believe accumulators would be more efficient, but flywheels would have less of a weight penalty. Each choice has advantages and disadvantages, but the principle deciding factor is cost.
The whole concept is based on the belief that if you can accomplish this with a 20% reduction in parts PER VEHICLE, you can produce a basic very inexpensive vehicle (say 10K new) that gets ungodly gas mileage, with may fewer parts that wear out and require reapir. Its win win from every perspective. Even the manufacturers can make money on cheap cars. Of course they will want to use the same system on more expensive cars but the object is to make the car inexpensive and so simple it would amaze you.
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Now lets talk stage 3. This is where you go after the greatest loss in energy, which is engine efficiency.
Gas engines currently peak at 35%
Diesels currently peak at 41%
Electric motors are approaching 90%
The largest diesels on the planet are about 50%
Free piston engines that convert combustion pressure directly into hydraulic fluid pressure have reached theoretical efficiencies of 58%.
My enigne design has the potential to surpass 58%, because even a free piston engine is a reciprocating engine. My design is not a reciprocating engine.
New engine designs are Billion dollar commitments. No manufacturer will touch that kind of development cost without proving the concept with many prototypes and destructive testing.
My design uses the mass of the engine itself to create flywheel storage of rotational energy. The engine transforms itself into a flywheel. 250 pounds of rotating engine mass only needs to be accleerated from 1000 to 2600 RPM to store the enegy necessary to accelerate a 2000 pound vehicle from 0-60 MPH on that 1600 RPm increase in RPM. We are not talking about high speed flywheels with the potential for catastrophic disintegration.
Maximum flywheel speeds would be 3500 RPM in generated speed with max speeds approaching 8000 RPM if regeneration was necessary at the instant when the 3500 RPM point had been reached.
In other words you are travelling down thee road and your flywheel has just been accelerated to 3500 RPM and some moron pulls out in front of you and you have to make a panic stop. The regeneration energy would increase the flywheel speed to 8000 RPM.
The engine also eliminates the need for any accumulator or separate flywheel for storage.
Now your system consists of the engine-flywheel (one component) a master IVT pump motor, integral with the engine, and 4 in wheel drive regenerating motors in each wheel.
You no longer need any throttle control, cooling system, transmission, prop shaft, axles, differentials. Only a single fuel injector is necessary becasue all air comes in through a single port. No valve train, because the rotating cylinders pass over ports that allow air in and exahust out (2 ports).
Now you have reached stage 3 where the potential for fuel economy should actually exceed the figures in the tables provided.
You also have a vehicle that, by design, hypermiles itself to perfection. As you improve the aerodynamics the mileage grows proportionately. This does not happen in conventional drivetrains, because as you improve aero, the engine eifficincy actually drops becasue you have lowered the sustained demand.
There are two pedals, the right one is the go pedal, while the left is the slow pedal. Both feet are on the pedals all the time. Push the right foot to go faster, left foot to slow down. The pedals are gimballed so when you push one down the other rises, like the rudder controls on older aircraft.
This is real stuff, and its getting damn close to implementation.
regards
gary
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10-29-2008, 09:05 PM
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#24
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Registered Member
Join Date: Apr 2008
Posts: 1,831
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I want to know more about stage 1. the one that you can retrofit onto an existing car for just the launch.
you said possibly available in 2009. was that a retro fit onto a vehicle? what would be the cost? I really like the idea.
it isn't that I don't like your other ideas but I work in design (electronic design, PAs to be exact) and I know how schedules go. time lines get stretched out and some projects get dropped all together (not that I expect that of yours). I think that if you could increase someones mileage by 40% over what they are doing right now, that would sell like hotcakes (depending on price).
I for one would be interested if the system was relatively inexpensive. keep us posted. hopefully one day, the hydraulic car will be available at our nearest dealer.
this is good stuff. I can't wait to see how this turns out
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10-30-2008, 05:18 AM
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#25
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Join Date: Apr 2008
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Country: United States
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Here are pictures of the model I built. The outer rim rotates while everything inside the black shaded ring is stationary.
The three photos show 3 postions:
Lowest foreward gear
Neutral
Lowest Reverse (or highest regeneration)gear
Any position between these maximums creates an effectively higher gear. The movements of the adjustable journal are very subtle, but the consequences are dramatic.
If you apply 5000 PSI pressure to each piston as it and its corresponding cylinder pass over the high pressure supply port (in the adjustable journal-not shown in the model). You transfer that force to the outer locating point of each piston. If the cylinder has a surface area of 1 square inch then you would be creating about 800 foot pounds of rotational torque directly on the outermost portion of the rim, on EACH drive wheel.
As the wheel starts to spin and you want to go to a higher gear, you reduce the stroke position and that is all that is necessary to go to a higher gear. Highest gear would be the slightest amount of adjustment from the neutral position.
Sitting still you are in neutral. When you want to accelerate you move the journal to a position that matches the desired rate of acceleration. Regeneration is simply reversing the stroke position. In fact, if you continue to apply that same sroke position the vehicle would actually go backwards after coming to a complete stop.
As you regenerate braking energy and the pressure rises, you simply reduce the stroke position to compensate.
Look at the model and understand it is basically an axle with a hub rotating around that axle. The diameter of the axle is enlarged to about 4 inches to allow an offset hole to be drilled through the axle, which allows the journal and its shaft to pass through the axle for external adjustment as well as providing a rotary valve for supply and return fluid passageways.
Think of it as a "smart" axle, like smart bombs. The smart portion is the 4 rotary cylinders and their pistons and the adjustable journal. The clyinders are highlighted with red paint, while the pistons are silver. Notice the lack of connecting rods, because the pistons and cylinders can each pivot on their respective end locations.
I'll be back later to answer other questions.
Pictures in next post, sorry I chose quick reply.
regards
gary
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10-30-2008, 05:19 AM
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#26
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Pics.
gary
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10-30-2008, 06:16 AM
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#27
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Registered Member
Join Date: Sep 2008
Posts: 139
Country: United States
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Democracy is two wolves and a sheep deciding what to have for dinner. Liberty is a well armed sheep contesting that decision.
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10-30-2008, 06:19 AM
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#28
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Registered Member
Join Date: Apr 2008
Posts: 6,624
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Quote:
Originally Posted by R.I.D.E.
Try this, drive your car using only the emergency brake for stopping. We drive conservatively as hypermilers anyway. I guarantee you I can drive my daily trip using only the emergency brake on my Honda. Tiny little drums are all I need because I try not to use my brakes at all. My design eliminates brakes altogether (in the conventional sense), with the exception of an emergency brake in case of a catastrophic system failure.
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I could drive with just rear brakes, but I'd be a lot closer to losing my braking traction, and it would be worthless in low-traction conditions -- rain, snow, ice, sand, etc.
Quote:
If you want to accelerate faster than that lmit you use the engine and the front wheels to accelerate faster, but in doing so you waste a lot more fuel.
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...and if you want to decelerate faster, you brake with the front wheels, wasting recoverable energy. Ok, I guess the point is that you just accept that.
The rear wheels are fine for accelerating and maintaining speed. That's well proven. I don't think you have to worry about how much acceleration power they can handle. What's the F/R weight distribution on a Civic VX? It can't be any more front-heavy than a pickup truck.
Quote:
When cruising at a constant speed the rear wheels (in the VX example) would be more than adequate to maintain any reasonable speed. If you need to accelerate uphill on an interstate on ramp with a full load of passengers, in heavy traffic, you would have to add engine power to do so safely.
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I seriously doubt you'd need the front wheels for acceleration traction in that situation. The center of gravity with a full load of passengers is moved rearward compared to the center of gravity with no back-seat passengers.
Quote:
Sure the system could be retrofitted to almost any vehicle, but if you try to do so through the existing powertrain you must run the drive pump-motors at much higher RPMs which is where the current designs loose a significant amount of efficiency, from 94 down to 75 %. That eliminates that configuration as a reasonable solution.
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The only reason I suggested using the existing axle and CV joints is because it sounds like you expect to have difficulty fitting the proof-of-concept hub devices into front wheels. Even so, you don't need to use high RPM; just gear your device 1:1 with the axle.
Quote:
Launch assist could be available by the end of 2009 (stage 1) with stage 2 within 18 months after that.
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If you're actually planning to bring stage 1 to market, it will definitely need to be in the front wheels. Hypermilers can recover lots of energy through the rear wheels, but the general public does a lot more hard braking. Just look at how the Prius is driven; it is often driven by jerks who have no interest in driving smoothly, and aren't even getting the EPA numbers from it.
Quote:
Now lets talk stage 3.
My design uses the mass of the engine itself to create flywheel storage of rotational energy. The engine transforms itself into a flywheel. 250 pounds of rotating engine mass only needs to be accleerated from 1000 to 2600 RPM
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Any worry about a gyroscopic effect? It could be bad for driveability and handling.
Quote:
make a panic stop. The regeneration energy would increase the flywheel speed to 8000 RPM.
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There has got to be a huge gyroscopic effect at that point.
Quote:
There are two pedals, the right one is the go pedal, while the left is the slow pedal. Both feet are on the pedals all the time. Push the right foot to go faster, left foot to slow down. The pedals are gimballed so when you push one down the other rises, like the rudder controls on older aircraft.
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If you're going to start messing with the standard interface, you can really change it to anything you want. How about a single pedal, hinged in the center, press the top/front to accelerate the the bottom/rear to brake (essentially your idea but with the axis rotated 90 degrees). Or, hand controls...I've always wanted hand controls.
I think changing the interface will hinder sales. People want the interface they're used to, and need it, and will call your system dangerous if you insist on changing the interface (and, at least while it's new, it WILL be dangerous -- people will not adapt their reflexes).
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10-30-2008, 06:22 AM
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#29
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Registered Member
Join Date: Apr 2008
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Quote:
Originally Posted by R.I.D.E.
Pictures in next post, sorry I chose quick reply.
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You can switch from the "quick reply" box to the full message composition interface by clicking the "Go Advanced" button. It retains everything you've entered and even gives you a preview of your post with what you've already entered.
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10-30-2008, 02:35 PM
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#30
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The ONLY reason why front braking works better than rear is because the fronts have more traction from the weight transfer and resist locking better.
Rear driven wheels tend to work better in terms of pure acceleration for the same reason.
Ya'll are getting too tied up in which wheels do what - if it spins, it turns the motor, which is all that needs to be done for this.
Also, holycow, he's not talking about the flywheel attached directly to the engine (this would jack up engine RPM's incredibly fast and probably toast your motor) Since the 40's people have been experimenting with putting a massive flywheel horizontal under the floor of a car and using that to store energy. I'm pretty sure that's what he's referring to on the flywheel storage device. Yes, it will have some decent gyroscopic effects, but not on the lateral plane so your steering, acceleration, and braking would all remain relatively unaffected.
The only 2 major issues with implementing hydraulics on the road are these:
1) Maintenance. People are freaking lazy, the system will be contaminated, pumps and motors will fry, all because somebody didn't stick to a maintenance schedule. That's not even counting leaking connections, bad welds or castings, or dry rotting hoses and the chances for a catastrophic failure. When most people can't remember when they changed their antifreeze last, I don't think that's the market to target a mass production hydraulic drive.
B)Potentially injuring someone if a resivior tank blows and sends shrapnel through the interior.
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