What makes cars fuel efficient?

[R.I.D.E.]

Another one

In the original rotaries the centrifugal forces meant all the oil (mixed with fuel) would eventually come out of the exhaust. reversing the cylinders reverses the effects of centrifugal forces which means you have to force the oil to the rings to lubricate them.

As a normal engine wears it consumes greater quantities of oil, this engine sould use less because of centrifugal purging of oil from the cylinder walls and rings.

regards
gary

[monroe74]

"Usually when people speak of reducing weight, they're talking about reducing weight while producing otherwise the same product."

It's a matter of degree, and it's a matter of semantics. When I make this year's model an inch or two shorter than last year's model, and also delete, say, the electrically-operated trunk lid, then I've indeed cut weight, while still producing what most people would think of as more-or-less "the same product."

Trouble is, we've been heading in the opposite direction. The result is we wake up one day and realize a Civic is now much heavier than an Accord used to be.

"there really are more legitimate purposes to driving different vehicles"

Naturally. And we all know that some people, like you (I assume), have a large vehicle because you really need one. But I think we also know that your situation is relatively exceptional. Just drive down the road and count the empty seats in SUVs, and the empty beds in pickups. Then figure out how many SUVs have never seen an unpaved road, or more than an inch of snow.

"One size does NOT fit all"

Good point. In my household there's one 2100-pound vehicle, and one 4400-pound vehicle.

"scrap steel is now pretty lucrative"

Commodity prices fluctuate, and it's true that steel prices have been rising lately. But the picture is not that simple. We're selling China a lot of scrap, but we're also importing a lot of finished steel from them. Anyway, I think Matt's point about cheap steel is basically correct. Adding (relatively) cheap steel to a vehicle is an easy way to make it bigger, more impressive, more profitable, and less efficient.

[monroe74]

"That is all that needs to change to transform the basic engine into a flywheel."

OK, I think you've answered my question. I think I actually understand most of what you're saying.

So the gnome design is applied to the engine, and the entire engine assembly acts as a flywheel (energy storage device). I realize this involves adding the key innovation in the journal design, which means you can let the piston speed (i.e., reciprocating travel inside the cylinder) become zero, while the whole engine assembly continues to spin.

But you're also applying the gnome design to the hydraulic pumps that live inside the wheels. Right?

[R.I.D.E.]

Correct Monroe, at first with the original design I knew it would not work, as a hydraulic drive pump The original configuration was 3 cylinders which would have created power pulsations when pressure was applied.

The second killer was the different volumes of fluid at the perimeter would create inbalance.

It would have been like driving a car with water in the tires and a clutch chatter you couldnt fix, regardless of the speed.

It was quite accidental when I realised the solution was 4 cylinders with the cylinders rotating around the center journal (just the opposite of the original engine).

Now the different fluid displacements occur directly over the center of rotation of the wheel so imbalance is not an issue.

With 4 cylinders I measured the displacement changes of each cylinder. The graph was a "bell curve" of displacement change. It wouldnt work with a separate connecting rod because that changes the bell curve.

It's called overlapping sinusoidial waves. When you overlap the individual cylinder graphs in the sequence they occur, the resulting total displacement is a continuous volume, which means you have no pressure changes at any constant displacement value. No pressure dampner is necessary to absorb pressure fluctuations.

If you pump any fluid out of this design the flow will be constant without pulsation. As you increase the stroke position the volume increases while the effective pressure decreases. Archimedes said give me a long enough lever and I can move the World. This design allows you to have a lever with instantaneous potential changes in length. You start out at maximum stroke, whcih is designed to produce the maximum torque at each wheel, to the limit of the tires ability to maintain traction with the pavement, as your speed increases the stroke position is reduced which compensates for the increased available power pulses as wheel speed in creases from 0 to 14 for a 2 foot diameter wheel at 60 MPH (times are per second). Reversing the stroke reverses the process and recaptures normally lost braking energy.

The model which utilized a fan clutch just happened to have 4 tapped holes where the two halves were bolted together. When I made the model it was not intended as a fluid pump, after playing with it and reversing the cylinders and pistons, as well as graphing the individual cylinder displacements that I realized that I had accidentally figured out a way to correct both of the major flaws that rendered the original configuration impractical for an in wheel drive.

A Nissan 4 wheel drive truck has almost 50% of its total weight dedicated to the powertrain.

Transmission
transfer case
prop shaftsX2
differentailsX2
flywheel
clutch
cooling system
induction system
some percentage of the suspension
some percentage of the frame itself
brake system

The percentage may not be 50% but it's close.

With the in wheel drives in each wheel you only need 25% of the power per wheel. Add a 250 pound engine and a 200 pound accumulator as well as 4 10-15 pound in wheel pumps and you have reduced the total weight by a truly significant margin, to say nothing about the number of manufactured components you no longer have to produce. These are also some of the most expensive individual pieces.

You also don't need to have the ground clearance necessary to have all that same powertrain hanging under the vehicle. to say nothing about the fact that your undercarriage can be practically smooth for aero improvements.


regards
gary

[monroe74]

"a 200 pound accumulator"

I thought energy is stored in the spinning engine. Is there another flywheel-like device?

Something very interesting, but also confusing, about your design is that you use the gnome concept (cylinders mounted in a spinning assembly) in two different places, in two very different ways (in the engine, as a type of ICE, and in the wheels, as a type of hydraulic pump).

The gnome concept itself is unheard of, for most people (if they don't know about aircraft history). Then you add a major twist (literally), with your novel idea to selectively let the pistons rotate along with the block. And then you use the gnome design in two very different ways, in the engine and in the wheels. That's a lot of novelty, wrapped up in one package. So I can see why people could have a hard time understanding what you're talking about.

I have a question about the axle-wheel design. Would high unsprung weight be a problem? If it was, I suppose you could do something like what Jaguar did with the rear brakes on the XKE (moved them inboard, so they were not part of the unsprung mass).

[R.I.D.E.]

The energy can be stored in the engine or in a an accumulator(or a combination of both).

They will probably not build the engine in my lifetime.

Using the engine as the storage requires more complexity in the powertrain than a simple accumulator with two wheel pumps in a launch assist axle.

Using the engine as the accumulator requires 2wheel pumps, a master pump and an engine, 4 wheel pumps if you want 4 wheel regeneration as well as 4 wheel drive.

The wheel pumps replace the brake components, moving them inboard would require axle shafts when they are not necessary. They would weigh about the same as the brake components you no longer need, so the sprung weight issue is basically a tradeoff.

The engine will realistically be a serious financial commitment, while a simple launch assist axle would require only a small percentage of that financial commitment, possibly less than 1%.

Yard by yard life is hard, inch by inch it's a cinch. As a potential investor would you choose a several hundred million dollar retooling commitment, or a several million dollar optional Launch assist axle, as an option on an existing vehicle platform.

My guess would be the odds of choosing the first option are practically nil, while the odds of choosing the second option, when the feasibility is absolutely certain is a no brainer. I will know the systems efficiency by Christmas this year, the launch assist option could be in production within 18 months after Christmas.

Build the launch assist, create the income stream necessary for the financial commitment it will take to produce engine prototypes that can be destroyed in catastrophic functional testing.

The path of least resistance, as well as the realistic approach.

regards
gary

[monroe74]

"a simple accumulator"

OK, believe it or not I was not familiar with the concept of a hydraulic accumulator. But I just looked it up, so now I am. I guess the accumulator would use compressed gas?

So if I understand correctly, you're basically talking about using hydraulics for energy storage and delivery, instead of electricity. And you can do this effectively by using a new kind of hydraulic pump that functions as an integral part of the axle-wheel assembly.

"They would weigh about the same as the brake components you no longer need"

OK, I imagined that might be true.

Hey, here's a wacky idea. I wonder if there's a way to envision your system as a retrofit to a car that's already on the road. Let's say you target a certain class of vehicle. Probably FWD. Let's say a certain generation Honda/Acura. Your product replaces the rear axle/wheel assembly. Presumably a small set of parts would fit many cars that are already on the road. The accumulator goes in the trunk/hatch area.

This could be positioned as a performance accessory. Putting the accumulator tank in the back is sort of like putting a NOS tank back there.

Working in your favor is that computer power is cheap, so the system could be controlled/modified by a cheap laptop, provided by you or the customer. Adapting the system to many different vehicles and conditions would ideally be done via software. Software would also let you tune to either optimize performance or economy.

I wonder if you could get your costs down to $5,000-10,000, for something like this. My wild guess is that there would be at least a small market, at that price. There are people who spend a lot of money preparing their Civic for the dragstrip, and maybe some of them would like the distinction of being to be able to smoke all four tires.

[StorminMatt]

Originally Posted by theholycow

I would argue both of those points. Steel costs more than ever, and scrap steel is now pretty lucrative. The reason is because of the huge increased demand that China has put on the steel market. I've heard that the US actually exports scrap steel to China, and makes a profit on it.

The scrapyard down the road from my house pays $170/ton for mixed crappy steel stuff and $270/ton for clean steel. I got $16 for a complete refrigerator, which surprised the hell out of me since I thought I was going to have to pay them, considering the cost of the hazardous waste disposal involved.

I googled for scrap steel price china and this was the first result:
http://query.nytimes.com/gst/fullpag...50C0A9629C8B63

Even if steel is more expensive than it was in the past, it is still cheap in comparison to the cost of trying to reduce the amount used.

[theholycow]

Originally Posted by StorminMatt

Even if steel is more expensive than it was in the past, it is still cheap in comparison to the cost of trying to reduce the amount used.

Good point, that's still very true.

[monroe74]

"it is still cheap in comparison to the cost of trying to reduce the amount used."

Yes, and the situation is even worse than that. It's not just that there's little or no incentive to reduce the amount used. It's that there's a positive incentive to always use more. In other words, there always seems to be more profit to be gained by making the vehicle a little larger and fancier (more features). This usually involves adding steel. The increased profit always seems to be more than enough to offset the marginal cost of the added materials.