Hydraulic Hybrids revisited

[user removed]

http://www.innas.com/Assets/files/Hydrid%20brochure.pdf

This is going to be a long post, so I will separate into a few sections.
The first will cover the basics.
Please do not hesitate to ask for clarifications.

I posted this link before but felt it was relevant to this thread

Same vehicle, engine, weight and performance. One conventional power train, the second a Hydraulic Hybrid.

Fuel consumption reduced by 50% with engine on time of 11.9% of the total time the vehicle was in operation on the test cycle.

I have been working on this design for almost 10 years, when the first spark of inspiration struck me. I was at Old Rhinebeck aerodrome, near Kingston New York at a gathering of on line flight sim players who loved the old Red Baron 3D combat flight sim from the late 1990s.

It was the first time I ever really looked at a WW1 rotary aircraft engine. It was a revelation in its era, with power to weight ratios that were far superior to any design of the era. In 1913 at the Reims air race a Deperdussin Monoplane flew a closed course at an average speed of 121 MPH. That was 3 times the speeds achieved just 3 years before.

The deperdussin used a 160 HP Gnome rotary engine, a design which used a fixed crankshaft with the rest of the engine rotating around the crankshaft.
What a had never realized before after close examination of a cutaway of an original engine, was that it did not require reciprocation to accomplish up and down motion of a piston in a cylinder.

Animated Engines, Gnome Rotary

This link is a moving illustration by Matt Keveney of an original rotary engine, that demonstrates the design basics.

The spark of inspiration was when I realized that if you could move the central axis of the connection point of the connecting rods to a position that was exactly the same as the central axis of rotation of the spinning engine block, you could transform the "engine" into a flywheel, that would be capable of storing its own generated power for a short period of time.

This point in the conceptual pathway was achieved in 2003. I immediately wrote a 43 page document explaining the concept and had it signed by 13 witnesses, most of them relatives. Combined with a Continuously Variable Transmission you could produce a vehicle that was capable of "pulse and glide" without changing the vehicles speed.

In other words, a vehicle that was "self hypermiling". To be able to pulse and glide a vehicle without speed variations was a problem that I never could resolve for almost 30 years, when I read about an Opel Kadett getting 124 MPH using the P&G tactic, while averaging 26 MPH overall, very close to the same speed average of the EPA city driving cycle.

I filed for a patent for the engine design in 2004. No reciprocating parts, no valve train, variable displacement and compression. My preferred configuration was a 2 cycle diesel with supercharging for cylinder scavenging, similar to a Detroit Diesel. but capable of running on many different fuels.

Absurdly simple, with out a head gasket, or any valve train, or connecting rods. One fuel injector, one glow plug for starting, a single induction and exhaust ports that were very close together to allow preheating of the intake charge with the exhaust residual heat. At 250 pounds the engine could recover (in flywheel mode) all of the available energy in a 60-0 MPH deceleration event by increasing its rotational speed by 1600 RPM in a 2500 pound car.

I tried to present the design to many different govt and private institutions and corporations, with no success. The Department of Energy wrote me a letter through Senator George Allen's office, stating they did not see any potential in the design. I offered the military free licensing rights in lieu of commercial application rights that development would produce. After 6 trips to the Senators office, I was told it was not the Senators job to make me wealthy, in spite of the fact that in doing so it would cure the necessity for imported oil in the US.

I wrote letters to every major auto manufacturer in the US, not a single response except GM who sent me a form letter basically saying they would look at my design, but pay me nothing for my unsolicited ideas.

It soon became apparent that I was going to get nowhere with any radical engine configuration, due to emissions issues especially with a 2 cycle Diesel configuration, in spite of the fact that it could have easily been configured as 4 cycle and incorporate any modern emission component.

After beating my hands bloody on the doors that had to open to succeed. I built a simple model that demonstrated the principles of operation. I took it to Detroit to a meeting with Next Energy and Ricardo, in Ricardo's offices in that city. This was in the spring of 2006.

Ryan Waddington, the Next Energy representative told me that my demonstration was the best he had ever seen. Ricardo commented that they were prepared for the engine concept demonstration but not the power train demo. Many days I had carried the small model around with me fiddling with it at traffic lights. Since the pistons and cylinders had identical connection points at each end (a wire eye for a porch type screen door spring!) they were reversible. Reversing the cylinders and pistons resolved all the issues with distribution of intake and exhaust fluids that existed when the pistons were connected to the central hub, instead of the cylinders themselves.

See photo at bottom for pictures of the model.

After two more years of efforts to get my foot in the door of those who could see this thing actually become a reality, Al Kornhauser at the Virginia Tech School of Engineering agreed to assign the design as a Senior project for 8 hand picked students.

A correspondent for the American Society of Mechanical Engineers contacted me about writing an article in the Capstone section of their August 2008 edition of their magazine. (Available of the web of I can provide a photo of the article)

In the meantime the concept had evolved into a Infinitely Variable-In wheel drive. Combined with a hydraulic accumulator the potential was better than 80% recovery of all braking energy in a vehicle. Acceleration with hydraulic energy alone would eliminate the huge losses in getting your car moving to the desired speed. Another advantage would be the fact that you could maintain reasonable speeds while cycling the cars engine to replenish the accumulator pressure, while applying the exact same amount of power to the wheels, regardless of the pressure level in the accumulator, by increasing the stroke position as accumulator pressures dropped.

All this is demonstrated in the first link to the INNAS design of a similar system, but mine has some advantages.

In other words, the car would hypermile itself, without driver input other than normal operation.

Now we are talking about a revolutionary change in the way vehicles operate. The additional benefit is a dramatic reduction in the number of parts necessary to build a car. I calculate the difference as a 25-30% reduction in the total number of parts that would be necessary to manufacture to build a complete vehicle. The in wheel drives require no more parts or weight than a conventional disc brake system.

All other power train components, torque converters, transmissions, prop shafts, differentials, half shafts, clutches, torque converters, etc, etc, simple are no longer necessary.

The engine itself no longer needs and throttle control or engine speed control. It basically runs at wot (without enrichment) and drives a 95% efficient hydraulic pump to charge a 96-99% accumulator. Power is applied directly to the wheel rims themselves, then to the tires and the pavement. Regeneration is tire to pump, to accumulator, and back to the tire. No simpler pathway of energy storage and conversion can exist to my knowledge. Engines can be downsized for even better mileage

Compared to the 80+% energy recovery of this system, gas electric hybrids are barely over 30%.

The vehicle could accelerate through several cycles of acceleration and braking-regeneration with no engine operation or fuel consumption.
0-80 on a fully charged accumulator
0-64 on the second cycle
0-51.2 on the third

No system can even come close to that level of intertial energy recovery.

When I first read about the OPEL that got 124 MPG, I was intrigued by the fact that it did not require the engine to be three times as efficient to make the vehicle 3 times more efficient. The negative was you could not expect traffic to tolerate your pulse and gliding on public roads, especially from 54 down to 15 MPH. Only WW2 type gas rationing would make that feasible.

I'll be back, the wife just got home, and my fingers need a rest.

Thanks for taking the time to read my novel .

regards
Mech

[blueflame]

Wow, amazing story. At least you can feel not alone, with all the others who have invented or discovered things only to be greeted by disbelief and sometimes ridicule.

Nikola Tesla got disheartened as a lot of his stuff was getting shelved instead of implemented. If you stated the earth was round they would kill you.

The emperor has no clothes.

[user removed]

Originally Posted by Frank Lee

If a piston is going up and down in a cylinder it is reciprocating.

Did you look at the animation Frank? (the one linked to matt keveney's site)

Two different axes of rotation, one at the big ends of the connecting rods. The other different axis is the center of rotation of the engine block and cylinders. That is the essence of the aircraft rotary engine of WW1.

In a conventional IC engine the con rod big ends never revolve around the crank journal unless the engine is coming apart.

Is a rotary vane pump a reciprocating engine? The vanes move back an forth in their respective slots.

Since the cylinders are rotating around one axis and the pistons and rods are rotating around another axis, there is no "reciprocation" in the sense as I understand it, hence the definition of a rotary engine.

In a conventional engine combustion pressure forces the piston to move away from the cylinder head and rotates the crankshaft through the con rod. In the WW1 rotary the combustion pressure forces the cylinder head away from the piston and transfers that force into rotation of the block and cylinders. Its the opposite reaction. The crankshaft was bolted to the airplane, and the propeller was bolted to the front of the engine block assembly.

The original engines produced ungodly amounts of torque.

After WW1 a German company actually built a front wheel drive motorcycle with a rotary engine in the front wheel hub.

Megola - Wikipedia, the free encyclopedia

here is a link to the Megola motorcycle.

America on the Move | Balzer automobile patents

Here is another link to Stephen Marius Balzar, who built a car with a rotary engine in the late 1890s. he donated it to the Smithsonian Institute in 1899.
Balzar designed the engine used by Samuel Langley in his aerodrome attempt, which failed because it lacked the sufficient structural integrity and control functions. Langley was subsidized by the Federal govt to the tune of $75,000 but was beaten by the Wright brothers.

regards
Mech

[rrhatbruce]

Ok, Old Mech. I'm with you on WWI rotary engines having the cylinders spinning in a circle, and via the crank throw, having the pistons rotating in another, offset circle. I've always liked that arrangement since the piston/conrod inertia isn't being continually started, stopped, then reversed. Do I understand correctly that part of your proposal is to reverse the orientation of the pistons and cylinders? You would be putting the pistons on the 'outer' circle and the cylinders on the 'inner' You would also be centrally locating the intake/exhaust plumbing allowing only one injector, one glow plug, etc. Right? I'm just trying to get a mental picture of where you're headed.

I'm also a fan of hydraulic hybrids since I read about the UPS delivery truck a year or so back. My (admittedly incomplete) understanding of the hydraulic hybrid concept is that the hardware, having been used in construction for years, is much more developed than the current electric hardware (Please do NOT take this as a slam on electric hybrids)

[user removed]

I think we can debate the reciprocation definition and loose the progression of the concept.

Just agree to disagree.

My conclusion is based on the definition of a rotary engine which is what it was called when it came on the scene.

A radial engine is definitely a reciprocating engine. Reciprocation of the pistons in the cylinders is converted to rotary motion by an oscillating motion of the connecting rod interface with the crankshaft journal.

Any way, back to the Hydraulic Hybrid evolution.

Once I had progressed to the point of focusing on an in wheel hydraulic pump motor. I considered the potential sealing issues of the pistons and cylinders. With displacement changes the volume of fluid in the displaced areas in each cylinder would have caused inherent imbalance of the rotating assembly especially if the displaced area was on the perimeter of the assembly. Trying to seal the connection between the pistons and cylinders as well as the rest of the connection points presented an almost impossible task.

By reversing the pistons and cylinders the passageways for fluid movement would be much simpler. I also came to the conclusion that instead of trying to seal of each individual interface, it would be much easier to just have all the components located inside a closed containment vessel. This way the designed tolerances would allow a very small amount of intentional leakage and the whole containment vessel would be filled with fluid at low pressure directly connected to the low pressure return circuit.

The logic was instead of fighting a small percentage of leakage, make the leakage work for you by using it for lubrication and cooling. So externally the complete component would look like a cake pan spinning around the fixed axle, with only a seal between the axle and hub-drum assembly subject only to low pressure circuit pressure levels. All internal components would be lubricated by the small amount of inherent leakage, which would be offset by the elimination of seal drag friction.

This thing would work completely submerged to a depth that equalled the low circuit pressure level, probably about 30 PSI. Another benefit would be in the event their was any air in the assemble it would be purged by centrifugal forces, also into the low pressure return circuit.

The engine concept went to the back burner due to the fact that a power train design can be quickly incorporated into existing vehicle architecture. My 2001 Echo has rear hub assemblies that bolt to the beam rear axle. This meant I could simply remove the existing hub assemblies and replace them with two of the pump motors. Adding a hydraulic pump to the engine would allow accumulator recharging if I wanted to continue further evolutionary development. In the first implementation it could simply be a launch assist recovery rear axle, capturing and reapplying normally lost braking forces.

It would also make acceleration significant better after a regeneration event, above and beyond the normal powertrain's capability.

The next phase would be to remove the power steering and substitute it with a manual unit. Then install a hydraulic pump with a toothed belt drive, which could recharge the accumulator at constant lower speeds to allow engine cycling while maintaining constant vehicle speed. Power demands above the abilities of the system would require normal engine and transmission supplementation of the standard power train.

The third phase (hopefully after an income stream was created by the launch assist commercialization, would be to build a dedicated vehicle with a pump-motor at each wheel, connected directly to the accumulator, with the engine (or motor) providing replenishment of accumulator storage levels as its sole function. The rest of the conventional power train components would no longer be necessary.

Consider the 5 states of vehicle operation

1.Idling-waste of fuel-eliminated in this design

2.Coasting-engine off-absolutely

3.Acceleration-can be by accumulator or both engine and accumulator. All 4wheels driven selectively together or separately. Each wheel has no connection with other driven wheels. Integration with current anti lock brakes and traction control is easy. Wheel speed sensors would change stroke position to adjust power or regeneration at each wheel individually. Current systems use brake application for traction control, and brake line pressure fluctuations for ABS. Applying brakes to an accelerating vehicle is a waste of energy. This design would control the power application and recovery at each wheel in microscopic increments. without wasteful brake application to control wheel spin on acceleration.

Proper sizing of the accumulator and wheel motor displacements would allow torque to be applied to each tire to the limits of the tires adhesion.

That means acceleration at the limits of all 4 wheels ability to maintain traction with the pavement.

0-60 potential in less than 5 seconds even on highly inflated LRR tires.

4. Deceleration with engine drag-eliminated

5. Braking-normal friction brakes would be eliminated, with the exception of an emergency brake in the even of a total system failure. A total system failure would require all 4 wheel pump motors to fail simultaneous, IE quadruple redundancy, something that exists on no vehicle today. Its not that I am an advocate of high performance 4 wheel drive road rockets. 4 wheel regeneration is essential to maintaining the highest possible energy recovery.

The 0-60 in 5 seconds quote would be from accumulator energy alone, and could be accomplished once while the engine was not even running!

An additional benefit of this system is it automatically compensates for improvements in aerodynamics and rolling resistance. Every vehicle in motion constantly bleeds energy to various sources of losses. Every improvement outside of the power train design would automatically result in less regeneration cycles of the power consuming engine or motor.

In the first link on the first post the INNAS BMW conversion only needed to run the diesel engine 11.9% of the time that the car was running through the test cycle. If the car was aero modded like Basjoos has done with his car that run time would probably drop by 50%.

In areas where you had sustained mountain climbs, it would be necessary to have the ability to bypass the accumulator and drive the vehicle directly with the engine. The sweet thing is the engine size is not really that important. A larger displacement engine would run for s shorter period of time to recharge the accumulator. No matter what the speed of the vehicle the engine would only run at its ideal BSFC with power generation to the accumulator or directly to the wheels regardless of the proportion of supply.

The end result would be a vehicle that was totally practical. It could even be an aero sedan with hydraulic lifting suspension that elevated the vehicle for off road driving or severe weather, like 12 inches of snow on the road. The in wheel drives would be impervious to the elements, capable of operation completely submerged.

Cooling of the hydraulic fluid would be accomplished at each individual wheel. You could even use any heat generated to help with heating the vehicle in winter, by insulating the wheel motors and capturing the heat in a radiator in the low pressure return circuit.

regards
Mech

[Frank Lee]

I think we can debate the reciprocation definition and loose the progression of the concept.

I agree and so I deleted my distracting posts. Carry on!

[user removed]

Now we are at the point where the concept seems to be a practical solution to the questions seldom asked.

1. How do you make lightweight, inexpensive vehicle that can incorporate all of the hypermilers strategies into the vehicle system itself, thus relieving the operator of the labor intensive efforts necessary to extract maximum efficiency for the fuel consumed?

Answer;

Lets assume my conclusions are basically correct. It's a win-win situation.

The manufacturer can now produce a vehicle that is 20% less expensive to manufacture. US auto manufacturers can now make money on small inexpensive cars, and even more money when the inevitable options are added to the vehicle.

The customer has no additional up front cost to factor into his cost analysis basis with a break even point some time years in the future.

Drive train component elimination in conventional vehicles also has the additional benefit of the "if it ain't there it can't break" scenario. No brakes to wear out. No transmission to fall apart. No clutch, differential, axle shafts, throttle control induction systems. With most of the eliminated parts being the ones that usually are needing service and repair. sometimes very expensive repairs, the cost to operate factor becomes a net positive benefit.

-------------------------------

2. I think the future is all electric drive. How do you propose to make your system compatible with a BEV platform?

Answer;

Electric vehicles still have one serious Achilles Heel (weakness). The weigh and power density of the battery itself. Since any car is constantly bleeding energy whenever it is rolling, how much storage do you really need? You will never need to accelerate from 0-70 MPH after the first acceleration event unless you want to risk incarceration. Battery's are for long term storage of energy. What you really need in a vehicle is capacitive short term storage of energy. Dragging around a 400 pound storage vessel is a real catch 22 situation, more weight requires more power to accelerate, so the larger your battery the more energy you spend dragging the battery weight with you.

I still don't see battery technology as practical for any vehicle that would require a range of more than 200 miles, and a refill time of less than 15 minutes. Maybe we will get there, but a $30,000 + commuter car with a range of less than 100 miles is just not in the cards for the vast majority of people. Imagine the DC area if every car was a BEV with a 100 mile range. I think you would have thousands of stranded cars with dead batteries on the sides of every major artery every day.

Great for the tow truck drivers.

Electric hybrids recover very little of the inertial energy in regeneration. I have seen calculations in the 22-33% range, some may claim as high as 40%, but few even dream of 50% regeneration.

The problem is when you have one panic stop from 60 MPH, you have to recover the energy in 20 revolutions of the wheels on your car. No electric recovery system can handle that surge of energy at this time. If that problem is resolved it will require some serious motor size and a large capacity capacitor. The easiest way to understand this is to consider the time to charge versus the time to drain an electric vehicle. The ratio is about 6-10 times the charge versus discharge time. Its not a situation that will be resolved in my lifetime, at least I don't think so without some new breakthrough technology.

Now take your BEV and add a 50 pound hydraulic accumulator and recover 80+% of your braking energy.

In other words the same power train will work with a battery and electric motor. The additional weight of the battery will cost you in an initial acceleration, but from there on that same weight means you will recapture more energy every time you must stop.

Take the Nissan Leaf, add a rear wheel hydraulic recovery and launch assist system and extend the projected range from 100 to 150 miles. That's a game changer, especially if refinement could get it to 200 miles, which is possible with a little improvement in the battery itself.

------------------------------------

3. How do we get off the fossil fuel addiction that is draining our national net worth?

Answer;

My family came to this country in 1634 as Indentured Servants. We have a huge vested interest in the continuing prosperity of the US, and have fought for this country in practically every conflict.

Today the US faces a critical mass situation, we are bleeding our national net wort at an astounding rate. At its peak the balance of trade deficit reached 600 billion a year due to oil imports alone.

If the govt is going to spend money they don't have, then they should spend it on a solution to our energy addiction, a Manhattan Project scale effort to solve the horrendous energy consumption gluttony we presently tolerate.

In correcting that outflow of capital we would also dramatically change the balance of global power. OPEC would disintegrate as the individual members could now be subjected to us refusing to import their cash crop of dino juice. Most every war ever fought was over economics. We will never stop religious fanatics from sacrificing their lives for their cause, but we could sure cut off the funding necessary for those efforts. At least it would be a positive benefit.

This does not even address the environmental aspects of the potential 50% reduction in global emissions, if energy efficiency improvements are applied to every aspect of oil consumption. Its not a conservative versus liberal confrontation as many would like us to believe.

Its spaceship earth and we are the crew. Its the only spaceship we will every have and we need to make sure it survives. There is no reason to wait to see if addressing global emissions consequences are factual or a myth, just fix the damn cars and other energy consumers and that will solve the problem, for free.

I consider it a compliment to be considered as a conservator of the future, that is the political category I will gladly accept as defining my objectives.

---------------------------------

4. Will my dream ever become a financial success?

I would not presume to assume that my configuration will be the last stage in the evolution of motor vehicles. I would like to think my time and energies would be rewarded, but there is a much greater issues at hand. That is because we are rapidly approaching a tipping point where any solution may be too little too late.

I appreciate every one's patience in taking the time to read these three rather lengthy posts. Knowledge is power and the more people who understand the real possibilities the sooner political pressure becomes enough to begin the real change we need to make in every aspect of the energy infrastructure.

This design has many applications in efficient energy conversion and storage, but that topic would make this thread become a fairly large novel.

Thanks especially to the forum operators for allowing me to take advantage of your forum. I intend to make a financial contribution to cover your costs, regardless of whether the pop ups stay or go .

If you have any questions feel free to ask.

regards
Mech

[cfg83]

Old Mechanic -

1. How do you make lightweight, inexpensive vehicle that can incorporate all of the hypermilers strategies into the vehicle system itself, thus relieving the operator of the labor intensive efforts necessary to extract maximum efficiency for the fuel consumed?

Answer;

Lets assume my conclusions are basically correct. It's a win-win situation.

The manufacturer can now produce a vehicle that is 20% less expensive to manufacture. US auto manufacturers can now make money on small inexpensive cars, and even more money when the inevitable options are added to the vehicle.

The customer has no additional up front cost to factor into his cost analysis basis with a break even point some time years in the future.

Drive train component elimination in conventional vehicles also has the additional benefit of the "if it ain't there it can't break" scenario. No brakes to wear out. No transmission to fall apart. No clutch, differential, axle shafts, throttle control induction systems. With most of the eliminated parts being the ones that usually are needing service and repair. sometimes very expensive repairs, the cost to operate factor becomes a net positive benefit.

I think the auto companies will love making small cars cheaper but hate the reduced maintenance costs. I read recently that dealerships don't make money on the cars they sell, they make money on the servicing of those cars.

But, a cheaper to build car scales very well to the profit margin on larger cars.

CarloSW2

[Air-Hybrid]

Old Mechanic,

As a newcomer to this site, but a long-term believer that non-electric hybrids are still a missed opportunity, I whole-heartedly commend your efforts here!

Your 'leap of imagination' to using the rotating cylinder bodies for their flywheel effect is a work of genius, in my opinion.

Of course, the added inertial resistance of this load does make the reliance on a accumulator for launch-assist indispensable - without the need of over-engineering the hub motors instead.

Taking the idea of a flywheel a step further (& halving the motor count) would it not be worth considering using only one transversely centred motor (with diff) flat on the floor of the engine compartment? Combine this with a pump to fill or empty the outer ring of the motor with hydraulic fluid & you have a variable flywheel device. The regenerative braking should still be able to work in reverse through short transmission step.


I, myself, have spent some time considering several configurations of a air-store hybrid using a four-stroke free piston (no crank) engine - i.e. two piston in phase work direct on a reciprocating hydraulic pump piston; low-press returns IC pistons to TDC (ideally through exhaust pressure scavenging via a hydrostatic system I have planned).
A accumulator would 'rectify' the pump flow and give an acceleration boost when needed.

The biggest hurdle has been the incompatibility with braking regeneration (regen, I feel has to be an incorporated feature in any hybrid design), when using free-piston engines.


Your solution is so much more elegant in combining these components.
Please keep us informed, especially on where the experiments at Virginia Tech. go.

I take my hat off to you, sir!

Tom (UK)

[user removed]

Thanks Tom.

I don't really feel like there is any "genius" involved. It's more a lifetime interest in vehicles of all types and how mankind developed efficient methods of extracting power from energy sources.

I appreciate the compliment but I truly feel like there is that spark of inspiration in every one of us.

To answer your question the motors could be mounted inboard like the disc brakes of the Jag XKE. They could also be incorporated into a transmission unit for front wheel drive or rear wheel drive.

The basic principle behind the positioning of them individually at each wheel is the elimination of as many conventional power train components as possible, even the axles that would transfer energy to the wheels if the motors were not in the wheels themselves. It could be that if the wheel vehicle was light enough inboard drive pump-motors might be the best method, but if the vehicle as a whole became lighter the pump-motors would follow suit.

I decided against using the outer portion of the engine for hydraulic pressure generation for two reasons. First would be balance of the assembly. Second would be pumping the mass of the fluid itself against the centrifugal forces of the spinning body of the machine.

Considering the motors themselves would weigh about the same as the brake components they replace, and would be constructed of very few parts that were simple to manufacture, as well as utilizing the existing axle bearings and axles that are an essential part of any wheeled vehicle, the only additional parts are the journaled shaft and the cylinders and pistons. The outer location of the pistons would also be the mounting points of the rims and tires.

This was a progression of thinking based on the simplistic approach or rationale. Try to make every component perform the maximum number of practical functions while eliminating the large number of individually manufactured components through which power must be transferred from the engine (or motor) to the wheels themselves.

Adding components adds complexity and some additional losses in power transfer. The losses may be small but the cost of unnecessary components adds to the cost of production.

That philosophy applies to every component of a complete vehicular system. If you used the original flywheel-rotary engine, you have to consider a catastrophic failure of the spinning mass of the engine itself. Most people would say it has to have a containment vessel. My experience with cars pointed me to using the front sub frame as a containment vessel. Place the engine withing the sub frame, and make it so you could remove it from the bottom of the cross member. Engine on the ground in 10 minutes.
Each wheel,s pump-motor would require less than 1 hours labor to completely overhaul, if it was ever necessary.

As far as the accumulator. It could be incorporated into the rear suspension cross member, or as an additional function of a tubular frame. This would make the weight of an accumulator perform double duty as a structural component of the vehicle itself.

When emissions regulations first became required in the US (the first was positive crankcase ventilation in 1963) I always disliked the way they were added on to existing engines in an attempt to make do with what you had in the parts bin. The early emission controlled cars were atrocious abortions of engineering.

When Nissan went to fuel injection in 1975, their engines did not even need EGR or a catalytic converter to pass federal emissions.

The modern equivalent is the pursuit of Homogeneous Charge Compression Ignition, which has the potential to eliminate after treatment of combustion byproducts.

While you all may laugh at me a consider me somewhat of a lunatic for even mentioning it. I consider a steam engine as a possible pathway. Not known for efficiency by most modern day engineers, there are two major benefits possible with steam power. First is external combustion produces no emissions requiring treatment. Our vent free natural gas fireplace exhaust it combustion byproducts into our house. We are breathing the exhaust without harm.

Another potential advantage of steam power is the advancements in insulation, combined with using fluids other than water for the "steam" lower boiling points, more effective heat transfer to modern multi tube boilers to me make the potential something that should be explored.

Its funny how the most efficient method of moving gross tonnage of freight is barely better today than the old steam locomotive. Many naval vessels are still using steam.
Steam could be used to directly create hydraulic pressure, with a system of stepped pistons resembling the old triple and quadruple expansion engines of long ago.

There is also a design for a free piston to direct hydraulic pressure generation engine that was in the EPA hydraulic hybrid documents almost 10 years ago. Ingo Valentin (google Valentin Technologies) has been pursuing this for decades, long enough for most of his patents to expire.

I especially liked the use of the suspension components for fluid transfer in Valentin's designs. They follow the principle of multiple utilization of components.

Steam also is multi fuel capable.

I like the free piston engine design because it uses the mass of the piston to compress the mixture for the next combustion event. I think the theoretical efficiency was quoted at 58% in the EPA documents. Combine that with Co generation of residual heat for driving the accessories and you might reach 70%.

I don't think many people understand (could easily be wrong) the compounding effect of individual efficiency improvements. As the gross efficiency issues are resolved, the losses attributed to smaller inefficiencies are compounded.

Also the system has to be able to self compensate for improvements outside the system itself. Currently if you reduce your rolling resistance and aero drag to the point where it takes 50% less energy to move your vehicle at a certain speed, the lower power requirements placed on the engine itself make it less efficient due to lower manifold vacuum and lower effective compression. Imagine what a 1st generation manual Honda Insight would do for mileage if the aero drag was reduced from .25 to .017 like Basjoos aerocivic. Heck you could even add another taller gear for even more improvement, increasing the load on the engine for better cruising efficiency.

Valentin thought his car would be capable of 130 MPG. I think his estimate was correct, and with further refinement it may be possible to reach 200 MPG.

It sure would be nice to see govt actually dedicate some of the money they are throwing away at really addressing the problem. The EPA test mule was 3800 pounds and they calculated the average MPG at 80.

regards
Mech