Vehicle: Car: Engine: Gas-Electric Hybrid
Hybrid Engine   (+14, -5)  [vote for, against]
A REAL Electric/Internal Combustion Hybrid

Seems to me the only hybrid automotive companies can come up with is not really a hybrid, rather two different engines running the same thing. my idea, which is far superior, would be an internal combustion engine, with a block of teflon-type material, pistons of teflon-coated magnets, and the heads would be powerful electromagnets. allows more direct magnetic attraction rather than pulling diagonally the way electronic motors i've seen work. the only problems i foresee are magnetic shielding between cylinders and getting a patent.
-- tkeyser, Apr 17 2001

(?) how it works http://www.monito.com/wankel/rce.html
the wankel engine explained [mihali, Apr 17 2001, last modified Oct 21 2004]

how that works http://www.turbinecar.com/sia/sia127.htm
According to this, component cost and steerability are the obstacles to wide acceptance. [reensure, Apr 17 2001]

Microwave Water Engine http://www.keelynet...energy/microeng.htm
can it work? Principle: Water is nuked in the combustion chamber [mreuler, May 05 2002, last modified Oct 21 2004]

Early motors http://www.sparkmuseum.com/MOTORS.HTM
[Fussass, Oct 04 2004, last modified Oct 21 2004]

(?) free piston alternator http://www.eere.ene..._van_blarigan.pdf -
update on technology [seamus, May 13 2005]

http://www.eere.ene...er_van_blarigan.pdf seamus's link, fixed [caspian, Feb 15 2006]

(?) Free piston generator http://www.freepistonpower.com/index.htm
being developed for use in hybrid cars. [caspian, Feb 16 2006]

Quasiturbine Diesel Hybrid Engine Electric_20Diesel_20Quasiturbine
[Willie333, May 19 2006]

You can probably go with a standard aluminum block, as it's non-magnetic, and aluminum-clad iron pistons (correct me if I'm misunderstanding your reason for using teflon). But one inefficiency of piston engines arises because the reciprocating motion of the pistons has to be changed to a rotary motion before it can be output to the wheels. On the other hand, electromagnetic motors work best as rotary devices. (The only electromagnetic reciprocating motor I can remember seeing was in an aquarium air pump--and a lot of applications that would logically use a reciprocating electromagnetic motor (like piston air compressors) go with a rotary electric motor and convert the rotation to reciprocation.)

You may gain efficiency by using your electromagnetic component to add power at the flywheel instead of the pistons. There is probably gobs of engineering involved, but I ain't no engineer. Good luck!
-- Dog Ed, Apr 17 2001


You get my vote (even though most of this is over my head) just b/c gas prices are annoying me.
-- Susen, Apr 17 2001


Y'know, tkeyser, you may not need any shielding since magnetic fields fall off so rapidly with distance. You could just design the engine with horizontally opposed cylinders, like a BMW motorcycle, or for a 4-banger maybe cylinders at 9 o'clock, 11 o'clock, 1 o'clock, and 3 o'clock if you catch my drift.

I assume you're going to use a big capacitor and energize each cylinder's electromagnet just as the piston approaches TDC to get the most pull out of your available current; that also minimizes unforseen goobers like eddy currents in the block.

I hope I haven't insulted your intelligence here. You're probably way ahead of me.
-- Dog Ed, Apr 17 2001


the reason for teflon was reduced friction, with built in aluminum shielding, but further thinking suggests that i might need an aluminum frame within the teflon.
-- tkeyser, Apr 17 2001


take a wankel rotary engine (found in the mazda rx-7) wrap a coil around its rotor, magnetize the chamber, and you've got a real hybrid engine, just like you described.
-- mihali, Apr 17 2001


easier said than done, as the wankel rotary, like the automatic transmission, works primarily by magic.
-- tkeyser, Apr 17 2001


so get a magician to do it for you! :-)
-- mihali, Apr 17 2001


Wait, what's the point here? The piston engine is highly optimized for internal combustion; the electric motor/generator is highly optimized for electromagnetic propulsion. Combining the two is likely to be less efficient, no matter how you do it.

The only advantage I can see is that it would save some space under the hood (which isn't really a problem with these vehicles). I suppose there would be one or two fewer bearings, too, but I can't believe that's not negligible.
-- egnor, Apr 17 2001


Why aren't washers and bearings half magnetic anyway? That would make sliding a spacer or washer into a gap or groove soo much easier.
-- reensure, Apr 17 2001


egnor: the point is that there is more direct back and forth attraction/repulsion action. (sorry, i forgot to meniton this). the magnets could also be switched around halfway through each rotation so that the pistons are attracted and repelled--an advantage that is not employed in either internal combustion or cocentric electric engines.
-- tkeyser, Apr 17 2001


I think the "direct back and forth attraction/repulsion action" isn't nearly as important as you think it is; to wit, I don't think it's important at all. If it was, people would build electric motors with pistons, and they don't, do they?
-- egnor, Apr 17 2001


you don't understand. the current electric motor works like a waterwheel, and they don't use those anymore now, do they? cocentric electric motors work fine for fans and stuff, but we're looking at something on a much larger scale.
-- tkeyser, Apr 17 2001


(Someone help me?)
-- egnor, Apr 17 2001


What's happening now in a concentric motor via a brush, you'd do with a piston sort of thing? Prism shaped block with and end view like 'X' and cone shaped pistons?

I was talking with a retired Chrysler engineer yesterday who was telling me about a turbine car he helped design. Said they only made two of them and it would run across town on a bottle of nail polish remover.
-- reensure, Apr 17 2001


Corner the market on Nail Polish Remover then!
-- thumbwax, Apr 18 2001


Correct me if I'm wrong, but nail polish remover is a damn sight more expensive than Gasoline.... And the fumes!
-- globaltourniquet, Apr 18 2001


Let's see here. Across town = which town? Let's assume your average-sized urban area. Call it five miles. One gallon of gasoline in Los Angeles right now is $1.90 or so, call it $2. One bottle of nail polish remover (ladies might help me) can be obtained for $1.50.

Five miles can be traversed across town by the average car in less than half a gallon of gas (petrol, for the other side of the pond).

5 miles by gasoline = <$1 5 miles by NPR = $1.50

So therefor, I do believe your Chrysler Cutex-mobile is a rather unpromising venture....
-- globaltourniquet, Apr 18 2001


egnor: re [Someone help me?]: I'm with you; conventional rotary electric motors are used even where reciprocating motion is needed--as I mentioned above, when driving piston-type air compressors.

But this is the Halfbakery--established engineering practices be d***ed!

We have to come up with a decent estimate of the force you can expect from an electromagnet given the available current and magnet size/windings. I made a bolt/telephone wire electromagnet for my son's edification; powered with 6 V dc it was quite weak. Which is why I think capacitors are necessary. Rotary electric motors use lots of little pulls between very closely aligned magnets to spin the rotor, and the simplest operate most efficiently at a particular speed.

Turbine car: what were the non-fuel costs? To my sorrow, I just can't buy a turbojet engine for the price of a cheap Ford. And the turbine may well explode into shrapnel during a minor wreck.
-- Dog Ed, Apr 18 2001


as far as creating power over a longer distance that would be a definite hurdle in my design, the engine would be 6 or 8 cylinders, "firing" in sequential order. the advantage that i can see over an internal combustion engine is power strokes all the time, rather than just once every two rotations. the advantage over a co(n?)centric electric motor would be less interference between that many magnets and electromagnets crammed together. however, as Dog Ed said, this is half-baked, if i do manage to get a patent and manufacture it, i have recorded everybody's names to assign credit. not that anybody really much cares...

RE: reensure: could you rephrase your last question? it's going over my head.
-- tkeyser, Apr 18 2001


OK, so I've come in late on this. What I think tkeyser is proposing is a petrol engine/linear dynamo. You could either generate electricity with it or power it with electricity.

I think thet there's a great future in this combo (electric motors have get peak power at low rpm when petrol/hydrogen engines are inefficient) but am not sure of the advantages of uncorporating the electrics in the engine block.

The only advantage I can see of doing this is to use electricity to get the engine moving (faster accelaration) and generate the power back by braking the engine with the dynamo.

...but you could do this just as effectively by sticking two separate devices on the same drive shaft.
-- st3f, Apr 18 2001


Is it okay, for magnetic shielding, to use asbestos for my head gaskets? Also, will this thing shock my hand even harder on a cold day? Or jerk the keys out of my hand if I leave her running while I go in for a drink?

Consider for a moment, tkeyser, that what your idea evokes is similar to how a muscle fiber contracts: a leap forward, hold, release, leap, hold, repeat. Multiply by the hundreds and you can see quite a force generated.
I thought that in order to provide the optimum improvement in performance, the engine would best be balanced by magnetic pull, instead of assisted into the power stroke as your idea suggests to me.
-- reensure, Apr 18 2001


re st3f: all hybrid cars now generate electricity during braking with their electric motor. that is called regenerative braking. i had that planned for my design, but, to tell the truth, it's wouldn't work as well with my design. i just looked at electric cars today and said "damn they suck". since im not really all that good at chemistry, i didn't think i could come up with a better battery, so why not a motor that produces more power? this design does not use gasoline(petrol, as you say). this one is emissions-free.
-- tkeyser, Apr 20 2001


A great idea, but maybe we are looking the wrong way here? A hybrid gas/electric engine would probably have to be based around a rotary engine design, but it would simply be not efficient enough compared to the dual motor designs currently available.

Alternatively, forget electric engines and focus on a hybrid gas/compressed air engine. Already in development - see www.zeropollution.com
-- mboxwell, Apr 21 2001


Internal combustion efficiency is established by compression ratio all other factors being equal. That is why a diesel is more fuel efficient. More efficient than that is Bourke engine built around WWII. See Experimental Aircraft Assosciation for a paper on the engine. As for a solenoid engine magnetic force is the attraction be it from the side or the end. No difference. But the mechanical system is very different. Conversion to rotary has losses and requires material(s). In engineering terms the electric motor is "a mature product".
-- Kirk, Aug 31 2001


Some products start out as kludges of already-matured devices (for example, a PC system combines aspects of typewriter, television, telephone, and magnetic recorder in ways that the original developers of those devices probably didn't imagine).

Turbines crop up periodically. I saw the Chrysler turbine car at the 1965 World's Fair; the design resembled '63 T-bird hardtop, and apparently the engine could run on "anything from alcohol to French perfume" {sound: large grain of salt being placed gently on table}. Chrysler announced that they nearly had the too-hot-exhaust problem solved, and that they would introduce a production model for 1967 (well, they *did* put a mild version of its tail lights on the 300, but that was all). {large grain of salt #2}

I like DogEd's idea of keeping the engine's motion circular. A really polytechnic motor might have three drive options on the same driveshaft (thank you, st3f): a suitably designed IC turbine, an electrical motor, and a flywheel, with drive duties apportioned by on-board computer (say, a space-hardened NASA surplus model) -- but even if you could get that to work, its complexity would make it hard for anyone but a factory-trained mechanic to service. The tech is the first step; the longer step (and it's a dilly) is getting people to accept it and weave it into their habits.
-- whatsbruin, Sep 06 2001, last modified Sep 07 2001


In the months since this was first posted I've come across two patents for piston engines driven by magnets; one has the magnets located in the cylinder walls and the other has them in the cylinder heads. So tkeyser is not alone in thinking this could work. Nice analysis, incidentally, whatsbruin.
-- Dog Ed, Sep 07 2001


The magnets-in-cylinder-walls concept sounds like a miniature mass driver. I'm guessing that you'd have to flip the magnetic polarity on those magnets just as the piston reaches the top of its travel, which (providing it's electrically practical) could give you an up stroke and down stroke of nearly equal power. If you bent the cylinder into a torus, you'd eliminate the connecting rods from the piston and have a kind of closed-loop mass driver -- but then how would you retrieve motive power from the system?

re: The Wankel rotary engine, apparently it had excellent acceleration and a smooth power curve when mounted in a Corvair (pre-Nader) test bed and in the original Mazda roadsters, but its gas mileage was disappointing compared to mid-'60s six-cylinder "economy" engines. Still, it should be possible to work out a range of "best" applications for a Wankel as a component of a hybrid system. At very least, wrestling with a hybrid concept seems an excellent exercise in defining "appropriate technology" for a specific application.

(BTW: Thanks, DogEd -- and I ain't no engineer either, but I'm hoping my nephews will teach me...)
-- whatsbruin, Sep 07 2001


I once took a class on electric machines. Here is what I think I remember from it:
1) Magnetic forces fall off *very* rapidly with separation. Force=(a constant)/distance^2.
2) The coils are wound on concentric electric motors such that the gap rarely exceeds a millimeter or two. This is accomplished in part by the use of multiple (sometimes dozens) of alternating "poles" distributed around the circumference.

In a reciprocating IC piston, the separation distance would be on the order of 20-70 millimeters. Remembering the inverse-square relationship between force and separation distance, I must conclude that any gains from having the magnets in line with the motion of the piston would be *far* outweighed by the losses from increasing the separation distance. (I just did a calculation and found that the force is 625 times stronger at 2mm than at 50 mm.)

So a linear electric drive would need coils along the sides of the cylinder, and would need the coils arranged in multiple alternating "poles" along its length. The coils could be driven with a controller similar to those used for modern industrial stepper motors. The drive rate would also need to be carefully coordinated with any concurrent combustion processes to keep the forces in phase with each other.
-- BigBrother, Sep 07 2001


Interesting angle. How about evacuating the cylinder?
-- whatsbruin, Sep 07 2001


I hope someone reads this . . . whoever had the idea of using electromagnets to drive the piston up and down the cylinder obviously has no background in engineering or physics for that matter. The pressures in a combustion chamber post-combustion are horrendous. For a magnetic to even come close to generating that kind of force at the speed necessary for an engine in a car, the resulting eddy currents caused by the necessarily rediculously strong changing electromagnetic fields would liquify the aluminum (or steel) block in a matter of minutes. Not to mention, you would need a hoard of batteries to power the thing anyway. Electric motors are fine the way they are. Look at the field propogation of a magnet in any high school physics text book. Then go and read about all the inefficiencies caused by converting a reciprocating motion to a rotary one. After that, come back and tell me if you still thing your idea is a good one.
-- R_Gutt, Mar 16 2002


[R_Gutt] Dude. You need to look around a bit and figure out what the HB is about.
-- phoenix, Mar 16 2002


Perhaps, one could consider the power latent in electric repulsion and attraction for an ic type motor. Rail launcher technology forces a 132 lb aluminum projectile to accelerate to 130 mph in 165 ft by reason of magnetic field reversals applied.(IEEE Trans Mag Vol 31, No1 Jan 1995 pp 510-515) Also, one person built an impressive iron-less aluminum repulsion motor with horse power greater than any magnetic motor I have read about. It is rated at 3kw per kg. -very powerful(IEEE Trans on Mag Vol 31, No 6 November 1996 pp 4226) And another consideration - If two aluminum plates 10" X 10" were insulated (in a vacuum) and an electric charge of opposite polarity applied at 3Mv per centimeter - the attraction is about 5700 lbs. (Carbon dioxide could be used under pressure for the insulator) (Scientific American Book of Projects for the Amateur Scientists by C.L. Stong. A fireside book published by Simon and Schuster New York. 1960) A powerful motor could be designed using the aluminum repulsion at TDC and the attraction could be designed in circular steps outside the diameter of the piston for up or down. Just an idea. davingw@mindspring.com
-- davidits, Apr 13 2002


Oo. Oo. Where's [Vernon]?
-- phoenix, Apr 14 2002


Folks, some aspects of this idea are baked! Several years ago in Popular Science I recall reading an article about a couple of inventors (French, I think) who built a gas/electric engine of the following general design:

Two pistons are placed at opposite ends of a connecting rod. The two cylinders are also diametrically opposed, the motion of the pistons is pure reciprocating. I think this engine used the two-stroke combustion cycle. The center region of the connecting rod is a strong bar-magnet. A coil surrounds this magnet. To start the engine, pulses of current are sent into the coil, and in solenoid-fashion the pistons move and an initial fuel-air mixture is compressed for ignition. When the engine runs, the motion of the connecting-rod magnet induces high-frequency alternating-current in the coil, which electricity can be carried away and converted into whatever form you want to use.

I was kind-of disappointed in reading that article; I had independently dreamed up the idea several years prior to that (a four-stroke version, but as usual, couldn't afford to do anything about it).
-- Vernon, Jun 04 2002


There he is!
-- yamahito, Jun 04 2002


I know this idea has been around a year or so, but alot of what I read is interesting. Perhaps the idea isn't so halfbaked. When I read the original description and several of the other comments, what came to mind are soleniods as the pistons.

The rod in the solenoid is the piston that turns the drive shaft. The coil around the piston would energize to attact it both directions. Variations could consist of 2, 4, 6, or 8 cylinder motors with the pairs opposing each other. When one piston is being pulled down, the other is being pulled up for double the power. As someone else mentioned, this might not be a very efficient motor. Then again, it might work great. No heat other than what the coils generate, no oil other than bearings. Electric generation or batteries would have to be used to power the solenoids.

Basically, if you want something that is designed and acts like an ICE, but runs on electricity, then this might be something to investigate.
-- dweislogel, Jul 24 2002


To dweislogel:

I had an idea similar to that a while ago, and I came to many of the same conclusions that you did. The fact that the engine would not have to maintain compression makes it much more efficient, and the lack of heat produced eliminates the need for oil or cooling systems. Another advantage would be that, during braking or coasting, the engine's process would be reversed, enabling it to recharge the power supply (by pushing the magnet through the coil). My only problem with this idea would be the duration of the power supply - you need a lot of current to supply that much electromagnetic force that quickly for any amount of time. So as sort of a compromise to this idea, I was wondering what would happen if you incorporated this solenoid-based engine into a typical internal-combustion engine. The pistons, rings, fuel injection system, valves, etc would all remain, with two exceptions: the cylinder walls would be set up to do double duty as solenoids, and the pistons would be magnetic. Under low load conditions, the combustion system would shut down and the valves could remain open, leaving the solenoid system to run standalone. Or, in order to compensate for the power usage, there could be a mix of solenoid-powered and combustion-powered cylinders running at any given time (i.e., in an 8-cylinder engine, at cruising speeds 2 or 4 cylinders would be combustion powered and the rest would be solenoid powered). Other advantages are that this system could eliminate the need for a starter or an alternator...and the obvious fuel economy benefit. The only issue I can see would be the effects of heat on the solenoid...unfortunately, heat and electromagnets don't mix well. But I suppose some sort of cooling system could be devised. Any questions/comments/complaints on this idea would be gretaly appreciated - post here or email me at macock2@tcnj.edu
-- vetteboy, Sep 16 2002


Has this idea been patented? I thought of it a couple of months ago, and then searched the nets to see if anyone else had patents or anything.
-- mojammer, Feb 05 2003


A nice idea. If i understand what your are saying, you could also only apply a short shot of voltage when the solenoid and connecting rod is in the ideal position to transfer as much energy as possible to the rotation of the crankshaft. That would be the most efficient way to transfer electrical energy into torque. If you eliminated the cranking assembly and just had a sliding permanent magnet piston in a tube a combustion pulse would push the piston through the tube performing compression at the other end, a coil surrounding the cylinder would extract excess energy for power.
-- venomx, Feb 09 2003


I am building a robot wars robot (see; www.robotwars.co.uk) I am trying to come up with the most compact and yet reliable hybrid powerplant. Anyone who has any ideas is welcome on this score. Because it will be custom built user acceptance and markatability are not a factor. I just need the most power for the smallest size and weight to produce the most electricity for the drive motors (which for reasons of reliability and low speed torque are 36V Lynch motors.) I do not care what fuel it runs on.
-- liaonet, Mar 11 2003


I am wondering why Electromagnetics could not be used to drive the piston in an engine, instead of fuel ( gasoline - disel )to use an electromagnetic pulse to push the piston, thus turning the cam shaft
-- garbon, Mar 16 2003


Not sure if the same, but... 1. http://www.sandia.gov/LabNews/LN10-22-99/cycle_story.html

2. http://www.students.ncl.ac.uk/jonathan.downes/html/RMH_abstract.htm
-- blueveil, May 05 2003


I've seen a website with this idea before. Apparently they have a few prototypes too. Don't ask me where I saw it, though. :)
-- rapid transit, May 20 2003


www.fuelcells.org is a great site i worked as an editor at. up to date hybrid and zero emission technology. sign up for the fuel cell update. could i just say again... ICELAND RULES! energy outside the box!
-- bubblegrrl79, May 20 2003


I am a supporter of this idea, unfortunately its because I had a similar idea last year and was planning to investigate it for my Masters thesis next year! So i'm not as original as I thought I was, can't win 'em all. Maybe you have a website where I can read more about your research? Good luck
-- ghogarth, Jul 28 2003


RE:My only problem with this idea would be the duration of the power supply - you need a lot of current to supply that much electromagnetic force that quickly for any amount of time.

Why can't you generate the electricity from the running engine? Using another electromagnet the way spark is generated for all engines today. Then you would have a perfect engine... right?
-- tecwiz001, Sep 03 2003


While in Junior High School one of the science projects we done was to build a motor. I decided on and built a 60 cycle residence repulsion coil engine. You should probably look at that engine model which can be found in the library to give you some ideas of how it may help with your project.
-- EnterpriseX, Oct 16 2003


long time gear head, and my recent thought of a electromagnetic motor that was based on a v8 or similer motor, led me to this site and others and I think this would be a really good thing to dig further into. To help all to understand this thing a little more think of grays splitting the positive idea add a very stong electromagnet to the head side of the motor, at the same time imagen to similar poles pushing away from eachother, then simply add magnetic pistons to a aluminum high temp lithium gease lubricated self contained bearing v8 with 180 off set stroke then simply pulse the electromagnet in the heads to push not "pull" because off efficiancy loss due to gravity add windage compression, then you will have a running motor. and just forget about gasses oils and all versions of petrol and burning fuels. "o" and by the way to get rid of cylender head compression insted of a perfict vacum wich on earth is not the easiest thing to do just open up the head and lower crank side to lose all efficiantcy robbing compesion from the "stokeing not revolving like a stator motor"electric system.
-- gearX, Oct 29 2003


i'm new to this whole idea but what if you steal a bit of technology from the maglev train. Construct a hollow cylinder with positively charged magnets lining the inside of this cylinder. now take a smaller cylinder that fits inside the first one. line the outside of the second cylinder with positivly charged magnets and seal the smaller on in side the larger one. would the interior cylinder not continualy spin due to repulsion or do i not know what I'm talking bout? if i'm right then yuo could capture the energy from the spinning cylinder and bingo there you have a magnetic motor.........i think
-- tintin220, Mar 22 2004


I think you are all missing a fundemental point. What gives you the electric power? If it's a battery, then modern electric motors would be way more efficient than a internal combustion engine that was modified. After all you are moving many unneeded parts when using the electrics. As far as generating electricity there is something that does it already called an alternator. Your car already has one. The main point I'm trying to make however is that in order to generate electricy to power a car, via an alternator or an engine modification, you must apply power to the generating device. And what createds the power? The burning of fossil fuels. You would not be getting free electricy. You would be adding work to the motor by forcing magnets against an opposite force to generate the electricity. I think fuel cells, electric/gas hybrids, or straight electric cars do this with less pollution and more efficiently. There is an electric car prototype out there that runs on notebook computer batteries that has a range of 300 miles and recharges in 3 hours from a standard outlet. Oh yeah, it goes 60mph in 3.6 seconds, which is faster that a Ferrari F355. One good thing about electric motors is you don't have to worry about compression building up to get power. Instant torque. Instant gratification. Just watch for whiplash.
-- Nitehawk, Mar 23 2004


What is needed is an steam engine driving an alternating alternator whose pistons are really superconducting electromagnets coupled to a rotary wankel surrounded by particle accelerators, an all that fixed to a flywheel moved by two opposite gerbils in tandem. All the energy can be used to electrolyze water and produce hidrogen which will then be cold fused, compressing air that is what really moves the wheels. All clean and ecological.
-- finflazo, Apr 18 2004


finflazo, that patent application was supposed to be a secret!
-- TerranFury, Apr 18 2004


Back about 150 years ago, most electric motor designs were reciprocating or similar. LINK. None of them worked as generators. I suspect it was only after dynamos were built and it was discovered by accident that they worked fine as motors that we started making motors on the waterwheel pattern.
-- Fussass, Apr 18 2004


I have been to that museum, [Fussass]. It's quite amazing. If you ever find yourself in Bellingham it is really worth visiting. The owner has purchased the surrounding buildings, including an old theatre next door, and plans to continue expanding the collection.

He's a Microsoft retiree.
-- bristolz, Apr 18 2004


Vernon's 2002 reference to the IC reciprocating alternator has merit.

This device has all the elements of an efficient hybrid in a single unit and exploits only the positive features of the IC cycle. The opposed pistons are 'free' of connecting rods and crankshaft and also have improved wearing qualities (x4) The IC problem of low torque at low revs is discounted as an electric motor - via a battery - powers the drive train.

Sandia has recently resurrected this idea as a research project - a 2-stroke cycle, fuelled with anhydrous ammonia no less! However it is no surprise to find that they have encountered the usual problems of fuel losses through the exhaust port as in petrol powered 2-strokes.

Compression ignition 2-strokes do not have this problem and a more reasonable arrangement - for now - might be 2 horizontally opposed supercharged bio-diesel injected 2-strokes, reciprocating the linear alternator which connects them.
-- seamus, May 22 2004


Can you run it on electricity to make gasoline? That'd be neat.
-- gabe, May 22 2004


Soon will. With Caterpillars reciprocating electric motor free-piston pumps, delivering crude.
-- seamus, May 23 2004


One very important point has not been considered. You never want parts in any motor, that move up and down. This always results in a energy loss which in turn reduces the efficiency. Unfortunately in most combustion engines you do not have a choice. So in order to increase the efficiency you have to decrease the weight of those moving parts as much as possible (pistons, connecting rods). Now if you make your pistons heavier the engine will inevitably lose efficiency. Fortunately the electric motor doesn't need parts that move up and down that's one of the reasons why it has such a great efficiency (over 90%). 'Electric driven pistons' is really, apart from any development issues, vibration issues, manufacturing issues, controlling issues etc. the last thing you want.

The reason why the rotary engine isn't that great even though it's mechanically more efficient is because it's combustion process (chemical efficiency) is pretty bad compared to a piston engine.
-- Globi, Jun 08 2004


forget about pistons think wankle turn the rotors into flywheels move electromagnets to the outside of rotors firing them to push the flyheel around. in each rotor self contained magneto firing its own magnet pulling residual magnet energy from delpleting drive magnetic fields increase voltage to all electromagnets via induction coil start the engine using smaller electric motor wich in turn is doubled as an accelerating motor all timing done by standard auto distributors all coils are standard auto coils juice is supplied via standard auto battery and standard auto alternater torque and hp suplied by flywheels.. see if this get the muscle pumping
-- zazenzero, Nov 26 2004


I've not read this point in any of the (many) other annotations on this idea. This is a hybrid engine, and hence the same set of pistons is functioning as an electric motor and an IC engine, as far as I can tell. The suggestion to use "teflon-coated magnets" as pistons doesn't stand up. Magnets denature at relatively low temperatures (below 200C).
-- david_scothern, Nov 26 2004


Borrowing from the design of the wankel rotary engine,it could be possible to build an enclosure surrounded by multiples of winding's switched constantly from north/south polarity. The rotational driven shaft again with it's own set of controlled polarity windings, would be driven constantly at greater and greater speed by the switching polarity's. The flywheel type action of the "driven" shaft would in turn generate electrical energy at it's hub (rotating at greater speed) to be used to supply or supplement the power needed to continue the action of the outer electromagnetic coils. The switching of the electromagnetic coils would have to be controlled via a 5x5 timing circuit for instance. Storage of the "generated power could be via capacitors. "Still thinking on the rest of it"
-- Thunderbucket, Dec 12 2004


Efficiency losses in IC motors is primarily from changing reciprocating motion to rotary, not from the movement of the pistons. The 'compression ignition IC 2 stroke - opposed free piston - horizontal alternator', I described delivers its output, via a cable, to an electric motor/battery powertrain.

Minuture versions of this device are at the prototype stage to replace batteries in military communication systems.
-- seamus, May 11 2005


//Efficiency losses in IC motors is primarily from changing reciprocating motion to rotary, not from the movement of the pistons.//

Actually, the biggest efficiency loss is probably the fact that the compression and expansion ratios are equal. If an engine is operating with intake pressure equal to ambient atmospheric, the only way to have more pressure in the cylinder during the power stroke than during the compression stroke is if the gasses have expanded such that there will be excess (useless) pressure in the cylinder at the start of the exhaust stroke. Throttling the intake will reduce the output pressure, but drawing vacuum in the throttle itself takes energy.

A compound engine which would double the expansion ratio would likely achieve considerable efficiency gains. The trick, which should be feasible, would be to have an engine which could switch between compound and simple mode based on power demand.
-- supercat, May 11 2005


I think you’re referring to a 4 stroke cycle. What’s the situation with a turbo, compression ignition, 2 stroke?
-- seamus, May 11 2005


I've been thinking about this and I really like the idea, here's my version:

A rod extends from the piston, in the top of the rod is a coil, which is used as an inductively powered electromagnet. The other coil surrounds the piston coil as closely as possible.

Power from the reciprocating engine is stored in a capacitor. A rotary electric motor/generator is attached to the gearbox. Torque on the motor/generator is controlled by the accelerator, clutch and brake pedals, and the reciprocating engine works at whatever speed is needed to generate enough power. Fancy electronics control the electromagnets, and make sure the times when the coils are unmagnetised are when they aren't needed.

The reciprocating piston can be stopped between cycles, sped up or slowed down, and the stroke length can be varied between strokes, so the intake stroke can be shorter than the power stroke when efficiency is desired, and both can be reduced for reduced power, if that's more efficient than slower or less frequent strokes.

The second piston is also controlled by inductive electromagnets, but can pump air into a compressed air tank, or take power from the compressed air. It doesn't have to resist the conditions of the combustion piston so it may be cheaper, and if it isn't conductive, the coils don't need to be separated from it. This is used for regenerative braking, and for starting power if the battery's low.

Another pair of pistons balance the motion of the first two.

The clutch, throttle and flywheel are unneeded, the alternator and starter motor are replaced, and the battery doesn't need to store much power.
-- caspian, Feb 15 2006


i think there is great potential with this idea. i first i thought, hey why can't electromagnetics produce enough force to push the pistons just like an explosion. well, doing that all the time would take way to much energy. maybe electromagnetics get the car moving...maybe there can be a rod surrounded by magnets and cause it to spin.

i'm sure others have already said some of these ideas, though the integration of all these ideas is where the secret lies. the true hybrid between electromagnetics and IC is very much withen our grasp.

maybe we just need to get away from the piston and electric (circular fan) ideas of what engines should be and come up with a whole new type.

i have a good idea with air pressure and pistons...check it out.
-- lolzcakes, May 19 2006


A quasiturbine is the best engine for this, and if it runs on diesel it's even better (biodiesel)!
-- Willie333, May 19 2006


I independently had pretty much the same thought the other day, which is funny 'cause this is 6 years post-first-post, which is maybe a good indication that there are good reasons for a lack of a concrete incarnation of this stuff. The whole Hybrid Synergy Drive thang is definitely a pretty fully-baked entity, and I bet we can rest assured that Toyota put the thought into this.

I was thinking along the lines of an Alu block and an Alu piston w/ either a Neodymium core or ring or something, and a coil of copper wire somewhere in/around the piston rings, i guess you'd call it a solenoid. Anyways, it would be pretty much just be adding a linear alternator where most of it seems to be happening anyways. I guess it might be possibly to "assist" the combustion engine by feeding current into the solenoid, and these "electromagnetic pumps" look something like that on the inside: http://www.gotec.ch/index1.htm I have to agree that that particular portion doesn't seem too practical, I don't know. But with the linear alternator side of things, I have a question: Is there any other resistance/ force needed other than the force required to physically move the magnet? Assuming you're already moving a magnet up and down, are you making it any harder by throwing in a coil of wire and drawing juice from it? Granted, Neodymium is ~2.8 times as heavy as Aluminium, but could you mix in some magnesium in there to balance things out? Pricey? Nah... I understand there's no such thing as "free" energy, but just maybe do you think there could be some "easily" harnessed energy that's being wasted? Could this be any better than using a regular old NON-linear alternator? What about having the coil in the piston and having a the cylinder lining be magnetic? Copper's facking heavy too, though...
-- topherator, Mar 14 2007


had the same idea a while back as well, but gave up on it because off a few issues:

induced eddy currents will place drag on the piston.

high powered magnets seem to be quite temperature sensitive.

increased reciprocating mass.

stray magnetic particles sticking to piston.

large gap between magnet and coil.

there were more, but i can't remember them all right now.
-- TIB, Mar 14 2007


I had quite the same idea, a while back as well.

I was thinking a ceramic engine block with copper coils and a large permanent neodymium magnet. Unfortunately they are quite fragile.
-- Melchior, Jun 05 2007


Heat demagnitizes. Even electromagents; the force of the solonoids will be reduced and they will loose efficiency.

How about working the electric motor into the clutch, brake disks, or drive line?
-- James Newton, Jul 24 2008



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