The Stelzer engine is a two-stroke opposing-piston free-piston engine design proposed by Frank Stelzer. It uses conjoined pistons in a push-pull arrangement which allows for fewer moving parts and simplified manufacturing. An engine of the same design appeared on the cover of the February 1969 issue of Mechanix Illustrated magazine. (Wiki search result.)
Well other car industries had the option also to use the patent in that case. At least this engine will help with reducing emissions in the long run overall.
Vibration should be minimal. Apart from the single cylinder prototype the pistons would be in pairs moving in opposite directions so vibrations would mostly cancel out.
Tell us when it is in MASS production then people will take notice and buy, otherwise it's an idea on a diagram, like others that manufacturers say will shock the car industry
1. There is no mechanical coupling to the drivetrain, so it is much smaller issue. 1.b In the most cases there would be at least 2 pistons that cancel vibrations partially or 4 that cancel totally. 2. Engineers know about the issue.
Vibrations are easy to fix. Opposing operations cancel the vibration of the other. Heating magnets is another easy fix. Cooling is academic But simply moving the generator body beyond the crank case, one end or both would separate the heat completely.
that 3rd engine seems like it could be an excellent generator engine... 1 cylinder 2 stroke on each side... essentially doubling the cylinder displacement and 2 generators harvesting power on each side...
They have a German Submarine in exhibition in a Chicago Museum, it contains a Free Piston engine, Opposed Pistons generating Gas moving a Turbine. German crew opened a sump to drown the U-Boot, but a group of fishermen found it and rescued it. It had also a 'Maxwell's Devil', a solid metal device, compressed air supplied from the vertical part of a 'T', one of side branches provides air hot enough for welding, the other side, freeze cold air. Blessings +
Interesting only if one could rebuild the same would become a millionaire overnight, technology is available already not one's ready even to replicate it.
A 10KG engine supplying 30KW to charge a 20KW hr battery pack and 4 20KW hub motors. Build me one one of these! A great way to electrify an old Citroën DS.
Your Aquarius motor could be adapted to an articulated arm above the sea water, this arm would react to the oscillations or waves of the sea water so that the back and forth supplies and produces electricity
The concept has come out for a long time, I think the biggest issue of the free piston is that you need to waste lots of power to decrease the speed of the piston.
For range extender we need split cycle generators, that can squeeze additional 10% of thermodynamic efficiency. Then stirling or thermoelectric module to extract additional 10 percent. 60-65% overall efficiency is possible.
As I watched this video, I was thinking Stirling myself. Further, as a stationary engine option, a Stirling based system might be a useful tool for converting solar heat (from some sort of collector) to charge up batteries.
An improvement to be certain but not without significant drawbacks. The piston/generator assembly represents asignificant amount of mass. That mass, if not adequately controlled, would shake the engine into self-destruction rapidly as evidenced by the table in the video. On the Toyota floating piston engine, they have created a hybrid 2/4 stoke engine. It still has an exhaust valve like a 4 stroke but uses intake ports like a 2 stroke. This design also has a vibration issue however, it is reduced by pre-compression of the charge. There is also the issue of the exhaust components weight. The exhaust exits at each end of the unit through a pair of solenoid operated valves. This requires a extremely long exhaust manifold. Why not go full 2 stroke with transfer and exhaust ports? You eliminate the heavy solenoids and valves and shorten the exhaust manifold significantly; reducing overall weight.
they could make an 8 cylinder version with similar fire timings to an inline 4, this would probably negate most of the vibration, and give enough power for larger cars or trucks
An interesting idea. Of course a lot of bits aren't shown i.e. radiator, water pump, air filter, fuel tank, silencer, fuel injection pump and starter motor (the linear electric generator could probably be used as the starter motor so a separate starter motor would probably not be required).
Electric cars also have one or more coolant pumps and radiators for the battery pack, motor, motor drive, on-board charger, cabin heating, etc., the generator would just be the hottest hop in the heat collection loop. With the new axial flux motors coming out, I suspect we'll see many hybrid vehicles ditching the conventional starter and alternator setup for an in-line axial motor-generator between the engine and transmission replacing the flywheel.
The free piston design would have been a good solution if it was introduced to the market 20-30 years ago. The second single piston engine is to cost efficient as it requires the permanent magnets. Using an alternative will make the engine heave and larger in size. The Third engine has promise but will be expensive to run as we transition from present fuels.
I personally think this kind of idea is brilliant. The Stelzer engine is a two-stroke opposing-piston free-piston engine design proposed by Frank Stelzer. It uses conjoined pistons in a push-pull arrangement which allows for fewer moving parts and simplified manufacturing. An engine of the same design appeared on the cover of the February 1969 issue of Mechanix Illustrated magazine. (Wiki search result.)
@sublunacy Sorry for taking so long to reply. What you are implying is that any imbecile is capable of demonstrating perfect precision engineering. I thank you for your kind assessment of my mental capability. I tend to think that a lot of inventions are brilliant. I tend to think that motor vehicles are brilliant and beautiful. The revheads and racers, as best as I can tell, are out to prove that they are worthy of the bubbly. It_s a lot of fun focusing on the red line 7000. It appears that some among us get their jollies taking the lives of others as opposed to risking their life. All very case-study interesting. I checked out your channel. I_m kind of wondering about it. Nothing major going on there that I can see. No disrespect intended. I mean, it_s so nothing i_m kind of wondering if it_s actually for real and not some sick joke being played upon me.
Free piston engines have been around since 1934, stelzer engine is a variation of that design where valves are in the middle and combustion happens at the bottom of the cylinders, this is not that its just a free piston engine
@shivamarya5225 Alright, so we are getting seriously inventive with our comments. I thank you for being such. I take it to are of Indian birth.Say hi to the Tata for me. It occurs to me now that it is on a road to Nowhere. That_s alright, apparently a lot of people want to go there.
@@doahadi1554 i don't care about tata, are u right in your head? does every american care about apple? or gm? like what kind of weird statement is that
Could be an interesting direction for hybrid cars. Usually you run electric. On a long trip you use this engine permanently to add charge to your battery and boost your range from say 300 km to 900 km. Efficiency may not be the biggest driver. We need small size of the engine and all its needed components (radiator, exhaust, reservoir etc.) combined with significant power output (a model airplane or model car engine is small but it lacks power output). Even weight is less important as we can remove e.g. 25% of the batteries compared to a full EV which saves several hundred kg's.
You may not want the generator to be large enough to charge the battery as that could lead to eventually running out of spare space for regen braking. If your generator is 2kW short from large enough to run the car and you have a 30kWh battery pack, you can run the car for 15h straight between charges by filling the gas tank. Designing this way gets you the smallest generator possible optimized to run continuously at a fixed load. No extra complexity for efficiently adapting to variable loads or dealing with a bunch of stop-start cycles per drive cycle.
@@teardowndan5364 There is no problem with a generator capable of charging the car. Many designs like the Toyota Prius, can drive and load the accumulator at the same time. You just stop somewhere between 60-70% charge, leaving enough room for long regenerative braking events while the cell voltage of the accumulator is still moderately high. Then you let drive the EV until you reach 30-40% charge or any moderately low cell voltage and turn on the generator again. One reason why this is a good design is engine/generator efficiency. Most highly efficient combustion engines produce way more power (20-60kw) at peak efficiency than the average car would need for a steady-state drive which is somewhere between 5-15kw. But any hybrid will usually be worse in short range compared to an EV and long-range to a pure combustion car because of the increase in weight for having two systems on board. Also price must be higher as you have to engineer and maintain more parts as a company.
@@MrHaggyy The only problem with a generator powerful enough to charge the car is that if it can do that, then you wasted more space and weight on an over-sized generator for the purpose of range extension (and supplemental heating in winter) than necessary. If you need 17kW to drive at highway speeds and have a 15kW generator, then you can drive 1500km on a 30kWh battery pack before needing to stop specifically for charging or having to drive at reduced speed/comfort.
What stops the piston (at TDC) so it doesn't hit the head and same at the other end BDC? And how does it start from stationary? All these computor generated images work fantastic, lets hear one running.
Keep in mind that you have a seriously strong electromagnet connected to the piston that acts both as a generator AND a linear electric motor. The electromagnet can be operated to push or pull the piston with variable strength in a matter of milli or even microseconds. Since the weight of the piston is known and the speed/exhilaration is measured down to microseconds level one can quickly add or subtract to or from the piston movement to make it stop exactly where you want. It is this same process that is used to control the compression ratio on the fly.
@@wrndlabs Good comment, but I'd have to see it to believe it. I would think that the magnetic (electric) power needed to stop the piston at the end of each stroke would far exceed the power generated in the preceeding (one) stroke.
Nice concept, simply amazing there’s no need to convert conversion of reciprocation in to kinetic momentum, that’s why no bunch’s of variable moving parts, very less engine components converting reciprocation energy into electricity by linear magnetic field, that’s very cool, only the things to be checked is how much electricity it’s getting from the system,,,, One of the most important thing is, it doesn’t requires to generate more torque to achieve acceleration, linear torque remains constant as no pressure on combustion chamber!!
This looks like a good solution for certain applications but not for all just like everything else in life. In the past engines designed for one field would be adapted and modified for other applications like automotive to marine but this could fill an area such as generator systems or other stationary machines like pumps.
Had a really interesting discussion with a friend, not certain what to think of it, so here I am trying to gather as much information as possible. Would really appreciate your comments on the same. A single-motor Rear-Wheel Drive (RWD) Tesla Model 3 base model is equipped with a 50-kWh battery and a range of 272-mile or 437 kms per charge. A 200cc motorcycle petrol engine generates 17-20kwh at ideal rpms with just 1 liter of fuel, Not sure how it will work but if 3 liters of fuel is required to recharge a battery bank of 50kwh means the same Electric vehicle can travel 272 miles or 437 kms in just 3 liters of fuel. Even if the fuel consumption is increased to 5 liters per charge means 87.4 kms per liter or even 10 liters per charge its still 43.7 kms per liter for a car. Whereas an average car travels only 10-19kms per liter. So a combination of EV + petrol engine is way more efficient than only EV or only petrol engine vehicles?
No it’s not possible and the problem lays on your assumptions. 1 Liter petrol stores 9kwh of energy. In its tranformation to movement you loose about 70% into heat, so you get only ~3kwh out of 1 Liter petrol.
@@niklasruhe2354 it is possible, i saw a working prototype & the test in person they used a regular 200cc engine set it at ideal rpms connected it to a gearbox and a 20kw axial flux low rpm permanent magnet generator from China and at 1 liter it generated 17kwh continuously. So your numbers are wrong
@@pcpatel01 @pcpatel01 an honda electric generator of 110 cc engine. Has tank capacity of full 12.5 liter and runs 7 hr on full load which is 2.8kwh. So total output will be 19.6 kw in 12.5 liter petrol. So, 1.56kw per liter. And 1 liter of petrol generate heat of 9.37 kw of energy considering density of petrol 750kg/m3 45000kj/kg calorific value. Don't know what Chinese are doing It might be some Nuclear power they are using OR might be your numbers can be wrong.
@shyamhingankar7442 read my comments properly and understand the basic working theory & difference between regular generators & a motorcycle engine connected to a low rpm axial flux generators. Well if you still dont believe feel free to test it both petrol engine & axial flux generator from China ate easily available & test it yourself the numbers are not wrong.
I question just how efficient these are. The delicate timing involved with intake and exhaust valve timing isn't allowed for using these designs. In a normal, Otto cycle piston engine, you'll find the lift durations and overlap between the intake and exhaust valves is ideal. This is because of their placement at the top of the cylinder and allows for the engine to properly exchange used exhaust gasses for fresh air (and fuel in the case of designs not using direct injection exclusively). A lot of overlap is allowed for, which can help to reduce emmissions by only partially exchanging exhaust gasses to the headers (sort of like an EGR does but simply via not removing all of the exhaust gasses so a portion can be burned in the next power stroke of that piston.
Idk just intuitively it makes a lot of sense that the intakes would be at the bottom of the stroke, because maximal vacuum would be achieved right at the end of exhaust meaning intake mixture is induced into the cylinder simply by that fact. At bdc maximal vacuum is achieved and right at that time intake is opened. It just makes sense. The only reason it's never done that way is because normally you have to go through the head and it wouldn't make sense to design valves driven from overhead or by tappets, but this design all makes sense perfectly.
ok, but so... basically, those piston engines are only electricity-generators? Because I don't see how they could transfer mechanical motion to, say, the wheels of a car, otherwise.
Such free piston engines are very easy from the design and manufacturing point of view, but they are rather complicated to controll. The best way to make them is to use a spring-mass-design, which is capable to accumulate the energy of several full power piston strokes. Otherwise they behave very rude with a lot of vibration due to running into their piston stroke limiting bumpers. This problem can be observed very easily in the video of the running engine, when the engine reacts with hard push into its suspension. The power control needs to work very fast and very precizely, so that the piston always keeps its stroke to maintain the compression ratio. Usually it is done by controlling voltage amplitude of the output AC which is directly proportional to the maximum piston speed. In case it is too low the generator input electronics must lose its break load, in the opposite case it has to enforce its break load. This power control narrows the power band very much around a certain design power, because the engine runs at a more or less fixed frequency and a certain minimum stroke. So it is usual to design the engine and its control to a fixed operating point at a fixed output power. For hybrid cars this is not such a hard constraint because you can manage your power requirement by use of a buffer battery, but in other application it may be.
The narrow power band isn't a bug, it is a feature: practically every gasoline-based EV range extender concept is only intended to run at constant load near wherever peak efficiency is for the engine type being used. Designing for constant load at constant RPM simplifies things. Slap a 15kW generator on a small EV, tell the EV that you are going on a roadtrip, EV starts the generator once you get on the highway and need 16-20kW to keep going or the battery drops below generator start threshold, you arrive at your destination with 5-20 fewer kWh left in the battery and the generator putting out a constant 15kW all the way.
@@teardowndan5364 this is correct. in the 1950ies, as they started in the Netherlands to use Phillps Stirling cycle engines without a battery buffer, the heat capacity of such engines was a challenge. They have used 2 cycles engines with a phase shift of 180 degrees between them. In oder to build up power or to reduce it they have used a pneumatic engine cycle short circuit valve in a pipe between the cold ends of both engine cycles. So they could keep the operating temperature at the hot end high all the time.
It violently vibrates, free piston engines can be made where the piston sits central in the middle instead of being spread out on the ends, which allows for variable compression rates as well
because fuel cells need hydrogen, which is a not-so-efficient energy vector, that requires expensive infrastructure for transport and storage, and a lot of energy to generate it, so the advantages in vehicle use are undermined from the disadvantages in the whole supply chain
Free piston engines can't easily be hooked up to get the mechanical power out. That's why it's cheaper and easier to attach a generator and use the electric power directly. It's more efficient and has less parts, much simpler. You can create an engine that is mechanical, but it requires much more complicated parts. The free piston doesn't have to go completely back and forth, it is free to travel, nothing connecting it, hence the name. Regular engines have a top dead centre, a measurable maximum distance from piston to head - this does not.
Power electronics does not like single phase. It takes a quad construction to cancel out vibration provided equal sizes for sub assemblies and single phase generation. A three phase solution would would be hard to balance for vibration. It gets heavy and complicated.
Wie wird der Motor angelassen? Was ist bei einer Fehlzündung oder Gemisch Fehler? Wie beseitigt man die Vibrationen? Ich glaube es ist wie bei den Stirling Motoren, hohe Ansprüche und in der Praxis nicht erfüllbar.
Correction:@peMac88. Looks very promissing. My LG fridge has a linear compressor, incorporating a linear motor to resonate the piston, or pistons if it has 2 opposing.
LiquidPiston rotary using steam// steam generator.. and a low pressure turbine before the condenser unit that feeds the steam generator at pressures up to 3100 psi
So this engine looks like the only connection to the wheels is from generated electricity as the magnet behind the piston on the shaft moving backwards and forwards past a coiled wire set up.
Generally you have around a 60-70% efficiency on turbos... so that puts your 40% efficient motor down to 20-30% efficiency once you add the electric motor losses as well
In Finland was free piston engine innovation "Sampower" but it didn`t reached to production level. They tried use it with hydraulics? In generator use, it micht be usable.
Wow, over 100 years development and the eficiency of this proposal is still only 40/50%. Surely even the most die-hard ic engine fan must realise the reign of the gas engine is over.
