Free Pision Engine

And speaking of Fuel Cells

Breakthrough in Fuel Cell technology

Here is a very simple engine:

Most bits on it would also be used for a gasoline version, e.g. fuel filter and lubrication system.

The only difference is that it has a piston instead of a carburettor and it has an injector. It doesn't need a fragile ignition nor a throttle.

The RPM is controlled by the injection pump, something which a gasoline engine can't do. To set a gasoline engine to a fixed RPM, you need a regulator and those things tend to oscillate since the throttle response of an engine is very slow and vague.

So a CLASSIC stationary diesel engine is much less complicated and far more reliable than a gasoline engine.

Watch what they do with a diesel truck at 2:05, try this one with a gasoline engine!


In the 60s, my dad was a member of the THW. Whenever Cologne became flooded (again), they used their trucks to ferry people from home to work, kids to school and delivered supplies. Their Magirus trucks were all able to handle 35 centimeters of water. When the water was deeper, they used their Magirus Jupiter trucks which were equipped with a snorkel. They attached an S-shaped pipe to the exhaust pipe to prevent flooding the engine when off. They had put the batteries onto the hood using an extension cable which came with the truck. When the water was as deep as in the video, the truck was unable to handle this according to the manufacturer. Then they removed the batteries and all the fan belts, disabled the springs on the air brakes and removed the alternator. The trucks were then refueled, started over the jump cable socket and then driven into the water for cooling the engine. The trucks could drive fully submerged but they couldn't do that due to the driver. The only engine related electric circuit except for the glow plugs and starter was the engine kill switch. Without electricity, those engines just kept running.
They had a drawbridge on top of the truck for the passengers which was lowered onto a 2th floor windowsill.

Nowadays, the modern trucks can't handle much more than 10 centimeter water and using rafts is too dangerous. Now they need to evacuate everybody, they can't support the residents any more.

you apparently didn't read a thing I said.

the free cylinder engine is nothing like a conventional engine with a reed valve head on one side of the engine block.
edison got better results with a rotary generator, because Edison was working with sinusoidal AC. if Edison had needed to convert to DC, anyway, he might have just made a linear generator, since he was going to have to go through a rectifier anyway. - but in Edison's era, he also needed a large flywheel to keep everything running smoothly.

a free piston engine will never have only one piston. every cylinder has two pistons - one on each end of the linear generator. a small car might only need a one cylinder engine (1 cylinder = two pistons) a truck might run 4 cylinders or more - but only use as many cylinders as were needed to maintain operating power, unlike a conventional engine which must turn the whole engine to work.

as for your "you should just use a fuel cell" contention. gasoline and diesel fuel cells are only 3 years from conception - which in R&D terms is about 3 months pregnant. not to mention the fact that I have been hearing about fuel cells for 20 years, and never seen one actually get to the consumer market.

"edison got better results with a rotary generator, because Edison was working with sinusoidal AC."



Edison wasn't working with AC. In fact, Edison HATED AC. While a simple rotary generator (alternator actually) produces AC, the generators Edison used converted that AC to DC by using a commutator and brushes. A commutator is a series of mechanical switches that keeps flipping the polarity of the coils in the alternator so that the current always flows in the same direction. In fact, they didn't even have powerful enough rectifiers back then to convert the AC to DC even if they wanted to. That's another reason Edison wouldn't have used a linear generator. It would have produced AC and he had no way easy way of converting that to DC although he probably could have come up with a mechanical switch arrangement if he had to.

you're right. I got Edison and Westinghouse mixed up. however, I noticed in confirming that, that Edison was not really into generator manufacture - he was in distribution and utilization.

www.gamezhero.com/games/teslawarofcurrents

en.wikipedia.org/wiki/War_of_Currents




No, the reason for "the war of currents" was not disliking the superior AC technology by Edison. Edison's problem was that he had patented DC only and Westinghouse had patents for AC. So in order to keep the monopole for electric applications, Edison had to make sure nobody would buy AC systems. This was nothing personal or a matter of belief, it was a pure battle of dominating the market.

Tesla originally had worked for Edison. Edison gave him the task of improving the Dynamo Machine and promised him a lot of money if he manages to boost the efficiency significantly. Tesla managed to come up with a super efficient and very simple and elegant design but Edison claimed that he made a joke and didn't pay any extra money at all.
Tesla had quit and offered his services to Westinghouse who had just earned a fortune for the invention of pneumatic train brakes and was looking for something to invest his vast amount money. The new "electricity market" was perfect and since Edison didn't bother to hold more general patents, all his patents only protected details of the machines, machines for DC. So Tesla and Westinghouse were able to patent their own machines since they were AC. And all Edison could do about loosing his monopoly was to play dirty.

In fact, there is no superior system! Looking at the European market which was more independent, you notice that the power distribution over distances was done in AC technology but local power generation and usage was always done in DC. The only advantage of the early AC technology was the power distribution but using AC for industrial usage wasn't practical at all! There was no proper way to have electric AC motors running at variable RPM with high torque. So all large factories had their own DC power plants, there was no need for AC at all.

There used to be a large factory in my area which had its own power plant until it was abandoned in the late 60s. This factory also provided homes for the workers and those were supplied with electricity from the factory - 210V DC! While the electric power was for free, it was only meant for lights and maybe a radio. Electric stoves were allowed, too but they were only allowed to be used during shift changeovers when the factory machines were stopped.

When the power grids grew and eventually were connected to each other, more and more factories could be built without their own power plants. Those used rectifying stations to run the industrial motors. At first they used numerous AC motors driving DC generators but then they used real rectifying systems based on mercury.

More and more DC power plants became replaced with rectifiers.
New factories were then equipped with two power systems. AC for the lights and for simple, fixed-RPM purposes and DC for high torque motors running with variable RPM.
Thanks to more sophisticated rotary current asynchronous machines, more and more industrial applications could be directly driven by AC, the rectifier stations became obsolete. Machines which had to run at very different RPMs like elevators and ropeways used a Ward-Leonard-control. This is just an AC motor running at a fixed RPM driving a DC Generator which in turn powers a DC motor. Using variable resistors connected to the field windings of the generator and motor, you can control RPM with high torque. Here is a neat video of an elevator still in use today!


Electric trains had to be used with DC since AC motors lack the torque to start moving. AC would require a gearbox and a clutch like for internal combustion engines. In fact the diesel electric train engines use the idea of the Ward-Leonard-control by driving a DC generator with the Diesel engine which in turn powers the gear-less electric motors inside the powered bogies. This system is still in use today for diesel powered trains.
So street cars used to be DC powered. There are still many of those around, some areas now use hybrid cars which can also run on AC using modern power electronics. Either to be able to be used in other areas which have converted to AC already or they intend to switch to AC in the near future. Some can even run on the European 15kV 16⅔Hz train system.

The 15kV 16⅔Hz system was invented by the Swiss. With all their steep hills, they couldn't use steam engines since they were way to heavy. The only practical solution back then was to use electric train engines. In fact, the Swiss had invented the electric trains. Before they came up with electric train engines, only small electric street cars existed and real trains were always steam driven. What made the idea of electric trains economic were the Swiss mountains which could provide vast amounts of hydroelectric power. In theory, they were able to make real powerful electric train engines fed by nearby hydroelectric DC power plants. But this would require switching the train engines often or construct hundreds of coal power stations in areas where hydroelectric power isn't available. Their solution was to come up with the 15kV 16⅔Hz system. The frequency is high enough to use transformers to allow a high tension power grid which is in fact the contact wire of the railroad but the frequency is low enough to have almost DC-like torque in the motors of the train.
They had chosen 16⅔Hz just because the common AC grid was 50Hz and ⅓ of the frequency was good for the purpose and related to the power grid. There was no way to convert the frequency back then and even today the train power grid is mostly independent to the common "lightening" grid using extra generators inside the power plants.
But using ⅓ the frequency had unforeseen consequences. Sharing the same ground, both grids can interact when unbalanced causing a massive DC offset current which stresses the grid, blowing fuses and frying transformers. So the unofficial frequency definition of the train power grid is "close to, but never, ever exactly 16⅔Hz"

There is no practical reason to use the 16⅔Hz any more since almost every single train engine in service now use rotary current motors and electronic frequency converters. But they had to keep the old standard for compatibility reasons. Changing this would require to replace the entire electric train infrastructure. I think they will change to HVDC eventually and can tap off the HVDC power grid. More and more high tension lines become DC since DC has less losses, especially at high voltages.

It's interesting how we went full circle for electrical power distribution.
DC to AC and now back to DC

The transformers, if they even use transformers, for that 16⅔Hz system must be huge.

well, it is advisable to coat your engine with silicone spray, and not have your fan spinning too fast when you hit the water. otherwise the fan becomes a propeller and drives itself into your radiator.

but gasoline engines are built with the expectation that they will get wet while driving, so the connections are made water resistant, and with a little bit of added water resistance can be driven submerged as long as the air supply is maintained.

It is. Almost ½ of the engine room. The actual motors are sitting between the wheels. So a good ⅓ of the entire train engine is the transformer and the power stage selectors switching the transformer coils. The rest of the engine room are pressure vessels, compressors and especially blowers to keep the transformer (and everything else) cool.
I like the sound of the classic power stage selectors. Here is a recording of the sounds inside an engine room. At 1:07, you can hear the power stage selectors work.


And her is a rather old "solid state" controlled train engine:

Very ugly sounds!

At least the modern ones are not that bad!