4 ms·
It looks like they replace the crankshaft with electromotive components, attaching the piston rod directly to either a linear actuator or a rotating generator.
by gills 18y ago
It looks like they replace the crankshaft with electromotive components, attaching the piston rod directly to either a linear actuator or a rotating generator.
At first I was pretty skeptical if the usefulness of such a device. The crankshaft in an engine transfers power to a load, but it also performs an elegant and complicated synchronization task for multiple cylinders and ancillary systems (like lubrication, cooling, fuel supply, ...).
But the crank also imposes a practical limit on stroke length because a long stroke in a small space gives you pretty high angles and less efficient power transfer. The short stroke puts an artificially-low limit on the fraction of energy from the combustion that can be recovered.
Attaching a kinetic-to-electric conversion device directly to the cylinder allows the stroke length to be longer (basically unbounded) so a larger fraction of the energy can be captured, and less wasted as heat.
Then a multi-cylinder engine basically becomes a computer program, where it's easy to implement fine timing, synchronization, load-balancing and load-prediction tasks using sensor networks.
I'm skeptical that it would be more useful than just dropping the mechanical conversion and it's relatively high losses, and using something like a fuel cell instead.
- Andys 18y agoLubrication, fuel, and cooling systems all work more efficiently when powered by electric motors. The reason is they increase drag unnecessarily at high motor rpms. (But they also cost more). I think this would be a logical way of making a car engine more efficient. Fuel cells are cool but the infrastructure already set up to refuel and maintain petrol engines is vast and not ready to go away yet.
- rbanffy 18y ago"the infrastructure already set up to refuel and maintain petrol engines is vast and not ready to go away yet." And that's precisely why ethanol engines are such a nice idea. I have been driving ethanol-running cars since my youth and can tell you they work just fine and have a pretty low carbon footprint, specially when compared to fossil-fuel based ones. I sincerely doubt they got their math straight.
- jibiki 18y agoIn terms of carbon footprint, a lot depends on where the ethanol comes from. For instance, if you're getting it from corn grown in the US, then you are doing it wrong... (The wikipedia article is kind of awful, but it touches on the main concerns: http://en.wikipedia.org/wiki/Corn_ethanol http://en.wikipedia.org/wiki/Corn_ethanol )
- rbanffy 18y agoWe are getting it from sugar cane in Brazil. While not the most efficient way, it's pretty good. Getting ethanol from corn is so stupid only a government could imagine it. I think I have owned only one car that ran on gasoline, an import from Argentina.