Y_Po wrote:I need explanation for their claims, not claims themselves. I really see no benefit of that engine layout.
Explanations have been equation light.
Motors have efficiency curves. Basic concept of modularity is to bring portion of usage higher on the motor efficiency curve. This allows the motor to average higher on the curve.
You are not answering the question.
Claim is fewer kWh in fuel per kWh at the wheels. Above is a list of methods. I'd enjoy more details myself. Still waiting on the demo which was supposed to occur by the end of last year. The newly inked deal is nice but I'm looking forward to the 100 mpg on the EPA combined cycle demo.
The big advantages are from reduction in friction. The pistons travel 1/2 as far (total) for any two stroke when compared to a four stroke.
In this design each piston travels only 1/2 of a given cylinders stroke (but there are 2 of them per cylinder) this reduces the piston surface velocity (a speed limiting constraint).
The engine is without traditional mechanical valves. Did you ever try to turn a camshaft by hand? The commensurate reduction in friction and torque requirements that valve train mechanism would require is a big winner.
The crankshaft is offset so that the throw of the pistons in nearly opposite each other reducing main bearing loads to mainly torque. This torque load is substantial, but carried by the crankshaft rather than twisting and pushing against an engine block. This balanced load therefore reduces the friction resistance on the main bearings as well.
While not helping the thermal efficiency in a compelling way, the fact that the power to weight ratio is high would improve any vehicle systems range (less weight to drag around and accelerate).
The advantage in modular design (particularly attractive for extended range operation - think original A-160 drone coptor). The design concept would include two modules coupled for full power(takeoff and travel)and would shut off a module for lower power operation. This eliminates parasitic drag from rotating the unused module and allows the operating engine to operate at a more efficient output than it would if it were sharing the load. I have wondered is the module displacement might be even more flexible if their output was say 1/3 and 2/3's or 40% and 60% so there would be a greater range of efficient output for operation.
Last edited Wed, 23 Feb 2011, 6:35am by devotEE
"We're living in a wiggly world."
"11% of any quantity = a shit ton"