Transcription
I'm Steve Arnold, founder of ESI and inventor of the continuously variable displacement engine and compressor drive system. I would like to thank the Department of Energy's office of energy efficiency and renewable energy vehicle technology office for their financial support getting the CVD system designed, prototype, and tested.
In this video, I'd like to introduce you to the concept and the benefits, as well as show you some of the progress that we made. The drive system can be used for engines or compressors. To fit the scope of the work into the DOE SBIR Phase II budget, it was necessary to prototype it as a compressor first. The forces and loads used in the design process were those of an engine, so at the conclusion of the project, it could be converted to an engine without significant redesign.
Now we'll see clips of the first prototype CVD compressor running and use simulation animations for detailed explanation of how the mechanism works. [Music]
Let's look at the rotating and reciprocating motions via a simulation animation. The crankshaft will rotate at constant speed, and the stroke will change, starting at minimum stroke, transitioning to full stroke, then back to minimum stroke. Even though the crankshaft rotates at a constant speed, one can visually see the piston speed slow down and speed up. The piston forces are transferred to the new TT wobbler, which then transfers the force to the crankshaft. The wobbler has a reaction connection to the crank case, which is done via special anti-rotation gears. Neither gear rotates; one is stationary and one rotates around the crankshaft centerline at a one-to-one ratio. The tricky part is that the angle between these gears varies depending on stroke.
Now let's watch a cutaway change stroke without the crankshaft rotating. As the hydraulic stroke control piston translates in the hydraulic cylinder, note that it captures the pivot plate which is pinned to the crankshaft. This connection allows tilting of the piston as well as the capability to shift off-center relative to the crankshaft centerline. There are precisely six degrees of freedom in the assembly, so parts motion is precise and repeatable. Also note the position of top dead center and bottom dead center as the stroke has changed; top dead center moves to adjust the compression ratio to the desired value throughout the range of stroke. We can see the articulated balanced weight move as the wedge cam changes the weight position axially and radially to adjust the balance during the stroke change. Every movement we have seen so far only happens when the stroke changes, so none of this has an impact on friction when the engine is running at a constant stroke, and the velocities are magnitudes slower than the rotating and reciprocating velocities. So the stroke change movements represent very small friction power.
Let's see a bit more testing. Now that we understand the basic function, we will start at minimum stroke, change the backpressure several times, then move to max stroke and again change the backpressure. We're good. [Laughter] [Laughter]
Thanks for your attention, and I'm always interested in feedback, so send it to Steve at ESI-INC.us. Thank you.