Friday, May 21, 2010

Can D-Drive Infinitely Variable Transmission Save Wind Energy?


The applications for an efficient, slip-free infinitely variable power transmission would be numerous, but I single out wind energy because it appears to be the "great white hope" of the environmental dieoff.left in western countries. Gearbox failure is a massively expensive scandal throughout the wind industry, and to this point none of the highly touted substitutes for gearboxes -- direct drives and continuously variable transmissions -- have proven themselves to be efficient, durable, and affordable in the field, on a large scale.

The world desperately needs a reliable, efficient, and affordable infinitely variable transmission. So what about the D-Drive? Brian Westenhaus takes a look:
To grasp what’s happening one has to understand planetary and orbital gear sets. In planetary sets there is a large outer (ring) gear with teeth on the inside. The inside teeth mate to a set of 2, 3, 4 or more little ‘planet’ gears (planet set) whose axles are tied together (by a carrier frame) such that they as a set mesh with the large outer gears inside teeth – and – with an inner gear’s (sun gear) outside teeth.

In an orbital gear set the inner gear drives an eccentric orbiting gear from the inside while the outside eccentric gear’s teeth drives to an outer ring.
Keep in mind that the large outer ring gear can turn or be locked, the planet gears must rotate on the carrier frame and the carrier that holds them can rotate or be locked. The inner sun gear too can rotate or be locked as well. The combinations make for some interesting speed ratios across the possible lock or rotate choices. Torque multiplication and over drive ratios can be made available. Planetary gear sets can be made extremely strong and simple and are relatively lightweight and robust.

What Durnin has done is stack two doubled planetary sets in a row behind an eccentric orbital set with the innovation of not locking one of the three axles, but to control the speed of rotation. Well, its not exactly that simple . . .

Power comes in to the inner gear of orbital set, which turns the eccentric ring and idles the outer gear. The ring gear is connected to planetary set #1 at the planet set. Stop. This planetary set isn’t your usual planetary set.

The second and third planetary sets have a double wide outer ring with the carrier planet and the sun – this is the D-Drive innovation. _Read much more at NewEnergyandFuel
We will have to wait and see whether the D-Drive can succeed in the wide number of niches to which it might reasonably be tried. As for wind energy, it is unlikely that anything can save large-scale wind farm styles of wind power. But off-grid wind has always had potential, and any transmission that can eliminate a significance weakness -- such as failure-prone gearboxes -- should be helpful.

The real holy grail of wind and solar is not direct drive, nor is it superconducting generators, nor is it offshore or high-altitude winds. The holy grail of intermittent renewable energies is cheap, reliable, large-scale power storage.

Even then, wind cannot possibly be competitive with clean nuclear, coal, gas, or enhanced geothermal (when perfected). The mathematics of wind energy precludes true competitiveness. But if you are psychologically addicted to something about large-scale wind energy, you should pray to whatever gods you believe in for a very cheap, very reliable, very durable, very scalable, power storage device.



Post a Comment

Subscribe to Post Comments [Atom]

<< Home

Newer Posts Older Posts