Automobiles, in the long term, will have to be weaned from petroleum, too. They will not, of course, go to gasohol -- corn-based and heavily subsidized gasohol is not making it in the US, and even the more efficient Brazilian gasohol industry is in deep trouble. They will either run on artificial fuel such as water-extracted hydrogen, or on electric power, in either case requiring abundant nuclear energy.
Mr Lovins and other conservation-minded scholars jealously guard the secret of what they would do with several millenia's worth of uranium that has no other uses but providing energy; but neither do they reveal that the low efficiency of electric conversion and transmission is still higher than that of the internal combustion engine.
However, not all the losses
¾that is, heat¾arise in the explosive gas or electric resistance of the motor. There is also rolling resistance in the tires, aerodynamic drag, and plain old friction in the gears and bearings.By using ball bearings, one can at least replace sliding friction by the much smaller rolling friction; but the teeth of gears slide over each other as they engage, for the principle of rigid gearing has not really changed from that depicted in the 1548 edition of Agricola's De re metallica.(*)
Enter a gear called "Anti-Friction Drive," which has only rolling, no sliding, friction. It is made by Advanced Energy Technology, Inc., in Boulder, Colo.
All gear drives transmit energy from one shaft to another, making the driven shaft turn slowly with great force, or fast but weakly, depending on the gearing ratio. The two shafts are parallel in a spur gear, and perpendicular in a worm drive. But there is a third way of engaging a large diameter to a small one: head on (shafts in line) with disks that engage each other via steel balls between them. To get different diameters, you have to make the disk positions eccentric, and the grooves ("races") in which the balls roll are a nightmare of kinematics
¾except to those of us who savor the beauties of epicycloids, trochoids, and other curves traced by a point on a circle when it rolls around another circle.The point (on the circumference) traces a hypercycloid if the circle rolls inside the other, and an epicycloid if it rolls outside it; if the point is not on the circumference, but fixed at a certain distance from it, the result is a trochoid.
GRAPHIC: A01_8201.TIF
More details of how the Anti-Friction Drive works can be gleaned from the pictures in a brochure available to AtE readers from Bill Fritz, A.E.T., Inc., Box 4544, Boulder, CO 80306. With the nomenclature explained above, mechanically minded readers should be able to figure out the workings of this clever drive, which is small, efficient, usable over a wide range of gearing ratios, and void of sliding friction.
But other readers may accuse us of being "too technical;" and this time they may have a point. In apology and partial compensation, we suggest the use of transcendental curves as nonlibelous invectives ("You low-down trochoidal epicycloid!").
* A book on machinery (chiefly mining), in Latin, published in Chemnitz, Saxony, with 289 fascinating plates (highly recommended to students of "appropriate" technology!). English edition (1950) $17.95, Dover Publications New York.
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Vol. 9, No. 5
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 9, No. 5 Date: November 23, 2004 01:23 PM Title: Free to choose
Copyright © 2004 - Access to Energy Newsletter Archive
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