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- From: camelsho@sportster.ksu.ksu.edu ( James A Seymour)
- Newsgroups: sci.energy
- Subject: Popular Science Fly Wheel Article
- Date: 21 Dec 1992 01:51:19 -0600
- Organization: Kansas State University
- Lines: 68
- Distribution: world
- Message-ID: <1h3t1nINNddb@sportster.ksu.ksu.edu>
- NNTP-Posting-Host: sportster.ksu.ksu.edu
-
- I'm not sure if this is the article which started the
- whole fly wheel discussion. However, its probably
- the one most widely read.
-
- Just so we are not talking apples and oranges, I am
- posting the text of that article with out permission.
- This comes from the January '93 issue of Popular
- Science, page 27.
-
- There is also a drawing that helps explain the text. If you
- are at all interested, I suggest you locate a copy of the
- issue and to see the diagram.
-
-
- ******************** Article Follows *****************************
-
- FLYWHEEL POWER
-
- A Seattle company claims its flywheel battery is the "missing link"
- that will enable electric cars to match the performance of vehicles
- powered by internalcombustion engines.
-
- The American Flywheel Systems (AFS) battery contains a pair of
- counter-rotating "rim wheels," suspended by magnetic bearings in a
- vacuum housing. The rim of each wheel is made from a high-tensile-
- strength fiber, such as Kevlar. Spoke tubes containg magnets connect
- the rims to lightweight hubs. An electric charge sets the wheels in
- motion, and they can perform work as they continue spinning--like a
- potter's wheel.
-
- The idea of using a flywheel to store energy is not new, but designing
- a device that works efficciently and safely has jproved difficult. To
- power a car, a flywheel battery must be capable of rotating at 150,000-
- 200,000 rpm. If the flywheel is a metal disc, it could break into
- shrapnel at that speed. And if it is a spoked wheel, the rim pulls
- away from the hub at high rpms.
-
- AFS claims to have solved some of these provlems. For example, the
- new battery's spoke-tube assembly allows the flywheel rim to expand
- without separating from the hub. And when the rim is spun so fast
- that it fails, the Kevlar fibers simply turn into "cotten candy,"
- says Edward W. Furia, chairman and chief executive officer of AFS.
-
- Furia says his new battery could make GM's proposed Impact electric
- car go as far as 600 miles on an overnight charge. The Impact now
- runs on 32 lead-acid batteries and has a range of about 80 miles.
- Replacing the lead-acid batteries with 20 flywheel batteries, each
- weighting 30 pounds, would also improve the car's acceleration,
- according to Furia. He says flywheel batteries have a high power
- density--they can give up energy quickly.
-
- "It's very important to overcome the perception of electric cars as
- glorified golf carts of greenmobiles," says Furia. "Electric cars
- should be capable of dazzling performance."
-
- The flywheel battery would last about ten times longer than a lead-
- acid basttery--which must be replaced after 25,000 miles. And since
- it uses no chemicals, it wouldn't create corrowsion or disposal
- problems.
-
- For now, the flywheel battery exists only as a computer simulation.
- It will take a bout two years to build a protype for a car, Furia
- estimates. The battery could also be aused to store electricty
- generated by solar or wind power.--Dawn Stover
-
- ***************************** End Article *****************************
-
- james seymour/camel/camelsho@matt.ksu.ksu.edu
-