Toothless gear idea has Toots’ in N.Z.

Press, 21 December 1981, Page 4

Toothless gear idea has Toots’ in N.Z.

NZPA staff correspondent Washington

An American who followed up a compound gearing system designed by a Timaru man has developed a prototype toothless gear which he believes is a world first.

Mr Rory Mcfarland, aged 29, the founder and president of a company in Boulder, Colorado, Advanced Energy Technology, inc., has an oil fortune behind him. He travels a lot, and when he does he checks patent offices for inventions that interest him. That was how he discovered Mr Robert Davidson’s gearing system, while he was on holiday in New Zealand in the summer of 1978-79. Mr Mcfarland said that Mr Davidson has sold his idea, which centres on a compound motion (with toothed wheels) similar to that found in spinning tops and planets, to a British company, Fenner, Ltd, which subsequently relinquished it. Mr Mcfarland bought the idea from Fenner, checked other designs round the world, and developed Mr Davidson’s design, though eventually moving a long way from it.

Mr Mcfarland said Mr Davidson was “the daddy” of the gearing system which uses a load-handling . wijich

using plastic nutating gears which another Mcfarland company, Toolmaster Inc., sells .in the United States for $5O, with sales running at 1000 a month. Mr Mcfarland said the toothless gears used a compound motion like that of the moon as it circled both the earth and the sun. Power was transferred through ball bearings instead of teeth.

The main advantage, he said, was that the gearing took up less room. He was interested in developing the gearing for the aerospace industry. The gearing also drives with “zero backlash,” which suits it for robotics. The gearing also reduces friction.

The Ford Motor Company has ordered prototypes to test in windscreen wiper motors, and the American Navy, a Boulder respirator company, and a tool manufacturer have also ordered prototypes to test.

Mr Mcfarland said the new gear was “revolutionary.” He said the breakthrough came when a former satellite designer joined a Mcfarland ' company , and “had a flash” last May that ball bearings could replace teeth in the designs they were working bn.

The computer-designed gear still has to prove its commercial viabilty, although a limited partnership has already put up SUSI.SM for further development. ■;

A Ford researcher said the gear was “very complex,” but it appeared to be doing what it was supposed to do.