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The concept
of using ball bearings to reduce friction in rotating components was not
new. The sketch by Leonardo da Vinci (1452 to 1519) shows the cup-cone concept
as used to provide a play-free pivot for a shaft. The diagram of a ball
race (below) is at a different scale. This unit, fabricated in 1780, provided
reduced friction for the rotating sail-house on a windmill. The balls are
of cast iron, 57 mm in diameter, and 40 were used in the race which had an outside
diameter of 860 mm.
The advent of the bicycle in the late 1800's
and its demand for low friction bearings introduced mass-production techniques
to the manufacture of small ball bearings. |
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