Redirected from Ball bearing
The ball bearing was an improvement on the roller bearing. Roller bearings are still used, however, when the sideways forces are too great for ball bearings.
An early example of a wooden ball bearing, supporting a rotating table, was retrieved from the remains of a Roman ship in Lake Nemi[?], Italy. The wreck was dated to 40 BC. Leonardo da Vinci is said to have described a type of ball bearing around the year 1500. One of the issues with ball bearings is that they can rub against each other, causing additional friction, but this can be prevented by enclosing the balls in a cage. The captured, or caged, ball bearing was originally described by Galileo in the 1600s. The mounting of bearings into a set was not accomplished for many years after that. The first patent for a ball race was by Philip Vaughan of Carmarthen[?] in 1794. The modern, self-aligning design of ball bearing is attributed to Sven Wingquist of the SKF ball-bearing manufacturer in 1907.
Some modern bearing assemblies require routine addition of lubricants, while others are factory sealed, requiring no further maintenance for the life of the mechanical assembly. The lubricant is intended to reduce friction. However, if the lubricant becomes contaminated by hard particles, such as steel chips from the race or bearing, sand, or grit, the lubricant quickly begins to act as a grinding compound. This greatly reduces the operating life of the bearing assembly.
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