In Italy Nano Lake found a built in 40 BC the Roman ships found earlier instances of ball bearings: a wooden ball bearings are used to support the rotary table. Lieangnaduo·da·fenqi is said to be around 1500 ever description of a ball bearing. Ball bearing various immature factors, it is important that occur collisions between balls, causing extra friction. But you can put the ball into a small cage to prevent this phenomenon. In 17th century, Galileo was "caged ball" did the earliest description of ball bearings. The end of 17th century, United Kingdom c. WA Luo designed and manufactured ball bearings, and installed in the mail to try as well as the United Kingdom p. patented the ball bearing Werth. First rolling bearings with a cage to put practical was the clockmaker John Harrison invented in 1760 to make H3 counters. End of 18th century Germany H.R. Hertz published papers on the contact stress between the ball bearings. Hertz achievements on the basis of Germany r. Striebeck, and Sweden a. Parmgren, who had a lot of tests, the development of the design theory and calculation of fatigue life of rolling bearings has contributed. Subsequently, Russian N.P. Petrov, application of Newton's law of viscosity calculation of bearing friction. First patent on balls channel is feilipu·woen in 1794, of Carmarthen.