Let's understand the history of bearing development

       The early form of linear motion bearing is to place a row of wooden poles under a row of skid plates. Modern linear motion bearings use the same working principle, but sometimes use a ball instead of a roller. The simplest type of rotating bearing is the bushing bearing, which is just a bushing sandwiched between the wheel and the axle. This design was subsequently replaced by rolling bearings, which replaced the original bushing with a number of cylindrical rollers, each of which acted like a separate wheel.

        An early example of a ball bearing was found on an ancient Roman ship built in 40 BC found on Lake Nami in Italy: a wooden ball bearing was used to support a rotating table top. Leonardo Da Vinci is said to have described a type of ball bearing around 1500. 

        Among the various immature factors of ball bearings, a very important point is that there will be a collision between the balls, causing additional friction. But this can be prevented by putting the ball in a cage. In the 17th century, Galileo Galilei made the earliest description of the "cage ball" ball bearing.

        At the end of the 17th century, the British C. Vallow designed and manufactured ball bearings, and installed them on the mail truck for trial and the British P. Worth patented the ball bearing. The first practical rolling bearing with cage was invented by watchmaker John Harrison in 1760 for the production of the H3 chronograph. 

        At the end of the 18th century, H.R. Hertz of Germany published a paper on the contact stress of ball bearings. On the basis of Hertz's achievements, R. Stribeck of Germany, A. Palmgren of Sweden and others carried out A large number of tests, and contributed to the development of the design theory of rolling bearings and the calculation of fatigue life. Later, N.P. Petrov of Russia applied Newton's law of viscosity to calculate bearing friction. The first patent for a ball ditch was granted by Philip Vaughan of Carmarthen in 1794.

        In 1883, Friedrich Fischer proposed the idea of using a suitable production machine to grind steel balls of the same size and with accurate roundness, laying the foundation of the bearing industry. O. Reynolds of the United Kingdom made a mathematical analysis of Thor's discovery and derived the Reynolds equation, which has since laid the foundation of the theory of hydrodynamic lubrication.