The development history of bearings.

The early form of linear motion bearings was to place a row of wooden poles under a row of crowbars. Modern linear motion bearings use the same operating principle, except that balls are sometimes used instead of rollers. The swivel bearing is a sleeve bearing, which is simply a bushing sandwiched between the wheel and axle. This design was later replaced by rolling bearings, which replaced the original bushings with many cylindrical rollers, each rolling element acting like a separate wheel.

An early example of a ball bearing was found on an ancient Roman ship built in 40 BC in Lake Nami, Italy: a wooden ball bearing was used to support the rotating tabletop. Leonardo da Vinci is said to have described a ball bearing around 1500. Among the various immature factors of ball bearings, a very important point is that the balls will collide with each other, causing additional friction. But you can prevent this phenomenon by putting the balls into small cages. In the 17th century, Galileo made the earliest description of "cage ball" ball bearings. At the end of the seventeenth century, C. Wallow of England designed and manufactured ball bearings and installed them on mail trucks for trial use. P. Worth of England obtained the patent for ball bearings. The rolling bearing with a cage that was put into practical use was invented by watchmaker John Harrison in 1760 to make 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. Striebeck of Germany, A. Pamgren of Sweden and others conducted a large number of experiments and contributed to the development of the design theory and fatigue life calculation of rolling bearings. Subsequently, N.P. Petrov of Russia applied Newton's viscosity law to calculate bearing friction. The patent for a ball channel was obtained by Philip Vaughan of Carmarthen in 1794.

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