The early form of linear motion bearing is to place a row of wooden rods under a row of skids. Modern linear motion bearings use the same working principle, but sometimes use balls instead of rollers. The simplest rotary bearing is the bush 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 many cylindrical rollers, each like a separate wheel.
An early example of a ball bearing was found on an ancient Roman ship built in 40 BC at Lake Nami, Italy: a wooden ball bearing was used to support a rotating table top. 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 there will be collisions between the balls, causing additional friction. But this can be prevented by placing the balls in small cages. In the 17th century, Galileo made the earliest description of the "cage ball" ball bearing.
At the end of the seventeenth century, British C. Vallo designed and manufactured ball bearings, and installed them on mail cars for trial use, and British P. Worth obtained a patent for ball bearings. The earliest practical rolling bearing with a cage was invented by watchmaker John Harrison in 1760 for the production of the H3 chronograph. At the end of the eighteenth 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. Palmgren of Sweden and others have conducted a large number of experiments, which have contributed to the development of the design theory and fatigue life calculation of rolling bearings. Subsequently, N.P. Petrov of Russia applied Newton's law of viscosity to calculate bearing friction. The first patent for a ball channel was obtained by Philip Vaughan of Carmarthen in 1794.
In 1883, Friedrich Fischer put forward 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. British O. Reynolds made a mathematical analysis of Thor's discovery and derived the Reynolds equation, which laid the foundation for the theory of hydrodynamic lubrication.