Sliding Bearings made of wear-resistant materials, also known as bearing bushings, bushings. Usually cast on the inner
surface of the pad, mainly in order to reduce costs, save valuable wear materials. Thickness 0.5-6mm, for large size or
important bearing. Bearing bushings are mainly to replace the shaft wear, there are also supporting the shaft operation,
friction reduction, vibration effect.
The earlist sliding and rolling bearing is made of wood. Ceramics, sapphires or glass are also used, steel, copper,
other metals, plastics (such as nylon, bakelite, teflon and UHMWPE) are commonly used.
From heavy-duty wheel shafts and machine tool spindles to precision watch parts, many occasions require rotating
bearings. The simplest rotary bearing is a sleeve bearing, which is just a bush between the wheel and the axle. This design
is then replaced by a rolling bearing, is to use a lot of cylindrical roller to replace the original bushing, each rolling
body like a separate wheel. The earliest put into practical use of cage with the rolling bearing is the watchmaker John
Harrison in 1760 for the production of H3 chronograph and invented.
An example of an early ball bearing was found on an ancient Roman ship found in Lake Minnesota. This woden ball
bearing is used to support the rotating table. The ship was built in 40 BC. It is said that Leonardo da Vinci had described
a ball bearing in about 1500 years.
Because of ball bearing's a variety of immature factors, there is a very important point is that there will be
collisions between the ball, resulting in additional friction. However, you can put the ball into a small cage to prevent
this phenomenon. 17th century, Galileo on the "fixed ball", or "cage ball" ball bearings made the earliest description. But
in the subsequent quite a long time, the installation of bearings on the machine has not been achieved. The first patent
on the ball channel was obtained by Cameron's Philip Vaughan in 1794.