| An
early type of linear bearing was an arrangement of tree trunks
laid down under sleds. This technology may date as far back
as the construction of the Pyramids
of Giza, though there is no definitive evidence. Modern
linear bearings use a similar principle, sometimes with balls
in place of rollers.
The first plain and rolling-element
bearings were wood, but ceramic, sapphire or glass can be
used, and steel, bronze, other metals, and plastic (e.g.,
nylon, polyoxymethylene, teflon, and UHMWPE) are all common
today. Indeed, stone was even used in various forms. Think
of the "jewelled pocket watch", which incorporated
stones to reduce frictional loads, and allow a smoother running
watch. Of course, with older, mechanical timepieces, the smoother
the operating properties, then the higher the accuracy and
value.
Wood can still be seen today in old water mills, and the water
itself had a part to play in the cooling/lubrication implications,
of such natural and commonly found, bearing resources.
 Rotary
bearings are required for many applications, fromheavy-duty
use in vehicle axles and machine shafts, to precision clock
parts. The simplest rotary bearing is the sleeve bearing,
which is just a cylinder inserted between the wheel and its
axle. This was followed by the roller bearing, in which the
sleeve was replaced by a number of cylindrical rollers. Each
roller behaves as an individual wheel.The first practical
caged-roller bearing was invented by horologist John
Harrison in his H3 chronometer of 1760.
An early example of a
wooden ball bearing, supporting a rotating table, was retrieved
from the remains of a Roman ship in Lake Nemi, Italy. The
wreck was dated to 40 BC. Leonardo da Vinci is said to have
described a type of ball bearing around the year 1500. One
of the issues with ball bearings is that they can rub against
each other, causing additional friction, but this can be prevented
by enclosing the balls in a cage. The captured, or caged,
ball bearing was originally described by Galileo in the 1600s.
The mounting of bearings into a set was not accomplished for
many years after that. The first patent for a ball race was
by Philip Vaughan of Carmarthen in 1794.
Friedrich Fischer`s idea
from the year 1883 for milling and grinding balls of equal
size and exact roundness by means of a suitable production
machine formed the foundation for creation of an independent
bearing industry.
The initials of the names"Fischers
Automatische Gußstahlkugelfabrik" or "Fischer
Aktien-Gesellschaft" became a logo which was registered
on 29 July, 1905. In 1962 it got the look it still has today,
and it finally became an integral part of the company in 1979.
The modern, self-aligning
design of ball bearing is attributed to Sven Wingquist of
the SKF ball-bearing manufacturer in 1907.
|
