Data Section
Basic Knowledge of Bearings
Here, we provide basic information on bearings.
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Structure and Function
Introduction
A surprisingly large number of bearings can be found all
around us. Take automobiles, for example: There are
100 to 150 bearings in a typical car. Without bearings,
the wheels would rattle, the transmission gear teeth
would not be able to mesh, and the car wouldn't run
smoothly. Bearings are used not only in cars but in all
kinds of machinery such as trains, airplanes, washing
machines, refrigerators, air conditioners, vacuum
cleaners, photocopy machines, computers and
satellites. Bearings enhance the functionality of
machinery and help to save energy. Bearings do their
work silently, in tough environments, hidden in
machinery where we cannot see them. Nevertheless,
bearings are crucial for the stable operation of
machinery and for ensuring top performance.
The term bearing incorporates the meaning of "to
bear," in the sense of "to support," and "to carry a
burden." This refers to the fact that bearings support
and carry the burden of revolving axles.
Structure
The ball bearings and roller bearings pictured below represent two typical types of the most basic bearings, known as
rolling bearings. Rolling bearings are made up of four elements: an outer ring, an inner ring as well as rolling and
cage elements and have an extremely simple basic structure.
Outer ring
Outer ring
Rolling
elements
(balls)
Cage
Inner ring
Ball Bearing
Outer ring
Rolling
elements
(rollers)
Cage
Inner ring
Roller Bearing
Cage
Rolling elements (balls)
Inner ring
Function
2
There will be less
frictional wear, extending
the operating life of the
machinery
Benefit
1
Machinery will
run more efficiently
Benefit
Benefit
The basic function of bearings is principally to reduce mechanical friction. Reducing friction means:
3
Preventing abrasion
burn and avoiding
mechanical
breakdown
Bearings also contribute to lower energy consumption by reducing friction and allowing the efficient transmission of
power. This is just one way in which bearings are environmentally friendly.
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Types of Bearings
A brief overview of typical bearings is presented as follows.
1
Deep groove ball bearing
This is the most widely used
bearing in the world.
5
Tapered roller bearing
The rolling elements are of the
tapered roller type. Because the
rollers are tapered, this bearing
is able to carry combined axial
and radial loads.
3
2
Angular contact thrust ball bearing
In this type, the rolling element
meets the inner and outer ring
raceways at a contact angle.
This bearing can carry radial
and axial loads.
6
Self-aligning roller bearing
This bearing has an automatic
aligning function to compensate
for minute misalignments
between the inner and outer
rings during operation.
3
Thrust ball bearing
Thrust ball bearings are
capable of handling loads in
the axial direction (axial loads).
They can support heavy loads.
7
Thrust needle bearing
This bearing is used in parts
such as compressors that
deliver the air in automobile
air-conditioning units.
4
Cylindrical roller bearing
The rolling elements are the
cylindrical roller type.
8
Cage and roller
This is one of several kinds of
bearings used in vehicles'
manual transmissions. It is
required to be highly durable.
Future of Bearings
Here, we introduce some themes on the further evolution of bearings.
Theme 1: Energy savings
While bearings require a level of precision measured in
nanometers, efforts continue to focus on securing
further improvements in the reduction of friction. The
smaller a machine becomes, the smaller its
components. Moreover, no matter how small machines
become, total energy consumption will be large when
viewed on a global scale. In order to produce even
greater energy savings, we should continue to seek out
even better ways of reducing friction using bearings.
Theme 2: Cleaner
Improving bearing technology can have beneficial effects
on the environment: a reduction in vehicle exhaust gas
emissions, for example. in addition, the vast majority of
bearings are made from steel that does not contain any
harmful chemical substances. This steel can be
recycled into new steel materials. Bearings offer
excellent potential as products for recycling and reuse.
Theme 3: Comfort
Machines must be agreeable for both people and the
environment. In the past, machines have supported
improved production; in the future, there will be
demands that machines help society and individuals
enjoy more fulfilling lives,. Also, the bearings that are
used in those machines must be asked to fulfill
functions and roles that differ from the old ones.
NSK will continue to work on research and
development "for people and the planet."
For further information, please access our website:
http://www.nsk.com/company/introduction.html
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