Introduction to Bearings & Types of bearings Video Lecture | Design of Machine Elements - Mechanical Engineering

kind students in this tutorial we'll be
discussing about an important machine
element bearings in coming up series I
will be discussing the classification of
bearing and then after the design of
journal viewing the design of rolling
element bearing and then after the
numerical problems and little objective
questions so you should look forward
with the next episodes
we'll be discussing with all these
points before you we beginning the
design process of bearings this may be
the first question in your mind why we
are using bearings in industries or in
machines why we are using bearings it's
a simple explanation suppose you are
using a shaft normally we are using
shaft to transfer power from one point
to another point in such a way that one
end will be connected with an electric
motor for that maybe an engine or
whatever the machine that you required
you need to connect shaft with that
rotating machine and you need to convey
that power with another point it in this
case will be connecting our shaft with
the belt right as you aware then a drive
will be connected on the opposite end of
the shaft the shaft will be under
different kind of loading that is the
loading due to the loads in that belt
that maybe some pending load there will
be some torsional load and all other
kind of dynamic unpredictable orders
will be on that shaft and this shaft is
right now almost like a cantilever beam
that one and a supported an electric
motor in other end is completely free
and due to this condition
there will be deflection within this
shaft suppose this shaft is a two feet
long one and while you turn on the motor
the shaft
begins to rotate as well as it will
deflect about its axis there will be a
up and down movement of the shaft with
respect to the axis so due to this
jerking due to this jerk movement
you can't continuously transfer over
with a good precision so to avoid this
kind of vibrations joking on shaft we
can use a support to avoid this dynamic
loads on that shaft you can go for a
welded support or maybe a static support
in the case of beams and all other kind
of platforms but it is not possible with
a rotating moving shaft so you need a
continuously moving support
to support this kind of shaft for that
purpose we will be using bearings so
these are the bearings which support
moving machine elements such as shaft so
this is a basic idea behind a bearing so
this is why we are using bearings in
industries so bearing is a machine
element which supports another machine
element may be known as journal and it
permit a relative motion between the
contact surfaces of members while
carrying the load so these are the two
important points the first one it
permits the relative motion between the
machine element and it also carries the
load so bearing will dealing with the
two function one it will carry the load
and the second one it will permit a
relative motion so that's a speciality
of fearing and we can discuss with the
classification of bearing
and the bearings are broadly classified
based on the direction of load so this
is the first kind of classification and
the first kind and the direction of load
is radial bearing so look at the first
feature in this kind of bearing the
loading will be perpendicular to the
axis of shaft these red arrows shows the
direction of the load and you could see
the load is directed perpendicular to
the moving rotating shaft so this kind
of bearings are known as radial bearing
and the second kind of bearings are
stressed Chi bearing or axial bearing in
this kind of bearing loading ads
parallel to the axis of rotating shaft
and this is the third kind in normal
practice in most of the application we
will be under radial as well as axial or
thruster load so this kind of bearing us
actually under a resultant or the
combination of radial intrest load so
these kind of bearings are known as
combined load-bearing so we'll be having
bearing with the radial load or thrust
load or sometimes both radial and thrust
load we move forward to next kind of
classification so this classification is
based on the nature of conduct the first
category under this classification is
sliding contact bearing as that name
indicate sliding takes place between the
fixed and moving element of peirong and
this kind of bearing also known as plane
bearing so here we have two kind of
element the first kind is asan shaft so
it's a moving element and the second one
is the bearing it's fixed element so the
moving shaft will be supported by the
fix at a housing of the peering through
this kind of arrangement is the better
picture of the bearing and we'll be
having a moving shaft and it also knows
as the journal or the shaft
within the bearing is what we call it a
channel and we'll be having a bearing
cap and between the bearing cavity and
the shaft there will be a clearance and
through that clearance will be supplying
oil and this lubricant help to reduce
the friction and build up the pressure
and this is what the components of the
bearing the channel clearance housing
and the bearing lining these are the
different kind of sliding contact
bearing or commonly known as the journal
bearing and you should note this thing
the sliding contact are commonly known
as a journal bearing hereafter when I am
using the journal bearing that I mayn't
sliding contact bearing okay the journal
bearings are again classified into
different category as per the bearing
housing there is full journal bearing so
these kind of channel will be having a
360-degree support all around the
rotating shaft the second kind is a
partial journal bearing so the support
is partial and third kind is filtered
channel bearing the difference between
the third kind and second kind is for
filter journal bearing the diameter of
the shaft will be bigger than that of
the diameter of the bearing but in
previous case the diameter of shaft is
smaller than that of the bearings and
the whole family of journal bearing
again divided into different category
based on the lubrication system that we
are using with between the shaft and the
fixed bearing here the first type of
journals are hydrodynamic bearing and
the second one is hydrostatic bearing
and in between will be having thin
filling litigation and zero filling
lubrication and I will explain how these
kind of pairings are working and what is
the difference between hydrodynamic
bearing and
Shattuck bearing in coming up videos so
please look forward for that and right
now I am simply showing you what are the
different types of journal bearing here
it comes the rolling contact bearing and
balls or rollers is introduced between
wing and fixed element and it is also
known as anti friction bearings and the
difference between a journal bearing and
the roller bearing is basically in
previous case we will be having the
sliding moment between the rotating
shaft and the fixed bearing but in this
case we introduced balls or rollers
sometimes the spherical bow in other
case may be a roller in special cases
may be a shepherd roller or the pin
rolling element or whatever the case
will be having a rolling moment between
the inner ring and the outer ring so
these are the components of a rolling
contact bearing you will be having an
inner ring that will be connected with
the shaft and there will be an outer
raise and between inner and outer we
have a rolling element so it will allow
a relative moment between the shaft and
the bearing and the speciality of this
kind of bearings as compared with the
previous journal bearing roller will
produce a less very less amount of
friction so due to this property this
bearing also known as anti friction
bearings the main advantage of rolling
contact bearing is it convert a sliding
movement it's a rolling movement and
that resulting high reduction in
coefficient of friction and the
coefficient of friction is about 0.001
to 0.002 and while designing a rolling
contact bearing we'll be dealing with
the fatica friction heat and what are
the lubrication that
one should use and kinematic use
material properties machining tolerance
and assembly of bearing and all these
factors should consider while designing
a rolling contact bearing I think you
almost get an idea how a bearing rolling
contact bearing works here we have the
inner ring and the diameter of the inner
ring what we call the bore of that
bearing so within that inner ring we'll
be fixing the shaft and inner ring can
rotate along with the shaft and the
outer ring will be fixed and the pole or
rollers allow the relative movement
between the inner ring and the outer
ring so these are the different types of
rolling contact bearing mainly available
in industry the first kind is ball
bearing the rolling element will be a
spherical ball in pole bearing we have
the group ball bearing filling not ball
bearing and clock on-deck ball bearing
the second category most of the bearings
are roller bearing instead of spherical
ball will be having cylindrical may be a
needle or otherwise a tampered and that
kind of bearings are roller bearings I
will be showing you the examples of some
ball bearing so this is what the deep
groove ball bearing the deep groove ball
bearing the speciality has it has a
limited number of poles and primarily
designed to support radial load that is
the load perpendicular to axis of shaft
but it also supports some thrust load
and if the thrust capacity is about 70
percentage of radial load capacity and
it's another kind of node that is a
filling notch balls the speciality of
filling notch balls bearing have the
same basic radial construction as the
previous but the filling nodes permit
more bolts to be used so it has high
capacity than deep groove ball bearings
and is another kind of ball bearing is
angular contact ball bearing you could
see
have an angular contact with the pool
and use by using that angular conduct it
can also support a better amount of
thrust force along with the axial force
and this is the difference between a
normal deep groove ball bearing an
angular contact bearing you could see
that angular contact with the outer rays
and the poor these are some other
standard bearings the crew filling Noach
angular contact sheltered and this is
what the self aligned the kind of ball
bearing will be having a special
geometry here speciality office and
self-aligned pyrenees it could
accommodate a little deflection in the
shaft by using this geometry so if there
is a minor deflection in the shaft you
can use self-aligned bearing it have a
capacity to align itself and it's the
story in nutshell the rings are
classified into two the first category
sliding contact bearing or general
bearings and the second category is
rolling contact bearings and within
sliding contact bearing we have I drew
dynamic bearings then hydro static
bearings then
thin film lubrication and then after the
zero filling lubrication and under
rolling contact tearing a ball bearing
falls under rolling contact bearing and
cylindrical roller bearings and finally
the needle bearings it is the total
classification of bearing or the family
of bearing and see you in next video