What is a differential
simply put a differential is a system
that transmits an engine's torque to the
wheels
the differential takes the power from
the engine and splits it allowing the
wheels to spin at different speeds
during cornering but at the same time it
gives equal torque to each wheel when
both wheels have the same traction
a system of gears in the differential
arrange in such a way that it connects
the propeller shaft to the rear axle
at the point you might be asking
why would each will spin at different
speeds from each other
so that's what we can discuss in today's
video
the differential is found on all modern
cars and trucks and also on many
all-wheel drive full-time vehicles
in 1827 the first conventional
automobile differential was invented by
a french watchmaker onesephor pecker and
it was used in steam-powered vehicles
in 1932 porsche used the first limited
slip differential
but why differential is needed in a
vehicle
when the vehicle is turning the
differential allows the outer wheel to
rotate faster than the inner wheel
this is essential when the vehicle turns
causing the wheel to move outside the
turning curve to roll further and faster
than the other
the differential allows the wheels to
rotate at different speeds so the car
can corner without putting excessive
wear on the tires
if the axle does not allow the wheels to
turn independently of each other the
tire of one veal will be pulled across
the ground
now let's find out what are the
different parts are used in a
differential
differential side gears or sun gears
planted gears or spider gears ring gear
or crown wheel
drive shaft
bevel pinion
an axle or half shafts
let me give you the overview of these
parts in detail
ring gear will transmit the power to the
planet pinions sun gears and finally to
the half shafts so that power will be
used to drive the wheels
two planet pinions or sometimes four
planet pinions are placed opposite to
each other and are meshed with the sun
gears to transmit the power to the rear
wheels by half shafts
the power from the gearbox is
transmitted to the propeller shaft or
drive shaft and thereby it will send to
bevel pinion
the function of bevel pinion is to
transmit the power from the propeller
shaft to drive the ring gear
there is not a single shaft which is
connecting two rear wheels but two half
shafts are used to connect two rear
wheels in the automobile and the crown
veal is free to rotate on the half shaft
these half shafts are splined to each of
the sun gears
two sun gears are employed for the
working of differential which are
opposite to each other and these sun
gears are connected to the half shafts
to drive the power
how differential works
the power from the engine is transferred
to the ring gear through a pinion gear
the ring gear is connected to a spider
gear which is at the heart of the
differential system the spider gear is
free to rotate in two different ways one
along with the ring gear and two on its
own axis
the spider gear meshes with two side
gears so power from the engine flows
from the pinion to the left and right
wheels
let's consider some cases
when the vehicle is moving in straight
direction then the speed of rear wheels
is same in the sense both will rotate at
the same speed
in this case the sun gears spider gears
and the ring gear will act as a single
unit and the two half shafts will
revolve at the same speed
in this situation when all the parts of
the differential act as a single unit
there is no relative motion among them
and that's the reason all the rear
wheels move with the same speed
the vehicle is taking a turn spider gear
plays an important role here
along with the rotation of the ring gear
it rotates on its own axis
so the spider gear is having a combined
rotation
when the vehicle is taking the right
turn then the distance traveled by the
left wheel is greater than the distance
traveled by the right wheel and the
speed of left wheel is greater than the
speed of right wheel
the turning of one sun gear will cause
the other sun gear to rotate in the
opposite direction which means if left
sun gear rotates in a particular period
of time then the right sun gear will
also rotate in the same period but of
course in the opposite direction
the torque from the final drive is
divided between two half shafts and the
spider gears are connected by means of
cross pin which are free to rotate about
it and does not change the torque among
the wheels
therefore the spider gear act as a
balance and divide the torque equally
between the two wheels on the axle even
when their speeds are different
in this way the torque is transmitted
when the vehicle is taking the turns
now let's take a look at the different
types of differentials and how they work
the different types of differentials are
open differential
limited slip differential
locking differential
torque vectoring differential
torsion differential
and welded differential now let's take a
look at how these differentials works
starting with open differential
these types of differentials are the
most essential and only allow individual
veal speed or slip to be changed
in good road conditions this allows the
outer wheel to spin at a faster speed
than the inner wheel
the problem occurs when road conditions
are not good such as on wet snow ice or
sand
using an open differential in your car
engine torque is transferred even though
the wheel has zero traction so that the
sliding tire can spin freely this type
of differential is often found in family
sedans and economy cars
if one tire loses traction the other
will lose power to maintain traction
open differential allows for different
deal speeds on the same axle which means
there will be no veal slip when going
around a corner as the outer tire will
travel further
from an efficiency point of view there
will be less energy loss through open
differential compared to other types
when traction is reduced in one wheel it
substantially limits the amount of power
produced by the vehicle
if one veal cannot dissipate as much
power the other veal receive an equally
small amount of torque
a limited slip differential works
similarly to an open differential
they transfer torque to each veal
independently under good road conditions
an open differential can cause the tire
to slip under hard cornering or heavy
acceleration
but a limited slip differential prevents
the amount of torque from passing into
the sliding tire the one with the least
resistance
this is done by the use of clutches and
plates within the differential
this allows the vehicle to power through
corners whereas a vehicle with an open
differential cannot
race cars off-road vehicles and other
performance vehicles use a limited slip
differential
limited slip differential allows for
different wheel speeds on one axle thus
reducing tire wear compared to a locked
differential
it also allows the veal to send torque
with more traction
it offers a very smooth operation
doesn't have the low speed clunkiness
typically associated with other limited
slip differential types that navigate a
tight area
it cannot lock completely because the
system requires a speed difference
between the two sides to transfer torque
when it is being used too often the
effective limited slip differential will
be reduced
these types of differential use a clutch
and springs to actuate the lock which
sends the same amount of power to each
veal no matter the traction condition it
essentially forms a solid axle
locking differential has the ability to
achieve a greater amount of traction
because the full amount of torque is
always available to one veal and is not
limited by the lower traction of a
single wheel
at higher speeds this is a drawback but
when off-roading or rock climbing it is
a huge advantage these type of
differentials are found on many off-road
vehicles and some performance cars
this can provide torque to move up to
the wheel with more traction
in various designs this will allow most
of the torque to reach the ground at any
given surface condition
it is simple and very effective
and it also provides a solution for
drifting situations where it is
desirable to keep the wheel speed
constant on the axle
one drawback of the locking differential
is that it would not allow for a
difference in wheel speed between the
right and left wheels that means
additional tire wear as well as tying up
within the drivetrain as a result
this type of differential uses a set of
sensors and electronics to receive data
from various matters road surface
throttle position steering system etc to
activate an electronically actuated
clutch and a controller
it is also known as an active
differential they operate in the most
efficient manner resulting in a truly
dynamic high performance driving
experience
a tort vectoring difference is found in
high performance rear wheel drive and
all-wheel drive vehicles
full-time four-wheel drive and all-wheel
drive have three differentials one in
front axle second in rear axle and third
differential is in the middle of
drivetrain which allows the wheels to
turn at the different speeds
this differential allows the outer wheel
to send more torque as it gets closer to
the turn
it enables complete control by the
designer the system can choose under
what conditions the vehicle will send
more torque to any one veal rather than
being reactive
it can send up to one hundred percent of
the potential torque to a wheel
though it does not have any drawbacks it
hits two things which are cost and
complexity
the torsion means torque sensing these
are types of limited slip differential
that use some accelerated gearing to
produce an impact without using a clutch
or fluid resistance
this can be achieved by adding a
collection of worm gears to a
conventional gear setup of the open
differential
these worm gears working on each axle
provide the necessary resistance to
enable torque transfer
this is achieved by having the worm
gears in a continuous mesh with each
other through connected spur gears
the continuous mesh between the two
sides of the differential has the
advantage of delivering quick torque
making it sensitive to changing road and
driving conditions
as soon as there is a speed difference
between them it starts sending more
torque to the slower wheel
also it reacts far more quickly than
limited slip differential
these systems do not require regular
maintenance because differential action
is dependent on friction throughout the
gear
when a wheel is in the air a torso
differential works similar to an open
differential and very little torque is
transferred to the drive axle
this is perfectly acceptable for road
use but it can be an issue for more
purpose-built vehicles on the track
this is a type of locked differential
and is known as a spool differential
it is welded permanently to a fixed axis
by an open gap
this is usually done in specific
situations where the features of lock
differential make it easier for both
wheels to spin simultaneously
this is generally not recommended
because the heat from welding can hazard
the component strength and increase the
risk of part failure
so what do you think about these
different types of differentials which
one is the best what are your thoughts
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