ANALYSIS OF AUTOMOBILE DIFFERENTIAL GEARGroup Members:Hamza Bin Omer (10M21A0318)Salman Saifuddin (10M21A0341)Shaik Ahmed (10M21A0346)Mohd Nasher Ahmed (10M21A0330)

What is a differential? Differential is a device capable of transmitting torque and rotation through three shafts, almost always used in one of two ways. In one of these, it receives one input and provides two outputs; this is found in most automobiles. In an automobile and other wheeled vehicles, the differential allows each of the driving wheels to rotate at different speeds, while supplying equal torque to each of them.

Purpose of a differentialThe differential is found on all modern cars and trucks, and also in many all-wheel-drive vehicles. These all-wheel-drive vehicles need a differential between each set of drive wheels, and they need one between the front and the back wheels as well, because the front wheels travel a different distance through a turn than the rear wheels.

Differential OverviewWhen turning, the inner and outer wheels have arcs of different turning radiiConsequently, the inner wheels travel less distance than the outer wheels

Differential OverviewBecause the turning paths of the inner and outer wheels are different, the wheels on both axles need to be able to spin independently of each otherA differential is used to allow the wheels to spin at different speeds

Differential FunctionWhen turning, the outer wheel turns at a high RPM with respect to the differential housingTherefore, the outer wheel axle turns its worm gear and its mating worm wheelThe mating worm wheels are meshed together by spur gearsPerfect Differentiation: as one wheel increases speed the other wheel decreases speed proportionallyTorque is maintained at both wheels while cornering

Working of Differantial

Torque Transfer in DifferentialThe torque bias ratio determines the amount of torque transferred and is dependant on the gear design5:1 ratio transfers 5 times the torque to the wheel with tractionIf one wheel loses all traction no torque is transferred to the wheel with traction

Different Types of DifferentialsOpen DifferentialLimited Slip Differential (LSD)Clutch LSDViscous Coupling LSDLocking LSDTorsen LSD

Schematic of an Open DifferentialThe Sun gear and Ring gear are identical and supply power to the drive axles. The planetary gears, or spider gears allow the axles to rotate at different speeds.

Parts of a differentialOur differential system consisted of eight unique parts. Six of these were used to construct the differential. These included crown gear, sungear, planet pinion, drive shaft and half shafts, which connect to the wheels. Two remaining parts made up our wheels.

Open DifferentialThe open Differential is a planetary gear set. Therefore the following equation applies

Open DifferentialThe number of teeth on the ring gear and sun gear are equal and the planetary gear formula is simplifiedThe angular velocity of the differential is equal to the average angular velocity of the axles

Open Differential ProblemsAs a result, if one wheel has little friction there is no resistance to its rotation and slipping occursThe slipping wheel will spin twice as fast as the differentialLeft rear tire slipping on sandy surface

Fortunately, the automobile differential solves this problem with only one transmission and one drive shaft for both driven wheels which called Torsen differential

The Torsen DifferentialThe Torsen Differential is capable of perfect differentiation

The Torsen Differential transfers power to the wheels with tractionTorque transferred to wheel with traction

Project overview Before we started our project, we researched the dimensions and overall shape of a differential system on internet and by visiting a car mechanic shop. After we acquired the necessary data, we started to construct our differential system. We reduced and normalized the dimensions that we collected for easier application of assembly.We scaled and normalized the dimensions we have gathered for easier drawing experience in Unigraphics.

Crown GearPinion gear

3-D MODELLING of Differential

Application of DifferentialsTorsen differentials are used in off-road and high performance all-wheel drive vehicles.

Torsens can also be handy on icy or dirt roads

Thank Q

*Open differential is the picture at the top leftClutch LSD is at the top rightTorsen Differential is the bottom pictureLocking LSD is at the bottom right

*Heres an open differential, the simplest, most basic differential. It is the most widely used differential because its the cheapest type to manufacture. *The slipping wheel will spin twice as fast as the differential because the angular velocity of the differential is equal to the average angular velocity of the axles