INSTITUTE OF AVIATION ENGINEERING

Transmission System

By : Kareem EL ShebanyAhmed Ashraf

The word ‘Transmission’ means the whole of the mechanism that transmits the power from the engine crankshaft to the rear wheels, providing the suitable variations of the engine torque at the road wheels, whenever required.

What is a Transmission?

Transmission System

Manual transmission

Fully automatic Transmission

Semi-Automatic Transmission

Continuously Variable Transmission

Types of Transmission

Components of Manual Transmission:

Clutch

Gearbox

Differential

Manual Transmission

It is a device which carries a power form engine to drive wheel through shafts.

It is located between flywheel and gearbox

What is clutch ?

Construction of Clutch:

How it Works?

Types of Clutches

1 -Single Plate Clutch

2 -Multi-Plate Clutch

3 -Cone Clutch

4 -Electromagnetic Clutch

5 -Centrifugal Clutch

Gearbox

It is the ratio of the no. of teeth on the driven wheel to no. of teeth on the driver wheel or the speed of rotation of the driver to the driven .

For example:

Gear ratio: G=(20/10)=2:1

(smaller gear is the driver)

Gear Ratio:

20 Teeth 10

Teeth

Constant mesh type

Synchromesh type

Sliding mesh type

Types of Gearbox

Constant Mesh Type

Dog Gear

Synchromesh type Gearbox

Synchro collar

Sliding Mesh type

o First Gear

o Second Gear

o Third Gear

o Fourth Gear

o Reverse Gear

Oldest and the simplest type of transmission Spur gears were used Main shaft gears splined to the main shaft Gear shift is achieved by sliding the gears on

main shaft Low mechanical efficiency Noisy operation

Sliding Mesh

The gears on the main shaft and lay shaft are in constant mesh

Main shaft gears are free to rotate Gear engagement is achieved by dog clutches

splined to the main shaft Helical gears are used

Constant Mesh

Gears are in constant mesh Instead of dog clutch synchroniser unit is used Each pair of gear has one synchroniser unit Gears are first brought into frictional contact

which equalizes their speed after which the actual engagement takes place

Synchro Mesh

Differential

Differential is a mechanism which provide different speed to tyres at cornering.

It provides equal torque on both tyre not power.

From the differential, power is transmitted to the rear axles and from there to the wheels .

Differential

Open Differential Limited-Slip Differential Locking Differential Auto Limited-Slip Differential

Types of Differentials