1. Automobile Engineering
TRANSMISSION SYSTEMS

2. Details of Faculty Mr.Y.Sureshbabu,ME,(Phd),PDAuE,MISTE
Course PPT Prepared by:
Mr.Y.Sureshbabu,ME,(Phd),PDAuE,MISTE
Assistant Professor
Department of Mechanical Engineering
Sri Eshwar College of Engineering

3. Transmission system
It is a system by means of which power developed by the engine is transmitted to the road wheels to propel the vehicle

4. Purpose of transmission system
To transmit the power from engine to rear wheel smoothly without vibration.
It enables the reduction of wheel speed at different load condition.

5. Components of transmission system
Clutch
Gear box
Slip joint
Universal joint
Propeller shaft
Final drive
Differential unit
Rear axle

6. Components of transmission system

7. Clutch
clutch is a mechanism which enables the rotary motion of one shaft to be transmitted at will to second shaft

8. Clutch
Clutch is device which is used to connect or disconnect the engine from the rest of transmission elements
It is located between engine and gear box

10. Purpose of the Clutch
Allows engine to be disengaged from transmission for shifting gears and coming to a stop
Allows smooth engagement of engine to transmission
VHS AUTO
12/2001

11. Functions of clutch
To transmit the power from engine to rear wheel smoothly without jerking or shock
It is used to connect or disconnect the power Whenever the required time (gear Shifting time)

12. Types of clutch 1.Friction clutch (i) single plate (ii) Multi plate
(iii) cone clutch
2.centrifugalclutch
3. fluid flywheel

14. Friction Clutches
A clutch enables two co-axial shafts to be engaged or disengaged while at rest or in relative motion.

15. Types of Friction Clutches
Disc or plate clutches
Cone clutches
Centrifugal clutches

19. Single plate clutch (or) diaphragm clutch

20. Clutch Linkage

21. Clutch components Flywheel – mounts to the engine crankshaft
Clutch Disk – the friction material assembly that provides easy engagement and firm torque transference
Pressure Plate – also known as “Clutch Cover” – this is the spring-loaded surface that locks the clutch
Throw-out Bearing – also known as “Release Bearing”
Pilot bearing –centers and supports the transmission input shaft
Clutch Cable – mechanical release mechanism for some vehicles
Clutch Master Cylinder – force-multiplying cylinder for vehicles with hydraulic release mechanisms
Clutch Slave Cylinder – used along with a Master Cylinder for hydraulic release mechanisms

22. Clutch plate or friction plate
Torsional springs
Friction lining
Splined boss (hub)

23. Pressure plate and housing
Clutch housing
Diaphragm spring
Pressure plate

24. Clutch housing It is mounted on the flywheel
Flywheel is mounted on crank shaft
VHS AUTO
12/2001

25. Clutches Splines to input shaft Of transmission Clutch Disk or
44-3 Construction of the Clutch
Clutch Disk or
Friction Disk
VHS AUTO
12/2001

26. Pilot Bushing or bearing
12/2001

27. Clutches Flywheel bolts to crankshaft Pressure plate & cover
bolt to flywheel
Flywheel bolts
to crankshaft
When unbolting pressure plate from the
flywheel, remove bolts evenly as not to
bend the cover. REMEMBER, this is
under high spring pressure.
If there is a chance you will be reusing
pressure plate, make alignment marks
to flywheel to maintain proper balance
BEFORE removal
VHS AUTO
12/2001

28. Single plate clutch

30. Single-plate Friction Clutch (Disengaged position)
Flat-plate friction clutches
Friction plate
springs W
Driven shaft
W (axial thrust)
Driving shaft T T
Friction lining
Pressure plates
Single-plate Friction Clutch (Disengaged position)

31. Single-plate Friction Clutch (Engaged position)
Flat-plate friction clutches T
W (axial thrust) W
Friction plate
Friction lining
Pressure plates
springs
Driving shaft
Driven shaft
Single-plate Friction Clutch (Engaged position)

32. Multi plate clutches
In a multi plate clutch, the torque is transmitted by friction between several pairs of co-axial annular driving faces maintained in contact by an axial thrust.
Both sides of each plate are lined with friction material, so that a single-plate clutch has two pairs of driving faces in contact.

33. Multiple plate friction clutch
This type of clutch has several driving members interleaved with several driven members. It is used in motorcycles, automatic transmissions and in some diesel locomotives with mechanical transmission. It is also used in some electronically controlled all-wheel drive systems. It is the most common type of clutch on modern types of vehicles.

34. Multi plate clutches n = no. of pairs of driving faces.
Then, for a plate clutch, the maximum torque transmitted is

35. Multi plate clutch driver driven No. of driving pairs n = 6
Pressure plates
Friction plates 2 1 4 3 6 5
No. of driving
pairs n = 6

36. Cone clutch α = semi-apex angle of the cone w T = μWrm cosecα
Only one pair of driving surfaces is possible, n =1 α w
Driving shaft
Driven shaft
Friction lining
The maximum torque transmitted =
T = μWrm cosecα

37. 2.Centrifugal clutch F=mrω2 ω Driven shaft Driving shaft
Friction lining
Total friction torque , T = nµR(F-P)
F=mrω2 ω P R

38. 3.Fluid flywheel

39. Fluid flywheel
The torque converter is a device which multiplies the engine torque and also serves as automatic clutch to transfer the engine torque to the transmission.
The torque converter also functions like a fluid coupling.
There are three basic parts of torque converter
1.Stator
2.Rotor (also called turbine runner) and
3.Impeller

40. Fluid flywheel
The impeller is directly connected to the engine crankshaft and starts rotating as soon as the engine starts.
The impeller has vanes on its inner side and is filled with fluid.
The turbine runner is connected to the transmission input shaft. The stator is a device which is located between impeller and turbine runner and it is mounted on the one way clutch so as to provide the rotation in one direction only.
When the engine starts, the fluid inside the impeller starts rotating and as the speed increases it starts flowing outwards on the vane surface due to centrifugal force. Due to this high force, the fluid moves towards the runner and strikes its vanes causing it to rotate in the same direction. This rotates the transmission input shaft.
The fluid in the turbine hits the vanes of stator which causes the fluid to hit the vanes of impeller again and the cycle repeats.
This function of stator causes the generation of torque to approximately three times the normal transmission.

41. Thank You