Types of Transmission

Types of Transmission as possible as give In details

1. W e l come

2. Prepared by N i l e s h k umar M ishra E n r o llment n o : - 1 7 2 3 9 1 1 E ngineering : - M e c h anical E ngineering S u b j ect : - I n t e r n a l C o m b u stion E ngine ( I . C . E ) Guidance By Prof Shyam Gupta (Lecturer in Mechanical Engineering Department ) SWARIM STARTUP & INNOVATION UNIVERSITY AT-BHOYANRATHOD,GANDHINAGAR

3. P r e s e n tation o n T y p e s o f T r a n s m i ssion system

4. WHAT IS TRANSMISSION SYSTEM?? The Mechanism that transmits the power developed by the engine of the automobile to the driving wheel is called the transmission system (or Power Train) 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.

5. COMPONENTS OF TRANSMISSION SYSTEM

6. PRINCIPLES OF TRANSMISSION S Y S TEM The torque produced by a petrol or diesel engine is not maximum at the start. It increases with increases of speed until at about 50 to 60% of the engine speed providing maximum H.P., maximum torque value is reached. In this case, some means must be used to increase or multiply the engine torque for starting vehicles from rest.

7. PRINCIPLES OF TRANSMISSION S Y S T EM Transmission means should provided usually a starting torque of about 13 to 15 times that of engine required at the road wheels when the clutch is engaged because the engine power is a function of torque and it’s speed. Therefore for a constant power output torque varies inversely with torque. Power = 2 π N T/ 60000 k For constant Power, T α 1/N

8. PURPOSE OF TRANSMISSION SYSTEM It enables engine to be disconnected from the r unning driving wheels. I t enables the running engine to be connected to t he driving wheel smoothly. It enables the driving wheels to be driven at different speeds. It enables turning of the drive round through 90 d egree. It enables the reduction of engine speed in the ratio of 4:1 incase of passenger car and in a greater ratio incase of lorries. It enables leverage between engine and wheels to be varied

9. Requirement of transmission system To provide for disconnecting the engine from the driving wheels When engine is running , connect the driving wheels to engine smoothly without shock Leverage between engine and driving wheels to be varied Enable the driving wheels to rotate at different speeds. Provide relative movement between engine and riving wheels To provide high torque at the time of starting the engine, hill climbing and accelerating

10. Transmission System - Layout

11. TYPES OF TRANSMISSION SYSTEM Fully automatic Transmission Semi-Automatic Transmission Continuously Variable Transmission Manual transmission .

12. Automatic Transmission Automatic transmission is a type of motor vehicle transmission that can automatically change the gear ratios as the vehicle moves , freeing the driver from having to shift gears manually An automatic transmission can automatically change gear ratios as the vehicle moves, freeing the driver from having to shift gears manually. The most popular form found in automobiles is the hydraulic automatic transmission. This system uses a fluid coupling in place of a friction clutch, and accomplishes gear changes by locking and unlocking a system of planetary gears.

13. A u t o matic t r ansmission Torque Converter : A type of fluid coupling, hydraulically connecting the engine to the transmission. This takes the place of a friction clutch in a clutch in a manual transmission. It transmits and decouples the engine the engine power to the planetary gears, allowing the vehicle to come to vehicle to come to stop with the engine still running without stalling.

14. Continuously Variable Transmission CVT provides infinite number of gear ratios (between a minimum & a maximum). Shifts automatically with an infinite number of ratios Seamless power delivery no torque interruption & power loss

15. Manual transmission Components of Manual Transmission Clutch G earbox Differential

16. W h a t i s a c l u t ch It is a device which carries a power form engine to drive wheel through shafts. It is located between flywheel and gearbox

17. Construction of clutch D I A P H R A G M C L U T C H

18. H o w it's work E n g a g e d

19. W h en the clutch is engaged (Means when you not pressed clutch pedal), the clutch plate is gripped between the flywheel and pressure plate. The friction linings are on both the sides of the clutch plate. The clutch plate revolves the flywheel because of the friction between the flywheel, clutch plate and the pressure plate. The clutch shaft also revolves with clutch plate. Clutch shaft is connected to the transmission gearbox. Now, the engine power is transmitted to the crankshaft and then to the clutch shaft and gearbox. Clutch always engaged due to the spring forces.

20. D i s e n gaged

21. When the clutch is disengaged (Means when you pressed clutch pedal), the pressure plate moves back against the force of the springs, and the clutch plate becomes free between the flywheel and the pressure plate. The Flywheel always rotating with crankshaft. Then, Clutch shaft speed reduces slowly and stops rotating.

22. Types of Clutches

23. 1 : - Single plate clutch

24. Single plate clutch is the most common type of clutch plate used in automobiles. It consists only one clutch plate which is mounted on the splines of the clutch plate. The Flywheel is mounted on the engine crankshaft and rotates with it.

25. Working Principle The pressure plate is bolted to the flywheel through clutch springs and is free to slide (Move) on the clutch shaft when the clutch pedal is operated (Engage and Disengage).

26. A d v a n t a ge a n d d i s advantag Single Plate Clutch is not expensive. It has little maintenance. Gear shifting is easier compare to cone clutch because pedal movement is less. Single Plate Clutch is more reliable because it does’t suffer from disadvantages of binding of cone. Greater force required to disengage because the springs have to be more stiff.

27. Applications Single plate clutches are used in trucks, buses, and cars etc. Single plate clutches used where large radial space is available. As sufficient surface area is available for the heat dissipation in Single plate clutches, no cooling oil is required. Therefore, single plate clutches are dry type.

28. 2 : - Multi plate clutch

29. Multi-Plate Clutch consists of a number of clutch plates instead of only one clutch plate like in the Single plate clutch. Friction surface also increased because of a number of clutch plates. Because of a number of friction surfaces, The capacity of the clutch to transmit torque is also increased.

30. Working Principle The plates are alternately fitted to the engine crankshaft and gearbox shaft. They are firmly pressed by strong coil springs and assembled in a drum type casing. Each of the alternate clutch plate slides on the grooves on the flywheel and the other slides on splines on the pressure plate. Thus, each alternate clutch plate has inner and outer splines.

31. The working of Multi-plate clutch is the same as a single plate clutch by operating the clutch pedal. The pressure plate rotates with the flywheel and It press against the friction plate. This forces the clutch plate and clutch shaft as well. When the clutch pedal is pressed, The clutch plates are released and flywheel still rotating because they are not fully pressed by the pressure plate. Thus clutch shaft also stops rotating.

32. Types of Multi-Plate Clutch Multi-Plate Clutches are two types. These clutches are used in automatic transmission. Multi-Plate wet Clutch When the clutch is operated in an oil bath, it is called a wet clutch. In this clutch plate, Thin plates of steel fitted to engine shaft (means drive shaft) and phosphor Bronze plates are fitted to the clutch shaft (means driven shaft). Multi-plate clutch has grooved surfaces for allowing the oil to flow through them. These grooves decrease heat generated when engage and disengage operations. Multi-Plate dry Clutch When the clutch is operated dry it is called dry clutch. This clutch has plates with friction material the same as in single plate clutch.

33. Advantages a n d d i s a d vantage Multi-plate clutch transmits high torque because of the number of friction surfaces. The overall diameter of Multi-plate clutch is reduced compare to the single plate clutch and transmit the same torque. It is used in heavy vehicle and racing cars to transmit high torque. It is used in two wheelers where there is a limitation of space. Multi-plate clutches are too expensive. Multi-plate clutches are heavy.

34. Applications The multi-plate clutches are used in racing cars, and motorcycles. The multi-plate clutch is used in heavy commercial vehicles to transmit high torque

35. 3 : - Cone clutch Cone Clutch having friction surfaces in the form of a cone.
The engine crankshaft consists of a female cone. The male cone is mounted on the splined clutch shaft. Cone clutch has friction surfaces on the conical portion. The male cone can easily slide on the clutch shaft.

36. W o r k ing p r i n ciple When the clutch is engaged (When the clutch pedal is not pressed) the friction surfaces of the male cone are in contact with the female cone due to the force of the spring. The power is transmitted from engine to transmission. When the clutch is disengaged (When the clutch pedal is pressed) the male cone slides against the spring force. Now, the power does not transmit from the engine.

37. A d v antage a n d disadvantage The normal force acting on the friction surfaces is greater than the axial force. Like in Single plate clutch, the normal force acting on the friction surfaces is equal to the axial force. The main disadvantage of Cone clutch is If the angle of the cone is made smaller than 200 the male cone tends to bind in the female cone and it becomes difficult to disengage the clutch.

38. A p p l ication Cone clutch is used in low peripheral speed applications. Cone clutch is common in automobiles and other combustion engine transmissions. It is also used in very specialist transmissions in racing, rallying, or in extreme off-road vehicles. Cone clutches are used in power boats. Small cone clutches are used in synchronizer mechanisms in manual transmissions.

39. 4 : - Electromagnetic clutch

40. 5 : - C entrifugal clutch

41. Centrifugal Clutch uses centrifugal force instead of spring force. This clutch is always in engaged position. And it does not have a clutch pedal to operate it. Centrifugal clutch is automatically operated with engine speed. The vehicle can be stopped in gear without stalling (stop running) the engine. And also the gear can be started in any gear by pressing the accelerator pedal.

42. Working Principle A centrifugal clutch works on centrifugal force. One side of clutch connected to the engine crankshaft and other side connected to gearbox shaft, chain, or belt. As engine R.P.M. (Revolutions Per Minute) increases, weighted arms in the clutch swing outward and force the clutch to engage position The most common Centrifugal Clutches have friction pads or shoes radially mounted that engage the inside of the rim of the housing

43. Working of Centrifugal Clutch On the center shaft (Driving or input shaft) there are an assorted amount of extension springs, which connect to a clutch shoe. When the center shaft (Driving shaft) spins fast enough, the springs extend causing the clutch shoes to engage the friction face. It can be compared to a drum brake in reverse order. The weighted arms force these disks together and engage the clutch and power transmitted.

44. W h en the engine shaft reaches a certain RPM (Revolutions Per Minute), the clutch activates, working almost like a continuously variable transmission. As the load increases the R.P.M. drops thereby disengaging the clutch and letting the RPM rise again and reengaging the clutch. If tuned properly, the clutch will tend to keep the engine at or near the torque peak of the engine . These results in a fair bit of waste heat, but over a broad range of speeds it is much more useful than a direct drive in many applications like mopeds and go-karts etc. Weaker spring or heavier shoes will cause the clutch to engage at a lower R.P.M. while a stronger spring or lighter shoes will cause the clutch to engage at a higher R.P.M.

45. A d v a n tage a n d disadvantage Centrifugal Clutch has less maintenance. It is not expensive. It does not need clutch pedal because it’s automatic. It helps to prevent the engine from stalling (stop running). Due to slipping and friction, There is a loss of power. It does not transfer a high amount of power because Centrifugal clutch shoes slip in heavy load condition. It causes overheating problems. Its engagement and disengagements depend upon the speed of the driving shaft.

46. Applications The centrifugal clutch is mainly used in mopeds and go-karts. It is also used in mini bikes, chainsaw, and lawn mowers etc. It is used in boats and paramotors to keep the engine running during stalling (stop running) and disengage loads during starting and idling.

47. Gearbox

48. Gear ratio I t 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)

49. Types of gearbox Constant mesh type Synchromesh type Sliding mesh type

50. 1 : - Constant mesh type

51. D O G GEAR

52. 2 : - Synchromesh type

53. 3 : - Sliding mesh type

54. Sliding mesh 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

55. Constant mesh The gears on the main shaft and lay shaft are I n 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

56. Synchro mesh Gears are in constant mesh I nstead 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

57. D i f f erential Differential is a mechanism which provide different speed to tyres at cornering. I t provides equal torque on both tyre not power. From the differential, power is transmitted to the rear axles and from there to the wheels .

58. T h e E n d