Study and prepare report on the constructional details of Automobile clutches

Aim

To study and prepare report on the constructional details, working principles and operation of the following

Automobile clutches:

• Coil Spring Clutch
• Diaphragm Spring Clutch
• Multi plate Clutch

Clutch:

The purpose of the clutch is to allow the driver to couple or decouple the engine and transmission.

When clutch is in engaged position, the engine power flows to the transmission through it (clutch).

When gears are to be changed while vehicle is running, the clutch permits temporary decoupling of engine and wheels so that gears can be shifted.

Principle:

• It operates on the principle of friction.
• When two surfaces are brought in contact and are held against each other due to friction between them, they can be used to transmit power.
• If one is rotated, then other also rotates.
• One surface is connected to engine and other to the transmission system of automobile.
• Thus, clutch is nothing but a combination of two friction surfaces.

Requirement:

1. It should ensure smooth engagement without grab or clatter.
2. It should have the clutch with two fold moment of inertia.
3. It should prevent gear clatter due to piston vibration caused by engine Crank shaft.
4. The effort required to disengage should be minimum.
5. It must be cost effective.
6. It must be easy to maintain and adjust.

Dismantling:Given- Single plate clutch assembly:

1. Mark the pressure plate and clutch cover position with respect to each other.
2. Place the clutch assembly on the clutch drive aligning the slot on the clutch finger with the thrust and seal on the pressure plate.
3. Compress the spring cups by clutch.
4. Loosen the mounting seat screw of the rotating plate on the retaining plate so removed.
5. Loosen the mounting seat screw of the clutch finger brackets and eccentric Pins

Inspection:Given- Single plate clutch assembly:

1. Visually check the fly wheel, ring gear and pressure for crankshaft.
2. Check the flatness of friction faces of the pressure plate with straight edge.
3. If flatness is not found within the specific limit without the pressure plate and flywheel can ground so not ground below the minimum specific thickness.
4. Check the free length and tension of pressure spring.
5. Check the pressure plate tension usually for any damage. Replace the clutch plate if any orsion spring found damaged.
6. Measure the thickness of clutch lever. Release if thickness of clutch lever is less than inimum specified.

Assembling:

1. Place the clutch fingers bush in the clutch fingers.
2. Fit the clutch bracket with eccentric pin.
3. Hand tighter the mounting set screw of clutch bracket.
4. Align the marks of clutch plate and pressure plate and place the clutch over the pressure plate.
5. Compress the spring with clutch finger.
6. Place the pressure pad on the pressure plate and tighten the pad mounting set screws.
7. Release the load from the spring and remove clutch cover assembly from the clutch jig.
8. Place the withdrawn plate, retaining plate on the clutch jig finger; tighten mounting set screws of the withdrawn plate.

Result:

Thus the given clutch assembly is dismantled, inspected and assembled

Viva Questions

1. What is the functioning of a clutch?Discuss various factors affecting the torque transmissions in a clutch
2. Explain the working of multi plate dry clutch
3. What are the essential properties required for a clutch facing materials
4. Explain in detail various causes of clutch troubles. How can these be remedied?
5. Compare the hydraulic and mechanical methods of operating clutches
6. Where and why we use multi plate clutches
7. Discuss the constructional features of a clutch plate
8. Describe semi and fully centrifugal clutches
9. With the help of a suitable diagram, describe the constructional features of a diaphragm type spring clutch
10. Derive mathematical expressions for the torque transmitted in a multiplate clutch with n no of plates
11. Compare dry and wet type of friction clutches.
12. Why are the clutch friction plates perforated?
13. What is the need of a clutch in an automobile?.
14. Why do we have springs in clutch friction plates?
15. What are the functions of a damper springs in a clutch driving disc
16. What is the necessity for cooling an engine?
17. Name various method of engine cooling?
18. Name the main components of water cooling system?
19. What is the function of radiator in cooling system?
20. What is the necessity of engine cooling?
21. State different S.A.E. viscosity rating of oil?
22. What is the multigrade oil?
23. Which solid lubricant is most commonly used in automobiles?
24. What is viscidity?
25. Give an example of synthetic lubricant?