1. ON –LINE LECTURE
By
Dr. R. C. Salunkhe
Assistant Prof.
Deptt. of FMPE, CAET, Godhra
Course Code : FMPE-3.5.2
Course Title : Tractor Systems and Controls
Topic : Clutch System
for
B. Tech Students of CAET Godhra
Semester: 5th
2. Clutch System
Function of Clutch
• The tractor is required to do many jobs, and according to
the requirement, the speed and torques are varied with
the help of the gear box.
• To change the various speeds or keep the gear box in the
neutral position, it is necessary to move gears from one
position to another, to engage or disengage them with
mating gears.
• The shifting of gears can only be possible when the driving
shaft is stationary.
• To make the driving shaft stationary it is necessary to
introduce a device between the engine and the
transmission which can allow the operator to engage or
disengage the transmission system from the engine.
• This device is known as the Clutch
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
3. Principle of operation of clutch
• Its works on the principal of friction.
• When one stationary surface is brought into
contact with a rotating surface, the stationary
surface also starts rotating.
• A driven plate mounted on a transmission shaft
enclosed in between two driving plates. When
the driving plates are away, they will rotate
together, but the driven plate will remain
stationary.
• Now, if by some means the two driving plates
are brought nearer, the driven plate will be
pressed in between the two rotating plates it
will start to rotate.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
4. • In actual practice one of the driving plates is the
flywheel and the other is known as the pressure
plate.
• The driven plate is a clutch plate made of
frictional material and directly mounted on the
splined end of the clutch shaft.
• In normal running condition, the pressure
springs keep the pressure plate in contact with
the clutch plate.
• When the foot pedal is depressed, the pressures
of springs allowing the clutch plate to move
backward thus the clutch shaft become
stationary.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
5. Principle of operation of clutch
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
7. Types of Clutch
Used in Power tiller
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
8. Main Components of Clutch System
(a) Clutch Plate
• There are two types of clutch plates on tractors : (i)
Solid-hub type and (ii) Flexible-hub type.
(i) Solid-hub type:
• In the solid-hub design the hub and plate are
fastened together securely and there is no
movement in the unit.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
9. (ii)Flexible-hub type:
• In the flexible hub-type has torsion springs and
friction disc between the plate and the hub.
• This design permits the facing and plate to
rotate with respect to the hub to the limit of the
compression spring.
• The action of springs serves to reduce torsional
vibrations and shocks between the engine and
the transmission during the clutch operation.
• These flexible clutch plates are slightly “dished”
when manufactured.
• This dishing allows smooth engagement of the
clutch facing with the flywheel.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
10. • Sometimes, instead of dishing the plates, cushion
springs are utilized.
• This cushion springs decreases in thickness by 1.2 to
1.4 mm when the clutch is engaged and thus serves
the same purpose as that required by dishing.
• The clutch plate hub is internally splined and mounts
on the splined part of the clutch shaft whose front
end rests on the pilot bearing placed in the flywheel.
• Clutch Facing Material: Examples are
- Woven asbestos fibre or molded asbestos fibre
rivetted on both sides of disc.
- Molded facing are made from asbestos fibre and
stach,
-Ceramic material, clay and metal substance which is
oven backed
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
11. (b) Pressure-Plate Assembly
• This assembly consists of a steel cover and a pressure
plate loaded with a number of thrust springs.
• The pressure plate carries three release levers which
pivot on floating pins retained by eye bolts.
• Adjusting nuts are screwed to the eye bolts which
pass through the clutch cover and are secured by
staking.
• Struts are interposed between lugs on the pressure
plate and the outer ends of release levers.
• Anti-rattle springs are fitted between release levers
and the cover.
• A release lever plate is fixed to release levers with
retainer springs.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
12. (c) Clutch shaft
• The front end of the shaft is smaller in dimension
and is supported on the pilot bearing in the engine
crankshaft flange. On the splined part of the shaft,
the clutch disc moves.
(d) Pilot bearing
• This may be a self-lubricated sealed ball bearing or
a needle bearing.
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
13. Components of clutch system
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
14. Working of single plate clutch system
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
15. Trouble –shooting of clutch system
1.Clutch drags: When pedal is depressed to disengage the
system, even driven plate rotates.
Possible causes Remedies
(a) Dirt or other foreign material in the
clutch plate
clean
(b) Improper pedal adjustment Adjust clutch pedal
free play
(c) Warped clutch plate Replace new lining
(d) Damaged pressure plate or clutch plate Install new parts
(e) Splines of the shaft tight or burred Clean and apply
grease
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
16. Trouble –shooting of clutch system
2. Clutch Slippage: Lack of firm contact between flywheel,
pressure plate and clutch is known as slip and will result in
disproportionate rise in vehicle speed when engine speed goes
suddenly high
Possible causes Remedies
(a) Oil or grease on lining Clean with petrol or replace
(b) Glazed surface of lining caused due
to constant rubbing of dust particles
Replace new lining
(c) Bent or tight release shaft Straighten and free the shaft
(d) Lack of clutch freeplay Adjust
(e) Worn out lining Replace
(f) Uneven adjustment of release lever
(finger)
Adjust properly
(g) Weak pressure spring Fit new set of springs
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
17. Trouble –shooting of clutch system
3. Clutch grabs: during engagement of the clutch the
vehicle moves with series of jerks.
Possible causes Remedies
(a) Oil or grease on lining Clean
(b) Glazed lining Replace
(c) Damaged pressure plate Replace
(d) Splines of the shaft or clutch
plate hub tight or burred
Clean and apply grease
(e) Bent or release shaft Straighten and free
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
18. Trouble –shooting of clutch system
4. Clutch noises:
Possible causes Remedies
(a) Weak or broken pressure
springs
Replace affected springs
(b) Excessive worn splines on the
shaft and clutch plate
Replace affected part
(c) Worn or dry release
bearings/pilot bearings
Replace affected part
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
19. Trouble –shooting of clutch system
5. Abnormal lining wear
Possible causes Remedies
(a) Insufficient pedal free play Adjust
(b) Overriding of the clutch
pedal
Caution the operator to
avoid this
(c) Weak or broken pressure
spring incapable of pressing
pressure plate against clutch
plate
Replace
(d) Warped pressure plate Replace
(e) Incorrect adjustment of
clutch fingers
Adjust properly
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
20. Design Problems on Clutch System
• Clutch design problem.docx
Write:
Practical No. 1 - Transmission system
Practical No. 2 - Clutch system
Assignment no.1- Design Problems on Clutch
System
Prepared by: Dr. R. C. Salunkhe, Assi. Prof. Deptt. of FMPE, CAET,AAU, Godhra
