The document provides an in-depth overview of tractors, detailing their types, transmission systems, hydraulic systems, and historical development in agriculture. It classifies tractors based on power, structure, and purpose, discussing major components like clutches, gearboxes, and hydraulic controls. Additionally, it covers the evolution of tractor technology and presents guidelines for selecting suitable tractors based on land, cropping patterns, and other parameters.

1. Tractors- Types
Transmission system- Clutch, Gearbox,
Differential and Final drive - Hydraulic
system
Tractor is a self propelled power unit having wheels or
tracks for operating agricultural implements and machines.
Its engine is also used as a prime mover for active tools
and stationary farm machinery through PTO or belt pulley.
Lecture - 04

2. Functions of tractor
Tractive power
- To pull and haul
Rotative power
To rotate
Hydraulic power
To lift and lower
propellsion power
To travel
Tractor power

3. TRACTORS
By use
By kind of prime
movers
By travelling
systems
By driving
systems
Farm
tractor
Forestry
tractor
Industrial
tractor
Military
tractor
I.C.E.
tractor
Steam
tractor
Electric
tractor
Wheel
type
Track/
crawler type
Half-track
type
Two wheel
drive
Four wheel
drive

4. Tractors : Classified based on
its power
• Up to 20 hp
• 21 - 30 hp
• 31 - 40 hp
• 50 hp & above
• 60 % tractor population in India is 31-40 hp
• In 1961 tractor manufacturing was started in India –
M/s eicher Good Earth

5. Tractor Development
• 1890 – George H. Harris of Chicago – patented a tractor
• 1906 – Gasoline Tractor – Charles W. Hart and Charles H. Parr, Iowa
• 1908 – First Winnipeg tractor trials were held
• 1911 – First tractor demo was held at Omaha (Nebraska)
• 1915-1919 – PTO was introduced
• 1920-1924 – All purpose tractor was developed
• 1936-1937 – Diesel engine and pneumatic tyre wheels were introduced
• 1950-1960 – Large scale manufacture of tractors
• 1960-1961 – Tractor manufacture was started in India – M/s eicher Good Earth
• 1962-1970 – TAFE- Madras, Hindustan- Baroda, Escorts - Faridabad, International Harvester- Bombay
• 1971 – Ford Tractor by Escorts
• 1973 – HMT Tractor
• 1974 – Pitti and Kirlosker Tractors
• 1975 – Harsha Tractors
• 1981 – Auto Tractors
• 1982 – Universal Tractors
• 1983-2003 – GCTL, MM, Sonalika, VST, L&T, Bajaj, etc
• Later – John Deere, New Holland, etc.

6. Tractor Journey

7. Parameters Automobile Tractor
Speed upto 200 kmph upto 35 kmph
Torque very low high
Total reduction ratio 16:1 100-200:1
Suspension Spring Without spring
Gear Synchromesh Sliding / constant/ syncro
No. of forward gears upto 5 upto 20
No. of reverse gears 1 upto 8
Front / Rear tyre size Same Different
Vehicle type On - road Off - road
Difference : Automobile vs Tractor

8. Parameters Automobile Tractor
Structure Normally closed Open
Engine type Diesel / Petrol Diesel
Accelerator Foot operated Foot / hand operated
Difference : Automobile vs tractor
Hydraulics Not available Available

9. CLASSIFICATION OF TRACTOR TYPES
S.No Parameters Types of tractors
1. Number of axles * one – Walking
* Two – Conventional, riding
2. Number of driven Axles •One –Conventional and Walking
* Two four wheel drive
3. Ground drive elements *Wheels and tyres,Lungs, strakes
* Track- Crawler,Track laying
4. Use of wheels *Traction –conventional
* Propulsion/cultivation-Power tiller

10. Classification
• Basis of Structural Design
– Wheel Tractor: Tractors, having three or four
pneumatic wheels are called Wheel Tractors. Four
wheel tractors are most common/popular.
– Crawler Tractor:. This is also called Track
Type or Chain Type Tractor. In such tractors, there is
endless chain or track in place of pneumatic wheels.
– Walking Tractor: Power Tiller is a walking
type tractor. This tractor is usually fitted with two
wheels. The direction of travel and its controls for field
operation is performed by the operator, walking behind
the tractor.

11. Classification of Wheel Tractors
Based on Purpose
• General Purpose Tractor: It is
used for major farm operations such as ploughing,
harrowing, sowing, harvesting and transport work.
This tractors have (i) low ground clearance, (ii)
increased engine power, (iii) good adhesion and (iv)
wide tyres.
• Row Crop Tractor: It is used for
furrow crop cultivation. Such tractor is provided with
replaceable driving wheels of different tread widths.
It has high ground clearance to save damage of
crops. Wide wheel track can be adjusted to suit
inter row distance.
• Special Purpose Tractor: It is
used for definite jobs like cotton fields, marshy land,
hill sides, garden, etc,. Special designs are there for
special purpose tractors.

12. Standard row crop tractor
• The Standard tractor was developed primarily for traction. It is
characterized by a drive through the two rear wheels, with
centre of gravity located at approximately one third the
wheelbase ahead of the rear wheels.
 Row crop tractors, in addition to
being suitable for traction work,
are especially adapted for use in
row crops, allowing quick
attachment of various tillage and
cultivation tools as well as
implements for such tasks as
mowing and handling forages.

13. Four wheel drive with smaller front steering
wheel tractor
• The Four wheel drive tractor with smaller front
steering wheel is simply a standard or a row crop
tractor with the front wheels also being driven. In
regard to price and traction, this type of tractor falls
between the standard and the four wheel drive tractor
with equal sized wheels. This tractor has become
particularly popular in Japan because of its excellent
steering and traction characteristics in soft, wet rice
fields

14. Four wheel drive with equal sized wheels
and articulated frame steering tractor
• Four wheel drive tractor have been developed so as
to be able to produce more drawbar power. The size
of 4WD tractors varies from 100 kW to more than
3000 kW. Four wheel drive tractors can be steered by
pivoting the tractor in the center or steering wheels.

15. Lawn and garden tractor
• Lawn and garden tractors have power output of less
than 15 kW and are primarily designed for the care of
large lawns. They can tow or carry a lawn mower, a
sweeper, a snow blower, a bulldozer blade and many
other attachments. Because these tractors have very
low clearance and are designed for light duty use, they
are not generally used for agricultural production.

16. Utility tractor
• Utility tractors, generally have less clearance than standard
or row crop tractors. They are used for many jobs on the
farm or ranch and are often equipped with a front loader.
Atypical used for such a tractor is clearing a feedlot.

17. Multipurpose / Reversible tractor
 A Multipurpose tractor is designed to operate
in either direction. It not only carries the
implement but also furnishes the power.

18. Skid steer loader tractor
• Industrial use but it is often used in agriculture
when turning room is restricted, such as in a dairy
or a fruit storage building.
• The skid steer cones from the method of turning,
which is exactly like that of a crawler.
• The wheels on one side are braked or reverse,
causing the tractor to skid on order to turn.

19. Selection of Tractor - Guidelines
Land holding 1 hp for 2 ha
Cropping Pattern 1.5 hp / ha (more than one crop)
Soil condition less wheel base or high ground
clearance, light or heavy soil
Climatic condition dry/hot/high altitude – air cooled.
Else water cooled
Repair facilities availability in local areas
Running cost less specific fuel consumption.
Specific fuel consumption is the
amount of fuel consumed by a
tractor or a vehicle for each unit of
power output).
Initial cost and resale value economic investment
Test Report Standards are adopted in
manufacture

20. Traction Wheels

21. Tractor Drive Line

23. Tractor Drive Line

24. Example
for a
Drive Line

25. Tractor Cut Section View & Drive
Line

26. Wheel Tractor – “Components”
• I.C. Engine
• Clutch
• Transmission Gears
• Differential unit
• Final drive
• Rear wheels
• Front Wheels
• Steering mechanism
• Hydraulic controls and hitch system
• Brakes
• Power take off (PTO) unit
• Pulley -
• Draw bar -
• Control panel -
Tractor Systems

27. 27

28. Tractor Clutch
Clutch is a device, used to connect and disconnect the tractor engine from
the transmission gears and the drive wheels. Clutch transmits power by
means of friction between driving members and driven members:
Types: Friction clutch, Dog clutch and Fluid coupling

29. Clutch

30. Sliding Gear
Transmission
If the engine power is constant, it is
obvious that for higher torque at wheels,
low spped is required and vice versa. So
the gear box is fitted between engine
and rear wheel for variable torque and
speed.

31. Constant Mesh
Transmission System
Synchronised
Trasmission System

32. Differential Drive

33. Differential
Differential unit is a special arrangement of gears to permit
one of the rear wheels of the tractor to rotate slower or
faster than the other.

34. Final Drive System
Final drive is a gear reduction unit in the power
trains between differential and the drive wheels.
It transmits the power finally to the rear axle
and the wheels.

35. Tractor Brake
Brake is used to stop or slow down the motion of the
tractor. It is mounted on the driving axle and operated by
two independent pedals. Each pedal can be operated
independently to assist the turning of tractor during the
field work or locked together by means of a lock. –
Mechanical brake / Hydraulic brake

36. Steering System
The System, governing the angular movement of
front wheels of a tractor is called Steering system.

37. Steering System

38. Hydraulic and Three Point Hitch
It is a mechanism in a tractor to raise, hold or lower the mounted or
semi-mounted equipment by hydraulic means.
Position Control: Constant depth of ploughing is maintained by
automatic adjustment o draft of tractor. The control lever can be operated
directly by the driver to raise or lower or hold the implement, mounted on
the linkage at any chosen height.

39. Draft Control: The working depth of any implement can be
controlled continuously without the need for a depth wheel on the
implement. The hydraulic control valve reacts to the changes in the
loading in either the top or lower links which are due to changes in
the draft or pull required by the implement. If the implement goes too
deep its draft increases and is sensed through top or lower links.
The control system then raises the implement until the draft is back
to the present level and the implement is at the original depth again
using the draft control system

40. Tractor with Mounted Implement

41. 3-Point Hitch

43. Draw Bar & PTO
PTO-Power Take Off:
540±10 rpm or 1000±10 rpm

44. 6 splines & 21
splines
Propeller
Shaft
Tractor PTO

45. PTO / Belt Pulley
• PTO – is a part of transmission system. It has a shaft, a
shield and a cover. The shaft is externally splined to
transmit tortional power to another machine. As per
ASAE standards PTO speed is 540 ± 10 rpm. Another
PTO is at 1000 ± 10 rpm.
• Belt Pulley – to transmit power from the tractor to
stationary machine.

46. Control panel of Tractor has
• Main switch
• Throttle
• Decompression lever
• Hour meter
• Light switch
• Horn button
• Battery charging indicator
• Oil pressure indicator
• Water temperature gauge

47. Terms associated with Tractor
• Wheel base – horizontal distance between the
front and rear wheels
• Ground clearance – ht of lowest point of tractor
from ground
• Track – distance between the two wheels of the
tractor on the same axle at ground contact.
• Turning space – diameter of the smallest circle
– outer most point of tractor at < 2 km/hr with
steering wheels in full lock
• Cage wheels – spaced cross bars – for more
traction in wet field

48. Wheel Base
Measurement of center of
hubs of front wheels to
center of hubs of rear wheel

49. Power take-off horse power (PTO hp)
It is the power delivered by a tractor through its
PTO shaft. In general, the belt and PTO horse power of a
tractor will approximately be the same. It is about 80-85 %
of tractor engine power.
Drawbar horse power (DB hp):
It is the power of a tractor measured at the end of
the drawbar. It is that power which is available for pulling
loads. It is 50-55 % of engine power.

50. Crawler tractor
• It is less important today in agriculture that it once was. It is
usually used on very soft soil or where stability of the wheel
tractor is problem. At one time crawler tractors were larger than
wheel tractors and thus they were used on some large farms.
 Track frame assembly
 Track chain
 Steering clutch
 Steering brake

51. Bull Dozer:
Primarily land leveling is done with the equipment
known as bull dozer. It is a high capacity self propelled field
machine for doing land development works. It is a crawler
tractor provided with two endless track instead of pneumatic
wheels. In the front it is provided with an adjustable dozer
blade for digging and moving the soil. For road transport, it
has to be mounted on a special trailer to avoid damage to tar or
concrete roads because of crawler tracks.

52. Power tiller or Walking tractor
• A Power tiller tractor is a two
wheeled tractor guided by
hand and used commonly in
the rice growing regions. The
power tiller is equipped with a
rotary tiller and powered by a
horizontal single cylinder
engine of 5 to 12 kW.

53. Depending upon the mode of operation, three
types of power tillers are there -
•Pull Type – This type of power tiller is used to pull
different types of farm implements.
•Tilling Type – This type of power tiller used to
drive the tilling device, such as rotary tiller or a
screw blade.
•General purpose Type – This type of power tiller
is used for number of farm operations, including the
types defined under pull type and tilling types.
•The power tiller now being marketed in our country
belongs to the general purpose type.

54. Power Tiller
• Engine
• Transmission gears
• Clutch
• Brakes
• Rotary unit
– Main Clutch-Transmission gears-Brakes-
Wheels-Rotary unit

55. Power Tiller - History
• 1920 – Concept
– Japan is the first country
• 1947 – First successful power tiller developed in Japan
• 1963 – Introduced in India
• 1962 – India – makes like Iseki, Sato, Krishi, Kubota,
Yanmar, Mitsubishi, etc manufactured

56. Uses of Power Tiller:
• Plowing
• Sowing
• Weeding & interculture
• Spraying
• Harvesting
• Operation of Thresher
• Hauling – Transport, etc

57. PT Uses

58. PT Uses

59. Thank You & Good Luck