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1. Dozer
A dozer is a tractor unit which has a substantial metal
plate (known as a blade).
The blade used to push large quantities of soil, sand,
rubble, or other such material during construction or
conversion work
Dozers typically equipped at the rear with a claw like
device (known as a ripper) to loosen densely compacted
materials

2. Applications of dozer
The typical applications of dozer used in many
construction projects are
Land clearing
Dozing (pushing materials)
Ripping
Towing other pieces of construction equipment, and
Assisting scrapers in loading

3. Dozing

4. Leveling

5. Ripping

6. Land Cleaning

7. Assisting scraper in loading

8. Types of dozers
1 Crawler type (track laying) tractor
2 Wheel type tractor
A Single axle
B Two axle
i. Single axle drive
ii. Two axle drive

9. Crawler dozer
• A crawler dozer is the machine that travels on
endless chains called tracks driven by sprockets and
has been developed as the most powerful and
compact machine for pulling and pushing of all
purpose

10. major components dozer
• The major components of dozers are vary among
makes, modes, and configurations
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11. Major components of dozer

12. Engine
• Dozers are powered by diesel engine. The engine
provides power to all operating systems

13. Blades
• The bulldozer blade is a heavy metal plate on the front of the tractor,
used to push objects, and shoving sand, soil and debris.
Universal Blade (U)
• This blade is best for lighter or relatively easily dozed material.
• The large wings on this blade make it the most efficient for moving
large loads over a long distance

14. Semi-Universal (SU)
• Semi-Universal blades combine the desirable
characteristics of U-blades and S-blades into one.
• The addition of short wings increases blade capacity.
• The wings provide improved load retention while
maintaining the blade's ability to penetrate and load
quickly in tightly packed material, and to handle a
wide variety of materials in production applications

15. Straight (S)
• Straight blades provide excellent versatility.
• Because they are smaller than SU- or U-blades, they
are easier to maneuver and can handle a wider range of
materials.
• S-blades are more aggressive in penetrating and
obtaining a blade load, They can handle heavy material
easily

16. Blade- Dozer performance
Bull dozers pushing potential is measured by two
standard ratios;
1. Horsepower per foot of cutting edge
2. Horsepower per loose cubic yard of material retained
in front of the blade.
Horsepower per foot (hp/ft) provides an indication of
the ability of the blade to penetrate and obtain a load.
• The higher this ratio, the more aggressive the blade.
Horsepower per loose cubic yard (hp/lcy) measures
the ability to push a load.
•VA higher ratio means that the bull dozer can push a
load at a greater speed

17. Blade adjustments
Tilt- the vertical movement of a blade end is
known as tilt. This movement is within the vertical
plane of the blade. Tilting permits concentration
of tractor driving power on limited length of blade

18. Tilting
Pitch: the control which allows the operator to vary
the angle of attack of the blade cutting edge with the
ground is a pitch. It is the movement of the top of the
blade toward or away from the tractor.

19. • Angling: Turning the blade so that it is not
perpendicular to the direction of the tractor's travel
is angling. This causes the pushed material to roll off
the trailing end of; the blade Rolling material off one
end of the blade is called "side casting".

20. Undercarriage unit
• Undercarriage units consist of two crawler units
• The driving sprockets is fitted at the rear end while
the idler wheel is fitted at the front end of the frame
• An endless chain passes over the driving sprockets and
the idler wheel and is supported in between by carriers
rollers and track rollers
• Shoes are fitted on the endless chain through out the
length
• The tensioning arrangements is fitted between the
crawler frame and the idler wheel to adjust the chain
sag

21. BULLDOZERS -TRACKED- OVAL DRIVE

22. BULLDOZERS -TRACKED-Delta drive
Advantages of delta drive:
•due to elevated engine and drive risk of getting
dust (mud) in is less
•longer operation (life) time increased bulk
clearance
Disadvantages of delta drive:
•higher costs of manufacturing
•more components long crawl belt

23. Power flow path on tractor
• Driving power from diesel engine (1) is transmitted to
transmission (4) through main clutch or torque converter (2) and
universal joint (3).
• The power, altered through selection of a proper gear speed
arrangement within the transmission according to load, is
transmitted to bevel pinion (6) at the rear end of the
transmission.

24. Cont…
• The bevel pinion and the bevel gear direct the power
into the right and left directions.
• Steering clutches (7) at both ends left and right of the
bevel gear shaft control the transmission of power
from the bevel gear shaft to the final drive, providing a
means for steering the machine in corporation with
brakes (8) installed on each steering clutch
• The power from the steering clutch goes to final drive
(9) consisting of a train of gears to turn sprocket. The
sprocket drives track to cause the machine to travel

26. Simple Sprocket Drive Operation
• Track drive system also has a drive sprocket that engages a chain
used to transmit drive torque supplied by an engine.
• Turning the sprocket engaged with the track chain pulls the chain
that is securely attached to track shoes. Moving the track shoes
produces the crawler-like track travel to take place.
• The combination Of chain and track shoe operates like both a self-
laying rail system and a road for the machine to crawl over
• The lower rollers on the track frame transfer machine weight to
the chain links and in turn onto the track in contact with the
ground
• To create a continuous return of chain to the drive sprocket, a
large idler wheel or idler sprocket is located opposite to the drive
Sprocket

28. Track-Type dozer Steering Systems
Differential Steering Systems
• Track-type machines that use steering clutches
and brakes can only drive one track when they
are turning. This is a big disadvantage when the
machine is under load and trying to make a
smooth turn.
• Differential steering action slows down one track
and speeds up the opposite track to make the
machine turn. In other words, it creates a speed
differential between the two tracks. Again, the
average speed of two tracks is the speed of the
machine

29. • The main components of differential steering systems are the transmission
output pinion, which supplies forward, reverse, and three-speed range inputs
to the system; the planetary differential assembly; a hydraulic steering
pump and motor; and the steering controls
• The steering motor is controlled by the operator, and as it rotates it turns
the machine left or right.
• The speed of the motor determines how sharp the turn will be, and the
direction the motor turns determines the direction the machine turns.

30. Hydraulic system
• A dozer blade controlled hydraulically
• The oil is sent to control valve from the gear pump installed
in the hydraulic tank.
• Here the oil pressure is developed for operation the blade in
four position
1. Raise
2. Hold
3. Lower
4. Float
• The safety valve is designed to control an abnormal pressure
rise beyond limit and to release the oil into the tank

31. Cont…
• The pressurized oil coming from the gear pump flow into
the control valve after passing through a check valve ,
which serves to check the backflow of oil
• A suction valve is provided to suck in make oil from the
hydraulic tank for filling up oil in the hydraulic cylinders.
• For example during the float the piston is lowered by the
weight of the blade and a vacuum is created in the upper
chamber s of the hydraulic cylinders
• The valve draws oil from hydraulic tank to prevent such a
negative pressure with in the cylinder

32. Cont…
.
Hydraulic tank
Control valve
Hydraubc pump

33. Cont…
• The hydraulic tank is located in front of the
radiator, with in the tank are the gear pump and
control valves
• The oil filter is fitted at the top and the oil drain
plug is fitted at the lower part for draining purposes.
• The oil strainer is installed with in the oil filter to
prevent entry of dust and dirt into the tank when
the tank is replenished with oil
• The oil level in tank can be checked by the oil level
gauge installed in the oil filter

34. Guidelines to Maintenance of Construction Equipment
Equipment maintenance: is any process used to keep equipment in
reliable working order. It may include routine upkeep as well as
corrective repair work.
 Proper maintenance of heavy machinery used in construction,
industrial, or mining applications is necessary to keep it in good
working condition and decides the actual life of the machinery.
• Poor maintenance of construction equipment may lead to unexpected
breakdown that results in loss of money, time, and endangers the
safety of workers.
The 7 major guidelines to be followed for the proper maintenance of
construction equipment are:
1. proper operation of the machinery
2. Perform regular cleaning
3. Perform a check of lubricants

35. Cont…
4.Record the Fluid Levels of the Machine
5. Perform Check for Wear in Construction Machines
6. Perform Misalignment Checks for Construction Machinery
7. Prepare Maintenance and repair schedule for the Construction
Machine
1. Proper Operation Of the Machinery. These can necessarily
help increase the life Of the machinery. Machinery may have
many operators during a project. Each operator has a defined
skill that differs. therefore the way of operating the machine
also varies.
• Other than the initial training for the operators, regular
training must be provided to keep up the skill and promote the
safe and correct operation of the machinery.

36. Cont…
• The proper operation of the machinery must be recorded as
a manual so that each operator can use it as a reference.
• The manual can be revised based on the work conditions and
project type.
2. Perform Regular Cleaning: Cleaning can help to preserve and
maintain heavy equipment
• The machinery is subjected to adverse environmental
conditions like rain, dust, mud, etc. Regular cleaning helps to
keep the conditions of different individual parts of the
machine, It also helps in maintaining the appearance Of the
equipment.

37. 3. Perform a Cheek of Lubricants: Lubricating the machinery at
proper intervals helps reduce friction around the moving parts.
•Following a good schedule for adding lubricants and checking the
lubrication enhances the machinery's performance and life,
•Among all the maintenance checks conducted on machinery,
lubrication is the most important check
•It is recommended to employ the right lubricant for the
respective components. The manufacturer 's recommendations
give most of the specifications.
• A proper check Of lubricants helps to diagnose problems
associated with the machinery parts
• The presence of contaminants in the oil indicates which part is
suffering from wear and tear

38. 4. Record the Fluid Levels of the Machine: Some construction
machines use more fluid and some use less.
• It is necessary to establish a written standard guideline so that
the machine's fluid levels are maintained.
• Any operational problems can be detected by the inspector by
looking at the periodic refill schedules.
5. Perform Check for Wear in Construction Machines: The main
factors that contribute to wear in construction machines are high
temperatures, friction, vibration, and the age of the machines.
• AS soon as the wear and tear are determined in machine parts,
it is recommended to bring the necessary replacement of the
parts as soon as possible

39. 6. Misalignment Checks for Construction Machinery: The
wheel alignment of the machines gets altered as they work in
very rough terrain. These machines are indeed made
compatible with such site conditions.
• It is essential to check the machine wheel for
misalignment to avoid unexpected working issues at the
site.
• Regular inspection done as a part of the maintenance check
must incorporate the cheek for misalignment,

40. 7. Prepare Maintenance and repair schedule for the Construction
Machine: It is essential to have a maintenance and repair
schedule to promote the preventive maintenance of the
machines.
•All the mentioned maintenance and checks must be recorded
and documented.