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1. Power Steering System
of Tractors

2. Steering
 The term applied to the
collection of components,
linkages, etc. which allow
for a car or other vehicle
to follow a course
determined by its driver.

3. History of Hydro-mechanical Power Steering
(HMPS)
 Hydro-mechanical power steering was the
first type to be used on agricultural tractors in the early
1950’s.
Suitable for small to medium tractors where power steering
can be an option to manual steering.
Once the size of the tractor becomes too big for manual
steering, hydro-mechanical
steering is usually not cost effective.

4. Components in Power Steering

5. Oil Reservoir
 Must be large enough to
hold more than all of the
oil for the system.
 Should be capable of
dissipating heat in oil.
Hydraulic Lines
 Flexible hoses due to the
steering components
movements.

6. It consists of vanes mounted radially on a
cylindrical rotor, which is eccentrically
located in the pump casing. The vanes
maintain a close seal against the casing
wall.
ideal for pumping low to medium viscosity
liquids, including LPG and those with
entrained gases, and can give a smooth, low
pulsation output. Pumping speed and
efficiency decrease with increasing fluid
viscosity.
Vane Type of Pump

7. a type of valve in which the
rotation of a passage or passages
in a transverse plug regulates the
flow of liquid or gas through the
attached pipes. The common
stopcock is the simplest form of
rotary valve.
Rotary Valve

8. Split Gears
 It converts the rotational motion
of the steering wheel into the
linear motion needed to turn the
wheels.
 It provides a gear reduction,
making it easier to turn the
wheels.

9.  contains the gears that transmit
the driver's steering inputs to the
steering linkage that turns the
wheels, and it multiplies the
driver's steering changes so that
the front wheels move more than
the steering wheel.

10. Recirculating-ball Steering
、

11. Advantages
 Preventing the wheels from transferring the load to the steering
column

.
Reducing the driver’s fatigue

.
Low input torque and continuous steering function

.
Oil output directly proportional to the steering speed
Disadvantages

.
Design has complications and increased in cost.

.
Fluid leakage.

13. The braking system is an important
system in the tractors used to slow
down or stop the tractor motion. It is
also used to prevent the tractor from
moving when it is stationary.
Brake 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 fieldwork or locked
together by means of a lock.

14. Brake works on the
Principle of friction
 When a moving clement is
brought into contact with a
stationary element, the motion
of the moving element is
affected. This is due to
frictional force, which acts in
opposite direction of the motion
and converts the kinetic energy
into heat energy.

15. Mechanical brakes Hydraulic brakes
Internal expanding
shoe type
External
contracting shoe
type
Disc type

16.  Two brake shoes made of frictional
material fitted on the inside of the brake
drum are held away from the drum by
means of springs.
 One end of each shoe is fulcrum
whereas the other is free to move by the
action of a cam which in turn applies
force on the shoes.
 The movement of the cam is caused by
the brake pedal through the linkage.
The drum is mounted on the rear axle
whereas the shoe assembly is stationary
and mounted on the back plate.

18. C

19. C

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22.  Hydraulic brakes make used of hydraulic
pressure to force the brake shoes.
 It works based on PASCAL’S LAW.

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26.  Heart of the hydraulic
brake system

27.  Second important Part in
the hydraulic brake system.

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30. Use the one recommended by the manufacturer:
 glycol based
 silicon based
Properties
 Low Freezing Point
 High Boiling point
 Must lubricate internal parts
 Must not evaporate easily