This document provides an overview of tractor hydraulics. It discusses the working principle of hydraulics based on Pascal's law and the advantages of hydraulic systems over mechanical systems. It then describes the main components of hydraulic systems including the reservoir, pump, distributor, valves, fluid, motor, hose, filter and cylinder. It also discusses the two main types of hydraulic systems - open center and closed center - as well as position and draft control of implements. Routine maintenance such as cleaning, refilling with clean oil, and regularly replacing or cleaning filters is emphasized for successful operation.

1. BY- HARSHIT JOSHI
GUIDANCE BY – DR. R.N. SHRIVASTAVA
DR. PREETI JAIN
College of Agricultural
Engineering Jabalpur

2. Tractor Hydraulics

3. Content
 Introduction
 Working principle
 Why Hydraulic System
 Parts of Hydraulic System
 Types Of Hydraulic System
(a) Based on center system
(b) Based on control
 Types of hydraulic pump
 Maintenance and Repair

4. Introduction
•A unit responsible for lifting and lowering an
agricultural implement
•Fluid is confined inside pipelines, reservoir and
cylinders
•Hydraulic pumps transfer the fluid from the
reservoir to the hydraulic system. This transfer
raises the energy level of the fluid by increasing its
pressure . The motor provide the power source for
the pump

5. Working Principle
The working principle of hydraulic system is based on
pascal’s law. This law states that the pressure applied to
an enclosed fluid is transmitted equally in all directions
.Small force acting on small area can provide higher
force on a surface of larger area.

6. Why hydraulic system
 Simpler than mechanical linkage systems
 System is flexible enough
 Power can be engaged or disengaged using a
simpler valve
 Input heavy force can be controlled easily
 A good range of speed operation is possible
 Is safer than mechanical system

7. Parts of hydraulic systems
Reservoir
Pump
Distributer
Valves
Fluid
Motor
Hose
Filter
Cylinder

8. Reservoir
It contains sufficient oil to move
the piston for lifting the load.
 Hydraulic filter
Hydraulic filters are used to protect your
hydraulic system component from damage
due to contamination of oils caused by
particles

9.  Relief valve
Relief valve are used in hydraulic systems to
limit the system pressure to a specific set level. If
this set level is reached ,the pressure relief valve
responds and finds the excess flow from the
system back to the tank.

10. Pump
•It forces the fluid from the reservoir to the
cylinder.
 Control valves
Control valve is a type of valve which control
the movement of hydraulic oil to have desired
direction ,magnitude and speed of lifting.

11. Hydraulic Motor
• A hydraulic motor converts hydraulic
energy into mechanical energy: A rotating
shaft .It uses hydraulic pressure and flow to
generate torque and rotation.
Hydraulic Hose
Hydraulic hose is specifically designed to
convey hydraulic fluid. It is typically
flexible, often reinforced and usually
constructed with several layers of
reinforcement since hydraulic system
frequently operated at high or very high
pressures .

12. • Types of hydraulic system
•Open center system
• Close center system

13. • Implement control
The tractor with a built In lift system is connected to the implement through a
specific type of mechanical linkage termed as three point linkage as a system is
known as mounted system . The implement is connected with tractor hydraulic
system at two bottom links and one top link .Both the bottom link are
connected with two lift arms through lift links .the lift arm is directly mounted
with rockshaft ,which is further connected with piston rod.Any movement of
the piston is transferred to the bottom links .The top link is used for connecting
the third hitch point of the implement and is adjustable for maintaining the
implement level and suction angle.Load sensing for the draft control can also be
done through the top link,which is spring loaded. In some tractor the lower
links are spring loaded for draft sensing. Depending upon the soil condition
and type of operation, the mounted implement can be controlled either by
potion control or draft control.

14. Position control
•In this system, constant depth of ploughing is maintained by
automatic adjustment of draft of tractor. In this system the
control valve can be operated directly by the driver to raise
lower or hold an implement, mounted on the linkage at any
chosen height.
• Draft Control
•Under this system of control, the implement is set for a
particular draft(drawbar pull) rather than depth. In varied soil
conditions the implement automatically takes more or less depth
to maintain the predetermined draft.

15. Maintenance and repair of hydraulic
system
•For successful operation of any hydraulic system,
cleaning and periodic maintenance is very
essential .If the operation is alert and keeps the
machine clean ,refills clean oil, replaces or clean
the filter regularly,keeps the tubes and rubber
hose tight and protect the system from dust and
other contaminants , the system will
undoubtedly work efficient with less trouble.