This document discusses the design of a hydraulic power pack for a special purpose 2-way boring machine. It was submitted by V.Veeranjaneyulu in partial fulfillment of the requirements for a Bachelor of Technology degree in Mechanical Engineering from Jawaharlal Nehru Technological University. The power pack is designed to provide a firm grip and easy holding of workpieces for the 2-way boring machine. The document covers basics of hydraulics, calculations for sizing the pump, reservoir, and electric motor for the power pack, selection of hydraulic components, and analysis of hydraulic fluids using ANSYS software.

1. iii
DESIGN OF HYDRAULIC POWER PACK FOR SPECIAL
PURPOSE 2-WAY BORING MACHINE
A project report submitted in the partial fulfillment for the award of
Degree of
BACHEL
OR OF TECHNOLOGY IN
MECHANICAL ENGINEERING
Submitted by
V.VEERANJANEYULU
Roll No. 08063A3449
SCHOOL OF CONTINUING & DISTANCE
EDUCATION
JAWAHARLAL NEHRU TECHNOLOGICAL
UNIVERSITY
HYDERABAD – 28
(2012)

2. iv
CERTIFICATE
This is to certify that the project report entitled DESIGN OF HYDRAULIC
POWER PACK FOR SPECIAL PURPOSE 2-WAY BORING MACHINE that is being submitted
by V.VEERANJANEYULU in partial fulfillment for the award of the Degree of Bachelor of Technology in
MECHANICAL ENGINEERING to the Jawaharlal Nehru Technological University is a record
of bonafide work carried out by him under my guidance and supervision. The results embodied in this project
report have not been submitted to any other University or Institute for the award of any degree or diploma.
Date:
SIGNATURE OF THE GUIDES:
Internal guide External guide
Y.VENKATNARAYANA MANOJ AGRAWAL
Asst. Professor Asst. Manager – ER&D, ED
Srinidhi Institute of Science & Technology. Hyderabad Industries Limited.
CHAIRMAN
PROJECT REVIEW COMMITTEE
(SRINIDHI INSTITUTE OF SCIENCE & TECHNOLOGY)

3. v
ACKNOWLEDGEMENT
It gives us immense pleasure to express my deep sense of gratitude to my external project
guide, Mr. MANOJ AGRAWAL, Asst. Manager in the Engineering Division of
HYDERABAD INDUSTRIES LIMITED, Hyderabad. For his valuable guidance, constant
encouragement, constructive criticism, simulative discussions and keen interest evinced through
out the course of the project. I am really fortunate to associate my self with such encouraging and
experienced guide.
I owe a deep sense of gratitude and sincere thanks to my internal guide
Mr.Y.VENKATNARAYANA department of Mechanical Engineering, Srinidhi Institute of
Science & Technology. My thanks extended to him for constant association, encouragement and
supervision in completing my project work.
K.DAMODHARAM

4. vi
ABSTRACT
This project is aimed at the design of hydraulic power pack for fixtures of 2-way line boring
machine. Use of hydraulic system for the purpose we ensure firm grip to the job and makes the
holding of the job much easier. It also is used to do some work like clamping, Transfer and
lifting of the component.
The power pack is an integral power supply unit usually containing a pump, reservoir, relief
valve and directional control valve. For the purpose of design of hydraulic power pack the
components that are to be designed are a pump, a reservoir, and an electric motor. The pump size
is selected by calculating the fluid flow rate, which is required by different cylinders to perform
various operations. By considering the discharge of fluid, the capacity of tank and the power of
the electric motor are calculated. The other parts like check valves, Oil cooler, flexible coupling,
seals etc. are selected as per the design requirements. Special emphasis is made on design of
power pack in which selection of elements, maintenance aspects, trouble –shooting methods is
dealt with.
Hydraulic drives and controls have become more importance due to automization and
mechanization. Hydraulic system is less complicated and has fewer parts. Due to this fact,
hydraulic systems are more advantageous than mechanical systems.

5. vii
CONTENTS
1. INTRODUCTION
1.1 BASICS OF HYDRAULICS
1.2 SPECIAL CHARACTERISTICS OF HYDRAULICS
1.3 FLUID POWER
1.4 BASIC PRINCIPLES
1.5 ADVANTAGES OF HYDRAULIC SYSTEM
1.6 APPLICATIONS OF HYDRAULICS
1.7 INTRODUCTION TO SPECIAL PURPOSE TWO WAY BORING MACHINE
1.8 INTRODUCTION TO HYDRAULIC POWER PACK (HPP)
1.9 WORKING OF HYDRAULIC POWER PACK
1.10 DESCRIPTION OF HYDRAULIC POWER PACK
1.11 DEFINITION OF HYDRAULIC COMPONENTS
1.12 HYDRAULIC SYMBOLS
2. LITERATURE SURVEY
3. DESIGN CALCULATIONS
4. SELECTION PROCEDURE
4.1 CIRCUIT DIAGRAM OF HYDRAULIC POWER PACK
4.2 BILL OF MATERIAL
5. HYDRAULIC FLUIDS
5.1 FLUID ANALYSIS BY USING ANSYS

6. viii
6. RESULTS
7. CONCLUSIONS
8. BIBLIOGRAPHY
9. APPENDICES

7. 1
1. INTRODUCTION
A great diversity of methods is available of methods is available for transmitting
energy from a prime mover to a neighboring or a distant point. By, employing liquid under
pressure continues to make head way in face of today’s competition .on he basis of equal speeds
and outputs the hydraulic machine might be more compact and lighter than the electrical one.
Hydraulic transmission is prominent when the work to be done requires flow of steady thrust,
which can, if necessary be indefinitely maintained. When extremely heavy thrusts have to be
developed of the order of 5000-30000 tones nothing else but hydraulic machine, the system will
press the basic advantage of silence, simplicity, smoothness of operation and ease of control.
1.1 BASICS OF HYDRAULICS:
The word hydraulics is derived from the Greek word ‘Hydro’, means water. This comprised all
things in affiliation with water.
The term “Hydraulics” means the transmission and control of forces and movement by
means of fluid.
The field of hydromechanics (fluid mechanics) is broken down as follows:
a. HYDROSTATICS:
It is the mechanics of still fluid.
Ex.: Transfer of force in hydraulics.
b. HYDRO DYNAMICS:
It is the mechanics of moving fluid.
Ex.: Conversion of flow energy in turbines in Hydro Electric power plants.
1.2 SPECIAL CHARACTERISTICS OF HYDRAULICS:
• High forces with compact size, i.e. high power density.
• Automatic force adoption.

8. 2
• Movement from standstill possible under full load.
• Step less change (control or regulation) of speed, torque, stroke force etc.
• Simple overload protection.
• Suitable for controlling fast movement process and for extremely slow precision
movements.
• Relatively simple accumulation of energy by means of gas.
• Combined with decentralized transforming of the hydraulic energy back into mechanical
energy, simplified central drive systems are possible giving a high degree of economy.
1.3 FLUID POWER
1.3.1 WHAT IS FLUID POWER?
Fluid power is energy transmitted and controlled by means of a pressurized fluid,
either liquid or gas. The term fluid power applies to both hydraulics and pneumatics. Hydraulics
uses pressurized liquid, for example, oil or water; pneumatics uses compressed air or other
neutral gases.
Fluid power is a term which was created to include the generation, control and
application of smooth, effective power of pumped are compressed fluid (either liquids or gases)
when this power is used to provide force and motion to mechanisms.
1.3.2 HOW FLUID POWER WORKS?
Pascal’s laws express the central concept of fluid power: “pressure exerted by a
confined fluid acts undiminished equally in all directions”.
Fig-1.1

9. 3
An input force of pounds (44.8 N) on a 1-sq.inch (6.45cm2) piston develops a pressure of 10
pounds per sq.inch (psi) (68.95 Kpa) through out the container. This pressure will allow a 10
sq.inch piston to support a 100 pounds (444.8N) weight. The forces are proportional to the piston
areas.
1.3.3 ADVANTAGES OF FLUID POWER:
Fluid power systems provide many benefits to users including:
1. MULTIPLICATION AND VARIATION OF FORCE:
Linear or rotary force can be multiplied from a fraction of an ounce to several hundred
tons of output.
2. EASY, ACCURATE CONTROL:
You can start, stop, accelerate, decelerate, reverse or position large forces with greater
accuracy. Analog (infinitely variable) and digital (on/off) control are possible. Instantly
reversible motion (in less than half a revolution) can be achieved.
3. MULTI-FUNCTION CONTROL:
A single hydraulic pump or air compressor can provide power and control for numerous
machines or machine functions when combined with fluid power manifolds and valves.
4. HIGH HORSEPOWER, LOW WEIGHT RATIO:
Pneumatic components are compact and lightweight. You can hold a five horsepower
hydraulic motor in the palm of your hand.
5. LOW SPEED TOQUE:
Unlike electric motors air or hydraulic motors can produce large amounts of torque while
operating at low speeds. Some hydraulic and air motors can maintain torque at zero speed
without overheating.
6. SAFETY IN HAZARDOUS ENVIRONMENTS:
Fluid power can be used in mines, chemical plants, near explosives and in paint
applications because it is inherently spark free and can tolerate high temperatures.

10. 4
1.3.4 FLUID POWER APPLICATIONS:
1. MOBILE:
here fluid power is used to transport, excavate and lift materials as well as control or power
mobile equipment. End use industries include construction, agriculture, marine and the military.
Applications include backhoes, graders, tractors, truck brakes and suspensions, spreaders and
highway maintenance vehicles.
2. INDUSTRIAL:
Here fluid power is used to provide power transmission and motion control for the machines of
industry. End use industries range from plastics working to paper production. Applications
include metalworking equipment, controllers, automated manipulators, materials handling and
assembly equipment.
3. AEROSPACE:
Fluid power is used for both commercial and military aircraft, spacecrafts and related support
equipment. Applications include landing gear, brakes, flight controls, motor controls and cargo
loading equipment.
1.4 BASIC PRINCIPLES:
1.4.1 PASCAL’S LAW:
Pascal’s laws express the central concept of fluid power:”states that the pressure or intensity of
pressure at a point in a static fluid is equal in all directions”.
Where force ‘F’ acts on an enclosed fluid via surface ‘A’, pressure occurs in the
fluid. The pressure is related to the amount of force applied to the surface vertically and the area
of application of force.
P=F/A
Fig 1.2 Explaining Pascal’s law

11. 5
Pressure acts on all sides equally and simultaneously. It is equal at all points. This is valid with
omission of the gravity force, which would have to be added according to the fluid level.
1.4.2 BERNOULLI PRINCIPLE:
Which states, “For the horizontal flow of fluid through a tube, the sum of the pressure and
kinetic energy per unit volume of the fluid is constant”?
The Euler’s equation derived along one streamline is called the “Bernoulli’s equation”.
V 2 / 2 + gh + p / ρ = constant
(Or)
V1 / 2 + gh1 + p1 / ρ = V2 / 2 + gh2 + p 2 / ρ =constant
2 2
Where,
V =speed ( m / s )
g =gravitational constant ( m / s 2 )
h =elevation ( m ).
p =pressure ( N / m 2 )
ρ =density (kg/m³)
1.4.3 CONTINUITY EQUATION:
The equation based on conversation of mass is called continuity equation. Thus for a
fluid flowing through the pipe at all the cross-section, the quantity of fluid per second is constant.
Q = ρAV = k
Where,
Q =Flow rate in kg/sec.
ρ =Density of fluid in kg/m³
V =Average velocity
k =Constant.
6

12. If the fluid is incompressible, then the density remains constant.
Then,
Q = ρAV = k
q = A1V1 = A2V2
Where,
q =Flow rate ( m 3 / s
A =Area ( m 2 )
The constant q represents the volume of fluid, which passes through each cross section of the
stream tube unit time.
1.5 ADVANTAGES OF HYDRAULIC SYSTEM:
1.5.1 OVER ELECTRICAL SYSTEM:
• The hydraulic engineer can decrease the amount of moving mass, much more
than what an electric engineer can do. In aircraft applications, fluid motors
weigh even less than ½ kg/KW power.
• In hydraulic drive, the dependence on the current is only up to the extent of
running motor coupled with the pump. If the electric supply fails then a diesel
engine or hand operated pump can be used unlike in fully electrical drive the
machine becomes idle.
• Whenever an electric spark is likely, the hydraulic system can manage quite
easily.
• Except solenoids creating linear forces, electrical drives cannot generally create
linear motions on their own. But hydraulic systems, by selecting fluid motors
or hydraulic cylinders, one can create rotary or linear motions, whichever may
be desired.
• Wherever vibrations exist, fine electric mechanisms are affected, but the
hydraulic systems are not.
7

13. • Laws that are simpler than those governing electricity govern the subject of oil
hydraulics.
1.5.2 OVER MECHANICAL SYSTEM:
• It eliminates the need of complicated linkages, gears, cams and levers.
• It consists of parts, which are not subjected to great wear as compared to parts
of mechanical system.
• It has flexibility of locating points too easily.
• It transmits force rapidly between two points located at great distances.
• It guarantees an automatic release of unwanted high pressure in case of
overload so that the system is protected against breakdown.
• It is sensitive in operation and gives instantaneous response to any operation.
• It eliminates the need of lubrication.
• It provides infinitely variable speed control not possible through mechanical
means.
• It is more economical than mechanical system.
1.5.3 OVER PNEUMATIC SYSTEM:
• It is less complex in construction compared to pneumatic system.
• Easier installation of hydraulic system.
• Noise free operation compared to pneumatic system.
• Low maintenance.
• Incompressibility of working fluid in a hydraulic system prevents power loss in
contrast with the compressible fluid of a pneumatic system associated with
considerable losses.
• Operating pressures are very high (50-200 bar) compared to pneumatic
pressures (5-8 bar).
• Feed control is difficult in pneumatic systems.
• More number of components of a pneumatic system makes it complex to
operate.

14. 8
• Also lubrication is required in a pneumatic system.
1.6 APPLICATIONS OF HYDRAULICS:
It is divided into 5 sectors as follows:
1.6.1. INDUSTRIAL HYDRAULICS:
Plastic machines
Presses
Heavy machinery
Machine tools
1.6.2. HYDRAULICS IN STEEL WORKS:
Lock gates and dams
Bridge operating equipment
Nuclear power station
Milling machinery turbines
1.6.3. MOBILE HYDRAULICS:
Excavators and cranes
Constructed and agricultural machinery
Automobile construction
1.6.4. HYDRAULICS IN SPECIAL TECHNICAL APPLICATIONS:
Telescopes
Antenna operations
Landing gear control of aircraft
1.6.5. HYDRAULICS OF MARINE APPLICATIONS:
Deck cranes
Bow doors
Bulkhead valves
Naturally this summary does not include all possibilities of application, since the
variety of hydraulically operated machines is too great.

15. 9
1.7 INTRODUCTION TO SPECIAL PURPOSE BORING MACHINE:
When market demand is high and the goods have to be supplied at lower
price, the need for mass production of the components arises. To offset the low level of
production by conventional machine tools, it is essential to develop machines for mass
production of components. The mass production components demand high productivity and
reliability of machine tools. The concept of SPM has been evolved to meet these requirements.
By the advent of SPM’s concept, it has become possible to achieve higher
production rates by cutting down un-productive time to minimum and by performing more
number of operations on a component simultaneously that is not possible on conventional
machine tools.
SPM is an essentially metal cutting machine tool, designed and built to perform a
given sequence of operations on a component to give the required output. They are component
oriented and hence the component forms the basis for their development. The SPM’s are
designed and built against specific requirements of machining on any component ensuring
desired accuracies, output rates and performing maximum operations in one loading. Hence these
machines are component oriented unlike conventional machines which are operations oriented.
1.7.1 ADVANTAGES OF SPM:
SPM offers good number of advantages over conventional machine tools such as:
1. Higher output
2. Greater reliability
3. Low machining cost per piece
4. SPM save floor space and labor cost.

16. 10
Fig-1.3 DIAGRAM OF CONVENTIONAL BORING MACHINE WITHOUT
HYDRAULIC POWER PACK
1.7.2 DISADVANTAGES:
a. Time consumption is high for clamping & decamping the work piece
b. Load variations are occurs
c. Difficult to clamping the work piece on the table

17. 11
FIG – 1.4 DIAGRAM OF SPECIAL PURPOSE TWO WAY BORING MACHINE WITH
HYDRAULIC POWER PACK:
1.7.3 ADVANTAGES:
1. It eliminates the human assistance for clamping & decamping of work piece.
2. Time taken is less for clamping & decamping of work piece.
3. Load variations are not occur.
4. Ensure firm grip to the work piece is high.
5. It can be clamped rigidly with less wear, greater accuracy and less noise
12

18. 1.8 INTRODUCTION TO HYDRAULIC POWER PACK (HPP):
Basically hydraulic power pack is a device that converts hydraulic energy into mechanical
energy. The hydraulic power pack is nothing but a movable hydraulic system. It contains all the
basic components that are required for a hydraulic system such as tank, pump, valves etc.
Mobility of hydraulic power pack makes them useful for several purposes where oil
pipelines from a stationary hydraulic system cannot be run. The principle on which power pack
works can be easily implemented at various sections with little or no modifications.
Fig-1.5
13

19. 1.9 WORKING OF HYDRAULIC POWER PACK:
1.9.1 WHEN FORWARD STROKE OF PISTON:
The system consists of a pump in fig a gear pump is shown, it may not be a gear
pump always (vane pump, axial pump, radial pump) an oil tank, a pressure relief valve, a
cylinder and a directional control valve
Fig-1.6
14

20. During the forward stroke of the piston, the pump which is driven by electric
motor Pumps the oil from the tank along the path “PA” into the Directional control valve .From
here the oil reaches the cylinder. When the load moves outwards, the oil on the other side of the
piston goes along the path “BT” in to the tank. The purpose of the pressure reducing valve is to
by pass excess oil to the tank, when the pressure in the pipe line increases beyond a set value.
1.9.2 WHEN RETURN STROKEOF PISTON:
Fig-1.7
During the backward stroke of the piston, the pump which is driven by electric
motor pumps the oil from the tank along the path “PB” in to directional control valve . From
here the oil reaches the cylinder. During the backward, the spool moves to the left and the oil
15

21. from the pump flows along the path “PB” in to the cylinder and the load moves inward. The oil
on the other side of the piston goes along the path ‘AT’ to the tank.
1.10 DESCRIPTION OF HYDRAULIC POWER PACK:
The power pack is an integral power supply unit, which basically determines
the working of the control unit.
Fig-1.8 HYDRAULIC POWER PACK
A hydraulic power pack offers a simple method of introducing hydraulic operation to
individual machines, with flexibility of being adaptable to other duties. It consists basically of an
integral electric motor, with associated tank. The pump or motor unit may be mounted on the
tank or separately. Packs are usually available in either horizontal or vertical configuration.
Relief and check valves are normally incorporated on the tank. The basic unit may then
be piped to the cylinders or actuators through a suitable control valve.
Hose assemblies are generally preferred to rigid piping for connecting the power pack to
actuators. With hose assemblies it is simpler to disconnect the power pack from one machine and
transfer it to another.
The hydraulic power packs consist of a reservoir that houses the hydraulic fluid, which is
the working medium. The capacity of the tank may vary accordingly to the requirements. The
reservoir is also equipped with an air breather at the top to maintain the pressure in the tank at
atmospheric pressure and it also filters the oil to 40 microns.
16

22. 1.10.1 COMPONENTS OF HYDRULIC POWER PACK
1. Pump
2. Reservoir/tank
3. Directional control valve
4. Pressure relief valve
5. Check valve
1.10.2 PUMP:
Pump is a device, which converts mechanical force and motion into hydraulic fluid power.
The purpose of a pump in a fluid power is to pressurize the fluid so that work may be performed.
The pump serves to create a fluid flow and to allocate the necessary forces to it as required.
FUNCTIONS OF PUMP:
• The liquid can be raised to a higher level by virtue of increase in the potential energy of
the liquid.
• There would be an increase in liquid pressure.
• Increase in the velocity of liquid by virtue of increase in kinetic energy.
TYPES OF PUMPS:
a) Positive displacement
i. Fixed displacement pump
ii. Variable displacement pump
b) Non- positive displacement
POSITIVE DISPLACEMENT:
Positive displacement pumps displace a known quality of liquid with each revolution of
the pumping elements (i.e., gears, rotors, screws, vanes) positive displacement. Pumps
displace liquid by creating a space between the pumping elements and trapping liquid in
the space. The rotation of the pumping elements then reduces the size of the space and
moves the liquid out of the pump.
17

23. FIXED DISPLACEMENT PUMP: In this fixed displacement pumps the stroke volume cannot
be changed.
VARIABLE DISPLACEMENT PUMP: In this variable displacement pumps the stroke volume
can be changed.
NON-POSITIVE DISPLACEMENT:
Pumps that discharge liquid in a flow is referred to a non positive displacement
DIFFERENT TYPES OF PUMPS:
Practically all hydraulic pumps fall within three design classification – centrifugal, rotary and
reciprocating. The use of centrifugal pumps in hydraulics is limited.
CENTRIFUGAL PUMPS:
Centrifugal pumps are classified as roto-dynamic type of pumps in which dynamic
pressure is developed. This pressure enables the lifting of liquid from a lower level to a higher
level. The basic principle on which centrifugal pumps work is that when a certain mass of liquid
is made to rotate by an external force, it is thrown away from the axis of rotation and centrifugal
head is impressed which enables it to rise to a higher level.
Fig-1.9 CENTRIFUGAL PUMP
RECIPROCATING PUMPS:
The basic principle of reciprocating pumps is to displace a fluid exerting thrust on it.
These types of pumps are also called as positive displacement pumps. In these liquid is sucked
18

24. and then is pushed due to thrust exerted on it by moving a member, which results in lifting the
fluid to a desired height. As such the discharge of liquid pumped almost wholly depends on
speed of the pump.
Fig 1.10 RECIPROCATING PUMP
ROTARY PUMPS:
Rotary pumps are self-priming and deliver a constant and smooth flow regardless of
pressure variations. All the rotary pumps have rotating parts, which trap the fluid at the inlet
(suction) port and force it through the discharge port into the system. Gears, screws, lobes and
vanes are commonly used to move the fluid. Rotary pumps are designed with very small
clearance between the rotating parts and stationary parts.
Fig 1.11 ROTARY PUMP
19

25. VARIABLE VANE PUMP :
Vane pumps operate quite differently from gear and lope type. A rotor with radial
slots is positioned off-center in a housing bore. Vanes that fit closely in rotor slots slide in and
out as the rotor turns.
Vanes are the main ceiling element between the suction and discharge ports and are
usually made of a non metallic composite material.
Vane-type hydraulic pumps generally have circularly or elliptically shaped interior
and flat end plates. (Fig. illustrated below is a vane pump with a circular interior) a slotted rotor
is fixed to a shaft that enters the housing cavity through one of the end plates.
Fig-1.12 VARIABLE VANE PUMP

26. A number of small rectangle plates or vanes are set into the slots of the rotor. As
the rotor turns , centrifugal forces causes the outer edge of each vane to slide along the surface of
the cavity of the vanes slide in and out of the rotor slots the numerous cavities, formed by the
vanes, the end plates, the housing, and the rotor, enlarge and shrink as the rotor and vane
assembly rotors. An inlet is installed in the housing so fluid may flow in to the cavities as they
enlarge .an outlet port is provided to allow the fluid to flow out of the cavities as they become
small.
20
With this variable pump , the displacement volume can be adjusted at the set maximum
operating pressure .In this case hewer the cam is a circular concentric ring . A spring 2 pushes
the cam into its eccentric outlet position towards the rotor. The maximum eccentricity and thus
the maximum displacement volume can be set by means of the screw 5.The spring force can also
be adjusted by means of the screw 6.there is a tangential adjustment of the cam by means of the
height adjustment screw 4.
The pressure, which builds up due to working resistance, affects the internal
running surface of the cam on the pressure side. This results in a horizontal force component,
which operates towards the spring.
If the pressure force exceeds the set spring force the cam ring moves from
eccentric towards zero position. the eccentricity decreases. the delivery flow adjusts itself to the
level required by the user.
If no fluid is taken by the user and the set pressure is thus reached, the pump
regulates flow to almost zero. Operating pressure is maintained, and only the leakage oil
replaced. Because of this, loss of power and heating of the fluid is kept to a minimum.
1.10.3 RESERVOIR:

27. Fig-1.13 RESERVOIR
21
A hydraulic system must have a reserve of fluid in addition to that contained in the
pumps, actuators, pipes and other components of the system. This reserve fluid must be readily
available too make up losses of fluid from the system, to make up for compression of fluid under
pressure, and to compensate for the loss of volume as the fluid cools. This extra fluid is
contained in the tank usually called a reservoir
In addition to providing fluid during shortage to system, the reservoir acts as a radiator
for dissipating heat from the fluid and as settling tank where heavy particles of contamination
may settle out of the fluid and remain harmlessly at the bottom until removed by cleaning or
flushing the reservoir. Also the reservoir allows contained air to separate from the fluid.
The inside of the reservoir generally has baffles to prevent excessive sloshing of the fluid which
also helps separating fluid return line and pump suction line. This settling technique helps avoid
contamination and also air to refrain from the system.
TYPES OF RESERVOIRS:
The various reservoirs are broadly classified as

28. • Vented (storage) and
• Sealed (pressurized and non-pressurized).
Vented reservoir is more advantageous than sealed reservoir, in that
it can be made smaller for the same fluid volume. Care should be taken to avoid over
filling, since this will reduce the air volume and Produce wider ranges of pressure, during
working.
1.10.4 DIRECTION CONTROL VALVES:
Direction control valves are designed to direct the flow of fluid, at a desired time, to the
point in a fluid power system where it will do work. The driving of a ram back and forth in its
cylinder is an example of a directional valve, same as selector, transfer and control valves. They
are ideal for machine tools, production and material handling equipment, marine auxiliary power
controls, off-highway and heavy construction equipment, and oil field and farm equipment.
22
Fig-1.14 DIRECTION CONTROLE VALVE
Direction control valves may be operated by difference in pressure acting on opposite sides of
the valve element, or they may be positioned manually, mechanically or electrically. Often two
or more methods of operating the same valve will be used in different phases of its action.
1.10.5 PRESSURE CONTROL VALVES:
Pressure control valves are used to control and regulate pressure in fluid power systems.
The maintenance or lowering of pressure can be achieved in a number of ways. Some valves are
designed to blow off pressure when a set level is reached, other times they are designed with
flanged ends to allow for ease of maintenance. Normally the valves are smaller than the line in

29. which it is attached. The design feature prevents the valve from throttling, which would cause
the seat to wear too quickly. The disc is moved by a pneumatic, hydraulic, electrical or manual
operator actuation.
Fig No : 1.15
23
In hydraulic systems pressure regulators are used to unload the system and
to maintain and regulate pressure at the desired values. When the system pressure decreases a
certain amount, the regulator will open, sending the fluid to the system. When the system
pressure increases sufficiently, the regulator will close, allowing the fluid from the pump to flow
through the regulator and back to the reservoir. The pressure regulator takes the load off the
pump and regulates system pressure.
1.10.6. CHECK VALVE:
Non-return valves or check valves are used in circuits, are combined in the
body of other valves, to provide flow in one direction only. The simplest type is the spring
loaded ball valve, although this has limited suitability for hydraulic services in high pressure
services, especially good sealing is essential and it may be necessary to design the valve with a
resilient seating valve.
Check valves are used in account to eliminate actuator movements (e.g. Cylinder
movement) and to maintain it in a hold position without creeping as might otherwise occur due
to direction valve spool leakage.

30. Fig-1.16 Check Valve
24
1.11 DEFINITION OF HYDRAULIC COMPONENTS:
ACTUATOR: A device used to converting hydraulic energy into mechanical energy. It can be a
motor or a cylinder.
BREATHER: A device, which permits air to move in and out of a container or component to
maintain atmospheric pressure.
CIRCUIT: An arrangement of component interconnected to perform a specific function with a
system.
CYLINDER: A device that converts fluid power into linear mechanical force and motion.
CHECK VALVE: A valve, which permits flow of fluid in one direction only.
CRACKING PRESSURE: The pressure at which a pressure actuated valve begins to pass fluid.
DRAIN: A passage or a line, from a hydraulic component that returns leakage fluid
independently, to the reservoir or vented manifold

31. DIRECTIONAL VALVE: A valve that selectively directs or prevents fluid flow to desired
channel.
DELIVERY: the volume of fluid discharged by pump in a given time, usually expressed in
gallons per minute (gpm).
FILTER: A device used to separate and retain insoluble contaminants from a liquid.
FLOW CONTROL VALVE: A valve that controls the rate of oil flow through the circuit.
FOUR-WAY VALVE: A direction valve showing four flow points.
LINE: A tube pipe or hose that acts as a conductor of hydraulic fluid.
MANIFOLD: A fluid conductor that provides multiple connection ports.
PLUNGER: Cylindrical shaped part that has only one diameter and is used to transmit thrust
through a ram.
POWER PACK: An integral power supply unit usually containing a pump, reservoir, relief valve
and directional control valve.
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SERVO MECHANISM: A mechanism subjected to the action of controlling device, which will
operate as if it were directly actuated by controlling device.
SOLENOID: An electro mechanical device which converts electrical energy into mechanical
motion, used to actuate direction valves.
SPOOL: A term loosely applied to any moving cylindrically shaped part of a hydraulic
component which moves to direction flow through the component
LAMINAR FLOW: Fluid flow in which particles slide smoothly along lines parallel to the wall.
Resistance to flow is proportional to the square of the velocity.
TURBULENT FLOW: Random local disturbances in the fluid flow pattern about a mean
average velocity. Resistance to flow is proportional to the square of the velocity.
REYNOLDS NUMBER: A dimensionless number relating fluid velocity V, distance as a pipe
diameter D, and fluid velocity.
1.12 HYDRAULIC SYMBOLS
These graphical symbols are as per ISO R/1219 with help of graphical symbols one may be able
to read function and working of a hydraulic circuit.

32. Line working (main)
Line Pilot (for control)
Line Liquid Drain
Flow Direction
Hydraulic
Line Crossing
Line Joining
Line with fixed Restriction
Flexible line
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2. LITERATURE SURVEY
The growth of oil hydraulics as a parallel development in transportation, farm and earth moving
equipment, industrial machinery, machine tool ship control, fire control, air craft missiles and
numerous other applications. Oil hydraulics; however forms one aspect of an overall systems
concept.
With the impact of rising costs and global shortages of fossil fuels like coal and
petroleum, the transmission system designers today are forced to critically consider his options
from the point of view of efficiency and overall economy. This has resulted in the introduction of
oil hydraulic machine components over the last decade, with remarkable increase in power
density and operating pressure, with greater overall efficiency. This trend is likely to continue
into the 1990’s with a major break through in materials and manufacturing technology.
In 1980’s we have seen the introduction of organic and synthetic fluids in a hydraulic
system on a very large scale. The coming decade shall also witness the introduction of water
based hydraulic fluids in industrial hydraulics. The problem today is not the development of

33. water-based fluids themselves, but in the design of hydraulic machine and components, which
use such fluids.
The rising costs and shortages of mineral oil based hydraulic fluid will certainly provide
the incentive to switch over to water based fluids. But in the various problems, which are yet to
be solved water hydraulics did not make any greet impact on industry in early half
1990’s.however any developments or research activities in this sphere will be of pioneering
nature and shall definitely be of great help to the organization engaged in such work.
There has been specific growth in the application of power during the
1960’s&1970’s.today the applications range from the artifices like gigantic machine tools,
injection molding machines, and presses.
These applications are likely to grow proliferate further in the future. During the last two
decades oil hydraulics has made great advances in the field of farm tractor, farm machinery and
implements. With the world facing the challenge of feeding and ever-increasing population, there
is bound to be phenomenal growth in farm mechanization.
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3. DESIGN CALCULATIONS
3.1 Factors affecting design of hydraulic circuits:
Space available: the available physical space within which a hydraulic cylinder or a fluid must
be accommodated may dictate the size of the cylinder or the fluid motor.
Force required: once the piston size is decided, the force required at the actuator depends on the
working pressure of the system. High the working pressure, lower is the size and weight of the
actuator, for the same force. But it results in many disadvantages.
Flow required: the speed of the actuator determines the flow capacity of the pump. Once the
flow capacity of the pump and the power of the systems working pressures are known, the power
of the prime mover can be easily be calculated. Thereby the size of the reservoir, the suction
strainer, the pipelines and all other valves are determined.
Environmental conditions: this determines whether the system should have ordinary or fire
proof hydraulic fluid in hazards condition, shock resistance on mobile use, non magnetic