Ppt Mech 5sem AHP

APPLIED HYDRAULICS AND APPLIED HYDRAULICS AND PNEUMATICSPNEUMATICS U5MEA23U5MEA23

Prepared by Mr. Jayavelu.S & Mr. Shri HarishAssistant Professor, Mechanical DepartmentVelTech Dr.RR & Dr.SR Technical University

UNIT I : FLUID POWER UNIT I : FLUID POWER SYSTEMS AND SYSTEMS AND FUNDAMENTALSFUNDAMENTALS Introduction to fluid power Advantages of fluid powerApplication of fluid power systemTypes of fluid power systems, General types of fluids

◦ Properties of hydraulic fluids ◦ Fluid power symbols

Basics of Hydraulics◦ Applications of Pascal’s Law ◦ Laminar and Turbulent flow ◦ Reynolds’s number ◦ Darcy’s equation ◦ Losses in pipe, valves and fittings

Introduction to fluid power Introduction to fluid power Fluid power is a term

describing hydraulics and pneumatics technologies.

Both technologies use a fluid (liquid or gas) to transmit power from one location to another.

hydraulics, the fluid is a liquid (usually oil), pneumatics uses a gas (usually compressed

air). Both are forms of power transmission, which

is the technology of converting power to a more useable form and distributing it to where it is needed.

The common methods of power transmission are electrical, mechanical, and fluid power.

Advantages of fluid powerAdvantages of fluid power high horsepower-to-weight ratio — You could probably

hold a 5-hp hydraulic motor in the palm of your hand, but a 5-hp electric motor might weight 40 lb or more.

safety in hazardous environments because they are inherently spark-free and can tolerate high temperatures.

force or torque can be held constant — this is unique to fluid power transmission

high torque at low speed — unlike electric motors, pneumatic and hydraulic motors can produce high torque while operating at low rotational speeds. Some fluid power motors can even maintain torque at zero speed without overheating

pressurized fluids can be transmitted over long distances and through complex machine configurations with only a small loss in power

multi-functional control — a single hydraulic pump or air compressor can provide power to many cylinders, motors, or other actuators

elimination of complicated mechanical trains of gears, chains, belts, cams, and linkages

motion can be almost instantly reversed

Application of fluid power Application of fluid power systemsystemConstructionMiningAgricultureWaste ReductionUtility EquipmentMarineOffshoreEnergyMetal FormingMachine ToolsMilitary & AerospaceOther Applications

Types of fluid power Types of fluid power systemssystemsFluid transport system

◦Transport of water from reservoir using pipe lines

◦Transport of oil in pipe to two countries.

Fluid power system◦Oil used in equipments to acquire

desire movement.◦Compressed air in pneumatics for

crane movements

Properties of hydraulic Properties of hydraulic fluids fluids Density

◦The density of a fluid is its mass per unit volume:

◦Liquids are essentially incompressible

◦Density is highly variable in gases nearly proportional to the pressure.

◦ Note: specific volume is defined as:

Cavitation◦Cloud of vapour bubble will form

when liquid pressure drops below vapour pressure due to flow phenomenon

Capillarity◦Liquid rises into a thin glass tube

above or below its general level. Vapour pressure

◦Pressure exerted by vapour which is in equilibrium with liquid

Compatibility◦Ability of hydraulic fluid to be

compatible with the system.Volatility

◦The degree and rate at which it will vapourize under given conditions of temperature and pressure.

Corrosiveness◦Tendency to promote corrosion in

hydraulic system.

Application of pascals lawApplication of pascals lawHydraulic press

Hydraulic jack

Laminar and Turbulent Laminar and Turbulent flowflowLaminarTurbulent

Reynolds numberReynolds number

Darcys equationDarcys equation

Losses in pipes, valves and Losses in pipes, valves and fittingsfittings

UNIT 2: HYDRAULIC SYSTEM UNIT 2: HYDRAULIC SYSTEM COMPONENTSCOMPONENTSSources of Hydraulic Power

◦construction and working of pumps – Variable displacement pumps

◦Actuators: Linear hydraulic actuators◦Single acting and Double acting

cylinders ◦Fluid motors.

Control Components: Direction control valve Flow control valves Electrical control -- solenoid valves. Relays,

Accumulators and Intensifiers.

Basic Pump ClassificationsBasic Pump ClassificationsHydraulic pumps can be

classified using three basic aspects:◦Displacement◦Pumping motion◦Fluid delivery characteristics

Basic Pump ClassificationsBasic Pump Classifications

Displacement relates to how the output of the pump reacts to system loads◦Positive-displacement pumps produce a

constant output per cycle◦Non-positive-displacement pumps

produce flow variations due to internal slippage

Basic Pump ClassificationsBasic Pump ClassificationsA non-positive-displacement

pump has large internal clearances◦Allows fluid slippage in the pump◦Results in varying flow output as

system load varies

Basic Pump ClassificationsBasic Pump ClassificationsNon-positive-displacement pump

Basic Pump ClassificationsBasic Pump ClassificationsThe basic pumping motions used

in hydraulic pumps are:◦Rotary◦Reciprocating

Basic Pump ClassificationsBasic Pump ClassificationsGear pumps are rotary pumps

Sauer-Danfoss, Ames, IA


Piston pumps are reciprocating pumps

Reciprocating piston movement


In a rotary pump, the pumping action is produced by revolving components

In a reciprocating pump, the rotating motion of the pump input shaft is changed to reciprocating motion, which then produces the pumping action

Basic Pump ClassificationsBasic Pump ClassificationsHydraulic pumps are classified as

either fixed or variable delivery◦Fixed-delivery pumps have pumping

chambers with a volume that cannot be changed; the output is the same during each cycle

◦In variable-delivery designs, chamber geometry may be changed to allow varying flow from the pump

Basic Pump ClassificationsBasic Pump ClassificationsGear pumps are fixed-delivery

pumps

Basic Pump ClassificationsBasic Pump ClassificationsPiston pumps may be designed

as variable-delivery pumps


When selecting a pump for a circuit, factors that must be considered are:◦System operating pressure◦Flow rate◦Cycle rate◦Expected length of service◦Environmental conditions◦Cost

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationGear pumps are positive-

displacement, fixed-delivery, rotary units

Gear pumps are produced with either external or internal gear teeth configurations

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationGear pumps are commonly used

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationPumping action of gear pumps

results from unmeshing and meshing of the gears◦As the gears unmesh in the inlet area,

low pressure causes fluid to enter the pump

◦As the pump rotates, fluid is carried to the pump discharge area

◦When the gears mesh in the discharge area, fluid is forced out of the pump into the system

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationGear pumps are available in a

wide variety of sizes◦Flow outputs from below 1 gpm to

150 gpm◦Pressure rating range up to 3000 psi

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationThe gerotor pump design is an

internal-gear pump◦Uses two rotating, gear-shaped

elements that form sealed chambers◦The chambers vary in volume as the

elements rotate◦Fluid comes into the chambers as

they are enlarging and is forced out as they decrease in size

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationThe gerotor is a common

internal-gear design

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationGerotor operation




Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationVane pumps are positive-

displacement, fixed or variable delivery, rotary units.◦Design is commonly used in

industrial applications◦Delivery can range up to 75 gpm◦Maximum pressure of about 2000 psi

Pump Design, Operation,Pump Design, Operation,and Applicationand Application

Vane pump consists of a slotted rotor, fitted with moveable vanes, that rotates within a cam ring in the pump housing◦Rotor is off center in the ring, which

creates pumping chambers that vary in volume as the pump rotates

◦As chamber volume increases, pressure decreases, bringing fluid into the pump

◦As volume decreases, fluid is forced out into the system

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationOperation of a typical vane pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationParts of a typical vane pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationVane pump may be pressure

unbalanced or pressure balanced◦Unbalanced has only one inlet and

one discharge, which places a side load on the shaft

◦Balanced has two inlets and two discharges opposite each other, creating a pressure balance and, therefore, no load on the shaft

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationPiston pumps are positive-

displacement, fixed- or variable-delivery, reciprocating units◦Several variations◦Many provide high volumetric

efficiency (90%), high operating pressure (10,000 psi or higher), and high-speed operation

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationA basic piston pump consists of a

housing that supports a pumping mechanism and a motion-converting mechanism◦Pumping mechanism is a block

containing cylinders fitted with pistons and valves

◦Motion converter changes rotary to reciprocating motion via cams, eccentric ring, swash plate, or bent-axis designs

◦Rotating the pump shaft causes piston movement that pumps the fluid

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationPiston pump classification is

based on the relationship between the axes of the power input shaft and piston motion◦Axial◦Radial◦Reciprocating

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationAxial piston pumps use two

design variations:◦Inline◦Bent axis

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationInline has the cylinder block and

pistons located on the same axis as the pump input shaft◦Pistons reciprocate against a swash

plate◦Very popular design used in many

applications


An inline axial-piston pump


Bent axis has the cylinder block and pistons set at an angle to the input shaft◦Geometry of the axis angle creates

piston movement◦Considered a more rugged pump than

inline◦Manufactured in high flow rates and

maximum operating pressures

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationA bent-axis axial-piston pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationRadial piston pumps have the

highest continuous operating pressure capability of any of the pumps regularly used in hydraulic systems

Models are available with operating pressure ratings in the 10,000 psi range


Two variations of radial piston pumps:◦Stationary-cylinder design uses springs

to hold pistons against a cam that rotates with the main shaft of the pump

◦Rotating-cylinder design uses centrifugal force to hold pistons against a reaction ring

When the main shaft is rotated, each piston reciprocates, causing fluid to move through the pump

Pump Design, Operation,Pump Design, Operation,and Applicationand Application A stationary-cylinder radial-

piston pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationLarge, reciprocating-plunger

pump designs were widely used when factories had a central hydraulic power source

Today, plunger pumps are typically found in special applications requiring high-pressure performance

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationScrew pumps have pumping

elements that consist of one, two, or three rotating screws

As the screws rotate, fluid is trapped and carried along to the discharge of the pump

The design of screw pumps allows them to operate at a very low noise level

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationA typical screw pump


The lobe pump is a close relative of the gear pump◦Two three-lobed, gear-shaped units are

often used to form the pumping element

◦Output flow is larger than a gear pump of comparable physical size because of pumping chamber geometry

◦Lower pressure rating than gear pumps◦Tend to have a pulsating output flow

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationOperation of a lobe pump


Centrifugal pumps are non-positive-displacement units◦Use centrifugal force generated by a

rotating impeller to move fluid◦Large clearances between the impeller

and the pump housing allow internal pump slippage when resistance to fluid flow is encountered in the system

◦Typically used in hydraulic systems as auxiliary fluid transfer pumps

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationOperation of a centrifugal pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationPropeller and jet pumps are non-

positive-displacement pumps◦Sometimes used to transfer fluid

within hydraulic systems◦Propeller pump consists of a rotating

propeller-shaped pumping element◦Jet pump creates flow by pumping

fluid through a nozzle concentrically located within a venturi

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationConstruction of a propeller pump

Pump Design, Operation,Pump Design, Operation,and Applicationand ApplicationConstruction of a jet pump

Directional control valvesDirectional control valves

Check valvePilot operated check valve Three-way and four-way valvesManually-actuated valvePilot actuated valve Solenoid actuated valveCenter flow path configurationShuttle valve

Directional control valvesDirectional control valves

Pilot operated check valvePilot operated check valve

Three-way valvesThree-way valves

Four-way valvesFour-way valves

Manually-actuated valveManually-actuated valve

Pilot actuated valvePilot actuated valve

Solenoid actuated valveSolenoid actuated valve

Pressure control valvesPressure control valves

Pressure relief valveCompound pressure relief valvePressure-reducing valve

Pressure relief valvePressure relief valve

Compound pressure relief Compound pressure relief valvevalve

Pressure-reducing valve Pressure-reducing valve

Flow control valve/ Needle Flow control valve/ Needle valvevalve

Restrictor needle valve

Weight loaded Weight loaded accumulatoraccumulator

Spring loaded Spring loaded accumulatoraccumulator

Diaphragm type Diaphragm type accumulatoraccumulator

Bladder type accumulatorBladder type accumulator

IntensifierIntensifier

UNIT 3: PNEUMATIC SYSTEM UNIT 3: PNEUMATIC SYSTEM COMPONENTSCOMPONENTS

Pneumatic Components: Properties of air. Compressors. FRL Unit – Air control valves, Quick exhaust valves pneumatic actuators- cylinders,

air motors.

Compressor constructionCompressor construction

Types of compressorTypes of compressor

Fig shows single-acting piston actions in the cylinder of a reciprocating compressor.

The piston is driven by a crank shaft via a connecting rod. At the top of the cylinder are a suction valve and a

discharge valve. A reciprocating compressor usually has two, three, four, or

six cylinders in it.

Piston type reciprocating Piston type reciprocating compressorcompressor

Screw compressorScrew compressor Screw compressors are also belong to the

positive displacement compressor family. In screw compressors, the compression is

accomplished by the enmeshing of two mating helically grooved rotors suitably housed in a cylinder equipped with appropriated inlet and discharge ports

Rotary vane compressorRotary vane compressor The rotor shaft is mounted eccentrically in a

steel cylinder so that the rotor nearly touches the cylinder wall on one side, the two being separated only by an oil film at this point.

Directly opposite this point the clearance between the rotor and the cylinder wall is maximum.

Heads or end-plates are installed on the ends of the cylinder and to hold the rotor shaft.

The vanes move back and forth radially in the rotor slots as they follow the contour of the cylinder wall when the rotor is turning.

The vanes are held firmly against the cylinder wall by action of the centrifugal force developed by the rotating rotor.

In some instances, the blades are spring-loaded to obtain a more positive seal against the cylinder wall.

Air In Air Out

Louver

Bowl

Filter Element

Sight Gauge

Drain Cock

FilterFilter

Air In Air Out

Adjustable Locking

Knob Main Spring

Diaphragm Assembly

Valve Assembly

Valve Spring

RegulatorRegulator

LubricatorLubricator

Quick Exhaust ValveQuick Exhaust Valve

1

2

Port 2 is connected directly to the end cover of a cylinder

Port 1 receives air from the control valve

Air flows past the lips of the seal to drive the cylinder

When the control valve is exhausted, the seal flips to the right opening the large direct flow path

Air is exhausted very rapidly from the cylinder for increased speed

1

2

1

2

Unit 4: Unit 4: FLUIDICS & PNEUMATIC CIRCUIT FLUIDICS & PNEUMATIC CIRCUIT DESIGNDESIGN

Fluidics – Introduction to fluidic devices, simple circuits Introduction to Electro Hydraulic Pneumatic logic circuits, PLC applications in fluid power control, ladder diagrams

Fluid Power Circuit Design: Sequential circuit design for simple applications using classic, cascade, step counter, logic with Karnaugh- Veitch Mapping and combinational circuit design methods.

FluidicsFluidics

Bistable flip flopBistable flip flop

SRT flip flopSRT flip flop

OR/NOR & AND/NANDOR/NOR & AND/NAND

Fluidic control of Fluidic control of pneumatic cylinderspneumatic cylinders

PLCPLC

Ladder diagramLadder diagram

PLC control of hydraulic PLC control of hydraulic circuitcircuit

Cascading circuitCascading circuit

UNIT 5: FLUID POWER CIRCUITSUNIT 5: FLUID POWER CIRCUITS

Speed control circuits, synchronizing circuit, Pneumo hydraulic circuit, Accumulator circuits, Intensifier circuits. Servo systems – Hydro Mechanical servo systems, Electro hydraulic servo systems and proportional valves.

Deceleration circuit, hydrostatics transmission circuits, control circuits for reciprocating drives in machine tools, Material handling equipments. Fluid power circuits; failure and troubleshooting.

Speed control circuitSpeed control circuit

Regenerative circuitRegenerative circuit

Pressure intensifier circuitPressure intensifier circuit

Accumulator circuitAccumulator circuit

Pneumatic motor circuitPneumatic motor circuit

Regenerative drilling Regenerative drilling machinemachine

Hydraulic fault diagnosisHydraulic fault diagnosis

Pneumatics fault diagnosisPneumatics fault diagnosis

Thank you.Thank you.

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Ppt Mech 5sem AHP