1. APPLIED HYDRAULICS AND PNEUMATICS U5MEA23
Prepared by
Mr. Jayavelu.S & Mr. Shri Harish
Assistant Professor, Mechanical Department
VelTech Dr.RR & Dr.SR Technical University

2. UNIT I : Fluid Power Systems and Fundamentals
Introduction to fluid power
Advantages of fluid power
Application of fluid power system
Types 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

3. Introduction to fluid power
Fluid power is a term describing hydraulics and pneumatics technologi es.
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.

4. Advantages 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

5. Application of fluid power system
Construction
Mining
Agriculture
Waste Reduction
Utility Equipment
Marine
Offshore
Energy
Metal Forming
Machine Tools
Military & Aerospace
Other Applications

6. Types of fluid power systems
Fluid 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

7. Properties of hydraulic fluids
Density
The density of a fluid is its mass per unit volu me:
Liquids are essentially incompressible 
Density is highly variable in gases nearly prop ortional to the pressure. 
Note: specific volume is defined as:

8. Viscosity Cohesion Adhesion
Viscosity is a measure of a fluid’s resistance to flo w. It determines the fluid strain rate that is gener ated by a given applied shear stress.
Cohesion
Intermolecular attraction between molecules of same liquid
Adhesion
Attraction between molecules of liquid and molecules of solid boundary in contact with liquid.

9. Cavitation Capillarity Vapour pressure
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

10. Compatibility Volatility Corrosiveness
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.

11. Application of pascals law
Hydraulic press

12. Hydraulic jack

13. Laminar and Turbulent flow

14. Reynolds number

15. Darcys equation

16. Losses in pipes, valves and fittings

17. UNIT 2: Hydraulic SYSTEM COMPONENTS
Sources 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.

18. Basic Pump Classifications
Hydraulic pumps can be classified using three basic aspects:
Displacement
Pumping motion
Fluid delivery characteristics

19. Basic 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

20. Basic Pump Classifications
A non-positive-displacement pump has large internal clearances
Allows fluid slippage in the pump
Results in varying flow output as system load varies

21. Basic Pump Classifications
Non-positive-displacement pump

22. Basic Pump Classifications
The basic pumping motions used in hydraulic pumps are:
Rotary
Reciprocating

23. Basic Pump Classifications
Gear pumps are rotary pumps
Sauer-Danfoss, Ames, IA

24. Basic Pump Classifications
Piston pumps are reciprocating pumps
Reciprocating piston movement

25. Basic Pump Classifications
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

26. Basic Pump Classifications
Hydraulic 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

27. Basic Pump Classifications
Gear pumps are fixed-delivery pumps

28. Basic Pump Classifications
Piston pumps may be designed as variable-delivery pumps

29. Basic Pump Classifications
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

30. Pump Design, Operation, and Application
Gear pumps are positive-displacement, fixed-delivery, rotary units
Gear pumps are produced with either external or internal gear teeth configurations

31. Pump Design, Operation, and Application
Gear pumps are commonly used

32. Pump Design, Operation, and Application
Pumping 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

33. Pump Design, Operation, and Application
Gear 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

34. Pump Design, Operation, and Application
The 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

35. Pump Design, Operation, and Application
The gerotor is a common internal-gear design

36. Pump Design, Operation, and Application
Gerotor operation

37. Pump Design, Operation, and Application
Gerotor operation

38. Pump Design, Operation, and Application
Gerotor operation

39. Pump Design, Operation, and Application
Gerotor operation

40. Pump Design, Operation, and Application
Vane 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

41. Pump Design, Operation, and 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

42. Pump Design, Operation, and Application
Operation of a typical vane pump

43. Pump Design, Operation, and Application
Parts of a typical vane pump

44. Pump Design, Operation, and Application
Vane 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

45. Pump Design, Operation, and Application
Piston 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

46. Pump Design, Operation, and Application
A 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

47. Pump Design, Operation, and Application
Piston pump classification is based on the relationship between the axes of the power input shaft and piston motion
Axial
Radial
Reciprocating

48. Pump Design, Operation, and Application
Axial piston pumps use two design variations:
Inline
Bent axis

49. Pump Design, Operation, and Application
Inline 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

50. Pump Design, Operation, and Application
An inline axial-piston pump

51. Pump Design, Operation, and Application
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

52. Pump Design, Operation, and Application
A bent-axis axial-piston pump

53. Pump Design, Operation, and Application
Radial 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

54. Pump Design, Operation, and Application
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

55. Pump Design, Operation, and Application
A stationary-cylinder radial-piston pump

56. Pump Design, Operation, and Application
Large, 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

57. Pump Design, Operation, and Application
Screw 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

58. Pump Design, Operation, and Application
A typical screw pump

59. Pump Design, Operation, and Application
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

60. Pump Design, Operation, and Application
Operation of a lobe pump

61. Pump Design, Operation, and Application
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

62. Pump Design, Operation, and Application
Operation of a centrifugal pump

63. Pump Design, Operation, and Application
Propeller 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

64. Pump Design, Operation, and Application
Construction of a propeller pump

65. Pump Design, Operation, and Application
Construction of a jet pump

66. Directional control valves
Check valve
Pilot operated check valve
Three-way and four-way valves
Manually-actuated valve
Pilot actuated valve
Solenoid actuated valve
Center flow path configuration
Shuttle valve

67. Directional control valves

68. Pilot operated check valve

69. Three-way valves

70. Four-way valves

71. Manually-actuated valve

72. Pilot actuated valve

73. Solenoid actuated valve

74. Pressure control valves
Pressure relief valve
Compound pressure relief valve
Pressure-reducing valve

75. Pressure relief valve

76. Compound pressure relief valve

77. Pressure-reducing valve

78. Flow control valve/ Needle valve
Restrictor needle valve

79. Weight loaded accumulator

80. Spring loaded accumulator

81. Diaphragm type accumulator

82. Bladder type accumulator

83. Intensifier

84. Unit 3: Pneumatic System Components
Pneumatic Components:
Properties of air. Compressors.
FRL Unit –
Air control valves,
Quick exhaust valves
pneumatic actuators- cylinders, air motors.

85. Compressor construction

86. Types of compressor

87. Piston type reciprocating 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.

88. Screw 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

89. Rotary 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.

90. Filter Air In Air Out Louver Filter Element Bowl Sight Gauge
Drain Cock

91. Adjustable Locking Knob
Regulator
Adjustable Locking Knob
Main Spring
Diaphragm Assembly
Air In
Air Out
Valve Spring
Valve Assembly

92. Lubricator

93. Quick Exhaust Valve 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 2 1 1 1 2

94. Unit 4: FLUIDICS & PNEUMATIC CIRCUIT DESIGN
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.

95. Fluidics

96. Bistable flip flop

97. SRT flip flop

98. OR/NOR & AND/NAND

99. Fluidic control of pneumatic cylinders

100. PLC

101. Ladder diagram

102. PLC control of hydraulic circuit

103. Cascading circuit

104. UNIT 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.

105. Speed control circuit

106. Regenerative circuit

107. Pressure intensifier circuit

108. Accumulator circuit

109. Pneumatic motor circuit

110. Regenerative drilling machine

111. Hydraulic fault diagnosis

112. Pneumatics fault diagnosis

113. Thank you.