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hydraulic subtopic
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Lecturer :
Dr. Mohd Fadzil Faisae b. Ab. Rashid
Synopsis - This course introduces hydraulic system, hydraulic
components, hydraulic system design, pneumatics system, pneumatic components, pneumatic system design, electro fluid power system and its design, as well as programmable logic controller (PLC) and its design.
By the end of semester, students should be able to:
CO1: Explain, design and analyze the hydraulic system
CO2: Explain, design and analyze the pneumatic system
CO3: Explain and analyze of electro fluid power system with electro components
CO4: Design and analyze of electro fluid power with programmable logic controller system via simulation and experimental
Mid-Exam 20%
Laboratory 15%
Project & Presentation 25%
Final Exam 40%
Total 100%
1. Esposito A, 2008, Fluid Power with Applications, 7th Ed., Prentice Hall
2. Ilango S. and Soundararajan V., 2007, Introduction to Hydraulics and Pneumatics, Prentice Hall of India
3. Parr, A. (2002). Hydraulics and Pneumatic: A Technician’s and Engineer Guide. 2ed. Butterworth Heinemann.
4. Norvelle, F.D. (2002). Fluid Power technology. West Publishing Company
5. Pinshes, M.J. and Ashby, J.G. (2002). Power Hydraulics, Pearson Prentice-Hall, Inc.
6. Croser, P and Ebel, F (2000). Pneumatic: Basic Level Text Book. Festo Didactic GmbH & Co.
The first and most wonderful hydraulic system. It includes a double pump delivering a fluid flow rate of about 10 L/min at 0.16 bar maximum pressure. This pump feeds a piping network stretching more than 100,000 km. That’s nearly two and a half times around the Earth. It operates continuously for a very long time, mostly maintenance free.
It is the human blood circulatory system. By the age of 50 years, the hearts of 10 men should have pumped a volume of blood equaling that of the great Egyptian pyramid (2,600,000 m3).
What is hydraulic?
What is pneumatic?
What is fluid power?
FLUID POWER
Hydraulics
Liquid-based systems
Water, oil (more commonly used)
Pneumatics
Gas-based systems
Compressed air, nitrogen
(occasionally used)
Technology that deals with generation, control and transmission of power, using pressurized fluids
Hydraulics – when the fluid is liquid
Pneumatics – when the fluid is gas
Science of forces movement transmitted by means of liquids
Hydro-mechanics – hydrostatics - hydrodynamics
Hydrostatics - the power is transmitted by increasing the pressure energy of liquid. E.g. car lifter, forklift etc.
Hydrodynamics - power systems is transmitted
by increasing the kinetic energy of liquid. These systems include a rotodynamic pump, a turbine, and additional control elements.
Electrical Hydraulic Pneumatic
Energy source Usually from outside supplier
Electric motor or diesel driven
Electric motor or diesel driven
Energy storage Limited (batteries) Limited (accumulator)
Good (reservoir)
Distribution system Excellent, with minimal loss
Limited, basically a local facility
Good
Energy cost Lowest Medium Highest
Rotary actuators AC & DC motors. Good control on DC motors, AC motors cheap.
Low speed. Good control. Can be stalled.
Wide speed range, Accurate speed control difficult
Electrical Hydraulic Pneumatic
Linear actuators Short motion via solenoid. Otherwise, via mechanical conversion.
Cylinders. Very high force.
Cylinders. Medium force.
Controllable force Possible with solenoid & DC motors. Complicated by need for cooling.
Controllable high force.
Controllable medium force.
Points to note Danger from electric shock
Leakage dangerous and unsightly. Fire hazard.
Noise
1. Very high force despite small components (if pneumatics,
bigger components are needed for high force, thus, incur high
cost as well as wastage of compressed air)
2. Very slow and linear movements (if pneumatics, too slow will
create jerking on the cylinder)
3. Very exact positioning (stops exactly on a point). Compared
to pneumatics, there’s a tolerance and if a load is given, it will
move a little.
4. Start-up under heavy loads (Possible to start the motor &
process a job with a load attached to it. This is because there
is oil in the actuator though the pump is idling).
6. When overload, stall without damage
7. Better power/weight ratio
8. Fluid is non compressible
1. Slow movement of actuators (Pneumatics
are faster)
2. Messy (Leakage may occur and if not
bothered, the surrounding area could be
messy. However, constant cleaning could
avoid messy.)
3. Dangerous!
i. It produces extreme pressure and if there’s a
leakage, oil will be forced out. Stopping the
flow with bare hand would result in a
punctuated wound.
ii. While in process, oil became hot and
flammable (though not easily happened).
Therefore, it is advisable to control the
temperature by limiting it (turning off the
machine if the limit is exceeded).
Machines – hydraulic presses, drilling, milling, bending,
cutting, CNC
Aerospace – plane landing wheel
Defense – tanks, gun moving mechanism
Marine – opening and closing storage, safety doors
Dam – lifting and lowering gates
Construction – crane, excavator, concrete mixer, etc
Mobile Hydraulics Stationary Hydraulics
Using manual hydraulics to control
•Crane
•Excavator
•Back-hoe
Using electro-hydraulics to control
•Press machine
•Molding machine
•Lathe machine