Week 1 1_introduction

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