chapter 1 introduction to fluid power - pbworks · pdf filethe fluid power field introduction...

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Chapter 1Chapter 1

The Fluid Power FieldThe Fluid Power Field

Introduction to Fluid PowerIntroduction to Fluid Power

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ObjectivesObjectives

Define the terms fluid power, hydraulic system, and pneumatic systemand pneumatic system. Explain the extent of fluid power use in current

society and provide several specific examples. List the advantages and disadvantages of fluid

power systems.

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only.3

Discuss scientific discoveries and applications important to the historical development of the fluid power industry.

Definition of Fluid PowerDefinition of Fluid Power

A fluid power system consists of a prime mover turning a pump to pressurize a fluid, which is transmitted through lines to an actuator that performs work.


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Definition of Fluid PowerDefinition of Fluid Power

Fluid power systems are generally grouped under two broad classifications:– Hydraulics

– Pneumatics

Hydraulic systems generally use oil as the system fluid while pneumatic systems use


system fluid, while pneumatic systems use air.

Fluid Power SystemsFluid Power Systems

Comparisons of hydraulic and pneumatic systems may be done by analyzing:– Operating pressure

– Accuracy of actuator movement

– Actuator speed

– Component weight


– Component weight

– System cost

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Hydraulic systems are accurate, operate at high pressures, are slow, and have strong components.


(Brand X)


Compared to hydraulic systems, pneumatic systems:– Are less accurate

– Are faster

– Have components that are lighter in weight


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Advantages of both hydraulic and pneumatic systems include easy control of:– Force

– Torque

– Speed

– Direction of actuators


– Direction of actuators

History of Fluid PowerHistory of Fluid Power

The natural movement of air and water was used in the earliest applications of fluid power.

Some industries still


Some industries still use this natural movement.

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Wind and watermills were used as prime movers to provide power until well into the Industrial Revolution, which occurred in the eighteenth and nineteenth centuries.



Early wind and watermills had very low power outputs. The output was usually in the 3 to 5 horsepower range, with an output of 15 horsepower considered high.

Historians feel that many early machines/devices were developed and


machines/devices were developed and operated using empirical knowledge, rather than scientific theory.

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Archimedes is credited with the discovery in the third century BC of the principle of buoyancy. This is one of the earliest recorded scientific theories.

Scientists such as Pascal, Boyle, Charles, Reynolds and others provided information


Reynolds, and others provided information that served as a theoretical base for the use of fluids in scientific and industrial applications.


James Watt perfected the steam engine, which influenced many aspects of the Industrial Revolution including fluid power components


p pand systems.

Comstock

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Accurate machining and the development of effective sealing devices had a positive effect on the early development of hydraulic presses.


Photo courtesy of Apple Rubber Products, Inc.


Compact, self-contained power units, which contained the prime mover, pump, and reservoir, were developed in the early 1900s.

These units had considerable influence on the development of fluid power as we know it today


it today.

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Self-contained power units


Continental Hydraulics

Fluid Power TodayFluid Power Today

Fluid power systems are used extensively throughout business and industry today.


y y

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Few products are not influenced in some way by fluid power systems.



Fluid power in various forms is widely used in everyday lifeused in everyday life.


PhotoDisc

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Review QuestionReview Question

The physical components in a fluid power t d t dsystem are used to _____, _____, and _____

power to produce the desired results in an application.


generate; transmit; control


Name six industries in which fluid power li ti t ib t t d il ti dapplications contribute to daily operations and

long-term business success.

Manufacturing, transportation, mining,


agriculture, construction, and recreation. (other answers are possible)

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The pneumatic fluid power system is generally id d t b th t i t tconsidered to be the most expensive to operate

because of the cost of _____, _____, and _____ the air.

compressing; conditioning; distributing


compressing; conditioning; distributing


It is generally believed by historians that much f th l d l t f fl idof the early development of fluid power was

based on _____, rather than on an understanding of scientific principles.

practical experimentation or tinkering


practical experimentation, or tinkering

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GlossaryGlossary

Actuator – A component used to convert the energy in

hydraulic fluid or compressed air into mechanical linear or rotary motion.

Archimedes– The individual credited with the discovery of the


yprinciple of buoyancy. The discovery was made in the third century BC.

GlossaryGlossary

Boyle, Robert– A scientist of the 17th century identified as one of

the first to study the characteristics of gases.

Charles, Jacques– A French scientist of the late 18th and early 19th

centuries who is credited with developing a


p gscientific law relating to the effect of temperature on the volume of a gas.

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GlossaryGlossary

Fluid powerTh t f i t lli d ti f– The transferring, controlling, and converting of energy using hydraulic and pneumatic systems.

Hydraulics– The study and technical application of liquids in

motion, especially oils and other blended liquids used in industrial systems


used in industrial systems.

GlossaryGlossary

Pascal, Blaise– A scientist of the early 17th century who is credited

with producing proof of many basic fluid principles.

Pneumatics– The study and technical application of air or other

gas in motion.


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GlossaryGlossary

Pump– A hydraulic component turned by the prime mover

that produces fluid flow, which transmits energy through the system.


GlossaryGlossary

Reynolds, OsborneA scientist of the late 1800s who did extensive– A scientist of the late 1800s who did extensive development work in the fluid mechanics area. Reynolds is credited with identification of the principles of laminar and turbulent flow.


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GlossaryGlossary

Watt, James– An inventor of the late 18th century who

extensively contributed to growth during the Industrial Revolution. Watt is typically identified as the inventor of the first practical steam engine.


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