MSY 1

Fluid Power ApplicationFluid Power ApplicationPhysical PropertiesPhysical Properties

Hydraulics & Pneumatics Hydraulics & Pneumatics

KMD 3133KMD 3133

22

ObjectivesObjectives

Understand;Understand;

1.1. Function -hydraulic fluid.Function -hydraulic fluid.

2.2. Term-fluid.Term-fluid.

3.3. Distinguish-liquid,gas.Distinguish-liquid,gas.

4.4. Define -weight, density and specific Define -weight, density and specific gravity.gravity.

MSYMSY

Objectives (cont…)Objectives (cont…)

6.6. Pressure, head, and force.Pressure, head, and force.

7.7. Differentiate-gage pressure,absolute Differentiate-gage pressure,absolute pressures.pressures.

8.8. Calculate-force,pressure.Calculate-force,pressure.

8.8. Pascal’s law Pascal’s law

33MSYMSY

MSYMSY 44

• Characteristics -crucial effect, application, Characteristics -crucial effect, application, performance,life.performance,life.

• Efficient-clean, high-qualityEfficient-clean, high-quality

• Modern Hydraulic-complex,carefullyModern Hydraulic-complex,carefully

• Special additives-desired characteristics.Special additives-desired characteristics.

INTRODUCTION INTRODUCTION HYDRAULICS FLUID HYDRAULICS FLUID

MSYMSY 55

Hydraulics Fluid Hydraulics Fluid IntroductionIntroduction(4)four primary functions;(4)four primary functions;

1.1. Transmitting power.Transmitting power.

2.2. Lubricating moving parts.Lubricating moving parts.

3.3. Seal clearances between mating Seal clearances between mating parts.parts.

4.4. Dissipate heat.Dissipate heat.

Transmitting powerTransmitting power

MSYMSY 66

Pump & Turbine

Lubricating moving partsLubricating moving parts

MSYMSY 77

Engine

EFFICIENCY OF FLUIDEFFICIENCY OF FLUID

88MSYMSY

99

PropertiesProperties

Ensure-practical,safety,cost Ensure-practical,safety,cost 1.1. Good LubricityGood Lubricity2.2. Ideal viscosityIdeal viscosity3.3. Chemical & environmental stabilityChemical & environmental stability4.4. Compatibility with system materialsCompatibility with system materials5.5. High degree of incompressibilityHigh degree of incompressibility6.6. Fire resistanceFire resistance

MSYMSY

Properties (cont…)Properties (cont…)

7.7. Good heat-transfer capabilityGood heat-transfer capability8.8. Low densityLow density9.9. Foam resistanceFoam resistance10.10.Non-toxicityNon-toxicity11.11.Low volatilityLow volatility12.12.InexpensiveInexpensive13.13.Ready availableReady available

1010MSYMSY

1111

PropertiesProperties

• In reality - no idealIn reality - no ideal

• Designers -closest to being idealDesigners -closest to being ideal

• Change periodically –viscosity & acidity Change periodically –viscosity & acidity increaseincrease

MSYMSY

Quality indicatorQuality indicator1.1. Viscosity.Viscosity.2.2. Water content.Water content.3.3. Foreign particle contamination level.Foreign particle contamination level.

1212MSYMSY

1313

Fluids – LiquidsFluids – Liquids

• Fluid-gases,liquidsFluid-gases,liquids

• Liquids – definite volumeLiquids – definite volume

• Shape-container.Shape-container.

MSYMSY

1414

Fluids – LiquidsFluids – Liquids

• Incompressible Incompressible

• Change-small,ignoredChange-small,ignored

MSYMSY

1515

Fluids – GasesFluids – Gases

• Gases –compressible.Gases –compressible.• Volume-vessel containing them.Volume-vessel containing them.

MSYMSY

1616

Fluids – GasesFluids – Gases

• Volume-influence, pressureVolume-influence, pressure

• Increase -volume to decrease.Increase -volume to decrease.

• Air-commonin, expensive and readily Air-commonin, expensive and readily available.available.

MSYMSY

1717

Fluids – GasesFluids – Gases

Advantages;Advantages;

1.1. Fire resistantFire resistant2.2. Not messyNot messy3.3. Can be exhausted back into the Can be exhausted back into the

atmosphere.atmosphere.

MSYMSY

DisadvantagesDisadvantages1.1. Compressibility – not suitable for accurate Compressibility – not suitable for accurate

positioning, rigid holdingpositioning, rigid holding

2.2. Due to compressibility – tends to be sluggish.Due to compressibility – tends to be sluggish.

3.3. Corrosive -OCorrosive -O22 and H and H2200

4.4. Added to lubricantAdded to lubricant

5.5. Limited pressures -250 Limited pressures -250 psi,explosion,compress create energypsi,explosion,compress create energy

1818MSYMSY