Lubrication Theory

Question 1

Basic purposes of lubrication ?

Answer 1

Reduce friction, Wear, Corrosion, Dampen Shock, Provide Cooling, Minimize contaminates

Question 2

Definition of Friction?

Answer 2

Force which acts between two surfaces to resist their sliding it rolling across each other

Question 3

Describe different types of friction?

Answer 3

Static Friction- Exists between a body at rest
Kinetic Friction-exists between moving bodies

Question 4

Dry Film

Answer 4

Natural lubricator(water vapor, oxide film, absorbed gases)

Question 5

Mixed Film

Answer 5

Metal-metal contact
High degree of friction
Single layer of lubrication

Question 6

Boundary Film

Answer 6

Some metal-metal contact
Thicker film layer
Startup/shutdown
Draws lubricant as component moves

Question 7

Full Film

Answer 7

Surfaces completely covered with multiple layers

Question 8

Full Film-hydrodynamic

Answer 8

Maintains separation of loaded surface
High pressure
High viscosity under increase load

Question 9

Full Film-Hydrostatic

Answer 9

Film is provided from outside source

Used for slow, heavy loads

Question 10

Oil wedge

Answer 10

Layer of oil that forms around journal when it starts rotating

Question 11

What is needed for oil wedge to be created by?

Answer 11

Cohesion, Adhesion, and Viscosity

Question 12

General classification of lubricants?

Answer 12

Liquid,Semisolid,Solid, Gas

Question 13

Liquid lubricant

Answer 13

Mineral oils from crude oil

Oils from animal or vegetable fats

Question 14

Semisolid Lubricant

Answer 14

Greases made by thickening agent

Question 15

Solid Lubricant

Answer 15

Teflon or graphoil

Question 16

Gas Lubricant

Answer 16

Required for separation or high temps.

Question 17

What make viscosity change?

Answer 17

Temps. Increases- viscosity lowers (think of water)
Press. Increases- Viscosity raises (syrup)

Question 18

Viscosity- Light oils

Answer 18

High speed
Low-Pressure
Low Temp.

Question 19

Viscosity-Heavy oils

Answer 19

Low speed
High pressure
High temperature

Question 20

Dynamic viscosity

Answer 20

Measure of force

Question 21

Kinematic Viscosity

Answer 21

Measure of velocity

Question 22

Flash point

Answer 22

Oil vaporized enough to ignite

Need spark or flame

Question 23

Fire point

Answer 23

Temp. when oil will continue to burn

Higher temp. than flash point

Question 24

Auto-Ignition

Answer 24

Flammable vapors from oil will burn without spark or flame

Question 25

Low flash point

Answer 25

Oil easily vaporized

Question 26

Properties of grease?

Answer 26

Light or heavy oil Thickener(soap most common) Additives(graphite,asbestos,zinc)

Question 27

Gravity/ drip feed

Answer 27

Lubricant above or beside point of required lubrication Adjustable needle valve Vibrating pin Wick oiler

Question 28

Natural lubrication methods?

Answer 28

Splash Oilers & Ring Oilers

Question 29

Pressure / Force Feed lube methods?

Answer 29

Wet sump -internal to machine Dry Sump-oil sump and pump external AirLine lubricators- oil flows through Venturi and sprays oil mist

Question 30

Oil purification methods?

Answer 30

Gravity settling, Lube oil conditioner, and Varnish removal system

Question 31

Gravity settling

Answer 31

Simple but very slow Large space requirements Lube oil storage tanks

Question 32

Lube Oil conditioner

Answer 32

Removes water particulates from MTLO system by filtering action

Question 33

Varnish removal system

Answer 33

Removes soft contaminants that cause varnish (sludge)

Question 34

Symptoms Improper lubrication

Answer 34

High temp. Vibration Noisy Components Eventual failure Chemical decomposition Contamination Temp. Inadequate flow Excess water/air in oil

Question 35

Lubrication Inside storage ?

Answer 35

Storage lockers Fireproof constructed rooms All lubricants easily accessible Markings clearly visible Use older lubricants first

Question 36

Outside storage

Answer 36

55 gallon drum placed on sides and covered Drum raised off ground(prevent corrosion)

Question 37

Safety handling lubricant

Answer 37

No smoking around lube storage Adequate ventilation Wear gloves,long sleeved shirts Safety glasses avoid eye contact

Question 38

Oil spills

Answer 38

Pigs contain soak puddles Oil absorbent container put under small leaks

Question 39

Call Environmental department when ?

Answer 39

Surface oil contamination Ground water contamination Air pollution

Question 40

Lubrication of plant equipment procedure?

Answer 40

Lubrication additions techniques Topping off lubricant levels Oil changes Greasing bearings What normal looks like