Lubrication

Question 1

What are the three main types of friction?

Answer 1

Sliding, rolling, and fluid friction

Question 2

This type of friction occurs when two surfaces slide over each other, such as in journal bearings, or pistons sliding in a cylinder

Answer 2

Sliding friction

Question 3

This type of friction takes place when a spherical or cylindrical body rolls over a surface such as ball and roller bearings

Answer 3

Rolling friction

Question 4

This type of friction occurs when there is no metal to metal contact and sliding occurs between the layers of oil within the film

Answer 4

Fluid friction

Question 5

The reduction of friction to a minimum by the replacement of dry friction with fluid friction is called?

Answer 5

Lubrication

Question 6

This theory thats that these forces cause unlike materials to stick together (polar attraction)

Answer 6

Adhesion

Question 7

This theory states that these forces cause molecules of like materials to stick together

Answer 7

Cohesion

Question 8

When the adhesive forces are strong in oil it’s said to be high in?

Answer 8

Oiliness or lubricity

Question 9

What is the resistance to flow called?

Answer 9

Viscosity

Question 10

Which viscosity is thicker and pours more slowly?

Answer 10

High viscosity

Question 11

This is the most important property of lubricating oil

Answer 11

Viscosity

Question 12

The higher the viscosity of the oil, the _______ the load it will carry

Answer 12

Greater

Question 13

The higher the journal speed, the ______ the oil viscosity needed to carry a specific load

Answer 13

Lower

Question 14

To minimize power losses, the oil should have the ______ viscosity able to carry the load on the bearing

Answer 14

Lowest

Question 15

Choose the oil that has the desired viscosity at which temperature?

Answer 15

Operating temperature

Question 16

Which two ways is viscosity measured?

Answer 16

Dynamic and kinematic

Question 17

This viscosity is determined by measuring the force required to overcome fluid friction in a film or known dimensions. It’s used most frequently in bearing design and oil flow calculations

Answer 17

Dynamic or absolute viscosity

Question 18

This viscosity is a measure of viscosity that is affected by the density of the oil. It is used to often compare lubricants when both are measured at the same temperature

Answer 18

Kinematic viscosity

Question 19

The most common instrument used to measure viscosity is called?

Answer 19

Saybolt viscosimeter

Question 20

The specific viscosity reaction of an oil whose temperature changes is indicated by what?

Answer 20

Viscosity index

Question 21

The higher the viscosity index number, the ______ the change in viscosity due to temperature

Answer 21

Smaller

Question 22

The _______ forms and forces the shaft up toward the centre of the bearing

Answer 22

Oil wedge

Question 23

When the film of oil fails for a short time it is called?

Answer 23

Boundary or marginal lubrication

Question 24

This occurs when you over-lubricate a threaded hole and it presses the liquid causing the casing to crack

Answer 24

Hydraulic lock

Question 25

Additives are divided into these three main groups

Answer 25

Air control, water control, and load capacity

Question 26

This is the ability of a petroleum oil to separate from water upon standing

Answer 26

Demulsibility

Question 27

This is the ability of a petroleum oil to mix with water

Answer 27

Emulsibility

Question 28

These are added to the oil to reduce the rusting of ferrous parts

Answer 28

Rust inhibitors

Question 29

These additives are used for heavy load or shock load conditions

Answer 29

Extreme pressure (EP)

Question 30

Load capacity additives are separated into these two groups

Answer 30

Anti-wear and Extreme pressure

Question 31

What are the two types of oil lubrication systems?

Answer 31

Once-through/wasted oil system and Encloses

Question 32

Squirt cans, wick-feed oiler, and drip-feed oilers are which type of lubrication system?

Answer 32

Once-through

Question 33

Ring oiler, splash, oil bath, and re-circulating and which type of lubrication system?

Answer 33

Enclosed

Question 34

This type of lubrication is recommended for high-speed bearings and high-velocity roller chain

Answer 34

Oil mist lubrication

Question 35

This is usually made by thickening lubricating oils with a soap

Answer 35

Grease

Question 36

Soap content for general use greases range from what percent?

Answer 36

7-18%

Question 37

This type of grease is made by combining fatty acid with a base metal

Answer 37

Simple soap grease

Question 38

What is the most commonly used soap grease

Answer 38

Lithium and barium

Question 39

What type of grease is made by combining various types of soaps to extend the service life of grease

Answer 39

Mixed soap greases

Question 40

These greases are made from special soaps and are multi-purpose

Answer 40

Complex soap greases

Question 41

These greases are used to suit special conditions of temperature, environment or service life

Answer 41

Non-soap greases

Question 42

These greases are designed to allow one grease to be used instead of three or four separate grades

Answer 42

Multi-purpose greases

Question 43

This type of grease is designed for shock loading or high-local-pressure areas

Answer 43

Extreme-pressure (EP) greases

Question 44

How is grease consistency measured

Answer 44

Penetration numbers

Question 45

The NLGI ranges grease from softest to hardest with what numbers

Answer 45

000, 00, 0, 1, 2, 3, 4, 5, 6

Question 46

The temperature at which grease becomes fluid enough to drip is called

Answer 46

Dropping point

Question 47

Common grease dropping points range from

Answer 47

135 C (275F) to 182 C (360F)

Question 48

How high should the oil bath cover the bearing

Answer 48

Covers the bottom of the outer race, but does not cover the centre point of the lowest ball or roller

Question 49

What does over-oiling produce

Answer 49

Churning and a temperature rise

Question 50

Should you use oil or grease for high speeds

Answer 50

Oil

Question 51

Should you use oil or grease for heavy loads at low or medium speeds

Answer 51

Grease

Question 52

What are the three types of cutting oils

Answer 52

Straight, emulsifiable, and chemical