Lubrication

Question 0

The 3 types of lubrication?

Answer 0

• Full Film
• Elasto-hydrodynamic
• Boundary

Question 1

Lubrication reduces friction?

Answer 1

-separating the moving surfaces with a film that has less friction than the moving surfaces

Question 2

Full Film

Answer 2

-thick enough to completely separate the surfaces with a continuous film

Question 3

Elasto-hydrodynamic

Answer 3

• completely separates two surfaces and is a type of full film lubrication
• but the two surfaces are loaded to the extent that deformation takes place in the loaded zone

Question 4

Boundary

Answer 4

• forms at low speeds
• forms when viscosity is too low to support the load
• forms if there is not enough lubricant

Question 5

3 types of friction and anti-friction bearings?

Answer 5

• Sliding
• Rolling
• Fluid

Question 7

Sliding Friction

Answer 7

-resistance as one surface slides over another

Question 8

Rolling Friction

Answer 8

• the resistance to movement of one surface rolling over another
• the deformed ball and deformed carpet as it rolls over it

Question 9

Fluid Friction

Answer 9

• resistance to flow within a fluid

- result of electromagnetic bonds

Question 10

Oil Wedge

Answer 10

• supports the shaft and relocates it within the bearing clearances
• it forces a full film of fluid into the loaded area
• dependant on speed, load pressure and viscosity

Question 11

1 cause of bearing failure

Answer 11

-improper Lubrication

Question 12

Flash Point

Answer 12

-lowest temperature at which the vapour above an oil will ignite when a flame passed over it

Question 13

Contaminants produced by lubrication breakdown.

Answer 13

Acid, sludge, varnish

Question 13

Functions of a lubricant

Answer 13

• to reduce resistance
• reduces friction
• protects against corrosion
• carries away heat
• carries away contaminants

Question 14

Viscosity Index

Answer 14

• a number that identifies the amount of change in the viscosity of a lubricant over a temperature range
• stability of the oil

Question 15

Pour Point

Answer 15

• the lowest temperature at which an oil is observed to flow

- 3 degrees above the temperature of oil that doesn’t appear to be flowing

Question 16

Absolute viscosity

Question 17

Ash

Answer 17

-detergents leave this residue when oil is burned

Question 18

Block Lubrication System

Answer 18

-divider valves are stacked to form distribution blocks to deliver oil

Question 19

Oil Mist System

Answer 19

• Above atmospheric pressure which helps keep contaminants out of the system
• bad cause the oil turns into a mist and gets into the air
• small high speed

Question 20

Viscosity

Answer 20

• how thick or thin the oil is
• measures the fluid friction
• decreases when temperature increases
• increases when pressure increases
• measured at 100 degrees C

Question 21

Air Oil system

Answer 21

• Oil pump to inject very small amounts of into oil lines
• supplies droplets of oil along the walls of the oil lines
• pressurizes system to prevent junk from getting in

Question 22

Oil starts to oxidize

Answer 22

55 degrees c

Question 23

Wax

Answer 23

• in Paraffin based oil

- cause issues at high temperatures in pipelines

Question 24

Petroleum based oil

Answer 24

- they do not wear out | - stable up to 55 degrees C

Question 25

Synthetic oil

Answer 25

- made from at least 10 chemical based - wide operating temp - fire resistant

Question 26

Additives

Answer 26

- 22% of the oil | - DO wear out

Question 27

TBN/TAN

Answer 27

- TBN (total base number) - TAN (total acid number) - a drop or rise in either of these numbers indicates oxidation is happening

Question 28

Grease

Answer 28

- liquid lubricant mixed with a thickener - Never mix different greases with different thickeners - thickeners are known as soaps

Question 29

Drop point

Answer 29

-Lowest temperature at which lubricant will begin to drip from a grease

Question 30

Molybdenum Disulphide

Answer 30

-additive of choice to make the film strong enough to support the load & separate the surfaces in a loaded zone

Question 31

Proper grease levels.

Answer 31

-the housing should be 1/3 full after the bearing is packed

Question 32

Proper oil levels in oil bath system?

Answer 32

-1/3 to 1/2 up the lowest rolling element

Question 33

What is the proper condition a coupling should be in?

Answer 33

-perfect alignment | not to company specs because the company doesn't know what the coupling is being used for.

Question 34

More clearance between bearing and housing means what?

Answer 34

-less load on that bearing

Question 35

Naphtha Based Oil

Answer 35

- base oil for grease | - imported

Question 36

What is the best thickener for conventional grease at high temperatures?

Answer 36

-Sodium

Question 37

Bottle Oiler

Answer 37

a bottle mounted on top of the bearing housing that rests on the surface of the shaft. Slight vibration causes oil to run down and lubricate the bearing

Question 38

Oxidation with oil

Answer 38

-it doubles every 8 degrees over 55

Question 39

CST or centistoke

Answer 39

-British unit of measure for viscosity accepted world wide

Question 40

Functions of detergents

Answer 40

- keep out sludge and fine deposits - clean up existing deposits - control acid buildups - act as an anti wear additive - act as an anti scuff additive - act as a rust inhibitor