Book 2 Chapter 31: Types Of Bearing Lubrication

Question 1

Explain boundary lubrication

Answer 1

Refers to lubrication where the surfaces are separated by only a microscopic film of lubricant. Takes place when the supply of lubricant is restricted or intermittent. A certain amount of metal to metal contact will exist between surfaces, but, as the surfaces are wetted by the microscopic film, friction and wear will be reduced. This “borderline” lubrication occurs between piston rings and cylinder walls in an engine.

Question 2

Fluid film lubrication, also called _________________, occurs when the lubricating film between surfaces is thick enough to completely separate the surfaces.

Answer 2

Flood lubrication

Question 3

Anti-friction bearings consist of moving components which “roll” between two surfaces called:
A) Races
B) Tracks
C) Grooves
D) Valleys

Answer 3

A) Races

Question 4

Explain the meaning of thrust.

Answer 4

Thrust is a reactionary force created when a machine such as a centrifugal pump moves water into it.

Question 5

All _________ must be cleaned from the outside of the bearing and the shaft.

Answer 5

Dirt

Question 6

Bearings can withstand operating temperatures up to ___________.
A) 200ºC (392ºF)
B) 150ºC (302ºF)
C) 120ºC (248ºF)
D) 85ºC (185ºF)

Answer 6

C) 120ºC (248ºF)

Question 7

A thrust bearing:
A) Prevents radial movement of the shaft
B) Prevents axial movement of the shaft
C) Must be installed on both ends of the shaft
D) Has a volute casing
E) Should rotate opposite to the shaft

Answer 7

B) Prevents axial movement of the shaft

Question 8

A Kingsbury bearing is which type of bearing?
A) Journal bearing
B) Shell bearing
C) Thrust bearing
D) Anti-friction bearing
E) Sleeve bearing

Answer 8

C) Thrust bearing

Question 9

Damage to bearings due to vibration while stationary is called:
A) Corrosion
B) Pitting
C) Fretting
D) Arcing
E) False brinelling

Answer 9

E) False brinelling

Question 10

Ring oiled bearings use metal rings to:
A) Position bearings on shafts
B) Lubricate several bearings at once
C) Draw oil up from a sump to the bearing
D) Feed oil by gravity to bearings
E) Feed oil hydrostatically to bearings

Answer 10

C) Draw oil up from a sump to the bearing

Question 11

A thrust bearing that does not utilize the oil wedge principle of lubrication is the:
A) Michell type
B) Vertical type
C) Collar type
D) Kingsbury type
E) Flotation type

Answer 11

C) Collar type

Question 12

When replacing or removing an anti-friction ball bearing the applied force should:
A) Always be against the inner race
B) Always be against the outer race
C) Be made only after heating the bearing
D) Not be transmitted through the bearing balls
E) Be applied suddenly and fully

Answer 12

D) Not be transmitted through the bearing balls

Question 13

A type of anti-friction bearing is the _________ bearing.
A) Sleeve
B) Ball
C) Journal
D) Spiral
E) Elliptical

Answer 13

B) Ball

Question 14

The key difference between fluid film lubrication and boundary lubrication is:
A) Fluid film lubrication actually keeps the rotating surfaces separated
B) The oil needs to be under pressure to make boundary lubrication work
C) Grease is a good lubricant for fluid film lubrication
D) There is no real difference between them
E) Boundary lubrication only carries away heat build-up

Answer 14

A) Fluid film lubrication actually keeps the rotating surfaces separated

Question 15

Anti-friction bearings consist of moving components which “roll” between two surfaces called:
A) Tracks
B) Races
C) Grooves
D) Sleeves
E) Valleys

Answer 15

B) Races

Question 16

All of the following are steps in a procedure for cleaning a bearing without dismantling it except:
A) Make sure all dirt has been removed from the outside of the bearing and the surrounding parts
B) The bearing refilled with the normal lubricant, either oil or grease as the case may be
C) After removing the end covers, a solvent can be sprayed into the end cover to flush out old lubricant and sludge
D) The end covers are replaced
E) Then a light lubricating oil is sprayed into the bearing

Answer 16

C) After removing the end covers, a solvent can be sprayed into the end cover to flush out old lubricant and sludge

Question 17

A poor quality lubricant can cause premature bearing failure due to:
A) Cracking or splitting of the bearing race
B) Hard pieces of lubricant being pressed into the bearing surfaces producing flaking and pitting
C) Uneven loading of the bearing
D) High operating temperatures
E) Indentations in the surfaces in contact with he balls or rollers

Answer 17

B) Hard pieces of lubricant being pressed into the bearing surfaces producing flaking and pitting

Question 18

Improper fitting can cause premature bearing failure due to:
A) The force applied indenting or nicking the balls or rollers
B) Uneven loading of the bearing
C) Hard pieces of lubricant being pressed into the bearing surfaces producing flaking and pitting
D) Cracking of the rollers
E) High operating temperatures

Answer 18

A) The force applied indenting or nicking the balls or rollers

Question 19

If the bearing can be easily replaced, such as in a car engine, it is termed a __________ type.
A) Ball
B) Journal
C) Roller
D) Shell
E) Sleeve

Answer 19

D) Shell

Question 20

Misalignment can cause premature bearing failure due to:
A) Indentations in the surfaces in contact with the balls or rollers
B) Uneven loading of the bearing
C) Cracking or splitting of the bearing race
D) Hard pieces of lubricant being pressed into the bearing surfaces producing flaking and pitting
E) High operating temperatures

Answer 20

B) Uneven loading of the bearing

Question 21

The moving or rolling members anti-friction bearings can be all except:
A) Journals
B) Parallel rollers
C) Balls
D) Barrel rollers
E) Tapered rollers

Answer 21

A) Journals

Question 22

Usually the cause of the bearing trouble is one of the following:
A) Proper viscosity
B) Improper bearing design
C) Temperature of oil too low
D) True alignment of shaft and bearing
E) Excessive oil supply

Answer 22

B) Improper bearing design