Alb Mod Bearing Maint B

Question 1

The two most common methods of delivering oil to bearings is using: (2)

Answer 1

• Hydrodynamic lube

- Hydrostatic lube

Question 2

Hydrodynamic lubrication uses ____ to deliver oil to bearings

Answer 2

velocity

Question 3

The two common methods of delivering oil to a bearing for hydrodynamic lubrication is using: (2)

Answer 3

• Pump

- Slinger ring, splash

Question 4

How does hydrodynamic lubrication compare to hydrostatic in regards to reserve capacity?

Answer 4

Hydrodynamic has more reserve capacity

Question 5

A disadvantage of hydrodynamic bearing lubrication is the occurrence of ____ at higher speeds

Answer 5

oil whirl

Question 6

Hydrostatic lubrication uses _____ instead of velocity to force the fluid film to the loaded area

Answer 6

pressure

Question 7

a hydrostatically lubricated/hybrid bearing is vulnerable to:

Answer 7

Failure of the pressure supply

Question 8

A hydrostatically lubricated bearing has a ___ load capacity than a hydrodynamic bearing of the same size

Answer 8

lower

Question 9

To support a full load, hybrid lubrication requires both:

Answer 9

hydrodynamic lube in addition to hydrostatic

Question 10

Both hydrostatic and hybrid bearings are fitted with:

Answer 10

restrictors, for oil

Question 11

What lubrication method could you use for a large, unbalanced load at high speeds?

Answer 11

Hybrid

Question 12

Hydrostatic bearings are best suited for:

Answer 12

slow speed, heavily loaded bearings

Question 13

What bearing would you use when maximum loads occur only when hitting high speeds?

Answer 13

hybrid

Question 14

Oil lift is produced by a hydrostatic supply of oil called:

Answer 14

jacking oil

Question 15

Jacking oil produces enough force to:

Answer 15

lift the journal off the bearing

Question 16

The surfaces of rolling elements are lubricated via an oil bath, splashing, oil jet or mist, and as the bearing rotates, a ____ is formed between the rolling element at each raceway

Answer 16

oil wedge

Question 17

When lubricant is wedged between a race and a rolling element, the extreme pressure causes the lubricant to enter a _____ state

Answer 17

elasto-hydrodynamic

Question 18

Two widely used air activated lube systems are: (2)

Answer 18

• oil mist

- air oil

Question 19

an oil mist system uses a compressor to provide compressed air at 10 to __ psi to atomize the oil

Answer 19

50

Question 20

Which system, oil mist or air oil, uses a vanturi?

Answer 20

oil mist

Question 21

With an oil mist system, you can have 3 typed of nozzles for different degrees of condensation. Which would you use for high speed, anti friction bearings?

Answer 21

Mist nozzle

Question 22

With an oil mist system, you can have 3 typed of nozzles for different degrees of condensation. Which would you use for chains, drives, gears, open bearings?

Answer 22

spray nozzle

Question 23

With an oil mist system, you can have 3 typed of nozzles for different degrees of condensation. Which would you use for slow moving slides and machine toolways?

Answer 23

condenser nozzles

Question 24

Air oil systems are used for:

Answer 24

medium to high speed anti friction bearings

Question 25

A bearing should be packed with grease ____ it is mounted

Answer 25

after

Question 26

What 3 parts may not be immediately obvious, and uncovered, on a rotating shaft? (3)

Answer 26

• Shaft key
• Flinger
• Set screws

Question 27

Keeping a machine clean allows these benefits: (4)

Answer 27

• Allows for accurate inspection
• Better heat dissipation
• Keeps free of corrosives
• Reduces bearing contamination

Question 28

It is important to inspect a machine while it is running because:

Answer 28

Noise, vibration, leaks are more easily detected

Question 29

A sour smell to lubricant indicates:

Answer 29

Acid build up from oxidization

Question 30

A change in oil colour indicates a:

Answer 30

breakdown in the lubricant

Question 31

Be sure the breather for a bearing case is clear, and that the sight glass is not:

Answer 31

discoloured, giving a false “full”

Question 32

Lubrication should be done when:

Answer 32

the machine is down

Question 33

Pump grease into a bearing until clean grease is expelled from the:

Answer 33

outlet port

Question 34

What is the first thing you should check when a bearing is running too hot?

Answer 34

oil level. Too high or too low.

Note: can also be caused by: external heat sources, breakdown of lube, degraded seals, alignment, incorrect clearances, or soft feet under housing

Question 35

Vibration in a bearing can be caused by: (4)

Answer 35

• Alignment
• Bent shaft
• soft foot
• misaligned or damaged (flat spot) bearing ring

Question 36

It is always important to check that a shaft can be turned:

Answer 36

by hand without anymore resistance than is normal

Question 37

What are some reasons that a shaft cannot be turned by hand? (5)

Answer 37

• Seals too tight
• flinger is dragging
• fan on motor touching housing
• bent shaft
• insufficient clearance

Question 38

When bearing noise becomes apparent, the bearing usually already has to be replaced within days or hours. Before this noise occurs, you will be able to detect a rise in:

Answer 38

temperature

Question 39

How can a constant level cup be installed on a bearing assembly wrong?

Answer 39

Can be mounted on the wrong side, and can be mounted too high or too low.