Year 2 - 1Da - Bearing Maintenance Part A

Front 1

Temperature is the result of what three things

Back 1

1)Friction in the Bearing

2)how fast the heat is dissipated

3) heat that is transferred from outside sources

Front 2

At what temperature does rapid oxidation of the lubricant start to occur

Back 2

55°C

Front 3

Should you be worried if a freshly installed or lubricated bearings heats up?

Back 3

No, the temperature will rise and remain about 15°C above normal for a few hours

Front 4

What happens to a bearing at 125°C?

Back 4

The Bearing begins to to distort and lubricant life is shortened

Front 5

Why would a machine have higher than average amperage readings?

Back 5

It indicates abnormal load on the machine.

Front 6

What is a quick way to check for a metal particles in oil?

Back 6

By submerging a clean magnet in the oil and then examining it for metal

Front 7

If the Bearing produces a loud hollow noise what does that indicate?

Back 7

Too much internal clearance

Front 8

What does it indicate if a bearing produces a high-pitched scream or wine?

Back 8

The clearance is too small

Front 9

If a bearing produces a growling noise what does that mean?

Back 9

The surfaces of the rollers and raceways are deteriorating

Front 10

The causes of bearing failure may be grouped into four categories, what are they?

Back 10

1) improper installation and handling

2) improper maintenance practices

3) improper selection

4) fatigue

Front 11

What is "built in contamination"?

Back 11

It refers to dirt introduced during the assembly of the machine

Front 12

If the shaft shows more than _______ of an inch run out at the shaft centre, seal seats or ends, it must be straightened or replaced

Back 12

0.001"

Front 13

What is brinelling?

Back 13

It is impact denting and makes the bearing useless. This denting can be caused by

-hammer blows

-dropping the bearing

-Shock loading on the machine from any source

Front 14

What is false brinelling?

Back 14

It is around depression worn into the raceway by a rolling element. It is caused when the bearing is not turning and vibration is present (like storage)

Front 15

What is the biggest cause of bearing failure?

Back 15

Contamination

Front 16

How does the oil mist lubrication system prevent contaminant?

Back 16

It produces a positive pressure inside the bearing housing. The positive pressure prevents any contaminants from entering under atmospheric pressure

Front 17

What are two of the main causes of vibration?

Back 17

1) imbalances account for half the causes of vibration

2) misalignment accounts for 40% (either shafts or bearings)

Front 18

How can you prevent static charges from passing through the bearing

Back 18

They can be short circuited the weight bearing by installing the ground brush

Front 19

At what temperature does a bearings load capacity start to exponentially decrease?

Back 19

200°C

Front 20

Define fatigue

Back 20

Fatigue is the failure or breaking up of any material after it has been repeatedly deformed

Front 21

What three things can you check by hand when the machine is down without tearing it apart?

Back 21

-turn the shaft by hand and feel for any roughness in the movement

-lift on the shaft to check for radial looseness

-push the shaft back-and-forth axially to check for excessive end float

Front 22

What is the most effective way to monitor the condition of a bearing while it is in operation?

Back 22

Vibration monitoring

Front 23

What checks should you make on the bearing if amperage readings are higher than normal?

Back 23

-housing temperature

-vibration level

-lubricant condition

-bearing noise

Front 24

List five conditions that increase the fatigue rate

Back 24

-Loads above the recommended load rating

-speeds above the recommended speed rating

-shock loads

-vibration

-Misalignment

Front 25

Card # 25

Back 25

Finished