7.11 Bearings Flashcards
1
Q
What do you test for in a bearing?
A
- excessive backlash or free play
- slow rotations (highlights damage, corrosion, wear)
2
Q
What makes a bearing serviceable?
A
- smooth, free play (radial + axial)
3
Q
Why must a bearing be replaced?
A
- showing any indication of fault or defect must be removed
4
Q
How do you clean a bearing?
A
- use any approved cleaning products for bearing
5
Q
What is used for final cleaning stage on a bearing?
A
- ultrasonic baths (high frequency sound passed through)
6
Q
Cleaned bearings that do not need to go on aircraft immediately should be coated in what?
A
- rust preventing oil
- specified coating recommended by the manufactuer
7
Q
What is a lubricant ?
A
- fluid or grease introduced between 2 moving parts to reduce friction
- improves efficiency and reduces wear
8
Q
Advantages of lubricants?
A
- Reduces friction and abrasion.
- Reduces heat generated by friction.
- Prolongation of service life.
- Prevents rust (corrosion).
- Keeps foreign objects (or contamination) away from rolling elements and raceways
9
Q
Why is too much lubricant bad?
A
- can run hot
- shorten service life
- can collect dirt which deteriorates bearing
10
Q
Grease generates high temp at high rotational speeds (T or F)?
A
- True
11
Q
What is grease suitable for?
A
- low rotational speeds
- oscillating functions
12
Q
At higher speeds is grease or oil suitable?
A
- Oil
13
Q
Loss of lubricant is prevented by?
A
- oil retaining device (seals, felt, rubber washers etc)
14
Q
Explain shielded/sealed bearing?
A
- prevent entry of dirt or fluids
- anti-freeze due to low temp encountered
- cannot normally be regreased
- if defect found usually replaced
15
Q
Wheel hub bearings are normally?
A
- tapered roller bearing
