Bearings And Transmissions

Question 1

In which direction do axial bearings accept loads?

Answer 1

Longitudinal (sideways)

Question 2

What problems may occur if bearings are over-greased?

Answer 2

Cause excess churning and generate extremely high temperatures

Question 3

What are the three functions of lubrication?

Answer 3

Provides a film to separate the moving parts
Carries away heat
Protects from corrosion

Question 4

Five basic types of anti-friction bearings?

Answer 4

Ball
Needle 
Tapered
Cylindrical 
Spherical

Question 5

What loads can ball bearings take?

Answer 5

Light radial loads

Question 6

What loads can needle bearings take?

Answer 6

High radial loads and very light axial loads

Question 7

What loads can tapered bearings take?

Answer 7

Axial and radial loads

Question 8

What loads can cylindrical bearings take?

Answer 8

Heavy radial loads and minor axial loads

Question 9

What loads can spherical bearings take?

Answer 9

High radial load

Question 10

What may happen if angular contact bearings are subjected to reverse loading?

Answer 10

Excessive stress

Increased temperature and vibration

Question 11

How does overheating affect bearings? How can it be detected?

Answer 11

Loss in hardness causing early failure
Ball and ring deformation
Destroy lubrication

Detected by discolouration of rings, balls, and cages

Question 12

What are the causes of misalignment?

Answer 12

Bent shafts
Burrs or dirt on shaft
Shaft threads or locking nuts not aligned

Question 13

Five bearing defects?

Answer 13

Contamination 
Lubrication 
Corrosion 
Misalignment 
Loose

Question 14

What is backlash?

Answer 14

The play between mating tooth surfaces at the tightest point of mesh

Question 15

What is a worm gear?

Answer 15

Special gears that resemble screws and can be used to drive spur gears or helical gears

Question 16

Most commonly used gear type?

Answer 16

Spur

Question 17

Where are bevel gears used?

Answer 17

To transfer power between intersecting shafts

Question 18

Where may a chain be used instead of a cable?

Answer 18

Where considerable force is exerted

Question 19

How are the dimensions of a chain classified?

Answer 19

Pitch

Question 20

Where are chains normally used

Answer 20

Control column installations
Aileron and elevator controls
Trim control systems

Question 21

What are bi-planer blocks?

Answer 21

Changing the directional plane of the chain

Question 22

What could be a fault if a chain can be pulled away from the sprocket?

Answer 22

Wear

Tension

Question 23

How are chains checked for elongation?

Answer 23

Cleaned
Placed on a flat surface
Stretched under load and checked against original dimensions
If over 2%, chain discarded

Question 24

Where are chains disconnected?

Answer 24

At design breakdown points

Question 25

How are screwjacks checked for backlash?

Answer 25

Clamp checking tool onto screwshaft adjacent to front of jack body
Position dial indicator rod to contact face of ball nut
Manually apply force to slat in retract direction and record reading on indicator
Allow slat to fully extend and record reading
Difference should not exceed 0.030”
Repeat three times
If backlash is excessive, replace screwjack

Question 26

How is a chain checked for articulation?

Answer 26

Moving it over a screwdriver at 180 degrees