433A Mechanical Drives and Bearings 2

Question 1

What is the main advantage of a helical gear over a spur gear?

Accepted Answer

Smoother and quieter operation under load

Answer

Lower manufacturing cost

Answer

Ability to transmit motion at right angles

Answer

No thrust load generated

Question 2

When checking a roller chain drive for wear, at what percentage of elongation should the chain typically be replaced?

Accepted Answer

3%

Answer

1%

Answer

5%

Answer

10%

Question 3

What causes fretting corrosion on a bearing's outer race in its housing?

Accepted Answer

Insufficient interference fit allowing micro-movement

Answer

Over-lubrication of the bearing

Answer

Excessive radial load on the bearing

Answer

Using incompatible grease types

Question 4

In a worm gear drive, which component is typically the driving member?

Accepted Answer

The worm

Answer

The worm wheel

Answer

Either component can drive

Answer

It depends on the gear ratio

Question 5

What is the purpose of a flexible coupling in a drive system?

Accepted Answer

To accommodate minor shaft misalignment and absorb shock loads

Answer

To increase the torque capacity of the drive

Answer

To change the direction of rotation

Answer

To provide a fixed connection between shafts

Question 6

What type of lubrication regime provides a full oil film separating bearing surfaces with no metal-to-metal contact?

Accepted Answer

Hydrodynamic lubrication

Answer

Boundary lubrication

Answer

Mixed-film lubrication

Answer

Dry lubrication