Millwright Certification Lubrication Systems and Practices

Question 1

What does the viscosity grade of a lubricating oil describe?

Accepted Answer

The oil's resistance to flow at a given temperature

Answer

The oil's flash point

Answer

The additive package in the oil

Answer

The oil's load-carrying capacity

Question 2

Which type of grease is most commonly used in electric motor bearings operating at high temperatures?

Accepted Answer

Lithium complex grease

Answer

Calcium grease

Answer

Sodium grease

Answer

Bentonite clay grease

Question 3

Over-greasing a rolling element bearing is dangerous because it can cause:

Accepted Answer

Excessive heat from churning and possible seal damage

Answer

Insufficient lubrication film

Answer

Bearing race corrosion

Answer

Reduced bearing clearance

Question 4

What is the primary function of a splash lubrication system in a gearbox?

Accepted Answer

To use the rotation of gears to splash oil onto mating surfaces

Answer

To filter contaminants from the oil

Answer

To pressurize oil to all bearing surfaces

Answer

To cool the gearbox through oil circulation

Question 5

What does a milky or cloudy appearance in gearbox oil indicate?

Accepted Answer

Water contamination (emulsification)

Answer

Oxidation of the oil

Answer

Metal particle contamination

Answer

Additive depletion

Question 6

An NLGI grade 2 grease is considered:

Accepted Answer

Medium consistency — the most common general-purpose grease grade

Answer

Very soft, nearly fluid

Answer

Very hard, almost solid

Answer

A food-grade lubricant classification