Question 1

Rusting surfaces are an indication of ____.

Accepted Answer

D

Question 2

What is an early indication that a bearing may be overheating?

Accepted Answer

Solid or caked lubrication can indicate overheating as it signifies that the lubricant has hardened due to high temperatures. This can lead to increased friction and wear on the bearing. Rust, etched raceways, and pitting may also indicate bearing damage, but they are not necessarily early signs of overheating.

Question 3

The most common problem with chain drives is that the chains are not checked and ____________________ often enough.

Accepted Answer

lubricated

Question 4

Failure of rigid couplings is usually indicated by a small pile of __________________ on the floor just below the coupling assembly.

Accepted Answer

The answer of Failure of rigid couplings is usually indicated...

Question 5

What is the leading cause of coupling wear?

Accepted Answer

Misalignment between the driving and driven components is the leading cause of coupling wear as it imposes stress on the coupling elements and causes them to deform or break down over time. Lack of attention, bad fillers, and overloading can all contribute to coupling wear, but they are not as significant as misalignment.

Question 6

When should a radial lip seal be replaced? Choose the best answer.

Accepted Answer

A radial lip seal should be replaced when it has nicks and/or small cuts, as these can compromise its ability to effectively seal and prevent leaks.

Question 7

Bearing failure is generally caused by a lack of ___________________ or overloading

Accepted Answer

The answer of Bearing failure is generally caused by a...

Question 8

What type of bearing should be used in a dirty environment?

Accepted Answer

Sealed bearings are the best choice for a dirty environment as they are designed to keep contaminants out and lubricant in, which will help to prevent premature failure of the bearing. Roller bearings and needle bearings may have exposed moving parts, which can lead to contamination buildup and wear over time. Plain bearings do not have seals and may also become contaminated easily.

Question 9

The two most common types of couplings are ___________________ and flexible.

Accepted Answer

The answer of The two most common types of couplings...

Question 10

What does it mean if the oil has a metallic look when you open a gearbox?

Accepted Answer

The answer of What does it mean if the oil...

Question 11

What causes the tension members to break in a V-belt or a positive-drive belt?

Accepted Answer

Tension members in belts are designed to handle a certain amount of load. Overloading the belt can cause the tension members to break. Overheating and old age can also contribute to belt failure, but overloading is the most common cause. Stretching does not directly cause tension member failure, but it can result in belt slip and decreased efficiency.

Question 12

Gearboxes contain _____ to keep the gears lubricated and cooled.

Accepted Answer

Gearboxes contain oil to keep the gears lubricated and cooled. This prevents wear and tear on the gears and helps to extend the life of the gearbox. Grease can also be used in some applications, but oil is the most common lubricant for gearboxes. Padding material and straw have no use in gearbox lubrication.

Question 13

The pulley should be changed when the the V-belt has dropped ____ into the pulley.

Accepted Answer

The answer of The pulley should be changed when the...

Question 14

On inspection, it is noticed that a seal has a slight amount of leakage. For what type of seal would this be desirable?

Accepted Answer

Packing seals are designed to allow a slight amount of leakage to provide lubrication and cooling to the seal and shaft. This helps prevent overheating and damage, making a small amount of leakage desirable for proper operation.

Question 15

What is compromised when a positive-drive belt begins to skip?

Accepted Answer

When a positive-drive belt begins to skip, it compromises positive traction, as the belt no longer maintains a consistent grip, leading to slippage and reduced drive efficiency.

Quiz 30: Mechanical PM