Module - Lubrication - Part B

Question 1

Proper level of lubricant in a rolling element bearing is

a) halfway up the second from bottom rolling element.
b) halfway up the top rolling element.
c) halfway up the lowest rolling element.
d) halfway up the complete bearing (to the centreline of the shaft).

Answer 1

c) halfway up the lowest rolling element.

Question 2

Movement of oil in a wick feed oiler is by

a) pump.
b) centrifugal force.
c) gravity.
d) capillary action.

Answer 2

d) capillary action.

Question 3

A measure of grease stiffness is referred to as

a) cone test.
b) drop point.
c) consistency .
d) viscosity.

Answer 3

c) consistency

Question 4

Thickeners for greases can be made from compounds that are classified chemically as

a) emulsifiers.
b) squeegees.
c) soaps.
d) solid solubles.

Answer 4

c) soaps.

Question 5

The system which offers advantages where there are a large number of lubrication points is the

a) drop feed lubricator system.
b) wick feed lubricator system.
c) ladder lubricator system.
d) centralized lubrication system.

Answer 5

d) centralized lubrication system.

Question 6

What is the formula for Surface Speed?

Answer 6

(RPM x π x Dia) / 12 = Feet per minute

Question 7

Why is it important not to allow the oil level in an oil bath lubrication system to go above the centreline of the lowest rolling element?

Answer 7

To avoid churning, which would produce extra heat.

Question 8

What are two disadvantages of a bottle lubricator?

Answer 8

1. Oil is not recirculated, but wasted.

2. It is restricted to uses where surface speeds are low.

Question 9

Should a constant level lubricator be mounted on the left or the right side of the housing if the rotation is clockwise?

Answer 9

Left side.

Question 10

What are two important functions of a sight glass on a lubrication system?

Answer 10

To monitor the oil level and the condition of the oil.

Question 11

Is it best to take an oil sample immediately after a machine has been running at its normal operating temperature or after it has cooled down?

Answer 11

Immediately after running, to establish a wear rate for the machine.

Question 12

What is a grease?

Answer 12

Grease is a liquid lubricant mixed with a thickener.

Question 13

How does a grease thickener work?

Answer 13

The thickener acts like a sponge to hold the lubricant and also controls the flow of the grease to the area to be lubricated.

Question 14

What is drop point referring to in a grease?

Answer 14

This is the lowest temperature at which the lubricant will begin to drip from a grease.

Question 15

What is one of the oldest grease thickeners used?

Answer 15

Soap

Question 16

Why should you not use grease with different thickeners?

Answer 16

Mixing results in a softer grease with a lower usable operating temperature.

Question 17

What does grease consistency depend on?

Answer 17

Consistency depends on type of thickener, quantity of thickener, and temperature

Question 18

What is the purpose of having EP additives in a grease?

Answer 18

To prevent damage from welding at the tips of the asperities on the loaded surfaces.

Question 19

What is an advantage of a single point grease application system?

Answer 19

Simple (no pumps, metering valves etc.), compact (no grease lines) and inexpensive.

Question 20

What is a disadvantage of a singe point grease application system?

Answer 20

When there is a large number of lubrication points, in which case more time is required to monitor the process.

Question 21

What types of grease cups are considered automatic?

Answer 21

Spring-loaded, and electric timer style.

Question 22

What is necessary before injecting grease into a grease nipple?

Answer 22

Clean the grease fitting thoroughly before attaching the grease gun.

Question 23

Give two advantages of centralized lube systems.

Answer 23

It eliminates the risk of contamination from dirt on a grease gun nozzle or dirt getting into a grease cup when you refill it, and metering valves ensure that the correct quantity of lubricant is applied.

Question 24

How full should the housing be for a grease-lubed bearing?

Answer 24

Housings should not be more than 1/3 full.

Question 25

What are the three types of solid lubricants often used in industry?

Answer 25

The more common types used in the millwright trade are graphite, PTFE (Teflon) and molybdenum disulphide

Question 26

What colour is graphite type solid lubricant?

Answer 26

Grey-black.

Question 27

Which solid lubricant has the greater load-carrying capacity, graphite or Teflon?

Answer 27

Graphite.

Question 28

Which lubricant may be used where oil and grease are not adequate?

Answer 28

Solid lubricants.

Question 29

Which is the best one to use to carry away heat (oil, grease, solid lubricants)?

Answer 29

Oil.

Question 30

Which is the best one to use to flush away contaminants (oil, grease, solid lubricants)?

Answer 30

Oil.

Question 31

Which is the best one to use if you need it bonded to a surface permanently (oil, grease, solid lubricants)?

Answer 31

Solid lubricants.

Question 32

What is the recommended level of oil in a bearing?

Answer 32

No higher than halfway up the lowest rolling element.