Bearringsuh 2

Question 1

Antifriction bearings are used where

Answer 1

Low starting friction is required

Question 2

What kind of bearing can support an axial load?

Answer 2

Thrust bearing

Question 3

Spotty, uneven wear in a sleeve bearing is caused by [BLANK] of the shaft

Answer 3

Bending

Question 4

When a shaft reaches its “critical speed”, the

Answer 4

Vibration becomes uncontrolled

Question 5

The loosest class fit of a shaft in a bearing is a [BLANK] fit. The tightest is a [BLANK] fit.

Answer 5

Running and sliding; force

Question 6

To distribute lubricant, plain journal bearings must have

Answer 6

Axial and circumferential grooves

Question 7

To keep lubricant in and dirt out, plain journal bearings may have

Answer 7

Bearing seals

Question 8

Split bearings may be either [BLANK] or [BLANK]

Answer 8

Split sleeve; precision insert

Question 9

In a trimetal bearing, the inner lining is made of

Answer 9

Antifriction material

Question 10

The extra lining material extending beyond half a circle in a precision insert bearing is called

Answer 10

Crush

Question 11

The ability of a plain journal bearing material to adjust to misalignment is called

Answer 11

Conformability

Question 12

The ability of a plain journal bearing material to absorb small particles is called

Answer 12

Embeddability

Question 13

What is the best material for plain journal bearings that operate above 500 degrees F

Answer 13

Aluminum-bronze alloys

Question 14

You need not replace bearings on high-speed equipment unless wear has increased the shaft clearance to [BLANK] times the original clearance

Answer 14

Two

Question 15

If you cut a new lubricant groove in a plain journal bearing, the width of the groove should be about [BLANK] the depth. The depth should be no more than [BLANK] the bearing’s wall thickness

Answer 15

Twice; one-third

Question 16

Which part of an antifriction bearing carries the least load during operation?

Answer 16

Cage

Question 17

Antifriction bearing that run at moderate to high speeds generally should be lubricated with

Answer 17

Oil

Question 18

The letters “BC” in the bearing designation 10BC02 indicate the bearing’s

Answer 18

Type

Question 19

The standard ball bearing with the closest tolerance is designated

Answer 19

ABEC-9

Question 20

How far out-of-round the inner and outer races of an antifriction bearing can be is called the [BLANK] runout of the bearing

Answer 20

Radial

Question 21

Even if nothing else cause the failure of an antifriction bearing, it will eventually fail due to [BLANK] of the [BLANK]

Answer 21

Fatigue; rolling elements

Question 22

Misalignment and excessive runout are major causes of bearing failure, exceeded only by

Answer 22

Inadequate lubrication

Question 23

A “floating” bearing is mounted in such a way that it can move

Answer 23

Axially

Question 24

In a fixed and floating two-bearing mounting, the fixed bearing carries the [BLANK] load

Answer 24

Thrust

Question 25

If a shoulder is cut on a shaft to support the inner race of a bearing, the shoulder should have (a)

Answer 25

Minimum runout

Question 26

Which type of ball bearing can best support loads from all directions?

Answer 26

Double-row angular-contact

Question 27

One advantage of the staggered roller bearing over an ordinary roller bearing is that it

Answer 27

Requires less space for the same capacity

Question 28

What kind of roller bearing is best for equipment that must run at high speed?

Answer 28

Cylindrical

Question 29

What kind of load(s) can a spherical roller bearing support?

Answer 29

Both axial and radial

Question 30

What part of a tapered roller bearing corresponds to the outer ring on other bearings?

Answer 30

Cup

Question 31

The best bearing for supporting very heavy thrust and shock loads is a [BLANK] thrust bearing

Answer 31

Tapered-roller

Question 32

A [BLANK] bearing can accept misalignment without losing any of its load-carrying capacity

Answer 32

Spherical roller

Question 33

A ladder bearing is a [BLANK] bearing

Answer 33

Linear-motion

Question 34

Which linear motion bearing reduces shaft deflection?

Answer 34

Open ball bushing

Question 35

Bearing units designed to provide adjustment for shaft-center distances are known as

Answer 35

Takeups

Question 36

A major function of a bearing seal is to

Answer 36

Retain lubricant

Question 37

The width of an oil seal is the

Answer 37

Thickness of the outer case

Question 38

An important element in selecting the right type of seal for a bearing is the [BLANK] of the shaft

Answer 38

Surface speed (in fpm)

Question 39

To ensure proper operation of a synthetic bearing seal, the shaft should be

Answer 39

Polished

Question 40

A spring closure ring on a bearing seal forces the seal against the

Answer 40

Shaft

Question 41

In general, lightweight oil should be used on bearings carrying [BLANK] loads and running at [BLANK] speeds

Answer 41

Light; high

Question 42

Combatting the most common contamination of lubricating oil requires

Answer 42

Cleaning the sump

Question 43

Internal wear of a bearing may be detected in drained oil by the presence of

Answer 43

Metal particles

Question 44

The National Lubricating Grease Institute specifies the hardness of a grease in numbers from [BLANK] to [BLANK]

Answer 44

000; 6

Question 45

When packing grease into a bearing, you should fill the bearing [BLANK] full

Answer 45

About half

Question 46

Early bearing failure often results from

Answer 46

Improper installation

Question 47

If hall or roller bearings are slightly misaligned when installed, they will

Answer 47

Fail sooner than they should

Question 48

If a newly installed bearing makes a high-pitched whine when it starts running, the bearing may be

Answer 48

Overloaded

Question 49

Excessive loading on a bearing causes

Answer 49

Brinelling

Question 50

Immediately after cleaning and inspecting a bearing, you should coat it with

Answer 50

Oil