Bearings

Question 1

What are the two types of basic bearings?

Answer 1

Friction and Anti-Friction.

Question 2

What are three other names of Friction bearings?

Answer 2

• plain bearings
• sleeve bearings
• journal bearings

Question 3

What type of contact exists between a Friction bearing and the shaft?

Answer 3

Sliding.

Question 4

What type of contact is between an Anti-Friction bearing and the shaft?

Answer 4

Rolling.

Question 5

What is used in Anti-Friction bearings that creates rolling contact?

Answer 5

• balls
• needles
• rollers (cylindrical - spherical - tapered)

Question 6

What is the outer casing of a bearing referred to as?

Answer 6

Housing or Pillow Block.

Question 7

What are the three general styles of Joint design bearings?

Answer 7

• flat joint
• gib joint
• angle joint

Question 8

What is Babbitt?

Answer 8

Common anti-friction lining material for bearings.

Question 9

What must be done to keep the shaft from binding after a bearing has been babbitted?

Answer 9

Relieve the corners.

Question 10

What is cut into a Babbitt for lubrication?

Answer 10

Oil Groove.

Question 11

Where should the Oil Groove be cut in a Babbitt bearing?

Answer 11

In the unloaded section.

Question 12

What are Shells?

Answer 12

Two piece liners installed in a bearing housing.

Question 13

What three common ways to hold Shells in position?

Answer 13

• dowels
• pins
• notch

Question 14

What is Crush?

Answer 14

The small amount of Shell that sits above the face of the bearing. When the bearing is assembled the shell is forced down into full contact with the housing.

Question 15

When using Friction bearings what is used to control Thrust (axial movement)?

Answer 15

Thrust Washer and/or Ball Thrust Bearing.

Question 16

What is End Float?

Answer 16

The amount a shaft moves axially in a bearing.

Question 17

What are the three types of load applied to a bearing?

Answer 17

• radial
• thrust (axial)
• angular (both radial and axial)

Question 18

How is the bore of a bearing indicated?

Answer 18

The last two digits of the bearing number.

Question 19

Up to 20mm what is the bore designated as?

Answer 19

00 = 10mm
01 = 12mm
02 = 15mm
03 = 17mm

Question 20

After what size is the bore diameter directly included in the bearing number?

Answer 20

480mm (6296).

Example of a 500mm. 62/500

Question 21

Who standardizes clearances for bearings?

Answer 21

ISO

Question 22

What is Push fit?

Answer 22

Means the bearing is installed by hand with no mechanical aids.

Question 23

What is Creep?

Answer 23

The very slow rotation of the push-fit bearing race.

Question 24

What are four ways to heat a bearing for installation?

Answer 24

• an oven
• heat lamp
• induction heater
• oil bath

Question 25

What is Positive Keeping?

Answer 25

Using a device to hold a bearing in place.

Question 26

What is used on the outer race for positive position?

Answer 26

- end caps with or without shims | - on small diameter bearings a snap ring is used

Question 27

What is used on the inner race for positive positioning?

Answer 27

- snap ring placed in a groove in the housing | - locknut and washer

Question 28

How is Float in a shaft prevented?

Answer 28

By having only one bearing in the shaft assembly axially fixed.

Question 29

Bearings that are not Fixed are called what?

Answer 29

Free or Floating.

Question 30

What are the three basic arrangements of Angular Contact Bearings?

Answer 30

- back to back (push fit) - face to face (push fit) - tandem (press fit)

Question 31

What are two types of Split Bearings?

Answer 31

Horizontal and Vertical.

Question 32

What type of bearing sits 90° to the shaft?

Answer 32

Flange Bearing.

Question 33

What are your most important consideration when selecting a bearing?

Answer 33

- bearing type - temperature - axial/radial load - type of setup

Question 34

What is Oscillating Load?

Answer 34

When the load shifts through an arc less than 180°.

Question 35

What is Reciprocating Load?

Answer 35

When the load shifts 180° from one side of the bearing to the other.

Question 36

What is the purpose of a Spherical Seat?

Answer 36

Allows the bearing to align its bore during installation.

Question 37

What is a Floating Bushing?

Answer 37

An outer bushing with a loosely fitted inner bushing?

Question 38

What is Oil Whirl and Oil Whip?

Answer 38

It is the breakdown of the oil wedge.

Question 39

What is a Hydrostatic Bearing?

Answer 39

A bearing that depends on an external pump to supply lubricant to support the shaft.

Question 40

What is a Hydrodynamic Bearing?

Answer 40

A bearing that depends on the speed of the rotation of the shaft to drag oil into the loaded area.

Question 41

What is Compressive Strength?

Answer 41

The strength of bearing material to support loads at maximum operating temperature.

Question 42

What is Fatigue Resistance?

Answer 42

Is the resistance of bearing material to resist cracking and flaking.

Question 43

What is Embeddability?

Answer 43

The ability of a bearing material to resist contaminants without failing.

Question 44

What is Deformability?

Answer 44

The ability of the bearing material to yield to misalignment or imperfections in the shaft.

Question 45

What is Wetability?

Answer 45

The ability of a bearing material to absorb lubricant.

Question 46

What is Spread?

Answer 46

The amount that the insert diameter is greater than the bearing housing diameter.