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48 Cards in this Set

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With ISO tolerance codes, what does an upper case letter mean?

It indicates the tolerance for a hole size

Which of the anti friction bearings is type "NA"

Needle bearing

Do integral rubbing seals require mounting?

They do not require mounting as they are part of the bearing assembly

What type of seals use a garter spring?

Q

What does the suffix RS and Z mean?

RS: rubbing seal


Z: non-rubbing seal

Another name for carb bearing is?

Compact aligning roller bearing

What is another name for a Conrad bearing?

Single row deep groove ball bearing

With horizontal split pillow blocks, at 55-______degrees stops should be installed at the ends of the base

55-120 degrees

Babbitt May also be referred to as.....

White metal alloy

List two bearing surfaces other than Babbitt

-Aluminum silicone


-aluminum tin

Before installing bearings you should inspect the housing for

-cracks


-burs


- out of round


-taper

Split bearings are held tightly to the housing because of these two things

Crush and spread

What is crush?

How much it protrudes above the bearing shell


--> needed for good heat transfer

What retaining features are used on a split bearing to keep it from rotating

Tabs and dowls

When inspecting a journal for taper, how Many positions along the shaft should you measure?

6

How is a housing check done?

With 0.005 mils shims and lead wire

What theory is based on hydrodynamic principals?

The wedge theory

Give two examples of elasto-hydrodamic film lubrication

-roller bearings


-gears

What is the contact angle for an angular contact ball bearing?

30-32 degree contact angle

Boundary film forms at low or high speeds?

Low

What are three reasons why we like petroleum based oil

-it doesn't brake down


-cheap


-has a good Viscosity

What has a higher viscosity index, paraffin based or naptha based oils?

Paraffin

List five things additives are used for

-extreme pressure


-deforming


-Demulsifier


-detergents


-deoxidizing

A shaft is always centred in a bearing housing. True or false?

False

Synthetic based oils are the least reactive. True or false?

False

Alight load running at a high speed needs a _______ viscosity

Low viscosity

A bottle lubricator is recommended for below how many surface feet per min?

250

List three key components of a pressurized lubrication system

-pump


-filter


-pressure relief valve


-blinds!

Oil mist lubrication is recommended for small high speed bearings. True or false?

True

What is the nominal contact load?

A line drawn through the area of contact at the inner and outer race, not under load

Define drop point

W

What are two common thickeners?

Soap and bentonite

What are the functions of a detergent in an oil?

1) controls acid build up


2) acts as an anti wear


3) acts as a rust inhibitor

What is the ability of a bearing to allow abrasive contaminants to become entrapped?

Embedability

What's the ability to retain a film of fluid?

Wetability

The ability to transfer heat to prevent hot spots?

Conductivity

Allows the material to yield to misalignment and imperfections in the shaft?

Conform ability

Resistance to cracking or flaking from rapidly changing loads

Fatigue resistance

What is another name for porous bronze bushing?

Sintered bronze or oilite

How can you pre-charge a pre-lubricated bushing?

By soaking the bushing in oil 90°C for half an hour

What is compressive strength

The bearing material must be strong enough to support the shaft loads at maximum operating temperature. Resistance decreases as compressive strength increases

What is embeddability?

How well a material will handle contaminants without failing. High embeddability allows abrasive contaminants to become embedded in the material

What is deformability?

Deformability allows the material to you to misalignment or imperfections in the shaft

What is wetability

Ability to retain a film of lubricant

What is bondability?

Bearing materials should form a good metallurgical bond to the backing material

What is compatibility

Must not seize or weld to the journal m under rubbing conditions such as during start up

What is false loading

A small chip or Burr can cause a bearing to support the load on only part of it surface

What percentage of oil can sintered bronze hold?

3-30%