Bearings And Seals 150402b Flashcards
Name two general classifications of bearings
Plain and anti-friction
What type of lubrication is recommended for high-speed applications?
Pressurized oil
Bearing loads can be expressed using what terms?
Combination of both radial and axial
The numbers C1 and C5 etched on bearing race Rings indicate the …
Clearance between rolling elements and race
The bearing style that would take up the least space is the…
Needle roller
Which anti friction bearing will provide the highest axial load resistance when used in pairs?
Tapered roller bearing
If a plane bearing having a 1.5 inch outside diameter is to be installed into a housing, then the approximate hole size for an interference fit would be?
a) 1.490”
b) 1.499”
c) 1.501”
d) 1.510”
b) 1.499”
Single row angular contact ball bearings are used for…
Radial and axial loads
The best method to install a new bearing on a shaft would be to…
Place the bearing and heated oil prior to installation
The width of an O-ring Groove should be approximately…
150% of the O-ring width
What is in the alloy composition of Babbitt metal?
Tin, lead, antimony, copper
When heating a sealed anti-friction bearing with heated oil, the temperature of the oil should be no more than?
175 degrees Fahrenheit
Lip seals are used to?
Retain lubricant and keep out contamination
When discussing o-ring Theory, backup washers will …
Increase the pressure the O-ring can withstand
One critical component of Machining an O-ring Groove would be to…
Break the edges of the groove
U-cup packings are most commonly found in ______applications
Hydraulic
A double lip seal is designed to…
Used to control internal seepage and prevent external contamination
Which of the following is used for static assemblies only?
O ring
U cup
Lip seal
Gasket
Gasket
Advantages of plain bearings?
Require less space
Quieter than roller
Cost Less than roller
More rigid than roller
Disadvantages of plain bearings?
More friction
Constant lubrication
What are solid plain bearings often called?
Journal bearings
What’s materials are plain bearings made from?
Bronze
Sintered bronze
Plastics
Babbitt
Which material does not Gall or seize with journals?
Bronze
Which material is commonly called oil-lite, is porous, and can be replenished in warm oil?
Sintered bronze
Which material is corrosion-resistant, easy to machine, quiet and requires little or no lubrication?
Plastics
Nylon-small bearings
Teflon- very slippery, no lube
Rubber- used when water is present
Which material can be cast in place or deposited on a stiff backing material?
Babbitt
Advantages of split plain bearings?
Replacement without removing the shaft
Clearances adjustable by shims
Uses locking tabs or dowel pins
Which plain bearing prevents axial movement of a shaft?
Plain thrust bearings
What do anti-friction bearings rely on rather than a film of oil?
Precision rollers
What are the advantages of anti-friction bearings?
Friction is low Less axial space required Maintains accurate shaft alignment Both radial and axial loads can be carried Lubrication is simple sealed or none
Three types of anti-friction bearings
Ball bearings
Roller bearings
Thrust bearings
5 types of ball bearings
Single row deep Groove Double row deep Groove Single row angular Double row angular Self-aligning internal and external
Name the five parts of a bearing
The outer ring an inner ring or race
Raceways
Rolling elements
Cage or separator
Which bearing is the most common type of bearing and is primarily for radial loads but can take moderate axial loads in either direction?
Single row deep Groove
Which bearing permits a higher radial load capacity than single row,
does not handle axial loads well,
and does not tolerate any misalignment
Double row deep Groove
Which bearing supports combination loads,
Must be pre-loaded in One Direction,
often used in pairs opposite each other,
and only tolerate a small amount of misalignment?
Single row angular contact
Which bearing is meant for heavy radial and axial loads and can take axial loads in both directions. Tolerates no misalignment
Double row angular contact
Which bearing can tolerate up to 1 and 1/2 degrees of misalignment?
Internal self-aligning
Which bearing support a much higher radial load than ball bearings and has elements that are Precision ground cylinders rather than balls?
Roller bearings
Which bearing is meant for very large radial loads, tolerate little or no end thrust?
Cylindrical roller bearing
Which roller bearing takes both radial and axial loads and tolerates up to 2 and 1 / 2 degrees of misalignment?
Double row spherical
Which roller bearing has the highest axial and thrust loading when used in pairs and is meant for large radio loads and large uni directional axial loads?
Tapered roller bearing
Which roller bearing is used in pairs to accommodate reversing loads and clearances are adjusted by moving Cup and Cone axially
Single row tapered roller bearing
Which roller bearing is meant for large heavy engineering applications matched to suit their function so not interchangeable?
Double row tapered roller bearing
Which roller bearing takes up less space than any other anti-friction bearing and has no inner race and meant for radial loads only
Needle roller bearings
Which bearing is meant primarily for thrust axial side loads and cannot take any radial load?
Thrust bearing
Which bearing can take a heavy thrust load and a moderate radial load
Spherical and tapered roller bearing
Which internal clearance designation provides for the largest clearance?
C1
C3
C5
C1
What is the rule of thumb for interference with the housing when installing plain bearings?
Point 00075” to .0001 per inch of diameter
What two material shims are used with split plain bearings
Stainless steel first brass otherwise
What do you use for a housing fit check on a bearing
Feeler gauges
What two things should you not do to a new bearing
Do not clean it and do not spin a bearing with an Air Blast
Never heat an unsealed bearing above _____ degrees Fahrenheit. Never heat a sealed bearing above _____ degrees Fahrenheit
250 unsealed
175 sealed
When seating a bearing in a housing do you direct the force against the outer or inner ring?
Outer ring
Four types of seals?
Gaskets, O-rings, U section Rings, lip seals.
O-rings…
Made of rubber like compounds
Meant to deform slightly
Nitrile, EPDM, calrez are different types
What is the rule for o-ring depth grooves and the width of the groove?
Static assembly 70% of the width of the O-ring
Dynamic assemblies 80%
Which of the group should be one and a half times the width of the Ring or 150%
When making o-ring grooves you must be sure to…
Break the edges of the top corners but don’t chamfer them
What is sometimes necessary to hold a U ring in position
A support ring
Which seal is designed to keep lubricant in and contamination out
Lip seal or double lip seal
Types of lubrication
Boundary sliding surfaces contact each other
Full film sliding surfaces are separated by a pressurized film of oil
