Bearings Flashcards
Anti friction bearings are used where:
Low starting friction is required
What kind of bearing can support an axial load?
Thrust bearing
Spotty, uneven wear in a sleeve bearing is caused by ________ of the shaft.
Bending
When a shaft reaches its “critical speed”, the:
Vibration becomes uncontrolled
The loosest class of fit of a shaft in a bearing is a _______ fit. The tightest is a ______.
Running and sliding;
Force fit.
To distribute lubricant, plain journal bearings may have
Axial and circumferential grooves
To keep lubricant in and dirt out, plain journal bearings may have
Bearing seals
Split bearings may be either _____ or ________.
Split sleeves or Precision Insert
In a trimetal bearing the inner lining is made of
Anti friction material
The extra lining material extending beyond half a circle and a precision insert bearing is called
Crush
The ability of plain journal bearing material to adjust to misalignment is called:
Conformability
The ability of plain, journal bearing material to absorb small particles is called
Embeddability
What is the best material for plain journal bearings that operate above 500 degrees
Aluminum bronze alloys
You need not replace bearings on a high-speed equipment unless wear has increased the shaft clearance to ______ times the original clearance.
Two
If you cut a new lubricant groove in a plain journal bearing, the width of the groove should be about _____ in depth. The depth should be no more than ______ the bearing wall thickness.
Twice; 1/3
Which part of a anti-friction bearing carries the least load during operation?
Cage
Anti friction bearings that run at moderate to high speed generally should be lubricated with what?
Oil
The letters B C in the bearing designation 10BC02 indicate the bearing ______.
Type
The standard ball bearing with the closest tolerance is designated
ABEC - 9
How far out of round the inner and outer races of an anti-friction bearing can be is called the ______ run out of the bearing
Radial
Even if nothing else causes the failure of an anti-friction bearing, it will ultimately fail due to ________ of the __________.
Fatigue; Rolling elements
Misalignment and excessive run out are major causes of bearing failure exceeded only by
Inadequate lubrication
A floating bearing is mounted in such a way that it can move
Axially
In a fixed and floating two bearing mounting, the fixed bearing carries any ____ load.
Thrust
If a shoulder is cut on a shaft to support the inner race of a bearing the shoulder should have a
Minimum run out
Which type of ball bearing can best support loads from all directions
Double row angular contact
One advantage of the staggered roller bearing over an ordinary roller bearing is that it
Requires less space for the same capacity
Which kind of roller bearing is best for equipments that must run at high speed
Cylindrical
What kind of loads can a spherical roller bearing support?
Both axial and radial
Which part of a tapered roller bearing corresponds to the outer ring on other bearings?
Cup
The best bearing for supporting very heavy thrust and shock loads is a _______ thrust bearing.
Tapered Roller
A __________ bearing can accept missalignment without losing any of its load carrying capacity.
Spherical roller
A ladder bearing is a _________ bearing
Linear motion
Which linear motion bearing reduces shaft deflection ?
Open ball bushing
Bearing units designed to provide adjustment for shaft center distances are know as
Takeups
A major function of a bearing seal is to
Retain lubricant
The width of an oil seal is the
Thickness of the outer case
An important element in selecting the right type of seal for a bearing is the ______ of the shaft.
Surface speed (in FPM)
To ensure proper operation of a synthetic bearing seal, the shaft should be
Polished
A spring closure ring on a bearing seal forces the seal against the
Shaft
In general, lightweight oil should be used on bearings, carrying ________ loads and running at ______ speeds.
Light; high
Combatting the most common contamination of lubricating oil requires
Cleaning the sump
Internal wear in a bearing may be detected in drained oil by the presence of
Metal particles
The National Lubricating Grease Institute, specifies the hardness of a grease in numbers from ______ to _______.
000 to 6
When packing grease into a bearing, you should fill the bearing ______ full.
About half
Early bearing failure often results from
Improper installation
If ball or roller bearings are slightly misaligned when installed, they will
Fail sooner than they should
If a newly installed bearing makes a high-pitched whine when it starts running, the bearing may be
Overloaded
Excessive loading on a bearing causes
Brinelling
Immediately after cleaning and inspecting a bearing, you should coat it with
Oil
