TPC 304 Bearings Flashcards
Antifriction bearings are used where
Low starting friction is required
Which 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(n) _____
Running and sliding; force
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-sleeve ; precision insert
In a trimetal bearing, the inner lining is made of
Antifriction material
The extra lining material extending beyond half a circle in a precision insert bearing is called
Crush
The ability of a plain journal bearing material to adjust to misalignment is called
Conformability
The ability of a plain journal bearing material to absorb small particles is called
Embeddability
What is the best material for plain journal bearings that operate above 500°F?
Aluminum-bronze alloys
You need not replace bearings on 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 _______ the depth. The depth should be no more than _____ the bearings wall thickness
Twice; one-third
Which part of an antifriction bearing carries the least load during operation?
Cage
Antifriction bearings that run at moderate to high speeds generally should be lubricated with
Oil
The letters “BC” in the bearing designation “10BC02” indicate the bearing’s
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 antifriction bearing can be is
called the ______ runout of the bearing
Radial
Even if nothing else causes the failure of an antifriction bearing, it will ultimately fail due to ______ of the ______
Fatigue; rolling elements
Misalignment and excessive runout 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(n)
Minimum runout
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 equipment that must run at high speed?
Cylindrical
What kind of load(s) 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(n) _____ bearing can accept misalignment 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 known 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; 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 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
