bearings and seals / packing test Flashcards
with friction bearings, the area of contact is relatively large and the pressure on the bearing material is usually low compared to anti friction bearings
true
False
true
friction bearings have 3 types of radial loads. which on shifts thru an arc less than 180 degrees
stationary
ocillating
reciprocating
alternating
oscillating
the choice of friction bearing and housing depends on load, rotational speed, support design and _______
direction of pull
rubbing speed
shaft size
bearing material
direction of pull
a split joint design that can give up to 270 degrees of bearing load (pull from sides and above split) is the_______
angle
4 bolt split
flat joint
gib joint
gib joint
journal bearings can be either split or one piece (bushing) and have metallic liner materials made of
babbitt
brass
nylon
phenol laminates
both the 1st and 2nd answers are correct
all the above
babbit and brass
plastic bearings such as nylon will have
a thermal expansion rate of 10 times that of steel
a fully staurated water expansion rate of 0.0256” per inch of material
the ability to run without lubrication
all the above
all of the above
2 of the common babbit bearing alloys are
tin, brass
bronze, lead
tin, lead
aluminium, antimony
tin and lead
a thick walled construction split bearing with a spherical seat will
self align its bore with the sag in the shaft decreasing the bearings load capacities
self align its bore with the sag in the shaft decreasing edge loading of the bearing
be used on light load applications
be made of sintered bronze
self align its bore with the sag in the shaft decreasing edge loading of the bearing
babbitt completely melts at ______degrees C, pours at __________degrees C, completely solidifies at ________ degrees C.
280, 370, 250
370, 450, 350
280, 370, 340
180, 250, 220
babit melts at 280
pours at 370
solidifies at 250
when dealing with babbitt, you should not
have water on or around the area where the pour is taking place
over heat the babbitt
use lead unless area is properly vented and wearing proper PPE
all the above
all the above
when fitting a poured babbitt bearing, you will relieve the corners of the bottom half of the bearing and add an oil groove
to the sides
to the top
to the unloaded area of the bearing
to the loaded area of the bearing
to the unloaded side
for cleance in friction bearings, a general rule of thumb is - 0.001” clearance per inch of shaft diameter
true
False
true
to adjust the clearance in a split plain bearing, you would
add shims to the joint to decrease the clearance
take out shims to decrease the clearance
scrape bearing in loaded section
scrape bearing in unloaded section
take out shims to decrease the clearance
when using plastigage, you must choose the diameter about equal to the bearing clearance, lay it down on the shaft, add cap and once it has been torqued down and then the cap removed, you will measure the
thickness with a micrometer
width with a vernier caliper
the thickness with a plastigage chart
the width with a plastigage chart
the width of the plastic gauge chart
crush and spread are built into the bearing shell to help lubricate the bearing liner
true
False
false
when removing plain bearings from a housing, the housing halves should be match marked for proper installation
true
False
true
small bushings will have to be ______ to bring the bore to the proper diameter
drilled
machined
reamed
none of the above
reamed
use a stone to remove any burrs from the journal and polish it with
emery cloth
crocus cloth
sand paper
draw filing
crocus cloth
always check the shaft straightness and the journal for out of round and taper. to do this, you would take _______measurements________ degrees apart around the journal. you would make these measurements at ____ different points along the journals length
3, 120, 3
6, 60, 3
3, 120, 6
3, 60, 3
3,120,3
a housing fit check is done by adding 0.005” shims under the bearing cap and using a 0.006” lead wire on top of the bearing insert. you then replace cap and torque. when cap is removed the lead wire should measure_________
the same clearance as in the bearing
1 or 2 mils
the same as the shim thickness
any of the above
the same as the shim thickness
use a hole or telescoping gauge to measure bore diameters. use a ___________ to transfer the measurements to a readable number
vernier caliper
tape measure
inside caliper
vernier micrometer
vernier micrometer
when driving in a bushing, you should first slightly chamfer the inside and outside edges and then use an adapter with adriver. the adapter helps prevent _________ of the bushing
improper alignment
collapsing
distortion
all the above
all the above
an ideal area of contact of a plain bearing after scraping would be spots about ____ over an area of ____ of the surface
1/16”, 50 %
1/8”, 50 %
1/8”, 85 %
1’\/16”, 85%
1/8th ,85%
end float is controlled by the use of a
radial plain bearing
thrust bearing
bushing without a collar
all the above
thrust bearing
hyrodynamic bearings need a designated________ for a given _____ for full film support
minimum speed, load
maximum speed, load
minimum speed, shaft size
maximum speed, shaft size
minimum speed, load
a plain bearing with an unsteady load at high speed will develope oil whirl
true
false
true
hydrostatic bearings are found on equipment tht operates ___________
at to slow a speed to form an oil wedge
with shock loads
at high speeds
the 1st and 2nd answers are correct
at to low a speed to form an oil wedge and with shock loads
thrust bearings can use direct lubrication and tilting pads to help form the oil wedge
true
False
true
embedability of a bearing material is its
resistance to cracking
ability to support shaft loads
ability to retain a film of lubrication
ability to handle contaminants
ability to handle contaminants
a lift check is used to check___________clearance
axial
radial
initial
radial
internal and external self-aligning bearings are used when
alignment is impratical or impossible to maintain
to accommodate angular misalignment when mounting
the are small amounts of shaft wobble
all the above
all the above
to load the balls into a conrad bearing you need to squash the outer rings diameter slightly
true
false
true
antifriction bearings have cages that ______________
prevent the rolling elements from rubbing
push the rolling elements thru the unloaded zone
guide the rolling elements
all the above
all the above
when using angular contact bearings in pairs, use the______________ configuration for axial loads in one direction
face to face
back to back
tandem
tandem
cylindrical roller bearings can handle radial loads only
true
false
true
tapered roller bearings will need to be ______________ to help the rolling elements turn
clearance
a shrink fit
force fit
preloaded
pre loaded
carb bearings are used in situations that have some mislaignment and axial float
true
False
true
if you had a bearing number of 6208 K RS, the clearance would be
C-2
less than standard
standard
more than standard
standard
if you had a series 6 bearing, it would be a ____________ bearing
tapered roller
ball thrust
deep groove ball
spherical roller
deep grove ball
if you had a 22208 bearing, it would be a ________ and have a bore of _______
double spherical roller, 40 mm
double ball, 8 mm
single cylindrical, 40 mm
single deep groove, 8 mm
double spherical roller 40 mm
a bearing ring subject to a stationary load will have a/an__________ to allow for creep
interference fit
press fit
push fit
force fit
push fit
if a bearing being mounted has seals, you would heat it up to _____ or if not sealed, heat to_______
120 c, 80 c
120 c, 120 c
80 c, 120 c
175 c, 250 c
80c for seals
120 if not sealed
when inspecting bearings, you find discoloration, this is a sign of
contamination
overloading
overheating
fatigue
over heating
residual clearance is measured
before it is mounted
after it is mounted
after it is running
any of the above
after its been mounted
mounting separable cylindrical bore bearings and needle bearings with no inner ring, you will use________to aid in installation
guide mandrels
guide sleeves
slight chamfers on shafts
all the above
guid mandrels
guide sleeves
slight chamfer on shaft
to find the internal clearance on a spherical roller bearing, you can use feeler gauges
true
false
true
when using the turning angle for axial drive up of tapered bore bearings with adapter sleeves, the larger the shaft will have
the smaller the turning angle
the larger the turning angle
the turning angle should be the same for all sized bearings
smaller than the bearing
the larger turning angle
when using oil injection to dismount a tapered bore bearing, you should back off the retaining nut (do not remove it)
true
False
true
if shaft runout is more than 0.001” or bearing seat wear exceeds 0.0005”, they need to be straightened, fixed or replaced
true
False
true
welding is done on a bearings outer ring (when in a housing) to _______________to help in the removal of the ring
expand the ring
to shrink the ring
melt the ring
none of the above
shrink the ring
if a bearing runs at a temperature higher than 55 degrees C, __________ will occur
rapid oxidation
temperatures will decrease
longer bearing life
full film strength
rapid oxidation
brinelling is
impact denting
spalling
fretting
fatigue
impact denting
imbalance and misalignment are the 2 main causes of vibration in bearings
true
false
true
improper selection of a bearing will include, wrong clearance, material or type
true
false
true