2ND 1 Flashcards
The main advantage of ball and roller bearings is_________.
a) they are easier to replace
b) they can carry heavy loads
c) they last longer
d) journal bearings are old fashioned
e) they have low starting friction
e) they have low starting friction
deep Groove ball bearings are designed for __________.
a) heavy thrust loads
b) radial loads and moderate thrust loads
c) heavy radial loads only
d) light radial loads only
e) light thrust loads only
b) radial loads and moderate thrust loads.
Angular contact ball bearings are designed for.
a) heavy thrust loads
b) light radial loads
c) heavy radial loads
d) moderate combined thrust and radial loads
d) moderate combined thrust and radial loads.
Deep groove ball bearings can carry heavier radial loads than radial bearings with filling slots because the deep groove bearing has more balls.
a) True
b) False
b) False
The only difference between a heavy duty bearing and a light duty bearing is the size of the balls.
a) True
b) False
a) true
When handling bearings which of the following should not be done?
a) Use clean newspapers on which to lay bearings while installing.
b) Use plenty of clean rags.
c) Leave bearings in box until ready to use.
d) Wash out completely, all grease in which a bearing comes packed.
d) wash out completely, all grease and which a bearing comes packed
Pressure should always be applied to the outer race when removing a ball bearing from a shaft.
a) True
b) False
b) False
What would happen if you attempted to pull a bearing on the shallow shoulder of an angular contact bearing?
It would disassemble the bearing and brinell and ruin the race
When a bearing must be pulled by the outer race because of a gear or shaft shoulder, what is the most important thing to remember?
Be sure the pull is steady and applied all around the outer ring
Why shouldn’t galvanized pipe be used as a drift to remove bearings?
The zinc on the galvanized pipe chips off and is liable to get into the bearing.
Sometimes the inner bearing cap can be used to pull a bearing.
a) True
b) False
a) True
A three-way puller is particularly useful in pulling …..
a) roller bearings
b) gears through the spokes
c) needle bearings
d) deep groove bearings
b) gears through the spokes
It is a good idea to smooth off a shaft with emery cloth before mounting a ball bearing.
a) True
b) False .
b) False
A shaft shoulder for a bearing should be about the height of the inner race.
a) 1/3
b) 1/4
c) 1/8
d) 1/2
d) 1/2
What should be the maximum temperature used to heat a bearing on a shaft?
a) 300°F
b) 180°F
c) 225°F
d) 400°F
c) 225°F
What will happen if a ball bearing is fit Loosely on the shaft?
With shaft rotation the inner ring would slip back. The slippage causes continuous wear
A ball or roller bearing should fit onto the shaft as tightly as possible to prevent rotation of the inner race.
a) True
b) False
b) False
Face-to-face mounting of duplex bearings allows a moderate amount of misalignment.
a) True
b) False
a) True
Tandem mounting of duplex bearings is used for heavy radial loads.
a) True
b) False
a) True
If one bearing in a duplex set is bad it is permissible to replace the bad bearing as long as it is replaced by one made by the same manufacturer.
a) True
b) False
b) False
The wiping lip of a seal should usually be turned toward the inside of the housing.
a) True
b) False .
a) True
Oil lubrication will permit about ………. the bearing speed of grease lubrication.
a) three times
b) one-half
c) twice
d) two-thirds
c) twice
The main advantage of oil lubrication over grease lubrication is its ability to circulate and cool the bearing.
a) True
b) False
a) True
About how full should a bearing housing be filled with grease.
a) 1/3
b) 1/2
c) 3/4
d) 2/3
a) 1/3
What is the main detrimental effect of over-lubrication in a grease lubricating bearing?
Overheating
What is the best method of removing grease from an over lubricated bearing while it is in service?
Remove the drain plug and leave it out until the excess grease is expelled.
Ball or roller bearings which have failed because they have been pinched in the housing can be recognized by……….
a) pitting of the races with brown discoloration
b) a definitely defined load track on opposite sides of the outer race diagonally across
c) excessive wear of the bearing cage
d) false brinelling in the inner and outer races
b) a definitely Defined load track on opposite sides of the outer race diagonally across
A cracked inner race may mean that the shaft is oversize.
a) True
b) False
a) True
Which one of the following should not be done in working with anti-friction bearings?
a) Use cotton waste to wipe bearings.
b) Treat a used bearings as carefully as a new one.
c) Use lint-free rags to wipe bearings
d) Wash bearings in clean solvent
a) use cotton waste to wipe bearings.
The oil reservoir of an anti-friction bearing is usually filled ……
a) to cover the bottom half of the top ball
b) one-third full
c) to the middle of the split line
d) to cover the bottom half of the bottom ball
d) to cover the bottom half of the bottom ball.
The lubricating oil film in a sleeve bearing is about……….thick.
a) .001” to .003”
b) .003” to .005”
c) .004” to .008”
d) .008” to .010” .
a) .001” to .003”
If you are looking at the end of a shaft turning counter-clockwise, the shaft will tend to assume a position to the left of the centerline on a journal bearing when the oil film is fully established.
a) True
b) False
b) False
In 1839 Mr. Babbitt devised a material for sleeve bearings which consisted of .
a) copper, lead and zinc
b) lead, iron and tin
c) zinc, chrome and tantalum
d) tin, copper and antimony
d) tin, copper and antimony.
The two types of thrust bearings in general use on large hydroelectric units are .
a) the spring type
b) the hydrodynamic type
c) the tilting shoe type
d) the hydrostatic type
e) the universal type
a) the spring type
c) the tilting Shoe type.
The G.E. type generator thrust bearing obtains its equalizing action from springs under the stationary segments.
a) True
b) False
a) True
The protective material on the bearing surfaces of the G.E. type generator thrust bearing should not be removed.
a) True
b) False
b) False
The basic elements of a Kingsbury thrust bearing are a rotating thrust collar, stationary tilting shoes, base ring, housing, lubricating system, cooling system and equalizing springs.
a) True
b) False
b) False
A Kingsbury thrust bearing is said to be “equalizing” if the load on the shoes is adjusted automatically.
a) True
b) False .
a) True
The principle behind the load carrying capacity of the Kingsbury type bearing is the formation of a wedge shaped oil film.
a) True
b) False
a) True
The main advantage of calcium base grease is its water resistance.
a) True
b) False
a) True
A trimetal bearing consists of a thin overlay of Babbitt on a leaded bronze lining on a steel back.
a) True
b) False
a) True
Turbine oil stability is its ability to resist foaming.
a) True
b) False
b) False
Viscosity index is a measure of an oils rate of viscosity with temperature.
a) True
b) False
a) True
The purpose of an oil ring in an oil lubricated oil bearing is to………..
a) prevent leakage of oil from the ends of the bearing
b) prevent leakage along the shaft
c) prevent leakage from the housing
d) carry oil to the bearing from the reservoir
D) Carry oil to the bearing from the resevoir.
