341 Flashcards
You can control chain tension in a chain drive by changing shaft centers or using an ____ sprocket
Idler
A roller chain should be allowed to sag ____ percent of the distance between sprocket centers
About 2
In chain operations the area of greatest load are the
Chain joints
You should make your first full scale inspection of a new drive chain after ____ hours of operation
24
Chain side plates that show signs of uneven wear usually indicate that the
Drive is misaligned
In a vertical chain drive without and idler the shafts should be installed at an angle of no more than
60 degrees
The most common cause of chain drive failure is
Improper lubrication
Which of the following describes the Type III lubrication method?
Splash
A scrapping or slapping noise during a test run of a chain drive may indicate that
The chain is striking something
Before using chain that has been stored on open reels you should
Clean it with solvent
After mounting sheaves and pulleys you should check their alignment with a
Straightedge
The best way to tighten a v belt that has stretched is to
Adjust the distance between sheaves
A splice commonly used on low speed flat belts is the ____ splice
Stepped
If a new flat bell is running well how long should you test run it under normal load.
48 hours
A burned spot on a belt probably indicates that
The belt is overloaded
What type of belt is installed on sheaves rather than on pulleys
V belt
If a v belt in a multi belt drive shows wear you should
Replace the full set of belts
Which of the following is the correct way to check a V belts tension
Apply a specific amount of force to the top side of the belt
Which of the following is the best way to take up slack in a flat belt
Adjust the center distance
The pulleys for a positive drive belt have an
Flange in each side
Which of the following drives permits practically no misalignment of the shaft
Gear
The critical dimension that ensures accurate meshing of a work and work gear is its
Distance between the centers
When mounting spur of helical gears that have only one hub you should position the hub
Away form the bearing
When cracked or broken areas appear on great teeth that are almost new the cause is probably
Foreign object
It the metal at the tips and roots of gear teeth has been gouged or worn, the cause is probably
To tight of a fit between gears
Which of the following happens to the open gearing during the run in period
Gears become pitted
The DP of a gear is the ratio of the number of teeth to the ___ in inches
Pitch diameter
Which of the following is used to check gear alignment after installation
Steel square
What should you do if spalling occurs in a open gear drive
Heat treat the teeth
Which of the following is the best solution for hearing with cracked rims
Replace the gear
When installing an enclosed gear drive on the floor you should mount the feet on the
Steel based pads
What component of an enclosed gear drive prevents the buildup of pressure or the formation of a vacuum inside the drive housing?
Breather
If an enclosed gear drive is to be stored in the plant for a long time, you should
Fill the drive completely with oil
Most unusual noises that develop after an enclosed gear drive has run a while onginate in the
Shaft bearings
What does discoloration of worm gear teeth indicate?
Burning caused by overloading
Which tool is used to check the levelness of an enclosed gear drive on its foundation?
Spirit level
Which is the most common method of lubrication for bearings on enclosed gear drives?
Splash
During the run in period, you should run the drive system at half load for ____ hr
8 to 10
After a gear drive’s first week of operation under full load, you should
Check the oil level
Which of the following is found on the nameplate of an enclosed gear drive?
Load capacity
Which element of a drive package should you move to set the coupling gap?
Motor
What instrument is used when very precise coupling alignments must be made?
Dial indicator
The onty kind of couplings that require lubrication are those that have
Metal to metal contact
A floating shaft coupling should be used when the
Drives exert axial thrust
if the power requirements of a driven machine have been changed so that overloading occurs, you can solve the problem by installing (the) (a)
Next large coupling
A coupling can serve all of the following purposes except
Insulate against high temperature
The gap between a spacer coupling and the hubs should be ___ in
0
What is the usual cause of whipping on a floating shaft?
Excessive misalignment
An uneven wear pattern on a gear-type coupling is usually a sign of
Misalignment
The slack in the fit between coupling components is known as
Backlash
