Alb Mod Anti friction B Flashcards
Proper preparation is essential to ensuring: (2)
- Efficient installation
- Damage-free installation
Regardless of the installation method you choose, what four things should be done? (4)
- Clean the machine and bearing assembly
- Inspect for damage. If damaged, why?
- Do a final cleanup of assembly area
- Organize tools and ensure they’re clean
A solvent bath for general use should be used for the initial cleanup, but for the final cleaning:
A clean bath of solvent should be used
While cleaning the machine, pay attention to the inside of the bearing housing. It is critical to the life of the bearing that ____ are flushed and wiped from the cavity
all abrasive particles
During cleanup on the shaft, it is critical that you keep _____ off the bearing seats, as you don’t want to alter the diameter
abrasives
During inspection of the housing, look for: (2)
- Cracks, nicks, burrs, corrosive damage that affects fit
- Grooves or marks from the outer ring spinning
If the bore of a housing is damaged, it must be:
Sleeved or discarded
When checking a shaft for damage, pay attention to: (3)
- Straightness
- Keyway and hub mounting surface
- Seal and bearing seats
When inspecting bearings, pay attention to:
Condition of rings (cracks, corrosion, discoloration or tracks from electric arching)
The area you assemble bearings/shafts/housings should be away from: (4)
- Grinding
- Welding
- Filing
- Machining
Although hot mounting can be accomplished on all sizes of bearings, it is most practical on bore sizes over:
20 mm
When cold mounting methods are not practical
When a bearing must be hot mounted on a shaft and installed in a housing at the same time, the housing must be:
Heated while the bearing is heated
The heating method you choose depends mainly on (2)
- Size of the bearing
- available equipment
Never heat a bearing above:
120°C or 250°F
Never heat a sealed bearing above:
80°C or 175°F
If you use an oil bath, what two things should you ensure? (2)
- Use new, clean, high temperature oil
- Do not place the bearing directly on the bottom of the oil bath
When mounting cylindrical bore bearings, ensure there is no gap between the bearing and the shoulder with:
0.0001” feeler
The process for hot mounting a bearing on a tapered sleeve is the same as for cold mounting, however:
No force is required to move the bearing up the taper
How would you ensure proper internal clearance when hot mounting a tapered bore bearing?
- When cold, firmly seat bearing on taper.
- Measure distance to shoulder
- Look up axial drive distance, subtract from distance to shoulder
- Mark position on shaft
When cold mounting, ensure the bearing ring with the clearance fit is the:
Bearing with the stationary load
You should cold mount bearings with bores ___” or less only
1.5”
You can cold mount a tapered bore bearing under 4” with a locknut. Over this size, you should use:
Hydraulic nut, or a nut equipped with jacking bolts
When mounting a bearing, always push on the:
Ring or rings being fitted
The most practical method for mounting a small cylindrical bore bearing is the:
Drive method
Needle bearings with a very thin wall on its cup should be installed with a mandrel to avoid:
crushing or distorting the bearing
A small cup can be installed with a press when convenient, however it may be more practical to use a:
Hammer and madnrel
To check if a cup has been installed properly, check that there is no gap between the cup and the shoulder with a:
0.0001” feeler
To prevent spinning or moving of the inner race, use a tapered adapter sleeve. When mounting a bearing on one, you are setting: (2)
- Internal clearance
- Axial position
Any sign of a groove or ridge on a tapered sleeve indicates a:
worn taper
On a tapered bore bearing, seat it upon the sleeve without the tab washer first. This is to:
prevent the tab from shearing off as it’s tightened
The tab on a tab washer that locks the nut receives virtually no force, it simply:
Prevents the nut from vibrating loose
The internal clearance on a bearing is the:
total clearance between the rolling elements and raceway, when one ring is pushed as far from the other as possible
When you use a dial indicator to check the distance one ring can be moved with respect to the other ring, you are doing what kind of check?
lift check.
This is only an approximate check
On roller bearings, the internal clearance can be measured with a _____ between the unloaded rolling element and the raceway
Feeler
Internal axial clearance is the:
Clearance between the rolling elements and race way when one ring is moved away from the other in an axial direction
internal radial clearance is the:
Clearance between the rolling elements and the raceway when one ring is moved away from the other in a radial direction
Initial clearance is the clearance in a bearing:
before it is mounted
Residual clearance is the clearance in a bearing:
after is has been mounted
Running clearance is the clearance in a bearing:
When it is running and at temperature
Preload is the:
load the rolling elements are under before any external load is applied
Preload is normally a ____ load on the rolling elements
axial
Preload is set by using:
Spacers or shims
Preload is also affected by the: (2)
Shaft and housing fits
The three ISO classes of preload are: (3)
Lighter
Normal
Heavier
Are preload designations standardized?
No
Preload is applied when: (2)
- The operating load is too light to make the rolling elements roll properly
- To reduce shaft deflection, make a stiffer assembly
What two things determine how much the initial clearance is reduced when installing a bearing? (2)
- tightness on shaft
- housing fit
The clearance in a spherical roller bearing is commonly checked with:
Feeler
Bearing clearance is set on a tapered bore bearing by forcing the bearing up the taper a predetermined distance. How can this distance be found?
Bearing tables
The two standard tapers for tapered bearing sleeves are: (2)
1:12(K) 1:30(K30)
The two methods for checking how far a bearing needs to be pushed up a taper is to use: (2)
- Tightening angle
- Dial indicator
With a tapered bore bearing, the 3 methods for setting the starting point from which the drive up is measured is to: (3)
- Seat firmly by hand
- Check clearance with feeler
- Use a pressure gauge and hydraulic nut
The tightening angle is useful for setting bearings that are:
Difficult to check with a feeler gauge
The tightening method isn’t considered accurate because:
The starting point for drive up can vary
For spherical roller bearings, you need to calculate the tightening angle based on how far the nut advances in one turn. This is based on the knowledge that a _____” advance axially reduces the radial clearance by 0.001” for a 1:12 taper
0.015
A _____ can be set against the inner ring so you can watch the amount of drive up as you install the bearing
dial indicator
When using a dial indicator with the drive up method of setting clearance on a tapered sleeve, what method would you use for finding your start point?
- measure initial internal clearance, with feeler gauge, after bearing is resting loose on the sleeve
- Begin driving the bearing up until you feel the feeler gauge pinched by the roller
The most accurate method for setting residual clearance is to use: (2)
Hydraulic pressure and dial indicator
The procedure for setting the starting point with hydraulic pressure is to:
pump hydraulic nut until starting pressure is indicated, zero dial, pump until dial indicator indicates proper axial drive up
When setting the internal clearance on a self aligning ball bearing, a rule of thumb is that the correct clearance is indicated by:
Slight drag when the outer ring is swiveled (for normal initial clearance only)
Note: It takes only a little force to arrive at the proper tightness according to the tightening angle.
Non destructive removal methods are used so the bearing can be reused. In preparation for removal, you should:
Remove any deposits or burrs from the shaft
List the non destructive removal methods: (6)
- Cooling
- Heating
- Oil injection
- Hydraulics
- Arbor press
- Drive
When cooling a shaft to remove a bearing, a _____ should be applied to the bearing to remove it before it begins to shrink with the shaft
steady pull
When using coolant, be cautious not to apply any to the part you are applying force to, because:
The coolant will make parts brittle
When heating a bearing, avoid the use of flame directly on the bearing. Why?
Could cause uneven heating and warping, as well as oxidization of rollers and raceways
This tool used to remove bearings is limited to cylindrical bearings with separable roller and cage assemblies
heating ring
Oil injection as a bearing removal method requires:
The shaft to be pre drilled
When removing a bearing with the oil injection method, the film of oil ensure what happens to the bearing and shaft during removal?
No abrasion damage
What is required when removing a bearing with the oil injection method on a cylindrical bearing and not a tapered bearing?
Pullers
What should you do when you remove a tapered bearing with the oil injection method?
Leave the retaining nut close to the bearing to ensure the bearing isn’t ejected at high speed
The hydraulic methods of non-destructive removal of a bearing include: (3)
- Hydraulic nut
- Hydraulic jack
- Hydraulic Press
A hydraulic nut can be used to remove a bearing from a tapered removal sleeve, however, if the bearing has a cylindrical seat, a ____ or a ____ is required for hydraulic removal
Hydraulic press or hydraulic ram
What hydraulic method could you use to non-destructively remove a bearing that is still on a machine?
Pull it with a hydraulic jack
When pulling a bearing off a shaft with a hydraulic jack, if at all possible, use a _____ behind the bearing
Bearing splitter
When using a jack to remove a bearing from a shaft, if the end of the shaft is threaded, use _____ to protect it
a smooth soft piece of metal
When using a hydraulic ram to remove a bearing, be aware of these two dangers: (2)
- The bearing may explode under pressure
- The tie rods connected to the strong back may spread and cause the ram to fly out
Note: you can help prevent this by ensuring the ram is centered on the shaft, the base of the ram is square on the strong back, and that you have a drilled piece of flat bar holding the tie rods from spreading
The type of puller you use depends on: (2)
- The type of bearing
- How it is mounted
The most secure and effective puller is the:
Bearing splitter
When there is not enough room for a splitter, what kind of puller can be used instead?
2, 3 or 4 jaw puller
Pulling on the outer ring should not be done on larger bearings, but it can be done to bearings under ____ inches by rotating the bearing/jaws as you apply pressure to the puller
4”
When using a puller, ensure you’re protecting the shaft ____
center
Never pull on the outer ring of a self aligning ball bearing, it may:
Explode under tension
List the destructive bearing removal methods: (5)
- Grinder
- Torch
- Drive
- Weld
- Pullers
When cutting a bearing inner ring off with a grinder, what steps should you take?
Cut the inner ring, not quite to the shaft, in two places 180° from each other. Finish cutting with a blow from a hammer and chisel
When cutting a bearing off with a torch, be sure to not direct the heat towards the shaft. This can:
bent the shaft
Driving a bearing off with a hammer and chisel is not usually successful on a shaft diameter over:
2 inches
To remove an outer ring from a bore with a welder, what would you do?
Weld in a zig zag pattern around the race. When cooled, it will shrink the race.
What kind of puller could you use to destructively remove a bearing?
4 jaw internal puller
Note: jaws are inserted between rolling elements and come with a wide variety of jaw styles
The collet style puller is fast and convenient, but causes:
Impact damage to ball bearings
