What is the plane bearing diametrical clearance for?
To allow grease to be applied.
Allows for a film of lubricant between the shaft and the bearing.
Allows grease to get to ball bearings in the inner race.
Is a clearance of 0.025 inch.
With a plain bearing supporting a shaft, when is the most likely time for the bearing to wear?
When the diametrical clearance exceeds 0.050 inch.
During engine start up when the journal rests on the bearing.
During high speed rotation of a shaft.
Too much lubricant in the bearing
What size is the plain bearing diametrical clearance..
What are anti-friction bearings?
Plain Bearing s.
Roller and ball bearings.
Which of the following are true about roller and ball bearings?
very high starting friction.
Can not carry heavy loads.
Suitable for reversing/oscillating movements.
Run hotter than plain bearings.
Ball bearings to take thrust loads/radial loads have..
Internal races are shallow.
Have thin rollers.
Internal races are especially deep grooved.
Must be a loose fit.
Ball bearings are used in..
Accessory drives, gearing and anywhere that a narrow bearing is needed.
Heavy oscillating loads.
Handle heavy shock loads.
Have a flat raceway.
Angular contact ball bearings are..
Do not depend on the angle they are set at.
Can handle high thrust loads with moderate radial loads.
Thin and needle like.
Roller bearings are..
cylindrical and follow flat raceways.
Have deep grooved races.
Have offset inner and outer rings.
Contain even amounts of ball bearings.
Caged needle roller bearings can support..
Light thrust loads used on propeller shafts.
Heavy radial loads and used in gear boxes.
Aircraft main wheels.
occupy much more space than other bearings.
Un-caged needle roller bearings ..
run at high speed, used in universal joints.
Can not run at high speeds, used in universal joints.
Take up more space diametrically than other bearings.
use small spherical bearings,
Caged needle roller bearings..
Should not be lubricated.
lubricated with grease can not be run at high speed.
lubricated with grease must be run at high speed.
Rollers must be allowed to skid.
Tapered roller bearings ..
Support Light radial loads used in aircraft wheels and helicopter masts.
Support heavy radial and thrust loads used in aircraft wheels and helicopter masts.
ball bearings at right angles to a shaft.
Are self aligning bearings.
Tapered roller bearings..
Outer race is called a cone and inner race a cup.
Inner race is called a cone,outer race a cup.
Are narrow hard ball bearings.
Are not set at angles.
The ratio of thrust to radial loading of a taper roller bearing can be catered for by variation of the taper..
Heavy thrust loads with little radial loads need a large taper angle.
Heavy thrust loads with large radial loads need a small taper angle.
Heavy thrust loads do not require a taper.
Large radial loads do not require a taper.
Purely radial loads are..
Well supported by taper roller bearings.
Not supported by taper roller bearings,
The same as thrust loads.
Along the axis of a shaft.
Used on engine prop shafts and Helicopter masts..
Take only radial loads.
The same as self aligning bearings.
Do not take loads but rotate freely.
How are interference fit bearings fitted?
Drilling out the bearing inner race.
Heating the shaft and squeezing the bearing on.
loosely allowing the bearing to creep.
Put the bearing in hot oil and slipped onto the shaft.
How is a bearing swaged?
Deforming the the bearing housing with a punch.
Adding extra loctite.
Rolling the circumference of the housing over the outer bearing race edge.
Securing the bearing with a circlip.
Aircraft bearings are designed to..
produce maximum friction and maximum wear resistance.
Minimum wear resistance and minimum friction.
Minimum friction and maximum wear resistance.
Maximum noise and minimum wear resistance.