Bearings and stuff

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..

• 0.004 inch

• 0.006 inch

• 0.005 inch

• 0.003 inch

What are anti-friction bearings?

• Plain Bearing s.

• Bushings.

• Split bearing.

• 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.

• cylindrical shape.

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.