7.11 Bearings Flashcards
How are bearings usually tested?
A. By checking for excessive backlash or free play during rotational checks.
B. By measuring their weight and size.
C. By applying high pressure and observing deformation.
A. By checking for excessive backlash or free play during rotational checks.
What must be done to cleaned bearings that are not installed immediately?
A. They must be stored in water-resistant bags.
B. They must be coated in a rust-preventing oil or specified coating, wrapped in greaseproof paper, boxed, and labelled.
C. They must be kept in a vacuum-sealed container without any coating.
B. They must be coated in a rust-preventing oil or specified coating, wrapped in greaseproof paper, boxed, and labelled.
What is likely the result of detecting nearly any flaw or defect in a bearing assembly?
A. The bearing can still be used after lubrication.
B. The bearing assembly is likely to be rejected and replaced.
C. The bearing can be repaired with minor adjustments.
B. The bearing assembly is likely to be rejected and replaced.
What is one benefit of proper lubrication in bearings?
A. It reduces friction and abrasion.
B. It increases the weight of the bearing.
C. It makes the bearing spin faster than its design limit.
A. It reduces friction and abrasion.
What does proper lubrication help reduce in bearings?
A. Heat generated by friction.
B. Gear backlash.
C. Noise during operation.
A. Heat generated by friction.
How does proper lubrication affect the service life of bearings?
A. It prolongs the service life.
B. It shortens the service life.
C. It has no effect on the service life.
A. It prolongs the service life.
How does lubrication protect bearings from rust?
A. It creates a barrier to prevent corrosion.
B. It increases the temperature of the bearing.
C. It removes rust already present.
A. It creates a barrier to prevent corrosion.
How does lubrication help keep foreign objects or contamination away from bearings?
A. By forming a protective layer on the rolling elements and raceways.
B. By cleaning the bearing after operation.
C. By dissolving contaminants completely.
A. By forming a protective layer on the rolling elements and raceways.
What must be done if bearings cannot normally be regreased?
A. They must be cleaned thoroughly.
B. They must be replaced.
C. They must be left to operate until failure.
B. They must be replaced.
What are the types of lubrication used in bearings?
A. Hydrodynamic lubrication, hydrostatic lubrication, boundary lubrication, and solid film lubrication.
B. Liquid lubrication, gas lubrication, air lubrication, and grease lubrication.
C. Surface lubrication, deep lubrication, heat lubrication, and anti-friction lubrication.
A. Hydrodynamic lubrication, hydrostatic lubrication, boundary lubrication, and solid film lubrication.
What separates the load-carrying surfaces in hydrodynamic lubrication?
A. A thin layer of air.
B. A thick film of lubricant.
C. Solid particles of graphite.
B. A thick film of lubricant.
What is a characteristic of hydrostatic lubrication?
A. It uses high-pressure air and oil to separate surfaces and doesn’t require any surface movement.
B. It relies on surface movement for lubrication to occur.
C. It uses only air to create a lubricating layer.
A. It uses high-pressure air and oil to separate surfaces and doesn’t require any surface movement.
What is a feature of boundary lubrication?
A. The oil film between mating parts is only a few molecules thick.
B. The surfaces are separated by a thick layer of oil.
C. The lubrication is applied using compressed air.
A. The oil film between mating parts is only a few molecules thick.
How is solid film lubrication typically applied?
A. By pouring it into the bearing housing.
B. By spraying, dipping, or brushing it onto surfaces.
C. By heating the bearing and applying molten lubricant.
B. By spraying, dipping, or brushing it onto surfaces.
What does solid film lubrication consist of?
A. Paint-like coatings of very fine particles of lubricating pigments blended with a binder and other additives.
B. A mixture of thick grease and oil.
C. Pure graphite particles applied under pressure.
A. Paint-like coatings of very fine particles of lubricating pigments blended with a binder and other additives.
What causes true brinelling in a bearing?
A. Excessive impact.
B. Lack of lubrication.
C. Excessive heat.
A. Excessive impact.
How is true brinelling identified in a bearing?
A. By the presence of hollow spots and lubricant loss.
B. By indentations in the bearing raceway and rolling elements, and an increase in vibration.
C. By visible cracks in the bearing housing.
B. By indentations in the bearing raceway and rolling elements, and an increase in vibration.
What causes false brinelling in a bearing?
A. Vibrations of the bearing while in a static state.
B. Excessive speed during operation.
C. Overheating of the bearing.
A. Vibrations of the bearing while in a static state.
How is false brinelling identified in a bearing?
A. By hollow spots that resemble brinelling dents.
B. By increased vibration during operation.
C. By visible wear on the bearing seals.
A. By hollow spots that resemble brinelling dents.
What causes galling in a bearing?
A. Bearing skids with metal-to-metal contact on its race, transferring metal from one surface to another.
B. Excessive vibration during operation.
C. Lack of lubrication in high-speed conditions.
A. Bearing skids with metal-to-metal contact on its race, transferring metal from one surface to another.
How is galling identified in a bearing?
A. By black pitting marks or reddish-brown rust.
B. By metal transfer, resulting from a welding or tearing action.
C. By increased noise during rotation.
B. By metal transfer, resulting from a welding or tearing action.
What causes corrosion in a bearing?
A. Excessive heat from overloading.
B. A chemical attack on the bearing materials.
C. Excessive lubrication build-up.
B. A chemical attack on the bearing materials.
How is corrosion identified in a bearing?
A. By black pitting marks or reddish-brown rust.
B. By cracks in the bearing raceway.
C. By hollow spots on the rolling elements.
A. By black pitting marks or reddish-brown rust.
What do slow rotation checks of raceways highlight?
a) Cracks and dents
b) Roughness, corrosion, and wear
c) Alignment issues
b) Roughness, corrosion, and wear
