7.11 Bearings SIPPO Flashcards
What should be done to a removed bearing that is not installed right away?
-Coat in rust preventative substance, wrap it in greaseproof paper, box, label
What must bearings be checked for?
Freeplay and excessive backlash
If there are any flaws to a bearing, what must be done?
Replace it
What does effective lubrication provide?
- reduces friction and abrasion
- reduces heat generated by friction
- prolongs service life
- prevents rust
- prevents contamination from entering rolling elements and raceways
If a sealed bearing cant be regreased, what must be done?
Replace it
What is hydrodynamic lubrication?
Load carrying surfaces of the bearing are separated by a thick film of lubricant
What type of lubrication uses air and oil? How?
Hydrostatic lubrication.
Air is forced in to the bearing area at a high pressure to separate the surfaces
What type of lubrication doesn’t require the motion of one surface relative to the other? Which do?
Hydrostatic: doesn’t
Hydrodynamic: does
What is boundary lubrication?
Oil film between mating parts only a few molecules thick. Viscosity not important.
What type of lubrication is applied by spraying or dipping a coating of very fine particles?
Solid film lubrication
What is true brinelling caused by?
Excessive impact
How does true brinelling appear on gears?
Appears as indentations in bearing cup raceways
What causes false brinelling?
False brinelling caused by vibrations of bearings whilst in a static state
What is galling?
when the rolling element of the bearing skids, leading to metal to metal contact on its race
How does corrosion appear on gears?
- black pitting marks or reddish brown rust areas on the rolling elements, raceways or cages
