M6.8 Bearings Flashcards
What are the two major groups bearings are divided into
Plain bearings and rolling element bearings.
What are The two further sub groups that bearings can be divided up into
Ball bearings and roller bearing
What are the two forces that bearings can be subjected to
Axial (along the shaft)
radial (acting at a right angle to the shaft)
What is required to ensure bearings have a longer service life
Lubricants and oils
What’s the downside of plain bearings
They can only carry light radial loads and it requires regular maintenance to avoid contamination
What are the two major types of bearings
Plain bearing
Rolling bearing
What’s better roller bearings or ball bearings and why
Roller bearings as they have a larger contact area meanings they can take higher radial loadings
With rolling element what are the sub categories of bearings
Ball bearings
Roller bearings
What’s the advantage of anti friction bearings over plain bearings
They produce less heat
Lower starting friction
Can carry heavier loads
What is a Axial load
Acting longitudinal ( too the side of the bearing )
What’s the benefit of an air bearing
They provide a zero friction Interface
What is the radial load
Acts vertically, weighing down the bearing
What must bearings have to reach a long service life
Lubrication and maintenance as they get contaminated with fod,filth etc
What’s the strongest type of bearing
Tapered roller bearings
What is synthetic lubed with
Water, also acts as a coolant
What is a problem with the sliding bearings
When first started it has a problem of insufficient oil in the bearings, which can be avoided by a grease pump
What is are two disadvantages of plain/ journal bearings
Take radial loads only
Get contaminated very easy - fod, filth
Gets replaced by anti friction
What are the 5 types of rolling (anti friction bearings)
Tapered
Spherical
Needle
Roller
Ball
What are some disadvantages of a ball bearing
Only spot contact,
Meaning on take light radial loads
Capable of high speeds but not heavy oscillating parts
What loads can the roller bearing take
More radial then ball
A limited amount of axial
(Allows axial to accommodate thermal expansion)
What are the advantages of needle roller bearings
Long thin roller therefore compact size
High radial load capacity
Light axial load capacity
What is a spherical roller capable of
Self aligning when minor angular displacement
High radial load capacity
However, if heavy load than stress is not evenly distributed
What are the advantages of a tapered roller bearing
Lots of radial and axial loads
Long life
Reduced size
Low price for long use
Less sensitive to contamination
What do air bearings provide
Use a thin film or pressured air to provide Zero friction interference
What loads do thrust bearings provide
Combination of radial and axial
