Plane Bearings Flashcards
What must be done before starting up to ensure there’s no damage to oil lift bearing
Checking oil must be brought up to pressure
What are the two main functions of journal bearings
To support radio load
To hold a journal in location accurately
How do you check the contact area of a bearing
By lightly coating the journal with Prussian blue and rotating it inside
What are two advantages of measuring bearings with clearance with plastigage instead of lift check
Plastigage provides a more accurate measurement of clearance
Plastigage reveals changers clearance along to Bearing
What is a plain bearing
Plain bearings have no rolling elements
What are the 2 main purpose of a Journal bearing
To hold journal and it’s required location
To support the intended radial load
What is a wrapped bushing
It consists of a thin steel shell lined with a soft bearing material such as lead or bronze
What is a Hydrodynamic bearings
They are designed to develop full film lubricant when the journal is up to operating speed a.k.a. oil wedge
what is a hydrostatic bearing
Hydrostatic bearings are found on equipment that operate too slow to form a Hydrodynamic film
Hydrostatic bearings depend on external pumps to provide pressurized film of lubricant to support the loaded shaft
What is compressive strength
The bearing material must be strong enough to support the shaft loads at maximum operating temperature
Fatigue resistance
Fatigue resistance is the resistance of the bearings material to crack and flake
High embeddability
High embeddability allows abrasive contaminants to become embedded in the material without failing
Deformability
Deformability allows the material to yield to misalignment or imperfections in the shaft such as change in diameter it ensures all parts of the bearing carry the the load
Wetability
Is the ability to retain a film of lubricant
Compatibility
Must not seize or weld to the journal under rubbing conditions such as start up
