State of Damage
State Description
Causes
Countermeasures
- Discolored inner ring raceway, rolling elements and cage due to temperature rises and the reaction of lubricant
- Poor lubrication
- Lubricant dissolves at high temperature to stain raceway surface
- Sharp rise in temperature
- Improve lubrication
- Axial lines on the raceways and rolling surfaces due to improper installation and dismounting
- Inner ring and outer ring misalignment during installation and dismounting
- Impact load during installation and dismounting
- Use appropriate tools
- Use press machine to prevent impact load
- Mutual center alignment during installation
- Rusting and corrosion of the bearing includes: crater rust of the raceways, rolling element surface, pear skin shape rust, crater rust of the same space distance with rolling element, comprehensive rust and corrosion
- Intrusion of water or corrosive material (lacquer, gas)
- Inappropriate lubricant
- Water-drop due to condensing of water vapor
- Stall at high temperature and moisture
- Improper anticorrosion during transportation
- Inappropriate storage
- Improve sealing
- Improve lubrication
- Improve anti rust measures and storage methods
- Pay special attention during use
- Inner ring, outer ring, rolling element and retainer discoloration softening, deposits and breaking due to drastically temperature rises during operation
- Poor lubrication
- Over speed
- Clearance is too small
- Intrusion of water and foreign particles
- Poor precision of shaft and housing, large deflection of the shaft
- Overload
- Improve lubrication
- Select proper bearings
- Proper fitting practice, bearing clearance and preload
- Improve sealing
- Adjust the precision of the shaft and housing
- Improve installation method
- Creeping refers to the relative sliding motion between the fitting surfaces when there is clearance between them
- It appears as excessive polishing on the fitting surfaces which have the creeping motion, sometimes there is scoring
- Insufficient interference or clearance fit
- Loose fastening of adapter sleeve
- Check the interference and implement locking measures
- Fasten adapter sleeve
- Check the shaft and housing precision
- Axial preload
- Fasten the end face of the bearing
- Glue the fitting surface to avoid creeping
- Coat lubricant on the fitting surfaces
- Wear caused by vibration and shaking between rolling elements and raceways propagation into false Brinelling
- Vibration, shaking and small amplitude swings during bearing transportation
- Poor lubrication
- Fix the location of the bearing and shafts during transportation
- Separate the bearing inner ring and outer ring package during transportation
- Preload the bearing reduce the vibration
- Use appropriate lubricant
- Wear caused by repeated mutual minute sliding between two contact surfaces
- Occurs at the contact surfaces between the raceways and the rolling elements
- Produces bronze or black wear powder, so also called fretting wear corrosion
- Poor lubrication
- Swing motion of low amplitude
- Insufficient interference
- Use appropriate lubricant
- Preload
- Check the interference
- Coat fitting surfaces with lubricant
- By wear, it means the friction leads to wear at the raceway or the roller end face, ring end faces and cage pocket
- Foreign material enters
- Development caused by etching or corrosion
- Poor lubrication, rolling element skidding caused by irregular movement
- Improve seal
- Clean the housing
- Thoroughly filter the lubricating oil
- Improve the lubricant and lubrication method
- Denting on the raceway or rolling surfaces due to the metal powder, foreign particles
- Roller spaced indents (true Brinelling) caused by incorrect handling or shock load
- Foreign particles such as metal powder
- Impact load during assembly or transportation
- Excessive load
- Clean shaft and housing
- Improve seal
- Filter the lubrication oil
- Improve installation and use methods
- By scratch, it means surface damage caused by collection of tiny burns resulting from skidding and oil film hot breaking on the raceway or rolling path
- Produce rough surface with hot sticking
- High-speed light load
- Acceleration and deceleration
- Impropriate lubricant
- Water ingress
- Improve preload
- Adjust bearing clearance
- Use lubricant with good oil film property
- Improve lubricating method
- Improve seal
- By pinching, it means accumulation of parts of the tiny burns on the gliding surface leads to surface damage
- Linear scars of the circumferential direction of raceways and rolling surface
- Axle toroidal pendulum scar on roller end surface
- Pinching at the rib face contacted with roller end face
- Overload, excessive preload
- Poor lubrication
- Foreign particles
- Inner and outer rings misalignment, shaft deflection
- Poor precision of axle and bearing box
- Check the bearing load, adjust bearing selection
- Appropriate preload
- Improve lubricant and lubricating method
- Check the shaft and housing precision
- Fish scale flaking on the raceways or rollers due to fatigue during bearing rotating under load
- Overload, improper installation, load moment
- Intrusion of foreign particles, water entering
- Poor lubrication, inappropriate lubricant
- Inappropriate bearing clearance
- Poor precision of housing, uneven rigidity of housing, shaft has large axial deflection
- Rusting, etching pit, scratching and brinelling
- False Brinelling further development
- Check the bearing load, adjust bearing selection
- Improve installation method
- Improve seal device, antirust while machine halt
- Use lubricant with adequate viscosity, improve lubrication method
- Check the shaft and housing precision
- Adjust clearance
