ball and roller bearings - NTN Bearing Corporation of America

TECHNICAL
INFORMATION
244
Trouble Observed Probable Corrective Action
Characteristic Cause
EXCESSIVE
VIBRATION
RUNOUT
INNER RING
WEARS LOOSE
ON SHAFT
OUTER RING
WEARS LOOSE
IN HOUSING
During
acceleration or
deceleration
periods
During operation
at fixed speeds
Shaft does not run
true. Shaft binds
when rotated by
hand.
Wear of the shaft
seat
Wear in housing
bore
Critical speeds
of machine
components
Unbalanced
rotating parts
Shaft bent
Cams, gears,
linkage
Misalignment
Bearing brinelled
Shaft bent
Bearing
misaligned
Bearing rings out
of square
Dirt
Machine
deflection
Incorrect shaft fit
Poor shaft finish
Housing fit
too loose
Unbalanced
forces
Poor finish
Soft housing
material
Stiffen shaft or other machine components to avoid
critical speeds.
Dynamically balance rotating parts.
Straighten and re-balance.
Adjust, improve or redesign.
Correct machine parts.
Replace bearing, avoid brinelling.
Straighten shaft and re-balance.
Correct machine parts and alignment procedures.
Check squareness of shaft and housing shoulders,
spacers and flingers, etc.
Wash all parts, replace with new bearing if necessary,
use clean lubricant, improve seals.
Stiffen machine members.
Use recommended shaft fit.
Smooth turn or grind shaft to size after
metalspraying or chrome plating.
Use recommended housing fit.
Dynamically balance rotating parts. Clamp outer
ring faces. Use cylindrical roller bearing and press fit
outer and inner rings.
Bore or grind housing I.D. oversize, press in a bushing
and finish bore or grind to size.
Use steel liners. Work-harden bore.