Millwright Certification Bearing Installation, Maintenance, and Failure Analysis 2

Question 1

What is the primary purpose of using an induction heater when installing a bearing on a shaft?

Accepted Answer

To expand the inner ring for an interference fit

Answer

An induction heater uniformly expands the bearing inner ring so it can slide over the shaft without force, preserving the interference fit without damaging the rolling elements.

Question 2

Which bearing failure mode is characterized by small pits forming on the raceway surface?

Accepted Answer

Spalling

Answer

Spalling occurs when subsurface fatigue cracks propagate to the surface, causing small pieces of material to flake away and leave pits on the raceway.

Question 3

When checking bearing clearance with a feeler gauge, what does excessive internal clearance typically indicate?

Accepted Answer

The housing bore may be oversized or the bearing is worn

Answer

Excessive internal clearance suggests the housing bore is too large, the bearing outer ring is worn, or the fit has been lost, all of which reduce load-carrying capacity.

Question 4

What is the recommended method for removing a press-fit bearing from a shaft without damaging it?

Accepted Answer

Apply force to the inner ring using a bearing puller

Answer

A bearing puller applies controlled axial force to the inner ring (the press-fit ring), preventing damage to the rolling elements and raceways that would occur from hammering or prying.

Question 5

Which condition would most likely cause a bearing to run hotter than normal during operation?

Accepted Answer

Over-greasing the bearing housing

Answer

Over-greasing causes excessive churning of lubricant, which generates heat from internal friction and can lead to seal damage and premature bearing failure.

Blog Practice Test

Blog Practice Test

Millwright Certification Bearing Installation, Maintenance, and Failure Analysis 2