Case Study: Advantages Of Using Band Filters with Acceleration Envelope

Step 1 - Identify the Problem

Findings

Can #13 Drive Side bearing’s readings indicate an inside race fault-cracked (suspect it has gone up the taper).

Dryer Can Speed = 123 rpm.

Recommmmendation: Suggest changing bearing out before shaft or housing damage occurs.

Step 2 - Before applying the bandpass filter

Amplitude will not necessary change or determine the severity of the fault with heavy mass equipment. Frequency content is crucial for slow speed analysis

Step 3 - Making some changues

Apply a band filter at the frequency range that the bearing rings to emphasize the bearing fault

When the High Pass Band Filter is applied the Inside race fault is seen clearly with the running speed sidebands

Step 4 - After applying the bandpass filter

On equipment that you are not familiar with, you should experiment with several filters because you do not always know where the bearing ring thanks to ERBESSD INSTRUMENTS®

Digivibe MX® software is capable of applying different band filters, a useful tool for an analyst

Step 5 - Errors and Corrections

Paper Mill planned to have the bearing replaced before further damage occurs

Step 6 - Things to avoid

Common issues

Avoidance: Potential catastrophic failure, shaft and/or housing damage

Example of when a taper bore bearing cracks, one set roller end up taking the load Similar bearing failure that ran for 1 week after the inside race crack was diagnosed A cracked bearing can produce catastrophic failure in the shortest time period than any other bearing failure,
except maybe cage failure