Setco 241 Spindle Repair

The Setco 241 spindle is grease lubricated, pulley driven, and capable of running up to 20,000 rpm.

CHALLENGE

This Setco 241 spindle was partially disassembled incoming, the front housing and shaft nuts had been removed.  The threads of the front shaft nut and on the shaft were galled.  The rear shaft nut was also galled on and had to be cut off. Shaft threads here were damaged as well.  After completing the rest of the disassembly and evaluation, we noted that the #2 front bearing suffered catastrophic failure.  We then measured the critical dimensions (bearing journal, housing, taper, etc.) and found a few issues.  First, the tooling taper ID and taper face had excessive runout, ID >40µm, Face >20µm.  Second, the front and rear bearing journal shoulders had very high runout, Front = 20µm, Rear = 24µm.  Lastly, the pulley journal was bent with extremely high runout of 212µm.  No other dimensional deviations were noted for this repair.

SOLUTION

The following actions were performed on this Setco 241 spindle:

• Clean, inspect overall dimensions.
• Manufacture and install new front and rear shaft nuts
• Rework front and rear shaft threads
• Grind, chrome plate, and finish grind (GPG) the tooling taper ID
• Straighten and (GPG) the pulley journal
• Kiss grind the taper face
• Kiss grind the front and rear bearing journal shoulders
• Replace all bearings, o-rings, and assembly screws

RESULT

After reassembly of all components, adjusting bearing preload, and undergoing break-in and testing procedures, this spindle passed our final quality inspection before being returned to our customer with a 1-year warranty.