Mazak Integrex 100 Spindle Repair

The Mazak Integrex 100 is designed to be a multi-tasking CNC milling center.  It comes fitted with this grease lubricated and stator driven spindle capable of running up to 12,000 rpm.

CHALLENGE

Our customer stated this Mazak Integrex 100 spindle was producing bad part finish and had a crunchy bearing noise.  When the spindle arrived at Northland Tool and Electronics, we noted that the shaft was locked up, would not rotate, and had end-play incoming. We had to fabricate a hydraulic plate to allow proper testing of the spindle prior to breakdown. After installing the hydraulic plate, tests checked good and we were able to get the shaft to unlock.  The bearings did sound very loud and “crunchy” as the customer had stated when the shaft was spun by hand.  During disassembly, we noted that the o-ring behind the front cover was stretched out and there was wet, dark grey particulate found in the cover and throughout the other components behind it.  After completing the breakdown and evaluation, we found that the front bearings had catastrophically failed.  There was no grease remaining in them and the ball cages were destroyed.  The #1 bearing inner race had spun out on the shaft journal causing minor fretting, but no significant damage.  We also found that the rear roller also had some contamination as well.  There were 2 blue thermistor wires that were cut and did not appear to be used.  Unfortunately, we were unable to check the pull force of the drawbar due to the tooling be Capto tri-lobe.  No dimensional deviations were noted for this repair.

SOLUTION

The following actions were performed on this Mazak Integrex 100 spindle:

• Clean, inspect overall dimensions
• Replace bolts, o-rings, seals, and bearings

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.