Kitamura Mycenter HX1000i Spindle Repair

The Kitamura Mycenter HX1000i is a very large CNC horizontal machining center.  It comes equipped with an oil mist and gear driven spindle capable of 8,000 rpm.

CHALLENGE

This spindle arrived at our facility seized because of a catastrophic failure of the rear roller bearing. When the cage that normally contains the rollers disintegrated, the crushed phenolic material migrated to the front of the spindle, contaminating the ceramic quad set. Another result of the rear roller failure was that several deep grooves were created in the rear housing bore as the destroyed bearing rotated. We also observed that the Big-Plus dual-contact tooling 50 taper ID was damaged, and that the face was worn down as well. In addition, we noted that the taper ID had been previously plated, and that the hard chrome was flaking where the ID had taken some hits.

SOLUTION

We performed a precision grind, chrome plate, and finish grind(GPG) of the rear housing bore to remedy the damage from the bearing failure. We also did a GPG of the 50 taper ID and kiss ground the face of the shaft to preserve the Big-Plus dual-contact functionality. When all components had been thoroughly cleaned, we reassembled the spindle with new bearings, setting the proper preload, and replaced the 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.