Kitamura Mycenter 3XIF Spindle Repair

The Kitamura Mycenter 3XIF is a CNC vertical machining center.  It is equipped with an oil mist lubricated and gear driven spindle capable of running up to 15,000 rpm.

CHALLENGE

This Kitamura Mycenter 3XIF spindle suffered a catastrophic rear roller bearing failure which allowed debris to contaminate the #3 and #4 bearings (rearmost in front quad set.)  The rear housing ID was within ISO, but was +2/-6µ egged and tapered, possibly what contributed to the rear roller failure.  It was noted that the tooling taper had poor contact and 4-5µ runout.  We also inspected the drawbar assembly and saw that the drawbar was very rusty. The gripper (collet) outer sleeve was rusted to the spacer collar and the grippers have heavy wear.

SOLUTION

The following actions were performed on this Kitamura Mycenter 3XIF spindle:

• Clean, inspect overall dimensions
• Replace ceramic bearing quad set and rear rolller bearing, grippers (collet), outer sleeve, and spacer collar
• Replace rotation prevention nut, front and rear labyrinth rings, o-rings, and assembly screws
• Grind, chrome plate, and finish grind the rear housing ID
• Kiss grind the tooling taper

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.