Enshu GE480H Spindle Repair

The Enshu GE480H is a CNC horizontal machining center.  It can come fitted with this air/oil mist lubricated and stator driven spindle that is capable of running up to 15,000RPM.

CHALLENGE

Our customer sent in this Enshu GE480H spindle stating that they expect there to be broken bearing spacer. Once the spindle arrived at Northland Tool we completed a full disassembly and evaluation.

This is what we found:

• Spindle rotated freely but the bearings felt worn when spun by hand
• Encoder failed incoming testing and will need to be replaced
• Rear roller bearing fretted against the journal and the housing but both measured within spec
• #2 bearing was heavily contaminated with a black particulate (Pic 1)
• Gripper fingers were worn and will need to be replaced
• Nose of the shaft made contact with the ID of the front cover
• The draw bar nut gauled and damaged the threads during removal
• ID 40 taper was worn and read AT Wrong on our air gauge
• Inner spacer spun on the shaft causing significant damage to both

SOLUTION

The following actions were performed on this Enshu GE480H spindle:

• Clean, inspect overall dimensions
• Replace bolts, o-rings , bearings, gripper fingers, and encoder
• Machine damage on the ID of the front cover and stone high spots on nose of shaft
• Grind-Plate-Grind (GPG) ID 40 taper
• Chase threads on draw bar and draw bar nut
• GPG front journal
• Manufacture replacement inner spacer

RESULT

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