Chevalier QP3572 Spindle Repair

The Chevalier QP3572 is a large CNC vertical machining center.  It comes standard with a grease lubricated and gear driven spindle capable of 6,000 rpm.

CHALLENGE

This Chevalier QP3572 spindle arrived at our facility and we noticed that the bearings felt rough when rotated by hand in assembly incoming.  Upon inspection,  we found that coolant contamination had washed all the grease out of the bearings.  The #1 front roller bearing had suffered a catastrophic failure, 2nd row rolling elements were destroyed.  We then measured the critical dimensions and found a couple issues.  First, the tooling taper ID was worn with very poor tool contact.  Second, the gripper fingers (collet) showed excessive wear on critical tool retention surfaces.  No other significant dimensional deviations were noted (bearing journals/ shoulders, housing bores).

SOLUTION

The following actions were performed on this Chevalier QP3572 spindle:

• Clean, inspect overall dimensions
• Kiss grind the tooling taper ID
• Replace bearings, bellevilles, grippers, 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.