Ingersoll T-1500 Spindle Repair

CHALLENGE

The customer reported that a cleaning rag became entangled in the upper drive spindle during operation.

Drive spindle was locked up and partially disassembled when received. Upon disassembly of the spindle, rag debris was found in the rear labyrinth. It appeared that increased pressure caused failure of the #3 bearing from excessive preload. When #3 bearing failed, the inner race was fused to the drive spindle shaft.

The main spindle tooling taper ID showed heavy wear with poor tool contact and measured with excessive runout of >20µ. The front bearing journal OD is undersized by -8/-9µ where #1 bearing locates (ISO is ±6µ). The graphite seal on the main spindle was broken during breakdown.
Gripper fingers (collet) & drive dogs (keys) were worn & damaged. Touch sensor ring is damaged.

SOLUTION

The following actions were performed on this Ingersoll T-1500 spindle:

• Clean, inspect overall dimensions
• Grind, chrome plate, and finish-grind main spindle tooling taper ID and front bearing journal OD
• Manufacture new touch sensor ring
• Replace all bearings, Bellevilles, grippers, graphite seal, drive dogs, seals, o-rings & 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.