Mori Seiki NV5000 Spindle Repair

The Mori Seiki NV 5000 is a CNC vertical machining center that has a BT40 taper.  It comes equipped with an oil mist lubricated and stator driven spindle capable of running up to 14,000 rpm.

CHALLENGE

This Mori Seiki NV5000 spindle was seized up when it arrived at our shop for evaluation and quoting. We discovered that the interior passages of the front cover coolant nozzles were clogged with metal chips. This led to catastrophic failure of the front pair of the angular contact quad set from contamination with coolant. We also noted excessive wear and runout >8µ in the tooling taper as well as some evidence of rubout on the front cover and coolant nozzles. The gripper (collet) components had light wear but were perfectly usable.

SOLUTION

After a grind, chrome plate, and finish grind of the tooling taper and some light machining of the front cover, we assembled the spindle with all new bearings, Bellevilles, o-rings & assembly screws. We did not replace the coolant plunger assemblies as the customer, like many others, keeps spare coolant plunger parts in stock.

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.