HSD ES988 Spindle Repair

HSD is a very popular spindle manufacturer that a lot of machine tool OEM’s use in their machines.  This HSD ES988 spindle is grease lubricated, stator driven, and capable of running up to 20,000 RPM.

CHALLENGE

Our customer sent in this HSD ES988 spindle stating that the spindle was noisy.  When it arrived at Northland Tool we were surprised to see that the spindle was actually seized.  After completing a full breakdown and evaluation, we recorded quite a few issues that will need to be addressed. First, the rear bearings had catastrophically failed and were extremely hard to remove from the housing.  The rear bearing housing was also egged and tapered.  Second, all the proximity sensors were damaged and very worn.  Third, the actuator seals and inside of the actuator were contaminated with a brown sludge and rust.  Lastly, the rear shaft nut was broken and cracked in several places which can be seen below.

Damaged Rear Shaft Nut

SOLUTION

The following actions were performed on this HSD ES988 spindle:

• Clean, inspect overall dimensions
• Replace bolts, bearings, o-rings, seals, proximity sensors, and rear shaft nut
• Grind, plate, grind (GPG) the rear housing

RESULT

After reassembly of all components and adjusting bearing preload, we put the spindle through a rigorous break-in and testing procedure to make sure it passes our final quality inspection. See below for the passing test reports:

Front Bearings Vibration Analysis Spectrum:                 Rear Bearings Vibration Analysis Spectrum:

Motor Analyzer Summary:

This spindle passed our final quality inspection and was returned to our customer with a 1-year warranty.