Voumard VMX 90 Bearing Failure
Northland Tool received this ID grinding spindle from a new customer because their spindles were failing prematurely in the machine. Their spindle rebuild costs had increased dramatically along with their machine downtime. When we disassembled the spindle we found out why. The coolant jacket was compromised and was leaking coolant into the interior of the spindle. The bearings were lubricated with grease even though it is an oil injected spindle. The bearings that were used had a top speed rating of 52,000 with grease. Front and rear shaft journals were undersized, front is -4/-5, rear is -6/-7 (iso is +/-2.5).
All these issues combined caused premature rear bearing failure.
Grind, chrome plate and finish grind the shaft front and rear journals.
Grind, chrome plate and finish grind the shaft pilot.
Replace bearings with ceramic
Replace all orings and pressure check the coolant jacket to insure there is no leaking
Adjust preload, balance, assemble and break in. Final quality control inspection.
There is a difference when it comes to spindle rebuilders. Make sure that your rebuilder is qualified to work on your spindle type and that they use the highest quality parts available when rebuilding your spindle.