Catastrophic bearing failure was the main cause of this spindle malfunction Continue reading to learn how Northland Tool performed this repair and converted a Weiss GHK 176239 spindle from grease-injected to permanent grease lubrication……Read More
Mazak Variaxis I-700 Spindle Repair
The Mazak Variaxis I-700 is a 5-axis CNC machining center. It can come fitted with this oil mist lubricated and stator driven spindle capable of running up to 18,000 rpm.
Our customer suspected they had a rear bearing failure in their Mazak Variaxis I-700 spindle. They sent it in for a breakdown and evaluation and we did some incoming tests. We test ran the spindle and it was extremely noisy. It was also noted that one of the power leads had been torn off close inside the actuator and all of the actuator bolts were loose incoming. The actuator leaked heavily when we attempted to test it for functionality and after removing the actuator we found multiple sheared and damaged o-rings. Lastly, the rear oil line had been severely pinched. After completing the disassembly, we found that the rear roller bearing was severely contaminated and had shifted away from the shaft shoulder. The rear roller inner race was able to spin on the shaft freely and the front bearings felt a little worn when spun by hand. The drawbar pulled good force and the grippers were in good condition. The field passed all incoming testing. We then inspected and measured all critical surfaces (bearing journals, bearing shoulders, housing, taper, etc.) and found a few issues. First, the rear roller journal was severely worn and the shoulder had been damaged. Second, the Big plus taper measured +7µ and was out of spec. Lastly, the rear of the actuator housing was damaged during breakdown and will need to be addressed.
The following actions were performed on this Mazak Variaxis I-700 spindle:
- Clean, inspect overall dimensions
- Replace bearings, bolts, o-rings, seals, encoder, and bellevilles
- Grind, chrome plate, and finish grind (GPG) the rear roller bearing journal
- GPG the 40 ID Big Plus taper
- Kiss Grind Rear roller journal shoulder
- Repair damaged actuator housing
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.
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Repair History - Here are examples of similar spindle repairs that may contain additional information that will help you. If you have additional questions, please contact us.
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