Agathon Combi 350 Coolant & carbide are lethal to bearings
Agathon Combi 350, 3500 RPM, grease lubrication, coupling driven
Our customer asked us to rebuild this grinding spindle because it was getting noisy during operation. One inescapable fact about the combination of cutting coolant & carbide grinding swarf is that it will eventually get into your spindle bearings and kill them. The entire interior of this spindle was contaminated with coolant which had washed out most of the permanent grease in the bearings. What was left of the normally white grease was black from the carbide which entered with the coolant. So not only was there a loss of lubrication, but the carbide had contributed to the wear which was evident on the bearing races & rolling elements. Fortunately for our customer, no significant dimensional deviations were noted on the shaft journals, housing bores or tooling interface.
After a thorough cleaning of all spindle components, we reassembled the spindle with new bearings, the spindle-side drive coupling & elastomeric spider, o-rings and assembly screws. We trim balanced the spindle during the test run-up and confirmed that the vibration & temperature readings were within specification.