An actuator including a threaded shaft and a carriage having a shaft
engaging portion coupled to the threaded shaft. The carriage is moveable
in a direction parallel to an axis of the threaded shaft upon a relative
rotation between the threaded shaft and the shaft engaging portion. A
ceramic bushing is coupled to the shaft engaging portion of the carriage,
the bushing surrounding the threaded shaft. The ceramic bushing is much
harder than heretofore used materials and results in greatly reduced
particulate formation. The carriage or portion thereof can be formed
around the bushing, e.g., by injection molding.