FAFNIR SUPERPRECISION BEARINGS
Ex-Cell-O Spindle Bearings
The original bearing design developed by Ex-Cell-O for use in their spindles incorporated inch dimensions and had bore and O.D. tolerances which were nominal to plus. The “EX” series of bearings are designed to meet Ex-Cell-O replacement requirements. These bearings are Fafnir WI construction.
More recently, Ex-Cell-O established a bearing design with the same inch boundary dimensions, but with bore and O.D. tolerances nominal to minus. These bearings are the Fafnir WO separable construction and the series is desig- nated “XWO.”
Repairing older spindles with the new style bearing, or newer spindles with the old style bearing without reworking of shafts and housings can result in improper shaft and housing fits. Measurement of shafts and housings, or reconditioning of parts should determine what style bearing is proper replace- ment.
The charts which follow show the physical dimensions and part number interchange of Ex-Cell-O bearings. The preload section should be based on the operating speed and the lubrication system of the spindle.
Spindle shaft and housing diameters were toleranced by Ex-Cell-O to properly fit each of their bearing series.
FAFNIR MM-EX AND MM-XWO BEARINGS FOR REPLACEMENT ON EX-CELL-O SPINDLES
Old design, MM-EX Bore and O.D. Tolerance Nominal + Tolerance “WI” Construction
New Design, MM-XWO Bore and O.D. Tolerance Nominal - Tolerance “WO” Construction
Note: These bearings not intended for new design applications. Consult your local Torrington Company Engineering Sales office