Timken Super Precision Bearings for Machine Tool Applications

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ENGINEERING
TAPERED ROLLER BEARINGS
Tapered roller bearings are generally used in two fundamental
spindle design configurations:
• Three-support mountings for heavily loaded or long spindles.
• Simple mounting of two single-row bearings.
Three-Support Mounting
Figure 74 shows the “box type” mounting using three bearings. The
two nose bearings are located axially (fixed position) and accept axial
forces in both directions, while the tail bearing is fitted as a floating
position to accommodate the thermal expansion of the spindle. The
floating position can be supported either by a tapered roller bearing or
a cylindrical roller bearing.
This kind of arrangement is mainly used for special heavy machines
running at low or medium speeds, or for long spindle designs.
Fig. 74. “Box-type” mounting with a TDO at the floating position.
94 TIMKEN MACHINE TOOL CATALOG