Machine Tool Bearings
Today's
machine tools offer enhanced capabilities promoting greater accuracy, higher
speed, and greater stability, which promise to deliver production benefits.
Superior performance is expected and a major part depends upon the bearings.
Bearings used to support spindles of machine tools must exhibit
characteristics unattainable by bearings for general applications. They
consist of various bearing arrangements. The rigorous application demands
have resulted in the development of high-precision bearings and bearing
arrangements
High-precision bearings are expected to have following characteristics -
- Narrow tolerances of dimension and form
- A large number of rolling elements with small diameters
- Low sectional height
- Light and strong cages
- Preloadable design
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The bearing size required for a given bearing arrangement is usually
determined by the load carrying capacity. Stiffness, fixed dimensions for
the tool holder, the spindle bore are also the major criteria to determine a
longer life. Where high radial stiffness is required, bearings with the
smallest possible contact angle should be used and vice versa. Tolerance
classes for precision bearings are standardized internationally.
Types of high precision machine tool bearings
- Angular contact ball bearings
- Cylindrical roller bearings
- Angular contact thrust ball bearings
- Hybrid bearings
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