Part i - spindle facts

Bearing Construction: Hybrid Ceramic
Figure 12.
HYBRID CERAMIC BEARING
given ball bearing size, without sacrificing any bearing life.
Newer bearing technologies using ceramic balls. The
ceramic balls, when used in an angular contact ball
bearing, offer distinct advantages over typical bearing
steel balls.
The ceramic balls have 60% less mass than steel
balls: This is significant because as a ball bearing is
operating, particularly at high rotational speeds,
centrifugal forces push the balls to the outer race, and
even begin to deform the shape of the ball. This
deformation leads to rapid wear and bearing
deterioration. Ceramic balls, with less mass, will not be
affected as much as steel at the same speed. In fact, the
use of ceramic balls allows up to 30% higher speed for a
Ceramic Balls Do Not React with The Steel Raceways: One of the most prominent
mechanisms of bearing failure is surface wear created by microscopic "cold welding " of the ball
material to the raceway. The cold welds actually break as the bearing rotates, creating surface
roughness, which leads to heat generation and bearing failure. The ceramic material drastically
reduces this mechanism, resulting in longer bearing life.
Ceramic Ball Bearings Operate At Lower Temperatures: Due to the nearly perfect
roundness of the ceramic balls, hybrid ceramic bearings operate at much lower temperatures
than steel ball bearings. This results in longer life for the bearing lubricant.
Ceramic Bearings Operate at Much Lower Vibration Levels: Tests have shown that
spindles utilizing hybrid ceramic bearings exhibit higher rigidity and have higher natural
frequencies, making them less sensitive to vibration.
Roller Bearings
Roller bearings are mostly used at lower speed application, but with higher Loads. They are
usually used in pair of two, opposite oriented to allow a high assembly's stiffness.
Ususally, those kind of bearings are grease lubricated.
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