Design Considerations
In both linear and/or rotary motion the purpose of a ball bearing is to
reduce friction. Slides and bushings utilize various materials that
tend to slightly reduce this friction problem. The ball bearing,
however will outperform these devices and can reduce the coefficient of
friction upwards of 100 times. The linear rotary bearing will offer
this tremendous advantage in all directions of motion.
To take full advantage of this phenomenon, certain design
considerations must be taken into account. Proper installation,
lubrication and shaft characteristics will be discussed in the following
paragraphs. Under "Design Considerations" shaft to bearing
selection is emphasized. Because this is the world's first bearing
to offer unrestricted linear rotary anti-friction motion, certain
parameters should be considered.
If the linear motion is prominent, greater clearance between bearing
and shaft is recommended. For example, a shaft classified as "A"
with a precision or super precision bearing is acceptable. If the
rotary motion is prominent, a class "B" Shaft is required with a precision
or super precision bearing depending on the degree of precise rotary
motion. If the rotary and/or linear motion requires a very high
degree of precision, It is recommended that a "matched set" arrangement of
shaft to bearing be considered. Here the bearing is matched to the
shaft from line to line to within a few tenths (millimeters) depending on
the diameter involved. Only in an extreme application would a press
fit be suggested (as in the use of an "R" shaft). It should be noted
again that the linear rotary bearing offers a considerable reduction in
the coefficient of friction. It, therefore, has an extended life
over such devices as bronze bushings, V-Ways and non-recirculating ball
strips. Another factor to be considered is that, as the latter
devices wear, their relative positioning is no longer accurate as
initially aligned. "Down Time" is extremely costly and the
consequences are obvious.
|
