ASIDES
Bearing good news
Colin Ledsome CEng FIED looks at one impressive instance of 20th century technology:
the Rolamite bearing
In September 1966, Donald F Wilkes, an engineer at Sandia
Laboratories (a subsidiary of Honeywell), invented a new
piece of technology: the Rolamite bearing.
This consisted of a pair of rollers constrained to run
together by a tensioned metal band between a pair of parallel
fl at surfaces (Figure 1). The frictional resistance on the rollers
was measured as 0.0005, one tenth of the best ball bearings at
that time, with no need for lubrication. It was patented in 1969
and hailed as the fi rst truly new technology of the 20th century
(a debatable suggestion).
Various confi gurations were proposed including multiple pairs
of rollers (Figure 2) and even differing roller shapes (Figure 3),
with modifi ed bands and tracks. The potential for applications of
this new technology were enthusiastically explored in a number
of articles, covering everything from domestic devices to solar
array deployment mechanisms.
Other proposals put forward suggested elastic materials for
the bands, giving some springing between the parallel tracks.
Valve systems were proposed, with ports opened and closed by
the band as the rollers moved.
There was a spin-off known as the Scrollerwheel (Figure 4),
which applied the basic principle to a rotating bearing. One of its
main advantages was the lack of a need for lubrication opening up
applications under water, at elevated temperatures or in space, where
any oils or greases boil off in the vacuum.
As with many new technologies, most of the proposals were
replacements for existing equipment in current use. Since the existing
kit performed almost as well as, or better than, the Rolamite, and their
performance was well known, it wasn’t taken up to any extent.
Thus, it has become another interesting technical idea looking for
a use. One day, it will be just what’s needed for a new application.
Figure 1 - Basic Confi guration
Figure 2 - Multi-Roller
Figure 3 – Other Roller Shapes
Figure 4 – Scrollerwheel
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