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Rolamite is a technology for very low
Compilation of Rolamite information and articles
Including pictures and applications.
Video of a homemade rolamite
Simple machines Bearings (mechanical) {{tech-stub
Rolamite is a technology for very low friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of ...
bearings developed by Sandia National Laboratories
Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force Bas ...
in the 1960s. It is the only elementary machine discovered in the twentieth century and can be used in various ways such as a component in switches, thermostats, valves, pumps, and clutches, among others.
Development
The Rolamite was invented by Sandia engineer Donald F. Wilkes and was patented on June 24, 1969. It was invented while Wilkes was working on a miniature device to detect small changes in the inertia of a small mass. After testing an S-shaped metal foil, which he found to be unstable to support surfaces, the engineer inserted rollers into the S-shaped bends of the band, producing a mechanical assembly that has very low friction in one direction and high stiffness transversely. It became known as Rolamite. The Rolamite uses a stressed metal band and counter-rotating rollers within an enclosure to create alinear bearing
A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. There are many different types of linear motion bearings.
Motorized linear slides such as machine slides, X-Y tables, roller tables and som ...
device that loses very little energy to friction. One source claims it is the only basic mechanical invention of the 20th century. Tests by Sandia indicated that Rolamite mechanisms demonstrated friction coefficient
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative lateral motion of t ...
s as low as 0.0005, an order of magnitude better than ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this ...
s at the time. There are known Rolamite versions that contain two bands that work in reciprocate parallel for more accurate kinematic transmission at the reverse motion.
A video of a Rolamite in operation, to serve as a warhead safety-switch accelerometer
An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is acce ...
, is available.
See also
*Scrollerwheel
A scrollerwheel is a mechanical device composed of a number of rollers (four or more) and connective bands under tension, which wrap around and weave between the rollers forming a self-supporting cluster possessing a central roller. The cluster of ...
References
Linear
* *Bishop,James E., (11/27/1973). "Remember the Rolamite? World's 27th-and Newest-'Elementary Mechanism' Still Works, but It Hasn't Revolutionized Technology" ''The Wall Street Journal'' Page 46.Rotary
*External links
Compilation of Rolamite information and articles
Including pictures and applications.
Linear
Video of a homemade rolamite
Rotary
Simple machines Bearings (mechanical) {{tech-stub