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This Stirling Cycle cooler, built by North American Phillips, tested the use of magnetic bearings and clearance seals in mechanical coolers. The cooler demonstrated the usefulness of these techniques by running for a total of 5 years. This particular model of Stirling Cycle cooler is not in commercial production, however.

Definitions:

Magnetic Bearings

In magnetic bearings, moving parts are held in place by magnetic forces, rather than by conventional bearings such as ball bearings or roller bearings.

Clearance Seal

The clearance seals in the Phillips cooler prevent helium gas from flowing past the cooler's moving pistons . Instead of using a rubber gasket or a layer of oil, these seals rely on precise machining of the pistons and the cylinders they pass through, so that the gap between the piston and the wall is too small for any significant amount of gas to flow through.

Phillips cooler with magnetic bearings and clearance seals.

• 320 x 200
• 640 x 400 D

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Curator: Brent Warner NASA Official: Susan R. Breon Last Updated: November 4, 2004