Browse Prior Art Database

Superconducting Diamagnetic Bearing

IP.com Disclosure Number: IPCOM000037632D
Original Publication Date: 1989-Apr-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Chaudhari, P: AUTHOR

Abstract

Bearings are commonly used in motors, generators, and other mechanical devices where one object has to be moved over the other but is attached to it. Bearings dissipate energy due to mechanical friction. Lubricants are used to minimize the amount of friction and also to prevent seizing. A diamagnetic bearing stops contact of the two materials but still enables one to move relative to the other. No lubricants are required and the loss due to friction can be small to zero.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Superconducting Diamagnetic Bearing

Bearings are commonly used in motors, generators, and other mechanical devices where one object has to be moved over the other but is attached to it. Bearings dissipate energy due to mechanical friction. Lubricants are used to minimize the amount of friction and also to prevent seizing. A diamagnetic bearing stops contact of the two materials but still enables one to move relative to the other. No lubricants are required and the loss due to friction can be small to zero.

When a material goes superconducting it expels magnetic fields giving rise to strong diamagnetism. This effect is used to produce a suitable bearing. A rotating shaft is used to illustrate how such a bearing might work in a motor or generator. The superconducting material 10 is placed around the shaft 12 as shown in Fig. 1. The bearing house contains a row of permanent magnets 14 with their poles aligned, for example, as shown in Fig. 1. The diamagnetic field generated in the superconductor prevents the shaft from touching the magnets, the shaft being free to rotate.

The superconducting materials can be applied by sintering techniques or by evaporation of films. If contact of the housing along its axis is to be prevented, positioning of the magnets and the superconducting materials can be arranged as shown in Fig. 2 and Fig. 3 (tapered shaft).

Disclosed anonymously.

1