A magnetic bearing is a bearing that supports a load using magnetic levitation. Magnetic bearings support moving machinery without physical contact. For instance, they are able to levitate a rotating shaft and permit relative motion with very low friction and no mechanical wear. Magnetic bearings support the highest speeds of any kind of bearing and have no known maximum relative speed
Magnetic bearings are difficult to design using permanent magnets due to the limitations described by Earnshaw's theorem while techniques using diamagnetic materials are relatively undeveloped. As a result, most magnetic bearings require continuous power input and an active control syste.m to hold the load stable. Magnetic bearings often use permanent magnets to carry the static load, while a power input is only used when the levitated object deviates from its optimum position. Magnetic bearings typically require a back-up bearing in the case of power or control system failure and during initial start-up conditions.
Magnetic bearings are used in several industrial applications such as electrical power generation, petroleum refinement, machine tool operation, and natural gas pipelines. They are also used in the Zippe-type centrifuge used for uranium enrichment. Magnetic bearings are used in turbomolecular pumps, where oil-lubricated bearings would be a source of contamination.
Other articles related to "magnetic, bearings, bearing, magnetic bearing, magnetic bearings":
... A magnetic compass points to magnetic north pole, which is approximately 1,000 miles from the true geographic North Pole ... A magnetic compass's user can determine true North by finding the magnetic north and then correcting for variation and deviation ... the direction of true (geographic) north and the direction of the meridian between the magnetic poles ...
... On aircraft or vessels there are even three types of bearings true, magnetic, and compass bearing ... Compass error is divided into two parts, namely magnetic variation and magnetic deviation, the latter originating from magnetic properties of the vessel or aircraft ... As discussed above, positive (easterly) variation indicates magnetic north being east of geographic north ...
... induction-based levitation system present in maglev technologies such as the Inductrack system, magnetic bearings could be used instead of complex control ... this - that has bypassed the Earnshaw's theorem issues - is the homopolar electrodynamic bearings invented by Dr Torbjörn Lembke ...
Famous quotes containing the words bearing and/or magnetic:
“Rosenbloom is dead.
The tread of the carriers does not halt
On the hill, but turns
Up the sky.
They are bearing his body into the sky.”
—Wallace Stevens (18791955)
“We are in great haste to construct a magnetic telegraph from Maine to Texas; but Maine and Texas, it may be, have nothing important to communicate.”
—Henry David Thoreau (18171862)