No abstract

The phenomenon of levitation has attracted attention from philosophers and scientists in the past. The recent advances, notably in power electronics and magnetic materials, have focused this attention within the last decade on the application of electromagnetic suspension and levitation techniques to advanced ground transportation. Regardless of the fact that there is, in effect, a separate technology involved for each electromagnetic method, the whole subject is given a blanket title of 'maglev'. There is also a very wide range of industrial applications to which magnetic suspension techniques could be profitably applied, particularly in the area of high-speed bearings to reduce noise and to eliminate friction, and yet only high-speed ground transportation has caught the imagination of the media. This review deals with the physics and engineering aspects of the four principal contenders for advanced ground transportation systems and describes the most up-to-date developments in Germany, Japan, USA and the UK in this field. This article also describes some of the very recent challenging developments in the application of electromagnetic suspension and levitation techniques to contactless bearings. A fairly comprehensive bibliography is given to enable the more interested reader to pursue the topic further in any one of the technologies dealt with in this review.

No abstract

The phenomenon of levitation has attracted attention from philosophers and scientists in the past. The recent advances, notably in power electronics and magnetic materials, have focused this attention within the last decade on the application of electromagnetic suspension and levitation techniques to advanced ground transportation. Regardless of the fact that there is, in effect, a separate technology involved for each electromagnetic method, the whole subject is given a blanket title of 'maglev'. There is also a very wide range of industrial applications to which magnetic suspension techniques could be profitably applied, particularly in the area of high-speed bearings to reduce noise and to eliminate friction, and yet only high-speed ground transportation has caught the imagination of the media. This review deals with the physics and engineering aspects of the four principal contenders for advanced ground transportation systems and describes the most up-to-date developments in Germany, Japan, USA and the UK in this field. This article also describes some of the very recent challenging developments in the application of electromagnetic suspension and levitation techniques to contactless bearings. A fairly comprehensive bibliography is given to enable the more interested reader to pursue the topic further in any one of the technologies dealt with in this review.

Defying gravity seems to have fascinated scientists and philosophers through the ages. Electromagnetic suspension and levitation, following on from aircushion vehicles, such as the Tracked Hovercraft and the Aerotrain, has been the focus of attention and research for passenger-carrying vehicles since the 1970s. Two major demonstration systems are now in operation: one in Germany and one in Japan. Besides application to passenger-carrying vehicles, controlled DC electromagnet technology has been applied to produce frictionless magnetic bearings, conveyor systems, flow meters, etc. This is becoming a rapidly expanding area, moving out of the realms of academe into one of considerable industrial importance. The applications now include high-speed machine tool spindles, ultra-centrifuges, turbo-alternators, corrosive-liquid pumps, gas compressors and high-vacuum pumps, fly wheels for energy storage, handling components for protective coating and weighing balances. New developments in superconducting materials have also aroused fresh interest in the electrodynamic levitation schemes such as the Japanese one.