14-11-2012, 11:21 AM
SEMINAR REPORT ON ACTIVE MAGNETIC BEARING
ACTIVE MAGNETIC.pptx (Size: 111.29 KB / Downloads: 243)
INTRODUCTION
A bearing is a machine element, which supports another moving machine element. It permits relative motion between the contact surfaces of the members, while carrying load.
Already in 1842 Earnshaw had demonstrated that passive (permanent) could made but it cannot stable in all spatial direction. For successful operation the unstable direction have to be electrically served. Hence the name ACTIVE MAGNETIC BEARING.
History
The evolution of active magnetic bearings may be traced through the patents issued in this field..
Early active magnetic bearing patents were assigned to Jesse Beamsat the University of Virginia during World War II and are concerned with ultracentrifuges for purification of the isotopes of various elements for the manufacture of the first nuclear bombs, but the technology did not mature until the advances of solid-state electronics and modern computer-based control technology with the work of Habermann[7] and Schweitzer.
PRINCIPLE OF OPERATION:
The application of the magnetic bearing is upon the principal that an electromagnet will attract a ferromagnetic material
The natural tendency of the stator is to attract the rotor until it makes the contact, An AMB system consists of electromagnet bearing actuators, position sensors
PARTICULAR FEATURESOF AMB:
Its No mechanical contact.
No oil contamination of process fluid.
Shaft position does not change with speed.
Wide range including high speeds.
Require space for control system.
CONCLUSION
The potential of the AMBs has not yet been exploited to the fullest extent due to complexities involved in their design and control. However, as newer and more advanced techniques develops, one can hope to have an easier and better control of AMBs. AMB have their own advantages, which gives them a special importance among other bearings.