Magnetic bearings give new meaning to spin control
In the past, their large size, high cost, and complicated controls ruled out practical application. But the last magnetic bearings are making commercial inroads in the natural-gas industry. Demonstration projects, limited in duration and results, may secure acceptance by powerplants, too. Alternatives to conventional oil-lubricated bearings have appeared from time to time. Steam- and gas-lubricated varieties are examples. But except for a few niche applications, no alternatives have garnered commercial acceptance. A relatively recent development, magnetic bearings, may finally break the mold. Potential benefits are enticing: A shaft suspended in air and positioned against end thrust by magnetic forces suffers negligible friction, thereby lowering starting torque and power losses; bearing wear, and in some cases, shaft seals, are eliminated, extending service life and reducing maintenance; repairs largely consist of a technician replacing a card in the control system, as opposed to a mechanical crew tearing down and replacing a conventional bearing; imbalance forces are canceled or controlled without transmitting large forces to the foundation; lubricants, which can contaminate process fluids and pose fire hazards, are eliminated or substantially reduced. These benefits have been realized for years in centrifuges, machine tools, and space applications. Now magnetic bearings are making substantial inroads in large-scale, industrial turbo-machinery, led by commercial use in gas pipeline compressors, along with demonstration projects on powerplant pumps and fans.
- OSTI ID:
- 418012
- Journal Information:
- Power (New York), Vol. 140, Issue 8; Other Information: PBD: Sep-Oct 1996
- Country of Publication:
- United States
- Language:
- English
Similar Records
Guidelines for the use of magnetic bearings in turbomachinery. Final report
Case history of magnetic bearing supported hot gas turboexpander