Active magnetic bearings provide revolutionary advantages for gas turbine engine rotor support. These advantages include tremendously improved vibration and stability characteristics, reduced power loss, improved reliability, fault tolerance, and greatly extended bearing service life. The marriage of these advantages with innovative structural network design and advanced materials utilization will permit major increases in thrust-to-weight performance and structural efficiency for future gas turbine engines. However, obtaining the maximum payoff requires two key ingredients. The first is the use of modern magnetic bearing technologies such as innovative digital control techniques, high-density power electronics, high-density magnetic actuators, fault-tolerant system architecture, and electronic (sensorless) position estimation. This paper describes these technologies and the test hardware currently in place for verifying the performance of advanced magnetic actuators, power electronics, and digital controls. The second key ingredient is to go beyond the simple replacement of rolling element bearings with magnetic bearings by incorporating magnetic bearings as an integral part of the overall engine design. This is analogous to the proper approach to designing with composites, whereby the designer tailors the geometry and load-carrying function of the structural system or component for the composite instead of simply substituting composites in a design originally intended for metal material. This paper describes methodologies for the design integration of magnetic bearings in gas turbine engines.

Kliman, G. B., 1987, “Composite Rotor Lamination for Use in Reluctance, Homopolar and Permanent Magnet Machines,” U. S. Patent No. 4,916,346.
Kliman, G. B., 1989, “Method of Fabricating Composite Rotor Laminations for Use in Reluctance, Homopolar and Permanent Magnet Machines,” U. S. Patent No. 4,918,831.
Knospe, C., Humphris, R., and Sundaram, X. X., 1991, “Flexible Rotor Balancing Using Magnetic Bearings,” presented at Recent Advances in Active Control of Sound and Vibration Conference, Virginia Polytechnic Institute and State University, Apr. 15–17.
Lyons, J. P., MacMinn, S. R., and Preston, M. A., 1991, “Flux/Current Methods for SRM Rotor Position Estimation,” Proceedings of the 1991 IEEE Industry Applications Society Annual Meeting, pp. 482–487.
Matsumura, F., Fujita, M., and Okawa, K., 1990, “Modeling and Control of Magnetic Bearing Systems Achieving a Rotation Around the Axis of Inertia,” 2nd International Symposium on Magnetic Bearings, Tokyo, Japan, July 12–14, pp. 273–280.
M. A.
, and
J. P.
, “
A Switched Reluctance Motor Model With Mutual Coupling and Multi-phase Excitation
IEEE Transactions on Magnetics
, Vol.
, No.
, pp.
Richter, E., Anderson, R. E., and Severt, C., 1992, “The Integral Starter/Generator Development Progress,” SAE Paper No. 920967.
Signorelli, R. A., 1983, “Metal Matrix Composites for Aircraft Engines,” NASA Technical Memorandum 83379.
Storace, A., 1989, “Turbine Engine Structural Efficiency Determination,” AIAA Paper No. 89-2571.
This content is only available via PDF.
You do not currently have access to this content.