Physical Properties of Rare Earth-Cobalt Magnets (Alternator Service Aging Study).
Abstract
The principal objective of this program was to investigate the long-term performance stability of an aircraft alternator, under conditions simulating its operation in flight. This alternator uses sintered Sm-Co permanent magnets in its rotor. As these are known to degrade with time at elevated temperature, and it was feared that magnetic flux losses or the physical disintegration of the magnets might cause the generator to fail, changes in the machine performance were correlated to the aging of the magnets in the rotor and in separate, static tests. The report describes the design of a test stand for subjecting the machine to cyclic operation at speeds up to 11000 rpm and thermal exposure in air up to 215C. Methods and special instrumentation for measuring the electric output of all the windings, the magnetic state of the individual magnets, and the average flux of each of the three magnet stacks are described.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1975
- Accession Number
- ADA027398
Entities
People
- Herbert F. Mildrum
- Karl J. Strnat
Organizations
- University of Dayton