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Title: Force versus current and air gap calibration of a double acting magnetic thrust bearing

Force versus current and air gap measurements were obtained for a double acting thrust bearing. Static force measurements were made for various air gap settings and bearing current combinations. The resulting data was reduced and an optimized expression representing the force versus current and air gap relationship of the bearing was found. In addition, a theoretical force model was developed using simple magnetic circuit theory and magnetic properties obtained from standard magnetic material tests. The theoretical and the experimentally derived force models were compared. Hysteresis tests were conducted with the thrust disk in the centered position for various current perturbation amplitudes about the design bias current. Hysteresis effects were shown to cause a difference between the measured force as the current was increasing as compared to when the current was decreasing. A second order polynomial expression was developed to express the coercive force as a function of the perturbation current amplitude. The bearing frequency response was examined by injecting sinusoidal currents of varying frequencies into the bearing. A maximum actuator bandwidth of approximately 700 Hz was determined. Above 700 Hz the bearing frequency response could not be distinguished from the test fixture frequency response.
Authors:
; ;  [1]
  1. Univ. of Virginia, Charlottesville, VA (United States)
Publication Date:
OSTI Identifier:
390757
Report Number(s):
CONF-950852--
TRN: 96:005769-0015
Resource Type:
Conference
Resource Relation:
Conference: 4. industrial conference and exhibition on applications of magnetic bearings, magnetic drives, and dry gas seals, Alexandria, VA (United States), 10-11 Aug 1995; Other Information: PBD: 1995; Related Information: Is Part Of Proceedings of the MAG `95 magnetic bearings, magnetic drives and dry gas seals conference & exhibition; PB: 384 p.
Publisher:
Technomic Publishing Co. Inc., Lancaster, PA (United States)
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING NOT INCLUDED IN OTHER CATEGORIES; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; MAGNETIC BEARINGS; COERCIVE FORCE; FREQUENCY RESPONSE TESTING; HYSTERESIS; COMPUTERIZED CONTROL SYSTEMS