Accession Number : ADA264716


Title :   Cryogenic Magnetic Bearing


Descriptive Note : Final rept. 1 Nov 1985-1 May 1991


Corporate Author : HONEYWELL INC GLENDALE AZ SATELLITE SYSTEMS OPERATIONS


Personal Author(s) : Andrus, James ; Kendig, John ; Kroeger, John


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264716.pdf


Report Date : Dec 1992


Pagination or Media Count : 98


Abstract : Magnetic suspension provides an alternative to rolling-element bearings for some precision gimbal applications. The Cryogenic Magnetic Bearing program includes studies of magnetic suspension for a gimbal bearing requiring long life (greater than 7 years); low runout (less than 5 microrads bore-sight error due to runout); and low, uniform drag torque. Additionally, the bearing is to operate is an oscillating mode, from room-ambient (300 deg K) to liquid nitrogen (77 deg K) temperatures at ambient pressure and in a hard vacuum (10 (exp-6) torr). Two magnetic suspension alternatives were studied: an all-active approach using electromagnets to control all five bearing degrees-of-freedom and a Passive-Radial Active-Axial (PRAA) approach using passive magnetics to stabilize four of the five bearing degrees-of-freedom and an electromagnet to control the fifth. The all-active approach provides a lower weight, better- accuracy bearing system than the PRAA system, but requires more quiescent operating power and is electrically more complex. The PRAA was selected for hardware study to produce a simple, low-power magnetic system.


Descriptors :   *BEARINGS , *MAGNETIC DEVICES , *GIMBALS , *CRYOGENICS , TEMPERATURE , VACUUM , LIQUID NITROGEN , TORQUE , BEARING ROLLERS , ELECTROMAGNETS , OSCILLATION , DRAG , SUSPENSION DEVICES , ISOLATION , PRESSURE


Subject Categories : Couplers, Fasteners, and Joints
      Machinery and Tools
      Electricity and Magnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE