Research on ambient temperature passive magnetic bearings at the Lawrence Livermore National Laboratory

Conference · Tue Apr 01 04:00:00 EST 1997

OSTI ID:632846

Post, R F; Tung, L S

Research performed at the Lawrence Livermore National Laboratory on the equilibrium and stability of a new class of ambient-temperature passive bearing systems is described. The basic concepts involved are: (1) Stability of the rotating system is only achieved in the rotating state. That is, disengaging mechanical systems are used to insure stable levitation at rest (when Earnshaw`s theorem applies). (2) Stable levitation by passive magnetic elements can be achieved if the vector sum of the force derivatives of the several elements of the system is net negative (i.e. restoring) for axial, transverse, and tilt-type perturbations from equilibrium. To satisfy the requirements of (2) using only permanent magnet elements we have employed periodic ``Halbach arrays.`` These interact with passive inductive loaded circuits and act as stabilizers, with the primary forces arising from axially symmetric permanent-magnet elements. Stabilizers and other elements needed to create compact passive magnetic bearing systems have been constructed. Novel passive means for stabilizing classes of rotor-dynamic instabilities in such systems have also been investigated.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: USDOE Office of Energy Research, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 632846
• Report Number(s): UCRL-JC--126208; CONF-9708143--; ON: DE98050860
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
AMBIENT TEMPERATURE
LAWRENCE LIVERMORE NATIONAL LABORATORY
LEVITATION
MAGNETIC BEARINGS
RESEARCH PROGRAMS
STABILITY