Dynamically stable magnetic suspension/bearing system

Patent · Mon Jan 01 00:00:00 EST 1996

OSTI ID:870322

Post, Richard F ^[1]

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1. Walnut Creek, CA

A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium. However, owing to the limitations imposed by Earnshaw's Theorem, the magnetic bearing systems to be described do not possess a stable equilibrium at zero rotational speed. Therefore, mechanical stabilizers are provided, in each case, to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. The magnetic forces exerted by these elements, when taken together, levitate the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations. At the same time, this equilibrium is made stable against displacements of the rotating object from its equilibrium position by using combinations of elements that possess force derivatives of such magnitudes and signs that they can satisfy the conditions required for a rotating body to be stably supported by a magnetic bearing system over a finite range of those displacements.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 5495221
• OSTI ID: 870322
• Country of Publication: United States
• Language: English

Related Subjects

dynamically
stable
magnetic
suspension
bearing
contains
subsystems
support
rotating
element
dynamic
equilibrium
limitations
imposed
earnshaw
theorem
systems
described
possess
zero
rotational
speed
mechanical
stabilizers
provided
hold
suspended
exceeded
critical
effects
permitting
achievement
achieved
collection
passive
elements
permanent
magnets
provide
magnetomotive
excitation
forces
exerted
levitate
external
force
gravity
arising
accelerations
time
displacements
position
combinations
derivatives
magnitudes
signs
satisfy
conditions
required
stably
supported
finite
range
magnetic force
magnetic forces
stable equilibrium
magnetic bearing
rotational speed
permanent magnet
permanent magnets
bearing systems
passive elements
rotating element
stable magnetic
forces exerted
forces arising
external forces
conditions required
dynamic effects
dynamic equilibrium
dynamically stable
magnetic subsystems
magnetic suspension
contains magnetic
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