Dynamically stable magnetic suspension/bearing system

Patent · Mon Jan 01 04:00:00 EST 1996

OSTI ID:870322

Post, Richard F ^[1]

---

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
• 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

/335/310/
accelerations
achieved
achievement
arising
bearing
bearing systems
collection
combinations
conditions
conditions required
contains
contains magnetic
critical
derivatives
described
displacements
dynamic
dynamic effects
dynamic equilibrium
dynamically
dynamically stable
earnshaw
effects
element
elements
equilibrium
exceeded
excitation
exerted
external
external forces
finite
force
forces
forces arising
forces exerted
gravity
hold
imposed
levitate
limitations
magnetic
magnetic bearing
magnetic force
magnetic forces
magnetic subsystems
magnetic suspension
magnetomotive
magnets
magnitudes
mechanical
passive
passive elements
permanent
permanent magnet
permanent magnets
permitting
position
possess
provide
provided
range
required
rotating
rotating element
rotational
rotational speed
satisfy
signs
speed
stabilizers
stable
stable equilibrium
stable magnetic
stably
subsystems
support
supported
suspended
suspension
systems
theorem
time
zero