Dynamically stable magnetic suspension/bearing system

Post, Richard F

Title: Dynamically stable magnetic suspension/bearing system

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Abstract

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 finitemore » range of those displacements. « less

Inventors:

Post, Richard F ^[1]

Walnut Creek, CA

Issue Date:: 1996-01-01

Research Org.:: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

OSTI Identifier:: 870322

Patent Number(s):: 5495221

Assignee:: Regents of University of California (Oakland, CA)

Patent Classifications (CPCs):: F - MECHANICAL ENGINEERING F16 - ENGINEERING ELEMENTS AND UNITS F16C - SHAFTS

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01F - MAGNETS

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F - MECHANICAL ENGINEERING F16 - ENGINEERING ELEMENTS AND UNITS F16C - SHAFTS
F16C39/063 - {Permanent magnets}
F16C32/0408 - {Passive magnetic bearings}

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01F - MAGNETS
H01F7/0242 - {Magnetic drives, magnetic coupling devices}

H - ELECTRICITY H02 - GENERATION H02K - DYNAMO-ELECTRIC MACHINES
H02K7/09 - with magnetic bearings

H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01F - MAGNETS
H01F7/0236 - {Magnetic suspension or levitation

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DOE Contract Number:: W-7405-ENG-48

Resource Type:: Patent

Country of Publication:: United States

Language:: English

Subject:: 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; /335/310/

Citation Formats


                    Post, Richard F. Dynamically stable magnetic suspension/bearing system.  United States: N. p., 1996. 
        Web.

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                    Post, Richard F. Dynamically stable magnetic suspension/bearing system.  United States.

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                    Post, Richard F. Mon .  
        "Dynamically stable magnetic suspension/bearing system".  United States.  https://www.osti.gov/servlets/purl/870322.

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@article{osti_870322,

  title        = {Dynamically stable magnetic suspension/bearing system},

  author       = {Post, Richard F},

  abstractNote = {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.},

  doi          = {},

  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {1996},

  month        = {1}

}

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