US 5,216,308 A · Magnetic bearing structure providing radial, axial and moment load bearing support for a rotatable shaft

Abstract

A magnetic bearing structure utilizes two adjacent electromagnetic bearings to provide controlled radial, thrust and moment load support of a shaft relative to a housing. The first bearing generates a high density controllable magnetic field to radially flux couple the shaft to the housing. A second bearing generates a high density controllable magnetic field to axially flux couple the shaft to the housing. In a preferred form, the first bearing circumferentially surrounds the shaft and includes a stator ring associated with the housing which holds several electromagnetic coils radially spaced from the shaft. Power supplied to the coils generates a radially polarized electromagnetic field surrounding the shaft. A pair of additional electromagnetic coils, or permanent magnets, circumferentially extend around the shaft to generate an axially polarized, constant flux magnetic field. Substantially all of the magnetic flux generated by both flux generation sources is directed radially through a primary air gap between the shaft and the stator ring to provide radial support for the shaft. The second bearing includes two coil housings between which a thrust disc associated with the shaft extends. Two arcuate permanent magnets within the disc generate a constant flux radially polarized magnetic field. Three pairs of electromagnetic coils, each subtending a 120 degree arc, are placed within the coil housings to generate an axially polarized, controllable magnetic field. Magnetic flux generated by the permanent magnets and the paired electromagnetic coils axially couples the shaft to the housing.

Claims30

Dependent claims

An electromagnetic bearing structure for supporting a rotatable member including a thrust disc with respect to a stationary member, the bearing structure comprising:

first bearing means associated with the stationary member, for generating a high density controllable magnetic field surrounding a first portion of the rotatable member, and for coupling the rotatable member to the stationary member through radially-directed magnetic flux;
and
second bearing means adjacent to the first bearing means and associated with the stationary member, for generating a high density controllable magnetic field surrounding said thrust disc, and for coupling the rotatable member to the stationary member through axially-directed magnetic flux;
wherein the first and second bearing means provide controlled radial , thrust and moment load support of the rotatable member relative to the stationary member.

1 more element

An electromagnetic bearing structure for supporting a rotatable member in a suspended position with respect to a stationary member, the bearing structure comprising:

means associated with the stationary member, for generating a radially polarized, controllable electromagnetic field surrounding a portion of the rotatable member;
means for directing substantially all magnetic flux from the electromagnetic field generating means radially through a single primary air gap between the rotatable member and the stationary member to provide magnetic flux coupling of the rotatable member to the stationary member;
and
means associated with the stationary member for generating an axially polarized magnetic field, the axially polarized magnetic field generating means being linked magnetically to the rotatable member through the primary air gap such that substantially all magnetic flux generated by the axially polarized magnetic field generating means is re-oriented to create a high density magnetic field with the magnetic flux generated by the electromagnetic field generating means across the primary air gap for flux coupling of the rotatable member to the stationary member;
wherein the electromagnetic field generating means includes an arcuate ring of high magnetic flux permeability, and a plurality of electromagnetic coils circumferentially positioned about the arcuate ring and radially spaced from the rotatable member;
and wherein the axially polarized magnetic field generating means is spaced radially outwardly from the plurality of electromagnetic coils and circumscribes the rotatable member to generate a relatively constant magnetic flux through the arcuate ring and across the primary air gap.

3 more elements

An electromagnetic bearing structure for supporting a rotatable member including a thrust disc, in a suspended position with respect to a stationary member, the bearing structure comprising:

means associated with the rotatable member and circumscribing a portion of the thrust disc, for generating a radially polarized magnetic field;
first means associated with the stationary member and adjacent to a first side of the thrust disc, for generating an axially polarized, controllable electromagnetic field;
second means associated with the stationary member and adjacent to a second side of the thrust disc, for generating an axially polarized, controllable electromagnetic field;
and
means for directing substantially all magnetic flux from the first and second means for generating an axially polarized electromagnetic field and the means for generating a radially polarized magnetic field, axially between the thrust disc and the stationary member, to provide magnetic flux coupling of the rotatable member to the stationary member.

2 more elements

Dependencies are inferred from the claim text.

Magnetic bearing structure providing radial, axial and moment load bearing support for a rotatable shaft

Life of this patent

Magnetic bearing structure providing radial, axial and moment load bearing support for a rotatable shaft

Life of this patent

Abstract

Claims30