Electromagnetic thrust bearing for coupling a rotatable member to a stationary member

An electromagnetic thrust bearing for axially flux coupling a rotatable member relative to a stationary member, the thrust bearing comprising:

• a thrust disc fixed to and extending radially from the rotatable member, the thrust disc having first and second opposite, axially facing, sides;
• first means associated with the stationary member and adjacent to the first side of the thrust disc, for generating an axially polarized, controllable electromagnetic field;
• second means associated with the stationary member and adjacent to the second side of the thrust disc, for generating an axially polarized, controllable electromagnetic field;
• first means associated with the stationary member and adjacent to the first side of the thrust disc, for generating a constant flux, high density magnetic field;
• second means associated with the stationary member and adjacent to the second side of the thrust disc, for generating a constant flux, high density magnetic field;
• and
• means for directing substantially all magnetic flux from the first and second electromagnetic field generating means and the first and second constant flux magnetic field generating means, axially between the thrust disc and the stationary member, to provide controlled magnetic flux coupling of the rotatable member to the stationary member.

An electromagnetic thrust bearing for axially flux coupling a rotatable member relative to a stationary member, the thrust bearing comprising:

• a thrust disc fixed to and extending radially from the rotatable member, the thrust disc having first and second opposite, axially-facing, sides;
• first means associated with the stationary member and adjacent to the first side of the thrust disc, for generating an axially polarized, controllable electromagnetic field, wherein the first electromagnetic field generating means includes a first solenoid having a first electromagnetic coil situated within a first ferromagnetic housing which circumscribes a portion of the rotatable member;
• second means associated with the stationary member and adjacent to the second side of the thrust disc, for generating an axially polarized, controllable electromagnetic field, wherein the second electromagnetic field generating means includes a second solenoid having a second electromagnetic coil situated within a second ferromagnetic housing which circumscribes a portion of the rotatable member;
• first means associated with the stationary member and adjacent to the first side of the thrust disc, for generating a constant flux, high density magnetic field, wherein the first constant flux magnetic field generating means includes a first pair of arcuately shaped, axially polarized permanent magnets radially spaced from one another and linked magnetically to the first ferromagnetic housing by respective pole pieces, and wherein the first pair of radially spaced permanent magnets are each linked magnetically to the thrust disc through a first air gap such that axially directed flux from the first pair of permanent magnets passes through the first air gap to create a high density magnetic field between the thrust disc and the stationary member;
• second means associated with the stationary member and adjacent to the second side of the thrust disc, for generating a constant flux, high density magnetic field, wherein the second constant flux magnetic field generating means includes a second pair of arcuately shaped, axially polarized permanent magnets radially spaced from one another and linked magnetically to the second ferromagnetic housing by respective pole pieces, and wherein the second pair of radially spaced permanent magnets are each linked magnetically to the thrust disc through a second air gap such that axially directed flux from the second pair of permanent magnets passes through the second air gap to create a high density magnetic field between the thrust disc and the stationary member;
• means for directing substantially all magnetic flux from the first and second electromagnetic field generating means and the first and second constant flux magnetic field generating means, axially between the thrust disc and the stationary member, to magnetically link the thrust disc to the solenoids and provide a magnetic flux path for the electromagnetically generated flux around the permanent magnets and the electromagnetic coils, and provide controlled magnetic flux coupling of the rotatable member to the stationary member;
• and
• means for determining axial positioning of the rotatable member relative to the stationary member, and for controlling axial positioning of the thrust disc by varying the magnetic flux generated by the first and second electromagnetic field generating means.