| 主权项 |
1. A flywheel levitation apparatus for a flywheel driven power storage system, the apparatus comprising:
a rotor formed of a magnetic material and having a rotor face, that faces upward in a vertical direction, wherein the rotor further comprises an axis of rotation that is substantially parallel to the vertical direction, wherein the rotor is supported for rotation around the axis of rotation and is configured to allow vertical movement of the rotor along the along the axis of rotation; a stator assembly comprising:
an arrangement configured to produce a steady magnetic flux such that the steady magnetic flux contributes to exerting an attractive magnetic lifting force in the vertical direction between the rotor and the stator assembly; andat least one pole piece formed of a magnetic material, the at least one pole piece having a projecting section extending downward toward the rotor face, wherein the rotor face comprises a cutaway section such that the projecting section is at least partially receivable in the cutaway section, and the magnetic lifting force varies based on an amount of the vertical movement, such that the magnetic lifting force decreases in response to a downward vertical movement and increases responsive to an upward vertical movement, and the variation in the magnetic lifting force per unit of vertical movement is smaller as compared to the variation in the magnetic lifting force per unit of vertical movement that would be exhibited in an absence of the cutaway section, wherein the projecting section of the pole piece includes a lower surface that faces downward toward the rotor, and the cutaway section has a floor that faces upward in a confronting relationship with the lower surface to define a gap, having a gap size, between the rotor and the pole piece, such that the gap size changes in response to the vertical movement of the rotor along the axis of rotation such that the rotor is operable in one of a large gap configuration and a small gap configuration, wherein the large gap configuration corresponds to a first gap size and wherein the small gap configuration corresponds to a second gap size, and, wherein, in the small gap configuration, the magnetic lifting force is smaller as compared to a magnetic lifting force that would be exhibited in a flywheel levitation apparatus having the same gap size in the absence of the cutaway section, and wherein, in the large gap configuration, the magnetic lifting force is larger as compared to a magnetic lifting force that would be exhibited in a flywheel levitation apparatus having the same gap size in the absence of the cutaway section. |
