A dual-coil radial spherical purely electromagnetic bearing

Abstract

The invention discloses a double-coil radial and spherical pure-electromagnetic bearing. The double-coil radial and spherical pure-electromagnetic bearing mainly comprises four stator cores arranged in the + / - X direction and the + / - Y direction, a first coil, a second coil, a sleeve, an air gap and a rotor. By adopting the spherical magnetic bearing structure, the electromagnetic force exerted on a rotation shaft always passes through the sphere center, when the sphere center of the rotation shaft coincides with the mass center, the torque generated by the electromagnetic force relative to the rotation shaft is zero, and therefore interference of radial twisting to axial translation is removed. In addition, by adopting the specific pole shoe structure in the stator cores, magnetic field distribution is more uniform in the peripheral direction; the double-coil structure is adopted in field coils of the stator cores, the turns of the two coils are different, the current of the coil smaller in turn is controllable, the current of the coil higher in turn is unchangeable, and the current response rate is increased compared with the single-coil structure; the differential mode is adopted in the controllable current, so that the control accuracy of the magnetic bearing is further improved.

Description

technical field [0001] The invention relates to a non-contact radial magnetic suspension bearing, especially a spherical pure electromagnetic magnetic bearing with double coils, which can be used as a non-contact support for rotating parts in small spacecraft, and is especially suitable for magnetic suspension flywheels or magnetic suspension control moment gyroscopes non-contact support. technical background [0002] With the development of aerospace technology, satellites, space stations and other spacecraft have higher and higher requirements for attitude control accuracy, and traditional mechanical momentum wheels can no longer meet the requirements. The magnetic levitation flywheel is supported by magnetic bearings, which eliminates the wear caused by mechanical bearings and improves the accuracy and stability of torque control. [0003] In the existing magnetic levitation flywheel or magnetic levitation control moment gyro structure, two degrees of freedom radial magn...

AI Technical Summary

Problems solved by technology

However, when the rotor deflects, the magnetic air gap between the stator and rotor of the magnetic bearing is uneven, resulting in uneven electromagnetic force in the magnetic pole surface, thereby generating a torsional moment relative to the center of mass of the rotor, that is, the translation control produces an interference torque to the torsion control

The permanent magnet bias radial magnetic bearing described in Chinese Patent No. 201010256248.6 and 200710065049.5 and the radial magnetic bearing with pole shoes described in 201010226322. Uneven air gap, resulting in a large torsional negative torque, which increases the load on the torsional bearing of the flywheel, thereby reducing the control accuracy and control torque accuracy of the flywheel rotor, and the angle of the pole shoe is very small, which is prone to magnetic density saturation, and It will affect the uniformity of the magnetic density distribution along the circumference, which will indirectly lead to the reduction of control accuracy

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