Double-coil axial spherical surface pure electromagnetic bearing

Abstract

A double-coil axial spherical surface pure electromagnetic bearing is mainly composed of a stator system and a rotating shaft. The stator system mainly comprises an upper stator iron core, a lower stator iron core and exciting coils. An upper spherical surface magnetic bearing and a lower spherical surface magnetic bearing are adopted, and electromagnetic force borne by the rotating shaft passes through a sphere center all the time; when the sphere center of the rotating shaft coincides with a mass center, torque generated by the electromagnetic force relative to the rotating shaft is zero, and therefore the disturbance of radial twisting to axial translational motion is eliminated; in addition, pole shoe structures are adopted in the upper stator iron core and the lower stator iron core, and magnetic field distribution on the circumference is more even; double-coil structure is adopted in the exciting coils of the upper stator iron core and the lower stator iron core, and the numbers of turns of the two coils are different; and the coil with the small turn number is controllable in current, and the coil with the large turn number is constant in current; compared with a single-coil structure, the current response rate is improved, the differential manner is adopted in the controllable current, and the control precision of the magnetic bearings is further improved.

Description

technical field [0001] The invention relates to a non-contact magnetic suspension bearing, in particular to a spherical pure electromagnetic magnetic bearing, which can be used as non-contact support for rotating parts in small spacecraft, and is especially suitable for non-contact support of magnetic suspension flywheels. 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 structure, a single-degree-of-freedom axial magnetic bearing or a three-degree-of-freedom axial magnetic bearing is generally used. No matter which scheme ...

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 magnetic pole surfaces of the permanent magnet bias axial magnetic bearings described in Chinese patent application numbers 200510011272.2 and 200710098749.4 are all cylindrical. When the magnetic bearing deflects, there is an uneven air gap between the stator and the rotor, resulting in a large torsional negative torque. , increasing the load on the torsional bearing of the flywheel

Thereby reducing the control precision and control torque precision of the flywheel rotor

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