A Two Degrees of Freedom Lorentz Force External Rotor Spherical Magnetic Bearing

Abstract

The invention discloses a two-degree-of-freedom Lorentz force external rotor spherical magnetic bearing, which includes a coil, a magnetic isolation boss, a stator spherical magnetic conduction ring, a magnetic isolation screw, epoxy resin glue, a mounting seat, a spherical magnetic steel, an isolation Magnetic ring, rotor magnetic ring, rotor lock nut and rotor sleeve, two pairs of coils are used to control the radial X and Y deflection of the magnetic bearing, and the two pairs of coils are fixed on the stator spherical magnetic ring by epoxy resin glue. The spherical magnetic steel is located on the radially outer side of the coil, and there is a certain spherical shell gap between the inner spherical surface of the spherical magnetic steel and the outer spherical surface of the rotor magnetic conducting ring, forming an air gap. Due to the use of the spherical shell-shaped air gap, the rotor can deflect at a large angle, which overcomes the shortcoming of the existing cylindrical air-gap Lorentz force magnetic bearing with a small deflection angle. In addition, when the rotor deflects to any position, the ampere force generated by the energized coil current is always tangent to the spherical surface where the coil is located, that is, the force arm of the force couple formed by the ampere force of each pair of coils is a constant value, thereby improving the control of the Lorentz force Torque accuracy.

Description

technical field [0001] The invention relates to a non-contact magnetic suspension bearing, in particular to a two-degree-of-freedom Lorentz force external rotor spherical magnetic bearing. Background technique [0002] Magnetic suspension bearings are divided into reluctance magnetic bearings and Lorentz force magnetic bearings. The former changes the magnetic flux by changing the air gap reluctance of the magnetic bearings, thereby controlling the electromagnetic force output by the magnetic bearings. Since the electromagnetic force is proportional to the square of the magnetic flux, and the magnetic flux is proportional to the magnetomotive force of the coil, the electromagnetic force of the reluctance magnetic bearing is proportional to the square of the coil control current, and the linear range after linearization is narrow. The air gap reluctance and magnetomotive force of the Lorentz force magnetic bearing are constant, the magnetic density and flux in the air gap are...

AI Technical Summary

Problems solved by technology

The Lorentz force magnetic bearing stator in this scheme is a cylindrical cup-shaped stator, and the magnetic gap is a circular column. The Lorentz force magnetic bearing can only deflect at a small angle, generally 1° to 3°, resulting in Magnetic levitation high torque flywheel output high torque time is short and the maximum output gyro torque is small

Due to the edge effect of the magnetically permeable material, the magnetic field inside the air gap in this scheme is not uniform in the radial direction, which causes the magnetic density acting on the control coil to change when the Lorentz force magnetic bearing deflects, thereby reducing the accuracy of the electromagnetic force

In addition, the Lorentz force cup stator in this solution is a non-metallic material with poor thermal conductivity, which is not easy to dissipate heat, resulting in high temperature of the magnetic bearing during operation, which reduces the reliability and life of the magnetic bearing itself

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