Low power consumption outer rotor radial magnetic bearing with upper-attracting and lower-repulsing structure of permanent magnet

Abstract

The invention relates to a low power consumption outer rotor radial magnetic bearing with an upper-attracting and lower-repulsing structure of a permanent magnet, belonging to the field of the magnetic suspension bearing. The magnetic bearing consists of an outer magnetic-conducting ring, an outer magnetic-insulating ring, stator iron cores, an exciting coil, an inner permanent magnetic semi-ring, rotor iron cores, an inner magnetic-insulating ring, an inner magnetic-conducting ring, an outer permanent magnetic ring, air gaps and a rotating shaft, wherein eight electromagnetic poles and four permanent magnetic poles are established in the positive and negative directions of an X axis and a Y axis of the stator iron core in total; the inner magnetic-insulating ring is arranged among permanent magnetic iron cores and an electromagnetic iron core on a stator; the inner permanent magnetic semi-ring is clamped between the two permanent magnetic iron cores in the negative direction of the Y axis of the stator by the inner magnetic-conducting ring; the air gaps are arranged among the stator iron cores and the rotor iron cores; the outer magnetic-insulating ring is arranged between a permanent magnetic iron core ring and an electromagnetic iron core ring; the outer magnetic-conducting ring is arranged between the permanent magnetic iron core ring and the permanent magnetic iron core ring; and the outer permanent magnetic ring is clamped at the middle part of the outer permanent magnetic ring. The structure can solve the problems of gravity and power consumption of the rotating shaft of the magnetic suspension bearing, thus leading the bearing to have the advantages of low power consumption, reliable performance and convenient manufacture and the like. In addition, the low power consumption outer rotor radial magnetic bearing can be used as no-contact support parts of rotating equipment, such as a wind-driven generator, a motor, a molecular pump, a high-speed bearing.

Description

Technical field [0001] The patent of the invention belongs to the field of non-contact magnetic suspension bearings. It is a low-power outer rotor radial magnetic bearing with a permanent magnet up-suction and down-repulsion structure. It can replace the current contact mechanical bearings and can be used as a wind power generator, motor, molecular Non-contact supporting parts of rotating equipment such as pumps, high-speed bearings, machine tools, and transportation. Background technique [0002] Magnetic suspension bearings are divided into three categories according to the excitation supply method: passive magnetic suspension bearings (magnetic force is provided by permanent magnets, also known as passive magnetic suspension bearings), active magnetic suspension bearings (magnetic force is provided by electromagnets, also known as active magnetic bearings), hybrid magnetic suspension bearings Bearings (magnetic force provided by permanent magnets and electromagnets). The...

AI Technical Summary

Problems solved by technology

The stability domain of passive magnetic suspension bearings is very small and uncontrollable, so it cannot achieve real stable suspension. Active magnetic suspension bearings use current to generate a bias magnetic field, which has a large operating current and high power consumption. Hybrid magnetic suspension bearings use permanent magnets instead of current generation. The bias magnetic field makes the permanent magnet bias magnetic field bear the main bearing capacity, and the electromagnetic field provides auxiliary adjustment bearing capacity, which reduces the power loss and the number of ampere turns of the excitation coil. On the other hand, in order to achieve low power consumption, the excitation The magnetic flux generated by the coil should not pass through the permanent magnet, but the existing permanent magnet bias magnetic suspension bearing generally places a permanent magnet on the electromagnetic magnetic circuit, and then reserves an air gap of a certain size under or on the side of the permanent magnet to allow electromagnetic field through

In this type of permanent magnet bias electromagnetic adjustment bearing, the permanent magnet bias magnetic field generates equal and large attractive forces on the magnetic levitation shaft from the four directions of ±X and ±Y, and the resultant force is zero, which cannot offset the gravity of the rotor itself, so The excitation current is not the minimum, and the system power consumption is not the minimum; the permanent magnet bias magnetic field and the electromagnetic field are superimposed, the attractive force on the side where the magnetic flux density increases becomes larger, and the attractive force on the side where the magnetic flux density decreases becomes smaller, unbalanced The force of the rotor produces the power of the radial movement of the rotor, but the magnetic flux on the side where the magnetic flux density decreases cannot be completely zero. This non-zero magnetic field will generate resistance to radial adjustment and affect the speed of dynamic response; depends on the specific size The air gap separates the permanent magnet magnetic circuit and the electromagnetic magnetic circuit. If the air gap is too large, the resistance of the electromagnetic passage will be greater. If the air gap is too small, the bias magnetic field established by the permanent magnet will become weaker.

Therefore, the current permanent magnet bias magnetic suspension bearings have shortcomings such as gravity interference, large power consumption, poor dynamic response, and magnetic circuit crossing.

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