Common magnetic circuit structures
The spatial structure of 3C products is extremely limited and requires high adsorption strength. The spatial structure does not allow for an increase in magnet size, and magnetic circuit design is needed to enhance the magnetic field strength;
🔹 In situations where magnetic field induction is required, overly divergent magnetic lines can cause Hall elements to accidentally touch, and magnetic circuit design is needed to control the magnetic field range;
🔹 When one side of a magnet requires high adsorption strength, while the other side needs to shield the magnetic field, the high magnetic field strength of the shielding surface can affect the use of electronic components, and magnetic circuit design is also needed to solve this problem;
🔹 In situations where precise positioning is required, in situations where a uniform magnetic field is needed... and so on
In all the above situations, it is difficult to meet the usage requirements using a single magnet, and when the price of rare earths is high, the volume and amount of magnets will seriously affect the cost price of the product. Therefore, we can modify the magnetic path structure of the magnet to meet different usage scenarios while meeting the adsorption conditions or normal use, and reduce the amount of magnets used to lower costs.
The common magnetic circuits can be roughly divided into HALBACH ARRAY Halbeck array, multipole magnetic circuit, focusing magnetic circuit, adding magnetic conductive materials, flexible transmission, single-sided magnetic, and focusing magnetic structure. Below we will introduce them one by one:
The HALBACH ARRAY array is an approximately ideal structure in engineering, with the goal of generating the strongest magnetic field with the minimum number of magnets. Due to the special magnetic circuit structure of the Haier Beck array, most of the magnetic field circuit can circulate inside the magnetic devices, thereby reducing leakage and achieving magnetic aggregation, and realizing self shielding effect in non working areas. The optimized annular Haier Beck magnetic circuit design can achieve a minimum of 100% shielding in non working areas. As shown in the figure, the magnetic field lines of the conventional magnetic circuit are symmetrically divergent, while the magnetic field lines of the Haier Beck array are mostly concentrated in the working area, thus improving magnetic attraction.
Multipole magnetic circuit mainly utilizes the characteristic of magnetic field lines preferentially selecting the nearest opposite pole to form a magnetic circuit. Compared with ordinary unipolar magnets, the magnetic field lines (magnetic fields) of multipole magnetic circuit are more concentrated on the surface, especially the more poles there are, the more obvious it becomes. There are two types of multipole magnetic circuits: one is the method of multi pole magnetization with a magnet, and the other is the method of adsorption with multiple unipolar magnets. The difference between these two methods lies in cost, but their actual functions are the same. The advantage of multipole magnetic circuit in small spacing adsorption is very obvious.
Focusing magnetic circuit is the use of a special magnetic path to concentrate the magnetic field in a small area, making the magnetic field in that area very strong, even up to 1T, which is very helpful for accurate positioning and local induction.
Magnetic materials refer to the use of magnetic field circuits to preferentially select the path with the lowest magnetic resistance. By using high magnetic conductivity materials (SUS430, SPCC, DT4, etc.) in the magnetic circuit, the magnetic field can be well guided, thereby achieving local magnetic concentration and isolation effects.
The characteristics of flexible transmission are non-contact flexible transmission achieved through the attractive and repulsive forces formed by magnets. It has a small volume, simple structure, and torque that can be adjusted according to the volume of the magnet and the size of the air gap, with a large adjustable space.
The characteristic of single-sided magnetism is to shield the polarity of one side of the magnet while retaining the polarity of the other side. It directly attracts a large suction force, but the magnetic attenuation amplitude increases with distance.
The characteristic of the magnetic structure is that the magnet and the iron yoke are arranged in relative polarity. As the ratio of magnet thickness to iron yoke thickness increases, the thicker the iron yoke, the smaller the divergence of magnetic field lines. The magnetic structure can be flexibly designed according to the size of the air gap, achieving optimal results and effectively saving magnets. The magnetic field is evenly distributed along the iron yoke, but the disadvantage is that the assembly cost is high.