Magnetic assemblies are magnetic functional units composed of one or more magnetic elements combined with non-magnetic parts (such as housings). These assemblies are not merely simple magnet combinations, but highly integrated units that include magnets and non-magnetic materials with specific magnetic patterns, shapes, and magnetic field strengths. The primary goal is to optimize the magnetic circuit to achieve maximum magnetic performance output.
Guangdong Dawa Magnetics Co., Ltd. has been focusing on precision magnet design and manufacturing for 33 years. Over this time, the company has accumulated rich application cases across various industries, becoming a leading expert in magnetic applications.
Below are two classic case studies from the company:
1. Halbach Magnet Array Assembly Case
1.1 Halbach Magnet Array Principle
The Halbach magnet array is a unique permanent magnet structure first proposed and gradually refined by American scholar Klaus Halbach in 1979 during electronic acceleration experiments. This magnet array strengthens the magnetic field in one direction through a specific arrangement of magnet units while weakening the field in the opposite direction. This feature makes Halbach magnet arrays widely applicable across many fields.
1.2 Halbach Array Construction
According to the designed array pattern, permanent magnets are arranged one by one on metal plates with specific magnetization directions. This process requires great care to ensure each magnet is positioned and oriented correctly. Typically, fixtures or positioning molds are used to assist in the arrangement, improving assembly precision.
1.3 Halbach Application Case
In the consumer electronics field, Halbach magnet arrays are widely used in Bluetooth headset charging cases, computer keyboards, foldable phones, and other areas. These small magnet arrays provide strong magnetic fields to meet design requirements.
2. Pot Magnet (Magnetic Assembly) Case
2.1 Pot Magnet Design Principle and Construction
The basic structure of a pot magnet includes a permanent magnet, an iron housing, and a gasket. The iron housing not only protects the fragile permanent magnet from breaking or cracking upon contact with hard surfaces but also plays a critical role in the magnetic circuit. The iron shell guides and focuses the magnetic field lines onto the open face of the pot magnet, forming a fully closed magnetic circuit. This makes the magnetic field path more direct and powerful, improving efficiency and extending service life. This enhanced efficiency is due to the higher magnetic permeability of the iron shell compared to air. As a result, the magnetic flux follows a more direct path. When the pot magnet attaches to ferromagnetic materials, a fully closed magnetic circuit is formed, offering stronger holding force compared to a simple magnet of the same size. Pot magnet assemblies are widely used in applications such as automotive part fixation, warehouse shelf holding, and track lighting fixtures. Additionally, pot magnets can be designed with internal holes or external threads to facilitate installation and fixation.
2.2 Factors Affecting Pot Magnet Strength
The magnetic strength of a pot magnet, also known as its pulling force, refers to the maximum pull force the magnet can generate. The pulling force of a pot magnet is typically measured using a high-quality low-carbon steel plate of a specific thickness. Factors influencing the pulling force include:
2.2.1 Air Gap: The air gap is a low magnetic permeability space in the magnetic circuit path and is a critical factor in magnetic circuit design. This gap significantly affects the magnet’s performance in applications. Typical low permeability gaps include air, paint, plastics, and other materials that are not attracted to the magnetic field.
2.2.2 Workpiece Condition: The magnetic permeability of the workpiece greatly influences the performance of the pot magnet. Workpieces with higher magnetic permeability are more favorable for optimal magnet performance. Additionally, the thickness of the workpiece is a key factor. If the workpiece is too thin, it may reach magnetic saturation, causing some magnetic flux to become ineffective. Surface conditions such as paint, oxidation, rust, or deformed surfaces can create small air gaps, which, though often overlooked, can significantly reduce the magnet’s pulling force.
2.2.3 Temperature: At high temperatures, the pulling force of all types of permanent magnets will decrease.
These two cases fully demonstrate the professional capabilities of Guangdong Dawa Magnetics Co., Ltd. in magnetic assembly design and manufacturing. With 33 years of experience in precision magnet R&D and production, Dawa Magnetics is dedicated to accelerating innovation and mass production of permanent magnetic materials for our customers!
