Method for manufacturing plastic bonded permanent magnet rotor with buffering layer

Abstract

The invention discloses a method for manufacturing a plastic bonded permanent magnet rotor with a buffering layer, belonging to the field of permanent magnet rotors. The technical scheme is that: the plastic bonded permanent magnet rotor comprises a metal shaft and a bonded permanent magnet; and the buffering layer is formed between the metal shaft and the bonded permanent magnet. The manufacturing method comprises the following steps of: I, molding and processing the buffering layer onto the outer side of the metal shaft by adopting a die pressing or injection molding way to form a semi-finished product; and II, molding and processing the bonded permanent magnet onto the outer side of the buffering layer by adopting an injection molding way or die pressing way to form a finished product. The invention has the beneficial effects that: the plastic bonded permanent magnet rotor with the buffering layer designed by the invention can be produced without changing the conventional production process and production equipment in the manufacturing method, and industrialization is facilitated; in the manufactured plastic bonded permanent magnet rotor, a buffering layer structure is arranged, so that the plastic bonded permanent magnet rotor can be effectively prevented from cracking in the molding processing or using process; and simultaneously, the cost is lowered.

Description

technical field [0001] The invention relates to the technical field of permanent magnet rotors, in particular to a preparation method of a plastic bonded magnet permanent magnet rotor with a buffer layer. Background technique [0002] In recent years, digital information technology and automation technology represented by office automation, home automation and industrial automation (3A) have become one of the high-tech hot spots that promote the development of modern society. Due to the advantages of easy storage and digitization of magnetic signals, and no physical contact during signal acquisition, magnetic materials have become important basic materials in modern high-tech fields. Traditional permanent magnets are usually manufactured by casting and sintering processes, and are widely used because of their good magnetic properties. However, traditional permanent magnets have high hardness, high brittleness, and poor processability, and it is difficult to make parts with ...

AI Technical Summary

Problems solved by technology

However, the thermal shrinkage rate of the plastic bonded magnet is much greater than that of the metal shaft, and the plastic bonded magnet is relatively brittle, and the permanent magnet rotor is prone to cracks during the cooling process after injection molding and during use.

Because the toughness of nylon 12 is better than that of nylon 6, the permanent magnet rotor made of nylon 12 bonded magnet is not easy to produce cracks during injection molding and use, while the permanent magnet rotor made of nylon 6 bonded magnet is easy to produce cracks, so permanent The magnetic rotor often uses materials such as nylon 12 (PA12) with a higher price as the base material, instead of nylon 6 (PA6), which is cheaper, has better temperature resistance and other comprehensive properties, and results in the material cost of the permanent magnet rotor. This is also one of the problems that need to be solved urgently in actual production.

In addition, the application fields such as the automobile industry continue to put forward higher requirements for the magnetic properties and temperature resistance of plastic bonded magnets, which means that higher magnetic powder fillings and high temperature resistant plastics are used, which intensifies the production of permanent magnet rotors. possibility of crack

[0006] In the process of realizing the present invention, the inventor found that the prior art has at least the following problems: since the thermal shrinkage of the plastic bonded magnet is much greater than the thermal shrinkage of the metal shaft rate, and the high brittleness of plastic bonded magnets makes permanent magnet rotors prone to cracks during processing and use; in order to minimize cracks during processing and use, only PA12 with a higher price can be used as the base material, resulting in The material cost of the permanent magnet rotor remains high; the automotive industry and other application fields continuously put forward higher requirements for the magnetic properties and temperature resistance of the plastic bonded magnets, so we can only use higher magnetic powder fillings and high temperature resistant plastics to achieve as much as possible. Relevant requirements, and this method intensifies the possibility of cracks in the permanent magnet rotor

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