Manufacturing process of permanent magnet direct current motor

Abstract

The invention relates to the technical field of motors and provides a permanent magnet direct current motor and a manufacturing process thereof. The permanent magnet direct current motor comprises a stator component and a rotor component arranged in the stator component, wherein the stator component comprises a shell and a magnetic shoe arranged in the shell; the rotor component comprises a rotor core and a rotating shaft which are arranged in the magnetic shoe; the shell is a hollow cylinder; and the hollow cylinder is formed by coiling at least one metal plate and assembling, shaping and butting with the rotor component and carrying out butt joint, so that the shell is stressed to be extruded during assembling and shaping, and the stator component is extruded; and therefore, the magnetic shoe and the rotor core achieve the coaxially requirements in theoretical design, and a uniform circular ring air gap is formed between the inner wall surface of the magnetic shoe and the outer wall of the rotor core. In the invention, the shell is a non-fixing piece and is molded in the manufacturing and assembling process, so that the tolerance change of the magnetic shoe can be avoided by adjusting the coaxiality between the shell and the rotor component by utilizing the mobility, and finally, the uniformity of the assembled air gap is guaranteed.

Description

technical field [0001] The present invention relates to the technical field of motors, and more specifically relates to a permanent magnet DC motor and an assembly process thereof. Background technique [0002] refer to figure 1 , a traditional permanent magnet DC motor, including a stator assembly 100' and a rotor assembly 200' disposed in the stator assembly 100'. The stator assembly 100' includes a shell-shaped thin-walled shell 110' with one end open, and a magnetic tile 120' fixed to the inner wall of the shell 110'. The rotor assembly 200' includes a rotor core 210' and a rotating shaft 220'. The rotor core 210' and the rotating shaft 220' are installed inside the magnetic tile 120' and rotate relative to the magnetic tile 120'. When this permanent magnet DC motor is working, there is a gap between the inner surface of the magnetic tile 120' in the stator assembly 100' and the outer surface of the rotating rotor core 210', and the gap is in the shape of a ring, which...

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Problems solved by technology

Like this, when shell 110 ' or magnetic tile 120 ' produce manufacturing error, adopt the above-mentioned assembling steps and promptly will appear as follows figure 2 The phenomenon of non-uniform air gap 300' shown in

However, since the magnetic tile 120' is made of sintered or bonded ferrite or RuFeB material, its texture is relatively hard, and there will inevitably be manufacturing errors during processing, especially relatively large errors in thickness.

Moreover, when the shell 110' is stretched and formed, cylindricity errors, tensile stress, stress concentration, and uneven thickness will occur, and weak parts will be generated locally in the parts, resulting in a decrease in strength. This will not only lead to uneven distribution of air gaps during assembly, but also In critical occasions, failure will occur when subjected to shock and vibration

[0004] Moreover, for the electromagnetic performance of the motor, the housing 110' is a part of the magnetic circuit. If the thickness of the housing 110' is too small, it is easy to generate magnetic field saturation, increase the hysteresis loss, and reduce the efficiency of the motor.

The casing 110' is produced by the traditional stretching process mentioned above. Due to the limitation of the process, only thinner plates can be used for molding. In this way, the final formed casing 110' has a thinner thickness, which is very prone to the above-mentioned electromagnetic efficiency problem.

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