Abstract: Based on the theory of internal magnetic field network partitioning of motors, the magnetic flux density distribution of typical DC linear motors is analyzed. Guided by the field analysis theory, a small permanent magnet DC linear motor is designed and calculated. Detailed calculation formulas for this small permanent magnet DC linear motor are listed, and actual parameter tests are conducted on the design results. Keywords: magnetic field network; permanent magnet linear motor 0 Introduction With the development of precision tracking technology, there is an urgent need for a drive element suitable for small-frame, low-inertia, and small-range motion angle (±20") motion systems. The reason is that high-torque, low-speed motors, due to their large number of poles, large diameter, and many brushes, generate large frictional torque and inertia, making the control system severely nonlinear and difficult to implement precision tracking. Therefore, it is necessary to design a DC linear motor capable of finite displacement, with only coils and no iron core or commutator. [b]1 Structure and Motion Principle of DC Linear Motors 1.1 Structure of DC Linear Motors[/b] A DC linear motor is structured to generate output thrust and displacement in its armature current-carrying conductor within a magnetic field. A typical DC linear motor is essentially the same as a rotating single-stage motor. A single-layer winding is wound around the outer surface of a cylindrical iron core made of low-carbon steel to form the armature. It consists of two coils with the same number of turns but opposite directions. The entire winding is impregnated with varnish to achieve a brushless (commutator-free) motor structure. The magnetic field-generating component consists of a low-magnetic steel shell and two end plates, within which a cylindrical excitation winding is placed. The armature is inserted into the inner hole of the magnetic field. When current flows through the excitation winding, a main magnetic flux is generated in the armature core. This flux forms a circuit through the air gap, pole shoes, end plates, and shell, as shown in Figure 1. The radial component of the air gap flux interacts with the armature current, generating a unidirectional axial force at each pole. [align=center][b]For more details, please click: Design of a Small Permanent Magnet DC Linear Motor[/b][/align]