Research on the one-way magnetic attraction force of the armature in a solenoid electromagnet

The one-way magnetic attraction force of the armature is studied for a given range of extreme deviations of the dimensions of structural elements in a solenoid electromagnet. This force is caused by magnetic flux irregularity in areas occupied by nonworking gaps. This is especially important for low-frequency machines and vibratory impact devices with an electromagnetic drive. The armature travel frequency of such devices reaches 50 s –1 under high friction losses. The one-way magnetic attraction forces of the armature, when the solenoid electromagnet construction symmetry is impaired, are numerically determined with the finite-element magnetic field simulation in the Finite Element Method Magnetics (FEMM) software. It is shown that the one-way magnetic attraction force of the armature and its components are comparable with the driving force in the specific gap under a given range of extreme deviations of the real armature gaps and drifts. To improve dynamic design accuracy, it is necessary to take into account irregularity of the magnetic field and the appearance of an armature magnetic attraction force component in the areas occupied by an inductor.