Linear Motor

JMAG can be used to model linear electric machines. When modeling a linear machine, it is critically important to have an accurate model of the forces on the tooth tips. This requires very accurate mesh that can account for model symmetry. If the mesh is not symmetrical, it may produce numerical errors in the force calculation. Accurate mesh is also necessary when testing precise movements of the components.

Evaluation Items

Cogging force, thrust force, attractive force, response, eddy current, residual magnetization, current control, induced voltage, efficiency, loss, heat generation, vibration and noise

Case Studies

Electromagnetic-Force Analysis

A harmonic analysis of the torque waveforms will help identify the optimal magnet skew. An appropriate skew angle will reduce cogging torque by 50% or more while maintaining the same thrust force. Reducing cogging torque will drastically reduce the amount of noise that the machine generates.


No Title
979 Yasuaki Sakamoto: "Development of a rail brake for railway vehicles derived from linear motor technology", JMAG Users conference 2014, 2014
AN-112 Application Catalog, "112 - Starting Thrust Force Analysis of a Linear Induction Motor"
AN-064 Application Catalog, "64 - Thrust Force Analysis of a Coreless Linear Motor"
AN-054 Application Catalog, "54 - Analysis of the Cogging Force of a Moving Coil Linear Motor"