Analysis of flat-type vibration motor for mobile phone

In the flat-type vibration motor, which is usually used in folder-type mobile phones, the air-gap flux from the magnet is in the axial direction. Accordingly, it is very difficult to get the torque using 2D FEM simulation. Also, because 3D FEM simulation takes so long time to get the result, the dynamic characteristics simulation using 3D FEM is not applicable for engineers who want to develop vibration motors in a short period. So, in this paper, we use 2D FEM simulation with an improved method to calculate the torque of the flat-type vibration motor and compare with 3D FEM results. From this method, we can get the faster method to simulate the transient characteristics of the motor using 2D FEM.