Analysis and Design of a New Linear Vibration Motor Used to Reduce Magnetic Flux Leakage in In-Vehicle Infotainment

Abstract

Linear vibration motors are becoming more popular for use in haptic applications owing to their better performance. However, a permanent magnet with a large volume causes massive magnetic flux leakage, which can be harmful to passengers with a cardiac pacemaker or an implantable-cardioverter defibrillator. The magnetic flux leakage is calculated using the 3D finite element method, which can also be applied to obtain the force factor. Then, the displacement and impedance are obtained to check the performance of the linear vibration motor by utilizing the finite element method. A prototype of a linear vibration motor is analyzed and verified based on the experimental results. Based on the analysis methods, three new designs are proposed to reduce the magnetic flux leakage to within 50 G. The final design shows a 93.07% reduction of the magnetic flux leakage while maintaining the same performance as the prototype. To verify the validity of the analysis results, three experimental results were obtained: the magnetic flux leakage, displacement, and impedance. The experimental results are in good agreement with the analysis results.

Keywords

• static magnetic field
• magnetic flux leakage
• linear vibration motor