Optimal Design of One-Folded Leaf Spring with High Fatigue Life Applied to Horizontally Vibrating Linear Actuator in Smart Phone

Abstract

Horizontally vibrating linear actuator (HVLA) instead of VVLA has been under study in a few past years and recently HVLA with thickness of 2.5 mm was developed. The one-folded leaf spring to guide the moving part is newly designed and applied in HVLA, but unfortunately it makes HVLA be wider. Accordingly, this paper presents the optimal design of one-folded leaf spring, which results in reduction of HLVA width. The commercial design optimization tool “PIAnO” was utilized based on design of experiments (DOE), approximation techniques, and optimization algorithm. In addition, for the vibration modal analysis and harmonic response analysis to generate metamodeling, the software “ANSYS” is utilized. The optimal width of leaf spring was reduced by 46% compared to the initial one, while all the design constraints were satisfied, which clearly showed the validity of the proposed design approach.