New damper design for noise control of washing machine

A fully automatic washing machine with vertical pulsator and 10 kg load capacity has most violent shake and or vibration, and worst dynamic stability, which result in maximum noise in dehydration. The mechanisms of noise generation and motions at stage of dehydration are analyzed. Dynamic impacting excitation is firstly clarified as the most important dominant factor in understanding acoustic behavior of the washing machine at the stage. A new damper is developed and designed on the basis of improving the degree of harmonics (DOH) of dynamic impacting force, which is employed as the critical criterion for damper design. Applying the damper developed reduces the washing machine noise 2.2 dB(A) and 4.7 dB(A) under conditions of normal and worst unbalance respectively.