Abstract: For the twin tub washing machine, the motion of spinning tub is firstly simplified to two degrees of freedom model, the equation of motion is then established by using D′Alembert principle. The dynamic equation is solved and the amplitude-frequency curves of two degrees of freedom are drawn. Then the influence of attached mass ring height on the spinning tub vibration is studied. At last, the finite element method is used to perform modal analysis and frequency response analysis for spinning tub, the CAE analysis result is to confirm the correlation and feasibility of the established dynamic equation.

Key words: Twin tub washing machine, Spinning tub, Equation of motion, D'Alembert principle, Two degrees of freedom model, Modal analysis, Frequency response analysis