Hai-Wei Chen, Wei-Xi Ji*, Qiu-Ju Zhang,Yi Cao and Sheng-Yao Fan
The Journal of Mechanical Science and Technology, vol. 26, no. 2, pp.335-343, 2012

Abstract : This paper discusses a method for vibration isolation of a vertical axis automatic washing machine with a hydraulic balancer. First, a way to isolate vibration through a small amplitude of the suspension rod’s axial force is proposed, and a base circle of a cone along which the lower joint of a suspension rod moves is discussed. Based on the circle, a geometric constraint involving the slant angle of the suspension rod, the deflection angle of the washing/spinning assembly, the suspension radius of the tub and the eccentricity of the system at the steady state is derived. Considering that the trace along which the suspension rod moves is also affected by the dynamics of the system, a governing equation satisfying the equilibrium conditions of the centrifugal forces and torques is obtained. Combing the geometric constraint and governing equation together achieves a general governing equation for vibration isolation of the system. Finally, the general governing equation is proven by simulations, and the relations between the optimal installing height and several parameters are discussed.

Keyword : Hydraulic balancer; Suspension rod; Vibration isolation; Washing machine