• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.05a
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• pp.1134-1139
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• 2003

Vibration problems are an intrinsic characteristic in a washing machine owing to rotation working mechanism. Therefore, a right comprehension of working principle and the analysis on dynamic behavior of a washing machine is essential to design anti-vibration or vibration reduction. In this paper, we choose two kinds of a washing machine: a suspension type pulsator/drum type washing machine. Each the structure and working principle of a washing machine is discussed briefly and the dynamic behavior of it is investigated, then, the vibration detection problems of transient or excessive vibration is tented in each category. Some vibration experimented results in a washing machine are presented also.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.24 no.2
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• pp.117-122
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• 2014

A novel method to reduce the vibration of drum type washing machine is proposed. Recently, as the capacity of the drum-type washing machine gets expanded and its washing performance is improved, its market share is increasing in the whole world. But, the capacity of washing machine is limited because of door size and built-in washing machine size. The vibration of washing machine is caused by unbalanced cloths in high spining drum, and the displacement of tub is maximized at transient range about 3 Hz(180 rpm). Previous researches were concerned about steady-state vibration in spinning. In this study, concerned about transient vibration and the displacement of tub is decreased by using gyroscope system. Mutibody dynamic model of washing machine include gyroscope is designed and the vibration of tub have been reduced by 44.7 % over original.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.996-1001
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• 2006

Automatic washing machines have been improved and popularized steadily since the first electric washing machine was produced in the early 1900's. Appliance industry has tried to obtain the performance of washing machine with large capacity, high energy efficiency, low vibration and low noise levels. As the installation peace of a washer becomes closer to the living space, vibration and noise problems become more important challenges. In general, a washing machine has four legs to support its body. Four legs of the washing machine should be attached on a floor. If not so, it may cause severe vibration or walking in the spin-drying process. Unfortunately, the floor of an ordinary house is bumpy in general, and the consumers will not accept bolting washing machines to a foundation; moreover, sometimes they move the location of their washing machines to utility rooms or bath rooms or kitchens and don't care for leveling the legs exactly. In this study, we devise an auto-leg system that prevents the occurrence of abnormal vibration and walking of washing machines. It is simply composed of a spring and a friction damper. Some experiments are implemented to show the dynamic characteristics of the three-dimensional auto-legged washing machine model that is located on the even or uneven ground. A spring parameter is optimized to adjust the length of the auto-leg system automatically up to 10 mm irregularity, and the friction damper is designed to decrease a resonance induced by the spring of the auto-leg system. Some numerical results show that placing the proposed auto-leg system in a washing machine makes good performance with low vibration, as well as low noise, regardless of the unevenness of the floor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1990.10a
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• pp.71-77
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• 1990

This paper describes the experimental analysis of the vibration and noise reduction for the washing machine of the home appliances. For the washing machine, the customers always feel electrical and mechanical noise and vibration. First of all, when the dehydration process is working, the washing machine has nonlinear problems and boundary conditions are varied with time. Therefore these problems are very complicated and difficult to analyze. We verify the sources of the noise and vibration and consider the countermeasure to reduce the noise and vibration level of the washing machine.

• Journal of Power System Engineering
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• v.18 no.3
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• pp.20-28
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• 2014

Most washing machines are now produced as a drum-type, where a washing drum mounted on a suspension system with springs and dampers, to minimize the transmittance of the vibration from the drum to the cabinet. The purpose of this paper is to develop optimized suspension system of the drum washing machine which minimizes transmission of disturbing vibration and force. In this paper, a method for optimizing suspension system of the drum washing machine is presented using ADAMS. The design variables to optimize are extracted using Sequential Quadratic Programming(SQP) in ADAMS. To evaluate optimized spring constants and damping coefficients of the drum washing machine, simulation was done to compare the vibration attenuation performances before and after the optimization. The results of simulation show that the optimized suspension system has better performance than before the optimization.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.1
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• pp.1-13
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• 1995

In order to investigate the effect of liquid balancer in washing machine, we identify the vibration characteristics of suspension system of washing machine and formulate the 4 D. O. F. system dynamic equations. As the washing machine rotates higher speed, it is emphasized to reduce the ecentric force due to unbalanced mass. Nowadays, the most effective cancelling method of eccentric force is known as the usage of liquid balancer. To determine the liquid distribution in liquid balancer, the fluid statics is considered. The system dynamic equations are solved by Runge-Kutta method and represent the good characteristics of real washing machine in X-Y plane. The accuracy of the numerical solution was examined by experiments. The simulation results show that the unbalanced mass has so much influence on vibration magnitude and the rotating shape of spin-basket. But the effect of mass reduction due to the dehydration of the spin-basket has little influence on transient vibration.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.28-31
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• 2014

This paper is concerned with the active vibration control of washing machine. To this end, a new control algorithm utilizing an acceleration signal as a sensor signal is newly developed based on the principle of a dynamic absorber. The resulting control algorithm was implemented digitally on the DSP board. The accelerometer and the active linear actuator were used as sensor and actuator for the active vibration control of washing machine. Experimental results show that the proposed control algorithm can be effectively used for a controller which uses an accelerometer.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.561-564
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• 2005

The quality of a rotating body such as a washing machine depends on the vibration characteristics. So, the researches to reduce the vibration of a washing machine are actively performing, but it is very difficult to conduct these experiments because there are many design parameters affecting the vibration behavior. Accordingly, in this study it was complete to build a modeling of a drum washing mashing to analyze and predict vibration behaviors. The design parameters which affect the vibration were found, and the method for the systematic analysis of the design parameters was suggested using axiomatic design. In the previous study, the effect of the gasket has not considered on vibration behaviors, but in this study it was considered. The simulation results showed good agreements with the experimental results in the vibration displacement and the vibration tendency of a drum washing machine.

• Journal of KSNVE
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• v.5 no.1
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• pp.85-93
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• 1995

The vibration of the dehydration process in a washing machine is important problem that affects the performance of products. In this paper, the upper structure of a washing machine is modeled as rigid body suspension system and, by numerical analysis, the amplitude of a spin basket and the transfer moment at a base plate are calculated. To examine the vibrational characteristics according to design variable change, the friction coefficient in anubber, the radius of curvature, the stiffness coefficient, initial length and locations of support springs are considered in the analysis. Experimental results are compared with those of analysis.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.9
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• pp.731-737
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• 2016

In the quest for improved capacity and accelerated dehydration speed of drum type washing machines, an increase in vibration emerges as a major challenge. In an attempt to derive a new design with reduced vibration, a full finite element model of washing machine has been developed, with experimental verification. After modal analyses of several design variants, a new design of the cabinet has been proposed. Forced vibration analysis of the new model suggests that 19% reduction in cabinet vibration amplitude can be achieved with this design.