• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.2
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• pp.60-65
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• 2010

Injection molding process is one of the popular manufacturing methods to produce plastic parts with high efficiency and low cost. The tub-drum for drum type washer is made by an insert injection molding process with aluminum alloy insert of windmill type and has a big and complex structure consisted of many ribs to sustain the strength. In this paper, the volumetric shrinkages of rib part and bottom part surrounded by a windmill type insert are analyzed according to the vertical and circumferential direction of tub-drum. Volumetric shrinkage and its difference according to the height or radius of tub drum inform the designer to reduce the warpage of tub drum, and the optimal design of tub drum can be done from the those results. The change of volumetric shrinkage according to packing pressure is also analyzed. It is very important to analyze the volumetric shrinkage of tub drum because it generates the wearing phenomena at the rotating part connected to an aluminum alloy insert due to the warpage of tub drum.

• 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 KSME Conference
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• 2003.11a
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• pp.205-209
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• 2003

The condensation water temperature $(T_{CW})$ distributions on the combi-drum washer of condensation type which the cloth washes, rinses, spins and dry cloth over a heater were measured using the thermocouples. During the drying process, in order to find out the relationship between the $T_{CW}$ distribution and the cloth dryness level $(C_{D1})$, the experiment was made for the dehydration rate of the cloth $(C_{D0})$ is 63%, the weight of cloth $(W_{C0})$ from 1 to 6kg. In result, according to $W_{C0}$ and $C_{D0}$, the distributions of $T_{CW}$ are very different. Using this tendency, it was appropriate and it developed the automatic drying algorithm and it was gotten dryness level regardless of $W_{C0}$, $C_{D0}$ and the other factor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.138-139
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• 2010

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.2
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• pp.148-154
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• 2014

This paper describes problems of the sensorless starting of horizontal axis washing machines with direct drive and suggests solution, which was experimentally verified. Horizontal axis washing machines have very difficult conditions for the drive starting, especially at full load. Inertia of the tub and water, torque from the laundry make load torque at starting higher than rated one and sometimes even higher than the maximum torque of the motor, which makes sensorless starting extremely challenging task. This paper suggests modified open-loop starting, where control system is closed shortly after beginning at low speed and rotates the drum until laundry restructuring. To ensure proper work of the sensorless algorithm at low speed additional measures for increasing of the estimation algorithm performance have been taken. These measures include special algorithm for the drive parameters estimation, which has been developed and verified by the experimental results.