The same with The,Development,of,a,New,Drum,Washing,Machine,with,Universal,Motor

　　Abstract: The brush with universal motor in the existing drum washing machines features easy-to-wear, poor reliability and low efficiency. In this paper, a new washing machine with universal motor is introduced. In this product, the technical performance indexes of the universal motor is improved, production cost is reduced, and also the service life is longer, because the lamination accuracy and optimization coiling method improving rotor""s lamination and the process control of low noise, low vibration, and abnormal-sound-free of the motor in high rotation speed are applied. Experiment indicates that this product features low noise and high overload ability, and its technical reliability, efficiency and noise are satisfactory.
　　Key words: Lamination Accuracy; Coiling Method; Noise
　　1 Introduction
　　Water and power saving of washing machine is an important technological development trend. Compared with pulsator washing machine, drum washing machine can save not only water, but also a great amount of detergent. Therefore, drum washing machine will be an important development trend in the future, and simultaneously the universal motor with high efficiency, high reliability and long service life will be the key of the future development.
　　Universal motor is mainly used under the conditions that a machine""s rotation speed is highly required, start torque is large and size is small. However, because of the existences of brush and commutator, mechanical noise, sparks and electromagnetic interference occur, affecting the service life and reliability of the motor. Universal motor is applied in drum washing machine, and the requirements on its technical indexes such as noise, dynamic balance, sparks and service life are also much higher. In the process of designing this product, the motor structural parameters were determined and the motor winding parameters are optimized by using the electromagnetic field finite element analysis and the computer aided design. In the process of attempting to making the sample of the product, technology improvement and material optimization can not only make motor completely reach the required performance indexes, but also reduce the winding copper quantity and the cost in contrast to the same sample machines. Therefore, the shortcomings of drum washing machine with universal motor are effectively solved.
　　2 Main Contents of the Project
　　Drum washing machine with universal motor has been listed as a national torch plan project, and its main contents are shown below: (1) motor""s main technical economic indexes and performance analysis, and optimized design of torque, rotation speed and output power characteristics; (2) the manufacturing of main parts as well as assembly process, including stator and rotor coiling, rotor""s dynamic balance, commutator technology, etc; (3) complete machine assembly process and performance test, and stable and reliable complete machine technical performance; (4) performance guarantee and stabilization of the key indexes such as noise, sparks, vibration and service life; (5) installation, equipment, process and test plan in batch production.