New drive system design in a laundry dryer machine

Recently, because of the increase in population and decrease in space per capita in cities, spaces used by people to dry their laundries have also significantly decreased. Moreover, lack of time that is brought by the rush of city life obliges people to use machines for their daily life frequently. Due to all these reasons, people verge to use dryer machines to dry their daily laundries. People who have already been using washing machines for their laundries, are also using the dryer machines to dry their washed laundries. As it is known, laundries which are washed in a turning tumbler in washing machine, are also dried in a tumbler in dryer machines. Therefore, due to the turning effect of the tumbler, laundries are damaged and eventually they wear out. This wearing affects especially delicate fabrics significantly. Some dryer machines in industry have some certificates that indicate that the relevant dryer can dry delicate fabrics. Among all these certificates, the most widespread one is named the Woolmark certificate. Dryer machines have the Woolmark certificate can dry wooly laundries softly without any wearing. At the end of this study, it is aimed to verify the drying properties of the machine dryers for delicate fabrics by subjecting them to such kind of certificate tests. Another problem brought by the recent conditions is the usage of energy in industry. Due to the lack of energy resources, like all other industrial areas, energy consumption limits have aroused in also white goods industry. All industrial machines are manufactured in determined regulations to enable more efficient usage of energy. Machines manufactured in such regulations have specific energy ratings and these ratings play an important role in market that machines will get into. Besides that, clients want that the machine they use have a low energy consumption for both environmental issues and lower financial losses due to inefficient usage of these machines. Energy efficiency index is used to determine the energy ratings of tumble dryers. This rating is determined by considering the consumed electrical energy by tumble dryer during the drying test which is executed in conditions specified via related regulations. Decrease in energy consumption ensures the decrease of energy efficiency index, thus energy ratings of the tumble dryer improves. There are 7 different energy ratings for tumble dryers. These ratings are known as A+++, A++, A+, A, B, C and D where A represents the most efficient energy rating, D represents the least efficient one. Drive systems of tumble dryers are composed of two stepped belt and pulley mechanism. Excitation taken from the electric motor is transmitted to the tumble via this belt and pulley mechanism. Belt and pulley mechanism is also used to decrease the engine speed from 2900 rpm to 54,2 rpm in tumble. Fans is directly bounded to the motor shaft. When electric motor is started, fans and tumble in mechanism also begin to operate. The first objective of this study is to stop the tumble's turning in a determined frequency by a developed algorithm and dry the laundries by only the hot air's effect to avoid or ease the harmful effect of tumble's turning motion. The another objective of this study is restraining the tumble's motion until the air heating systems reach their full performance to improve energy efficiency by preventing the energy loss during the term that tumble does not operate. In this study, tumbler dryer machine types were discussed and working principle of each type was elaborated. An extensive literature research was conducted to investigate the significant studies. Moreover, patents and patent applications in the literature were examined. Existing tumble dryer machine system was investigated and belt and pulley mechanism calculations were done. In addition to these calculations, pulley forces that are emerged by the belt and bar forces, belt convolution angles and pulley circular velocities were calculated. Within the scope of this study, a new drive system for tumbler dryer machines was designed to solve the laundry wearing and energy efficiency concerns. In this context, an innovative clutch mechanism was integrated to the traditional drive system, which drives the fans and tumble together on the purpose of dividing the drive system transmit to the fans and the tumble. Analysis were executed for the designed system and accordingly, prototypes were manufactured. Prepared prototypes were tested and system's efficiency was evaluated by considering the results. Problems encountered during prototype tests were detected, in this direction, design was improved and eventually, final design was obtained. Statistical structural analyses were carried out for the ultimate design and the stress on the correspondingly loaded parts was examined. The resulting stress was compared with the yield stress of these parts. With the help of statistical structural analyses of deformed parts, the deformation amount was determined and whether the deformation problems were fixed was predicted before producing the prototype. The properties of belts in the system were not changed during the design and the new system was developed in accordance with the existing belts. It was not needed to calculate belt tensions for this new belt and pulley system since the existing belts remained unchanged. Therefore, the functionality of the belt and pulley mechanism is not to reconsider, and the test effort of the new system was diminished. Extra costs were eliminated by utilizing the same bearings in the new system. Newly designed pulleys are intented to be manufactured via aluminum injection methods as it was in the previous system. In order to obtain the proper precision of the pulleys, the application of metal cutting prosess was planned after aluminum injection method. Other parts in the new developed system are to be manufactured by the plastic injection method. Raw material of the plastic parts was selected very attentively as the temperature and moisture are relatively high in drying machine. Fast prototyping machines were used for producing prototypes. Aluminum pulleys were processed by CNC milling machines. 3D printers were utilized as a manufacturing proses of prototype plastic parts. AC motor was used fort the actuator system in the new design. The cost occuring by the use of DC motor fort he components that convert AC power supply to DC power supply were eliminated by use of the AC motor. The results were outlined and the potential studies in the future were mentioned at the end of the project. A new design for tumbler dryer machines which was conducted in Arçelik A.Ş. Digital Modeling and Structural Desing Team constitutes the context of this thesis study.