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| 2nd Draft | |||||||||||||||||
| Introduction: | |||||||||||||||||
| ����������� As a group, we decided to do our team based reverse engineering project on an oscillating house fan. We will begin with a history of the fan and then branch out into different categories regarding the applicable aspects of engineering with respect to our oscillating fan. We have included a description of the mechanical, electrical, and industrial engineering aspects of the fan, and we have also analyzed the marketability, ethics, cost effectiveness, and improvability of the current fan design. We would like our project to demonstrate how many areas of engineering apply in our daily lives and how engineering is constantly helping people in their daily lives | |||||||||||||||||
| The History of the Fan | |||||||||||||||||
| ����������� The fan is one of the earliest known mechanical inventions. Throughout time, fans have been regarded as a symbol of status or fashion and as an implement used to keep oneself cool. The first known fans were usually constructed out of large leaves or feathers and were usually operated by servants to keep their masters cool in the hot summer. In the Middle East, many examples of these early fans have been discovered in Egyptian and Assyrian tombs. Some of the most famous of these fans were found in King Tutankhamen?s tomb. They were made out of pure gold and ostrich feathers. Many other cultures also employed the use of such fans. In the Americas, the Aztecs, Mayas, and many South American cultures used fans for a variety of religious ceremonies. In the Mediterranean, the Greek culture used fans that had a piece of linen stretched over a leaf shaped frame. The Roman culture also used fans, which consisted of large pieces of painted wood. In the China, many early groups of people believed that fans were in some way related to mythical and historical folklore. Later on, the Chinese developed the folding fan during the Ming dynasty between the years of 1368 and 1644. At this time, these fans became very popular among the Chinese people and were even used as weapons known as tieshans or iron fans. Around this time, fans made their way over to Europe with the help of the Crusaders. The mass importation of fans didn?t come until the 15th century when Portuguese traders began to bring fans back to Europe from the Orient. | |||||||||||||||||
| These fans became very popular and many high class women of the time were seen holding fans in various portraits.� | |||||||||||||||||
| ����������� The first mechanical fans, the punkahs, were developed in the Middle East in the 1500?s. These fans were huge wooden frames mounted to the ceiling that were covered in canvas. They were operated by servants known as punkah wallahs, who pulled on pieces of rope that made the fan move back and forth. The next innovation in fan technology didn?t come for nearly 300 years. A man named Dr. SchuylerSkaats Wheeler combined the research and technology of Thomas Edison and Nikola Tesla to make the first electric house fan. This fan consisted of a motor and two blades that rotated and created a small amount of air flow. 1882, Philip H. Diehl improved on Wheeler?s design and developed a way to mount one of his fans on the ceiling of a room, thus the ceiling fan was born. He then went on to found Diehl & Company and began to sell these fans. He branched out into making table fans, industrial fans, and all sorts of other variations.� He continued to make improvement on his fans and eventually developed a gearing system that allowed table fans to oscillate back and forth so that they could do a better job at circulating air. Since then, these fans have been an easy and cheap way to cool off rooms and to move air around, and to this day, are still one of the most common forms of air circulation. | |||||||||||||||||
| Mechanical engineering Aspect: | |||||||||||||||||
| ����������� Mechanical engineers deal with many aspects of a household fan such as air moved, aerodynamics of fan blades, oscillation, balance of the fan, and the stand to support the fan. First, mechanical engineers work on the amount of air flow from fan. The goal is to have the greatest amount of airflow with the minimum amount of power used and the least amount of unwanted noise. This goal is obtained by reducing friction between moving parts of the fan, and by working with electrical engineers to make sure enough power is given to the motor to create enough force to rotate the fan blade. Also, by limiting the vibrations when the fan is operational to prolong the life of the fan and cut down on unwanted noise. Mechanical engineers also work on the aerodynamics of the fan blades used. The desire to have the blades push the most amount of air through the fan, but also keep the dust collection to a minimal. | |||||||||||||||||
| ����������� Mechanical engineers must also construct the oscillation of the fan which is a feature that most consumers look for. After taking apart the fan we discovered that the oscillation works by a series of gears and a swing arm, which is attached to the main motor. After discovering this, we must also design the stand of the fan, so it can support the weight of the fan and also while the fan is oscillating, it will not tip over. | |||||||||||||||||
| Electrical Engineering Aspect: | |||||||||||||||||
| ����������� The electrical engineering aspect of an oscillating variable speed fan is numerous and essential for making the fan work properly and efficiently. The run through for the basic design consists of an electric motor, a control panel to select the speed, circuitry to control the speed, and general wiring need to transfer power from one point to another.� � | |||||||||||||||||
| Industrial Engineering Aspect: | |||||||||||||||||
| When designing a fan, the manufacturing cost, safety, and efficiency must be taken into account. It is clear that the designers of this fan addressed the manufacturing costs by using plastics instead of metals where ever possible. For example they seemed to have used an injection molding technique to make the frame/stand which would greatly increase efficiency and reduce manufacturing costs with respect to machining every part that they needed.� They also used plastic gears where ever possible due to the fact that plastic gears are much less expensive than metal gears. The motor was the only feature of this fan that seemed to neglect cost effectiveness and emphasized quality since it was made out of non-inferior materials. The aspects of safety were show by the way the engineers used a cage to surround the fan blades to keep people from coming into contact with them. The cage was made out of metal and also seemed to emphasize safety over cost effectiveness. | |||||||||||||||||
| Conclusion: | |||||||||||||||||
| In conclusion, there are many aspect of the normal house fan with respect to the many branches of engineering. It demonstrates the use of mechanical engineering by being a device with multiple moving parts and gear systems. The electrical engineering aspect is shown by the use of a DC motor and a simple control panel to regulate the speed of the motor. Finally, the industrial engineering aspect is manifested in the materials that the designers used and the way in which they used them to efficiently and cost effectively produce this fan. | |||||||||||||||||
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