DESIGN METHODS

Design Methods & Technology Project

Table of Contents

Introduction3

Management5

The Brief6

The Market6

The product design Specification7

Conceptual Design8

Morphological Analysis9

Weight and RateMatrix11

Detail Design12

Design+Review12

Failure+Mode+and+Effect+Analysis18

Component+Design+Specification18

Conclusion19

References21

Design Methods & Technology Project

Introduction

Design variations of washing machines differ by manufacturer, but the general principles are essentially the same, and can be divided into two halves, the washer's control system and the washer's mechanical system. The washer control system consists of the timer, control boards, load size selector (pressure switch), a water temperature selector, lid switch. The mechanical system includes the motor, transmission, clutch, inner and outer wash tubs, suspension system, agitator, pumps, water valve, and a belt or motor coupling. (Atmel Corporation 2007: 136)

Between 1851 and 1871, approximately 2000 patents were granted in Great Britain and America for a variety of washing appliances, which had to be filled with heated water and used either rotating drums, gyrators or dollies to agitate the clothes. Most of these machines needed to be hand-cranked and clothes tended to get tangled around the rotating dolly elements. The tangling of the clothes was a problem that inventors overcame using an oscillating movement.

In the first decade of the 1900s, electric motors were incorporated into the design of washing machines, but manual systems still predominated until well into the 1920s [1]. It was due to the greater availability of electric power that the use of domestic washing machines grew rapidly, and machines such as the one illustrated in Fig. 2 were common at the time. However, water heating still remained as a problem, only resolved by the end of World War II. During the post-war years, some companies produced sleek, top-loading washing machines that incorporated mangle-like wringers and some had improved automatic controls, requiring less supervision. The top loading models have become popular in America, but in Europe the front-loading washing machines have become standard. The latter model allows space-saving and it is commonly sited in the kitchen. This is one of the reasons why styling has played a very important role in the design of washing machines in Europe from the 1960s to the present day . Nowadays, washing machines are much more energy-efficient by adjusting the power consumption to the size of the load. New generations of machines are currently being developed in Europe that will be even more energy-efficient and will also eliminate the need for ecologically harmful detergents .

Washing machines clean clothing by forcing a water and detergent mixture through fabrics. The action of forcing detergent infused water through your clothing fabric is what enables the detergent to chemically loosen dirt embedded in the cloth and separate it from the fabric. Count your blessings; in the old days, people would beat wet clothes against a rock loosen dirt!

In top loading washing machines the agitator ratchets back and forth dragging clothing down to the bottom of the washer tub. The clothes then move back to the top where the agitator grabs them again. In a front-loading washing machine, the clothes tumble through water in the base of the washer tub over and over ...