The principal behind washing cloths is to
push water and soap through the fibres of the material, rinse it
out and then get out as much excess water as you can prior to
drying. While washing machines have advanced a lot their
principals of operation have stayed much the same.
The most popular washing machine the top loader can be broken down
into a few parts. Firstly the timer is like a clock but with
several switches attached to it, when the clock ticks through it
cycles it can turn on the pump, the inlet valve or the motor.
Today many washing machines use a small dedicated processor
instead of the mechanical timer, manufacturers find it cheaper to
make a circuit board instead of a mechanical part. Also you can
add more features easily and sell the computer controlled machine
for much more money.
The next major part of the machine is the drum assembly and gear
box. The inner drum is where you put your washing it has hundreds
of holes in it not only to let the water in but to also force the
water out during the spin cycle. If you ever used a centrifuge in
science class at school this is what is happening to your washing
during the spin cycle. The outer drum is fixed to the washing
machine and sits around the inner drum, its purpose is only to
hold and catch the water used during the wash cycle.
The plastic part in the centre is called the agitator. The
agitator is not attached to the inner drum as it looks, in fact
the agitator is capable of turning in opposite directions to the
inner drum, it does this via the machines complex gearbox that
turns both the inner drum and agitator.
The next parts the washer couldn't do with out are the solenoid
valves and pump. the solenoid valves are normally mounted near
where the water goes into the machine. they are kind of like your
only they are operated electronically. When the timer get to the
stage of the wash cycle that needs water it turns on the solenoid
valve so the tub fills with water. A pressure sensor senses when
the water is at the desired level and once the tub stops washing
the clothes the pump gets switched on to drain out the water, all
this is controlled by the timer.
The last thing the machine could not do without is the electric
motor that sits at the bottom of the tub and drives the gearbox,
the gearbox is often connected to the motor by a belt and both are
attached to the outer drum which is connected to the machines
cabinet by blocks of rubber. The Rubber helps stop the machine
vibrating out of your room during a spin cycle, washing machines
often use blocks of concrete to help the stay steady.
Front loaders work in much the same way but they don't need an
agitator as the tumbling action of the drum has the same effect of
pushing the water through the material. Front loading washing
machines have a more elaborate sealing system and interlocked door
so water wont spill out of the machine.
Edison invented the electric chair but he was not
pro capital punishment. He wanted to give AC power a bad image as he
was implementing he own DC power network. The first tests of the
chair were on cats and dogs.