Abstract:
In many places including an ordinary house, factory,
resting place and the like where men spend part
of their time, an electric fan makes them feel cool and
refreshed. It is primarily used for controlling the air
in a room or ventilating. In particular, during the
season of high temperature, it is an important
appliance men cannot do without in daily life.
The electric fan consists of four main parts; fan,
guard, motor and stand. The fan is usually of plastic
screw type but sirocco fans are also used. The motor
is usually of induction type but a condenser motor
is also used. The electric fan is characterized by the
rotation of a swinging device, which is converted to
the reciprocating motion by a worm gear and crank
rod, making the entire fanning device to swing from
one side to the other with a fulcrum located in the
stand.
Though electric fans are limited in use depending
upon regions and seasons, they are most suitable for
small and medium businesses which can be established
relatively easily with small investments on the foothold
of universal technology.