Wind Turbines
Gear Box is one of the most crucial component of a
wind turbine. As can be seen from the image given below a gear box is placed
between the main shaft and a generator. Gears also provide a connection
between a low-speed shaft to a high-speed shaft. The essential duty of gears
in a wind turbine is to increase the rotational speed of the rotor blades.
The rotational speeds are about 30-60 rotations per minute, which the gears
change to generation speeds of about 1000 to 1800 revolutions per
minute(rpm). This is the rotational speed needed by wind turbine generators
for producing electricity. In the case of gear boxes of a wind turbine, the
gearbox maintains an uniform a speed increasing ratio. So it is not the gear
box of an automobile where it is used to increase the speed.
Planetary Gear Box
Wind turbines of 450 KW or more uses an integrated planetary gearbox. It
comprises of a planet gear along with two normal stages. The planet gear is
a very unique form of toothed gear. The form of planet gear that is used on
wind turbines comes with a similar basic design. They are:
- Ring wheel: Interior toothed gear wheel.
- Planet Wheels: Three numbers smaller toothed gear wheel.
- Planet Carrier: The common carrier arm which carries the above three
wheel.
- Sun gear wheel: A centrally placed toothed gear wheel.