Nomenclature
components. Examples are main rear
frames, front frames (when they are
not cast configurations) and generator frames. These can vary in size up
to 10 by 8 by 16 sq. ft., with weights
up to 20,000 lbs. Items in this sector
typically have significant quality specifications that require coordinate measuring machine inspection and NDT—both
in-process and upon completion—using
methods such as dye pen, magnetic
particle, and ultrasonic.
Figure 1
Each of the four major wind turbine sections—tower, hub, blades, and nacelle—must withstand tremendous temperature and wind conditions. During operation, blade tip speeds
commonly exceed 160 miles per hour.
have as many as 22 major component
groups and 8,000 subcomponents.
A wind turbine has four major sections—the tower, hub, blades, and the
machine head, or nacelle (see Figure 1).
Wind Energy Conference:
Opportunities for Suppliers
Green Manufacturer Network
Aug. 31 - Sept. 1, 2010
Cedar Rapids, Iowa
The event is dedicated to helping fab-
ricating and machining shops identify
and capitalize on opportunities in the
wind energy supply chain. Highlights
of the conference include a tour of
the Acciona Wind Turbine Generator
Assembly Plant; a procurement panel
discussion featuring representatives
from Acciona Windpower NA LLC,
Clipper Windpower Inc., and Vestas
Nacelles A/S; and technical presenta-
tions on manufacturing wind turbine
components.
See www.greenmanufacturer.net
for details and registration.
Within the utility-grade wind energy
sector, manufacturing opportunities are
generally categorized as small, large,
and A—critical.
The small category is composed of
components such as simple sheet metal guarding and bracketry that are commonly made in most manufacturing facilities. This type of work generally has
few code requirements, is constructed
of carbon steel, and usually is open-toleranced.
Large sector components typically
include large bracketry, custom crane
structurals, towers, and some nacelle-supporting structurals. Again, generally
they are made of carbon steel. In some
rare cases, aluminum and stainless
steels are used. Most components in
this sector must adhere to American
Welding Society (AWS) D1.1- or D1.2-
type welding requirements and are subject to nondestructive testing (NDT)—
both in-process and upon completion.
The third sector, commonly known as
A, includes the largest and most critical
Nacelle
Most turbines currently being installed
in North America are one of two distinctly different designs—conventional
gear-driven and direct-drive permanent-magnet (PM).
Gear-driven Nacelle. This type is the
most common. These nacelles can be
as large as 150 U.S. tons.
Some of the manufacturing operations needed to produce the 8,000
subcomponents for this unit are metal
fabricating, machining, casting, and
forging (see Figure 2).
Both the main frame and the generator frame are commonly fabricated, but
some designs call for them to be cast.
•;Rotor;Lockout;Disk—casting,
machining
•;Main;Shaft—forging,;machining
•;Shrink;Disk—;forging,;machining
•;Brake;Assembly—casting,;machining
•;Cooling;Cabinet—fabrication
•Guards;and;Structural;Framework—
fabrication
•;Generator;Frame—Metal;fabrication,
ductile iron casting, machining
•Main;Frame/Bed;Plate—Metal;fabri--
cation, ductile iron casting, machining
Direct-drive PM Turbine Machine
Head/Nacelle. In a direct-drive configuration, the rotor hub assembly directly
drives the generator without the need
for a gear train arrangement. This design can reduce nacelle weight and size.
However, direct-drive configurations can
place additional demands on the initial
