When considering the world's expanding need for new energy resources, and the desire to lessen the impact of such additional consumption upon the ecosystem, wind energy is presented as the one with the greatest potential to fulfill such needs, and perhaps the most underutilized at the present. "The most comprehensive study to date found the potential of wind power on land and near-shore to be approximately 72 terawatts. Currently humans use about 7 TW from all sources globally.": source Think Global Green. At the present time, worldwide production of electrical energy derived from wind represents about 2% of the total output, that of the USA being about 2.3%, with a number of European countries obtaining substantially more output from wind, ranging from between 14 - 17%.
- EOS - root
Energy Generation - Wind Power
CMS provides CNC machining center technology for the following components of the typical HAWT power generation unit (Horizontal Axis Wind Turbine):
- Mold and model manufacturing: molds are used for the production of the components made in composite materials, which is principally GRP, reinforced glass fiber and carbon fiber, with the components being blades, hubs, nacelle covers, and cones, and the materials used to manufacturer the mold being polystyrene foam, EPS, epoxy and polyurethane pastes, modeling block and tooling board, and fiberglass
- Molds for the rotor components: blades, reaching up to 60 meters in length (~197') with a root diameter of up to 4 meters (~160"); hub, to which the blades attach; and cone, which covers the hub and blade connections
- Molds for the nacelle, the housing in which the main hardware components are located - gearbox, generator, brakes, yaw motor, etc. - and which is divided in 2 sections, lower and upper housing
- Component machining and trimming:
Poseidon - machining components for wind energy generation
Poseidon, CMS' moving bridge class CNC machining center, provides a range of large working envelop sizes for the molds required for wind turbine components, tuned with high speed acceleration/deceleration machining characteristics for the substantial amount, and lengthy time involved, of surfacing programs, including CMS' heavy duty 5-axis working unit, all important factors for machining model and molds parts for HAWT (Horizontal Axis Wind Turbine) units, as well as the GRP machining work involved on the blade roots, hubs, cones and nacelles.
Example of the time to produce the molds for a complete wind blade:
Blade size: 45850 x 4400 x 1395 mm (150.4' x 14.4' x 4.6')
- The blade is split in three section longitudinally: left, right, and central
- The cycle time is divided between roughing the EPS foam (Expanded Polystyrene) and finish milling the putty of the three sections
- Roughing on the EPS foam is done in one step, with a 40 mm Ø roughing tool, and a step over of 30 mm
- Finishing on the paste is done with a toroidal tool of 25 mm Ø r3mm at tips, step over of 5 mm for a good surface finishing, milled in 5 axis fashion Completed part (composed of left, right, and central): Area: 209 m2 (2250 sq') Roughing : 6 hours 56 minutes Finishing : 28 hours 26 minutes Productivity: 5.89 m2/h (63.4 sq'/hr) Poseidon's basic working envelop and working head characteristics are: Strokes:
- From X axis 2.5 m to 41.0 m (8.2' to 134.5')
- From Y axis 2.6 m to 8.5 m (8.5' to 27.9')
- From Z axis 1.3 m to 4.0 m (4.3' to 13.1'), non-telescopic version standard and telescopic versions available where reduced height limitations exist Working units:
- From PX5 working unit with 12 kW power (16.1 hp) at 12,000 rpm, maximum 24,000, liquid cooled, S1 rating, A axis +/- 120°, C axis +/- 270°
- To KX5 working unit with 15 kW power (20.1 hp) at 12,000 rpm, maximum 24,000, liquid cooled, S1 rating, A axis +/- 120°, C axis +/- 270°
- To KX5 working unit with 28 kW power (37.5 hp) at 4,300 rpm, maximum 24,000, liquid cooled, S1 rating, A axis +/- 120°, C axis +/- 270° 16 place tool changing magazine standard, with additional expansion possible
Poseidon - large working envelop and special fixtures for wind blade machining
This Poseidon, with large work envelop, is also specially equipped with a unique fixture for holding wind blade components for machining processes, while leaving a lot of additional space in its work envelop for placement of molds and other projects to be worked.
Poseidon - large format with APC tables for machining blade components
This large Poseidon is equipped with CMS' special APC tables, Automatic Pallet Changing. The tables provide for a nonstop, protected, pendular work cycle, or can be slaved together to work as one large table when needed, and are equipped with CMS' gridded hole table surface for easy location of fixtures, or projects, and compressed air and vacuum connections for fixtures requiring them. Since the time to load and unload, as well as to set up for different large components, can be long, providing for a nonstop work cycle greatly impacts and benefits the overall production time.
EOS - root
EOS - CMS Solution for Root blade CNC machining
The EOS CNC machining center has been designed using the proven CMS philosophy. It’s a solution that exploits CMS' broad 5 axis CNC machining experience in the sectors of aluminium, composite materials and resins machining, as well as production of large size patterns and moulds.
CMS designed EOS in response to the demands from the wind energy sector in order to achieve an effective and efficient way to carry out machining operation required on root section of wind blades—such as drilling radial and horizontal holes, flattening operations, and so forth.
EOS - Machine architecture
EOS is a horizontal 5 axis CNC High Speed Machining Center with a movable vertical beam.
Flexibility is the foundation of the EOS machining center, combining CMS' typical characteristics of sturdiness and reliability coupled with high safety standards and precision, high speed and ease of use for carrying out any kind of milling, aperture machining, contouring, finishing, drilling and 3-dimensional machining using up to 5 simultaneously interpolated axes.
EOS' compact design results in an excellent “factory space/working area” ratio; the working area is easily accessible for load/unload operations, fixture set-up as well as the ergonomic considerations related to the operator.
All EOS' mobile mechanisms have been designed so as to balance and optimise the strength/weight ratio and are driven by high-performance motors which result in top-end speeds and accelerations, combined with the highest rigidity values.
Traditional HAWT (Horizontal Axis Wind Turbine)
Shown to the left is the traditional HAWT (Horizontal Axis Wind Turbine), with its 3 large composite wind blades, attached to the hub, which drives the turbine shaft to convert the wind power into commercially usable electricity. The use of such power generation systems has increased exponentially in the last 10 years, as techniques, designs and technology for efficiency in power production, along with improved methodology and machinery, have lowered the cost per kilowatt hour on these units.
Shown to the right is a new generation of theoretical technology, using a vertical axis design, in which the entire system is mounted at ground level, the base of which is a solid heavy structure on which the fan mounted. The entire structure is magnetically levitated from beneath and the sides so that mechanical resistance is reduced to essentially zero, and to the outside an additional wind power boost is achieved with a large directional wind scoop, which funnels air to the fan.
Basic wind turbine structures
Aside from the tower, CMS provides CNC technology for the basic wind turbine structures shown in this photo, both for producing the required molds, as well as the specific CNC machining processes associated with them: blades, hub, cone and nacelle.
Closer look at the basics of the HAWT, wind energy generating system
In this photo a closer view is seen of the basic HAWT, wind energy generating system. To the top left is shown the hub, to which the blades attach. In the top center the upper and lower nacelle housing can be seen, which is a very large structure compared to the men working on it. To the bottom left is shown the cone, which covers the blade roots and hub. To the bottom center several blade sections have their root portion showing, which attach to the hub. To the right can be seen the assembled halves of a wind blade after being joined together with the blade ready to move to the next production process, the root work still needing to be done.
Side connections being machined in the root blade by EOS
Face connections being machined in the root blade by EOS to match up with the side connections
Facing off the root blade
Facing off the root blade connection is shown here, an operation which requires getting the connection face correctly aligned with the hub into which it will be mounted, as well as perfectly flat for a solid, tight connection to the hub.
EPS - Mill, Paste and Machine
An overview of the mold making process in which an EPS substrate (Expanded Polystyrene) is roughed out, followed by a finishing pass, after which the CNC controlled application of a curable paste takes place, completed with the finish milling of the paste, resulting in a high quality mold surface—techniques being used for wind blade mold creation.
CMS' EOS - Wind blade root machining
Overview of root blade machining processes, along with holding and position of the wind blade.
EOS - blade root machining
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