Patent Application
20100078528
1. Technical Field
The subject matter described here relates to cable trays, and, more particularly, to a cable tray for a wind turbine.
2. Related Art
A wind turbine is a machine for converting the kinetic energy in wind into mechanical energy. If the mechanical energy is used directly by the machinery, such as to pump water or to grind wheat, then the wind turbine may be referred to as a windmill. Similarly, if the mechanical energy is converted to electricity, then the machine may also be referred to as a wind generator or wind power plant.
Wind turbines are typically categorized according to the vertical or horizontal axis about which the blades rotate. One so-called horizontal-axis wind generator is schematically illustrated in
The wind turbine tower 4 is typically constructed by rolling arcuate sheets of steel and securing the end of those sheets together to form closed rings. The rings are then stacked on top of each other to form the length of the tower. These rings typically have different thicknesses, with the plates getting thinner toward the top of the tower. The rings may also have different shapes, changing from cylindrical to conical as one moves up the tower. Due to the large size of the finished tower 4, and the logistical constraints against transporting such a large structure, it is impractical to assemble the entire tower 4 before it is shipped to the installation site. Therefore, as discussed in commonly-owned co-pending U.S. application Ser. No. 11/969,463 (Attorney Docket No. 229524) for “Wind Turbine Tower Joints,” multiple, prefabricated ringed tower wall sections will often be shipped and then welded and/or flanged to each other at various joints 20 in wall of the tower 4.
As illustrated in the partial interior view of the tower 4 shown in
Various drawbacks associated with such conventional approaches are addressed here in by providing, in various embodiments, a cable tray for a wind turbine tower, including a first section; a second section spaced apart from the first section; and an elastomer connecting the first section to the second section.
Various aspects of this technology will now be described with reference to the following figures (“FIGS.”) which are not necessarily drawn to scale, but use the same reference numerals to designate corresponding parts throughout each of the several views.
The exemplary cable tray 32 shown here includes a first section 34, a second section 36 spaced apart from the first section. However, any other number of sections may also be provided. As shown in
A flexible conductor 40 connects the first section 34 and second section 36 in order to provide a path for electrical currents to pass between the two sections. For example, the conductor 40 may include a braided cable or wire. The flexibility of the connector 40 further helps to isolate the first section 34 from the second section 36 and dampen vibrational energy moving between the sections. Alternatively, or in addition, the conductor 40 may be arranged as part of the elastomer member 38. For example, conducting members may be embedded in or secured to the elastomer member 38. The connector 40 may also help to provide a ground path through the cable tray 32. Similarly, the ground bar 28 (shown in
Some or all of the first and second sections 34 and 36 may be configured as the U-shaped trough shown here. For example, a typical U-shaped trough may include a substantially flat base plate 42, and walls 44 arranged on each side of the baseplate. However, other trough shapes may also be used including C-shapes, V-shapes, W-shapes, U-shapes, multiples thereof such as UU-shapes and VVV-shapes, and/or H-shapes, with or without substantially flat base plates.
Flanges 46 extend from each wall 44 for securing the tray. For example, the flanges 46 may be provided with holes 48 for securing a bracket 50 to the cable tray 32 in order to stabilize and/or otherwise secure the tray 32 against the inside wall of the tower 4. For example, the bracket 50 may be secured to the cable tray 32 with bolts 52 and/or other suitable fasteners. In the illustrated embodiment, the bracket 50 is provided with upturned feet 54 at each end for resting against the interior wall of the tower 4.
As noted above, any number of sections may also be provided. For example, a third section 56 may be connected to a free end of the first section 34 either directly to the first section or with a coupling 58. As shown in
The technology discussed above offers various advantages over conventional approaches. For example, the cable tray 32 is provided without rungs that are otherwise difficult and time consuming to fabricate. The cable tray 32 also offers beneficial vibrational characteristics in that it has a different natural frequency of the tower and provides for isolation and/or damping of vibrational energy moving between the various sections 34, 36, and/or 56. Multiple sections of the tray 32 can also be easily connected using the coupling 58. The cable tray 32 is also easy to use since lines of various sized can simply be laid on the base plate 42 between the walls 44 and then secured with cable ties or other fasteners in the slots 60. The cable tray 32 may be grounded and/or used to support mounted lights or receptacles.
It should be emphasized that the embodiments described above, and particularly any “preferred” embodiments, are merely examples of various implementations that have been set forth here to provide a clear understanding of various aspects of this technology. One of ordinary skill will be able to alter many of these embodiments without substantially departing from scope of protection defined solely by the proper construction of the following claims.
The subject matter of this application generally relates to commonly-owned, co-pending U.S. patent application Ser. No. 12/169,310 for “Cable Bridge for a Wind Turbine Tower” filed on Jul. 8, 2008 (Attorney Docket No. 230584) which is incorporated by reference here in its entirety.
