Patent Application
20180258910
The present disclosure relates in general to turbines for converting wind energy into electrical energy and more particularly to a horizontal axis wind turbine.
Wind turbines generally fall into two categories: horizontal axis and vertical axis. A horizontal axis wind turbine is mounted on a vertical tower, and includes a blade assembly that rotates about a horizontal axis to turn the rotor of an electrical generator. Because the blade assembly must always be pointed into the wind, a wind vane or servo motor is provided for rotating the turbine about the longitudinal axis of the tower. A vertical axis wind turbine has a vertical rotor shaft and does not need to be pointed into the wind.
Horizontal axis wind turbines have higher rotational speeds, and are generally more efficient and more commonly used than vertical axis wind turbines. However, the high rotational speeds result in high stresses on the blades, bearings, and gearboxes of these types of wind turbines, which can lead to cracking and failure of components. This in turn can lead to high maintenance and repair costs, and unacceptable down times.
The above problems are addressed by this disclosure as summarized below.
An apparatus for converting wind energy into electrical energy includes a turbine having a horizontal shaft, a plurality of blades, a blade mount supporting the blade assembly for rotation about the horizontal shaft, and a turbine mount supporting the turbine for rotation about a vertical axis.
In one aspect of the disclosure, the blade mount includes a pair of spaced apart face plates encircling the shaft. A plurality of mounting blocks extends between the plates. Each mounting block includes an opening for receiving a blade. In a preferred embodiment, each mounting block includes two spaced apart mounting plates, each having an opening. The opening in one of the plates receives a proximal portion of the blade, and the opening in the other plate receives the blade distally of the first opening. Each of the blades preferably has an airfoil-shaped cross section, and each of the openings in the mounting blocks has an airfoil-shaped perimeter matching the cross-section of the corresponding blade.
In another aspect of the disclosure, the face plates include a front face plate defining a first bore and a rear face plate defining a second bore coaxial with said first bore. The first bearing assembly includes a front bearing coupled to the front face plate and a rear bearing coupled to the rear face plate. The front and rear bearings support the horizontal shaft for rotation within the first and second bores.
In still another aspect of the disclosure, a disc is integrally connected to the rear face plate by at least one bar extending perpendicularly to the rear face and the disc. A piston and caliper assembly cooperates with the disc to function as a brake stopping or slowing rotation of the blades when necessary. In another aspect, the disc is annular and encircles the generator.
In yet another aspect of the disclosure, the turbine is connected to a vertical tower by a turbine mount including a connector plate coupled to the turbine and a connector ring connected to the tower. A pair of bearings, including an upper bearing above the connector ring and a lower bearing below the connector ring, supports the vertical shaft for rotation within the connector ring. An end cap may be coupled to the connector plate and to a lower end of the vertical shaft for rotation therewith, wherein the lower bearing is sandwiched between the end cap and the connector ring.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
An apparatus for converting wind energy into electrical energy, indicated in its entirety in
A nose cone 19 in front of the blade mount 14 and a nacelle 21 to the rear of the blade mount 14 give the turbine a streamlined geometry that reduces sound and minimizes drag, resulting in optimal aerodynamic performance. A turbine mount 18 connects the turbine 12 to a vertical tower or pole 20 and allows the turbine to rotate about a vertical axis in response to forces exerted by the wind on a yaw vane 22 mounted on an elongated tail 24 extending from the back of the turbine 12. This ensures that the blades 16 face into the wind for maximum output.
The nacelle 21 encases a generator 26, seen in
The blade mount 14, shown in greater detail in
Each of the face plates 34, 36 includes a central bore 48. A horizontal shaft 50, best seen in
An annular disc 60, best seen in
The central opening 66 of the annular disc 60 concentrically surrounds the generator 26, which is secured on its rear side to an enlarged flange 68 at the front end of the housing 69 of the gearbox 28. Together, the rear face plate 36, annular disc 60 and mounting bars 64 define a cage or enclosure that substantially protects and stabilizes the generator 26.
A second enlarged flange 70 extending at a right angle from the lower end of enlarged flange 68 serves as an attachment surface to which a circular connector plate 72 at the top end of the turbine mount 18 is bolted or otherwise secured. As best seen in
A plurality of elongated fastening rods or bolts 92 extend through the connector plate 72 and the bore 94 of vertical shaft 74. The threaded lower ends of the bolts 92 are received in mating threaded holes in an end cap 96 that holds the elements of the turbine mount 18 together in a compact and stable arrangement.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
