|Title of Invention||
VERTICAL-AXIS WIND TURBINE SYSTEM
|Abstract||A vertical-axis wind turbine system for harvesting wind energy substantially is described and illustrated. This wind turbine is a simple and safe domestic roof mounted system comprising of rotor blades mounted on a flange and connected to a gearbox and alternator. The rotor blades are rect~ngular disks which are feather-like material reinforced and cushioned. The rectangular disks fixed in three or more rows in five or more columns are hinged on the frame of the rotor blade which can be lifted up to 80 degree angle. The unique design of the rotor blades and the material of construction used are to gain maximum torque at low wind speeds in range of 2.00 to 25.00 km. The overall efficiency of this wind turbine is better than the conventional type achieving more than 50 % efficiency.|
|Full Text||FII-1.1) OF INVENTION
This invention relates to a wind turbine rotating on the vertical axis at low speed for generation of electrical power.
BACKGROUND OK INVENTION
A wind turbine is installed on top of a tall tower which collects kinetic energy from the wind and converts it to mechanical or electrical energy that can be harnessed for practical use. Mechanical energy is most commonly used for pumping water in rural or remote locations, but it can also be used (or many other purposes (grinding grains, sawing, etc). Wind electric turbines generate electricity for homes and businesses and for sale to utilities. Greater use of wind energy means a cleaner environment with healthier air and more income to landowners and economically weaker villages and communities in the country. It means relying more on an energy source whose “fuel” is free1 and will never be exhausted.
If the wind speeds are below cut-in speed (7-10 mph) there will be no output from the turbine. As wind speeds increase, turbine output increases and produces more power. Wind turbines produce no pollution and by using wind power one can offset pollution that would have been generated by the power utility company. Over its life, a small residential wind turbine can offset approximately 1.2 tons of air pollutants and 200 tons of greenhouse gases (carbon dioxide and other gases which cause climate change).
A wind turbine subsystem includes- a rotor, or blades, which convert the wind's energy into rotational shaft energy; a nacelle (enclosure) containing a drive train, usually including a gearbox; and a generator,” a tower, to support the rotor and drive train: and electronic equipment such as controls, electrical cables, ground support equipment, and interconnection equipment.
There are two basic designs of wind electric turbines”, vertical-axis, or “egg-beater” style, and horizontal-axis (propeller-style) machines. Horizontal-axis wind turbines are most common today, constituting nearly all of the “utility-scale” (100 kilowatts, kW, capacity and larger) turbines in the global market.
Vertical-axis wind turbines en me in two flavors: lift- and drag-based designs. Drag-based designs work like a paddle used lo propel a canoe through the water. If you assume that the paddle used to propel your canoe did not slip, then your maximum speed would be about the same speed you drag your paddle. The same holds true for the wind. The three-cup anemometers commonly used for measuring wind speed are drag-based vertical-axis wind turbines.
In the lift-based vertical-ax is types, each blade sees maximum lift (torque) only twice per revolution, making for a huge torque (and power) sinusoidal output. A 500-kW two-bladed vertical-axis turbine we have on site has two or three rotational speeds that must be gone through quickly to get up to operating speed and several modes within the operational band.
Vertical-axis wind turbines are very difficult to mount on a high lower to capture the higher level winds and hence are normally mounted on lower height towers. Cables are usually used to keep the turbine erect. They also impose1 a large thrust loading on the main turbine bearings and bearing selection is critical. Like all types of turbines, replacing main bearings requires that the turbine be taken down.
Horizontal-axis wind turbines are most common today, constituting nearly all of the “utility-scale” (100 kilowatts, kW. capacity and larger) turbines in the global market. However, the horizontal-ax is wind turbines are presently very elaborate and expensive.
OBJECTS OF INVENTION
The primary object of this invention is to make improvements in the vertical-axis wind turbine that is to make turbines sturdier, cheaper and more efficient for domestic or household application mainly by modifying the design of the rotor or blade to combine, the drag as well as the lift mechanism and to improve the bearing and transmission mechanism.
URIEF DESCRIPTION OP INVENTION
The vertical-axis wind turbine system developed has three rotors or blades fixed on a round flange type housing base. The housing is fixed to a shaft extended directly on the gearbox. This gearbox is attached with an alternator for generating electrical power. The entire system is mounted on a sturdy stand of suitable height.
DESCRIPTION OF INVENTION WITH REFERENCE TO 'fill' DRAWINGS
Further objects and advantages of this invention will be more apparent from the ensuing description when read in conjunction with drawing and wherein:
Fig.l shows the schematic top view of the vertical-ax is wind turbine system of the present invention.
Fig. 2 shows the front cross sectional view of the vertical-axis wind turbine system of the present invention.
Referring to Fig.l. the vertical-ax is wind turbine system comprises of a sturdy steel frame [ 1 ] to mount, support and house the transmission and the alternator system. The housing system  consists of the shaft which connects to the gearbox and in turn to the alternator. The rotor  consists of moving (80 degree angle) natural bird feather-like material arranged and fixed or hinged in three or more adjacent rows. The arm of rotor is a rod 14] that connects the rotors to the flange 15] mounted on the shaft , The shaft  is in turn connected to the gearbox housing [2 ].
CONSTRUCTION OF FEATHER-LIKE MATERIAL OK THIS ROTOR
The feather-like material is very light and high in mechanical strength. It is reinforced and cushioned so that it can withstand strong wind currents. The material is rectangular disk in structure freely hinged from one side (from the top side) on the frame so that the disk can rotate (about 80 degrees) to lift itself and give space to wind to flow easily when it moves to opposite side (rarer side). When rotor moves to direction of wind the rectangular disk comes down (rests on the frame) and blocks the wind (at right angles). B locking of wind by the rectangular disks leads to
pushing of the entire rotor blade. This in turns helps in moving of the rotor blade. The three arms of the rotor are fixed at 120 degree to each other and the edge (one third of length from outer edge) of the rotor blade is slightly bent inwards at an angle of 10 degrees or more. As the rotor moves the shaft also moves al the same speed and this energy is transmitted to the gearbox directly.
CONSTRUCTION OF THE FLANGE AND HOUSING
Flange is a round plate with suitable attachment provision for fixing the rotor arms. The flange is in turn mounted on a shaft which has bearings at two ends for smooth running. The shaft is mounted on the gearbox directly which is fixed on the frame.
CONSTRUCTION OF THE GEARBOX AND ALTERNATOR
The helical type gearbox is with simple lightweight gears, less friction, low transmission losses and less friction bearings and bushing attachments. The gearbox ratio is of 1:5 and 1:10 to improve the speed required for the alternator.
The alternator is mounted directly on the gearbox. It is low power generator suitable for low speed wind turbine. It is a permanent magnet type and has power output in the range 3 watts to 10 watts and 10 watts to 30 watts depending on the gearbox ratio and speed of the wind currents. The output voltage ranges from (3 volts to 16 volts and current 100 milli amperes to 2000 milli amperes. This output power generated can be stored in suitable batteries for utilizing this power through an inverter for domestic applications.
CONSTRUCTION OF FRAME
The sturdy steel frame for mounting, supporting and housing the transmission and alternator system is very simple. The frame consists of 4 legs with a height of 6 feet from the base and is fabricated with mild steel angles with a wider distance at the bottom, between the legs. This enables the frame to withstand high wind speeds and vibrations of the rotors.
|Indian Patent Application Number||352/CHE/2006|
|PG Journal Number||36/2012|
|Date of Filing||01-Mar-2006|
|Name of Patentee||NANJUNDA SWAMY|
|Applicant Address||C/o Krishna Reddy, No. 1170, 6th Cross, K.N. Extension, Yeshwanthpur, Bangalore-560 022|
|PCT International Classification Number||F03D11/00|
|PCT International Application Number||N/A|
|PCT International Filing date|