The present invention relates generally to the wind turbines employed for generating power. More particularly, the construction of vertical-axis wind turbine running at constant speed with its unique construction of blades and methods of operation of turbine for efficiently generating electrical power.

BACKGROUND OF THE INVENTION

With the depletion of hydrocarbon fuels and increasing emphasis on environmental impact, alternative sources of energy have been sought. One source of alternative electrical energy is wind mills. Windmills have been in existence for centuries and have been used to grind grains, to pump water, and, more recently, to generate electricity (such windmills are typically referred to as "wind turbines"). Wind turbines are generally either horizontal-axis wind turbines or vertical-axis wind turbines. Due to increase in the carbon emission in the environment, it has become necessary to opt for green energy which is now-a-days achieved through many ways like solar, wind, tidal, etc. In all these practices we can produce pollution free energy but there are some major drawbacks to them. One of them is that it is not economically viable. For e.g.: about 8 to10 years are required to recover the cost of one windmill. In general the existing windmills produce about 30 % energy of their installed capacity throughout the year (kw/h basis) however there is no consistency because of the fluctuation of the wind speed as per the geographical distribution.

In every technology practiced comes with limitations like In solar, they can produce energy for only 8-10 hours in a day or in tidal, due to the change in cycles, energy production is only at 40%-50% in the entire day. Same goes in producing energy by wind. As wind is not consistent anywhere in the world, it is not possible to generate electricity throughout the day. If windmill is designed for a wind speed of 50kmph, then whenever wind speed drops, the production of windmill will also fall simultaneously. This drop is not at an equal rate. If wind speed drops by 40%, the energy produced drops by one-fifth to one-sixth of total capacity, hence they are not commercially viable.

Thus, there is a need in the art for an efficient wind turbine that can be used in various locations, under various wind conditions, without being subjected to high stresses.

The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.

OBJECT OF THE PRESENT INVENTION The principle object of the present invention is to provide consistent wind energy using wind turbine despite of inconsistent wind velocity. Yet another object of the present invention is to make a vertical axis wind turbine to improve the utilization of inconsistent wind velocity to generate energy.

It is further an object of the present invention to make a simple and compact design for blades for vertical axis wind turbine for generating energy at constant speed

Yet another object of the present invention is to provide a vertical axis wind turbine which although achieving above mentioned objectives still has a longer life .

Also further the objective is to achieve the above mentioned activities with the devices that are durable, sturdy, compact, safe, simple, versatile, ecologically compatible, energy conserving, and cost-effective. Additional advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several aspects of the invention and together with the description, serve to explain the principles of the invention. Figure 1 is a diagram illustrating the structure of vertical axis wind turbine having variable circumference of its blades.

SUMMARY OF THE INVENTION PUT CLAIM 1 AS INVENTOR LIKES FROM TWO SETS DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention may be understood more readily by reference to the following detailed description, examples, drawings, and claims, and their previous and following description. However, before the present devices, systems, and/or methods are disclosed and described, it is to be understood that this invention is not limited to the specific devices, systems, and/or methods disclosed unless otherwise specified, as such can, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. As used in the specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "blade" can include two or more such blades unless the context indicates otherwise.

Ranges may be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

As used herein, the terms "optional" or "optionally" mean that the subsequently described event or circumstance may or may not occur, and that the description includes instances where said event or circumstance occurs and instances where it does not.

Reference will now be made in detail to the present preferred aspect(s) of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used throughout the drawings to refer to the same or like parts. Referring now to the drawings, wherein like reference numerals designate corresponding or similar elements throughout the several views, an exemplary vertical axis wind turbine according to the present invention as depicted in figures in particular can be referred The drawing discloses a preferred embodiment of the present invention .While the configuration is preferred ,it is envisioned that alternate configurations of the present invention may be adopted without deviating from the invention as portrayed The preferred embodiment is discussed here .

In the accompanying drawings reference numerals for various used parts is as:

Function of each part without departing from the scope and purpose of the invention may be summed as.

The Sleeve (02) helps to hold the screw type arm (10). In this sleeve, the screw type arm (10) is fixed with the help of bearings and because of this sleeve; the screw type arm (10) will rotate freely but remain fixed in one place.

Helical gears (04) gears are fixed between shaft (12) and screw type arm (10) and they will transfer rotational movement from shaft (12) to screw type arm (10).

Anemometer (06) helps to measure wind velocity and will signal the motor (18) to rotate clock wise or anti clock wise and change the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) to control the rpm (revolution / rotations per minutes) in various wind speeds.

Threaded part (08) will be fitted on screw type arm (10) like a nut and on this, part wind catching element (16) will be fixed.

Screw type arm (10) are important parts to change . the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) When motor (18) will rotate, through the shaft (12) and helical gears (04) this arm will rotate clock wise or anti clock wise. Accordingly, part (08) will move forward or backward and the wind catching element (16) is fitted on part (08) which is why this wind catching elements will change the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) accordingly.

Independent shaft/s (12) is connected to screw type arm (10) and motor (18) - this shaft is fitted between the gear box (24) and the motor (18). One end of this shaft is fitted to motor (18) and the other end to helical gear (04) to transfer the rotational movement from motor (18) to screw type arm (10).

Hollow shaft (14) is the main shaft of variable axis wind turbine. One end of this shaft is connected to alternator (20). It is hollow thus enabling the fixation of the motor ( 8), shaft (12), and the gear box (24) into this to rotate the screw type arms (10) for changing the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16)

Wind catching elements (16) because of this wind turbine rotates.

Motor (18) take signals from anemometer (06) and will rotate clockwise or anti clockwise and give rotational movement to the screw type arms (10).

Alternator (20) will generate the power. Arms (22) which will be fixed to the hollow shaft (14) - these arms will hold the sleeve (02) and into this sleeve (02) the screw type arm (10) is fitted. These arms (22) are fixed to hollow shaft (14). Number of said arms can vary according to the design (e.g.: two blade designs will require four arms, three blades will require six arms and four blades will require eight)

Differential gear box (24) is fitted in the hollow shaft (14) and will help to transfer rotational movement from motor (18) to screw type arms (10).

The effort of inventor is to have a design with constant speed =velocity Where (velocity = angular rotational speed of hollow shaft *distance of the central axis of this shaft to an axis through centre of gravity of wind catching element )

To maintain the constant speed of the turbine on different wind velocities, the design is such that the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) is made to change.

With reference to Figure 1, the vertical-axis wind turbine comprises an alternator/turbine (20) to which one hollow shaft (14) is connected. Plurality of arms (22) connected to said hollow shaft (14), and the design of arms is based such that, if the design is for four blades the number of arms (22) is eight. A motor (18) is attached with the independent shafts (12) in said hollow shaft (14),This shaft(12) is connected to differential gear box. In gear box the helical gear (04) is connected to said independent shaft (12). This helical gear is in mesh with two another helical gears (inventor will like to give reference numeral to this gear) which are at end of arm (10). In the arm (22) there is one sleeve (02) which holds screw type arm (10) enabling free rotation (tell whose) however (who is)unable to move from the fixed place. As shown in Figure 1 , one helical gear (14) is attached to each screw type arm (10) in the differential gear box (24). A threaded part (08) is attached to each screw type arm (10), to this threaded part (08) wind catching element (16) is connected and on top of said shaft (14) an anemometer (06) fixedly placed. Thus anticipating the wind flow at about V1 (Kilometer per hour); said anemometer (06) reads the wind speed and accordingly drive the motor (18) thereby said motor through said shaft (12) rotates the screw type arm (10) and thus, rotation of said screw type arm reduces the distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) .

Therefore, as there is reduction in of distance from the central axis point (hollow shaft part 14) and the wind catching element (part 16) rpm of the turbine is maintained as desired irrespective of wind velocity and whenever wind velocity increases, anemometer (06) will take the readings and accordingly said motor (18) will drive said shaft (12) to rotate said screw type arm (10) and when they will rotate, the threaded part (08) which will move outwards and the wind catching element (16) will also move simultaneously because the wind catching element (16) is fitted to part (08) and when wind catching elements (16) moves outwards, the circumference will increase because of this the rpm of the turbine will be maintained as required even if wind velocity increases. More particularly how the motion of wind catching element is transferred to hollow shaft rotation can be understood as : The part 8 is a nut which has threading on the inner side. When the screw (part 10) will rotate, part 8 which is the nut will not rotate because it is connected to the wind catching elements (part 16) and because of this, part 8 will move back and forth (horizontally) parallel to the ground. Now the arm (part 22) and the screw (part 8) is one assembly and acts as a single component arm. Now one can understand when the wind catching element (part 16) will move back and forth (horizontally)inventor has to tell whether it is rotary movement conversion of wind catching element , it will transfer the rotating movement to the nut (part 8) and the nut (part 8) will transfer it to the screw (part 10) and the screw (part 10) will transient to the arm (part 22) and finally the arm (part 22) will transfer it to hollow shaft (part 14) because they are all connected to each other. The present invention provides a method of generation of wind energy by using a vertical axis wind turbine having a variable circumference of blades wherein said circumference is maintained according to the pre-programmed, calculating the wind velocity, required rpm and to maintain this required rpm, the circumference should be adjusted accordingly.

EXAMPLE 1

If the alternator requires two hundred rpm to produce energy at its full capacity, then this VAWT will be designed in such a way that at 50kmph of wind velocity, the turbine will run on 200rpm and as wind speed falls, anemometer will take readings and indicate the motor to rotate in such direction that the screw type arm will rotate and bring the wind catching elements towards the center decreasing the circumference or the diameter of the blades. Because of this, turbine speed will be maintained at 200rpm despite of falling wind speed.

Thus the present invention provides a vertical axis wind turbine which has advantages of producing maximum energy compared to other wind turbines because of its changing circumference/ diameter and maintaining required rpm at lesser wind speed and producing energy at its full capacity. Because of this consistency will be maintained in producing energy and more energy means that it will be more economically viable.

It will be clear that modifications can be made to the disclosed invention without departing from the scope of the invention. The invention is therefore not limited to the disclosed claims. While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the scope of the invention are desired to be protected.