Abstract:
A modular wind turbine has been developed that includes a turbine housing that contains a circular stabilization ring. The turbine also includes a central hub with multiple airfoil blades that are attached to the interior of the circular stabilization ring. A drive shaft extends from the central hub that turns an electric generator with multiple magnets and coils that generate electricity upon rotation of the of the drive shaft.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a modular micro wind turbine for generating electricity. More specifically, the present invention relates to a ducted micro wind turbine containing more than two power generating units. 
     BACKGROUND ART 
     Centralized power distribution can have major impact to communities when the distribution system is taken down either from natural or man-made disasters. Solar panel production can provide some amount of power if the distribution system goes down. However, clouds frequently block the collection of energy to allow solar panel energy production. Solar panels also stop power generation during the night time hours. 
     One potential solution is large commercial grade wind turbines that generate significant amounts of power. However, these large commercial grade generators must be located away from the consumers. Distribution and transmission systems are required to move the power from the large commercial generation facility to the consumers. Large commercial grade wind turbines cannot operate in high wind conditions due to the inertia generated by the large turbine blades. Consequently, a need exists for smaller micro wind turbines that can provide a localized, efficient source of electrical energy. 
     SUMMARY OF THE INVENTION 
     In some aspects, the invention relates to a modular wind turbine, comprising: a turbine housing that contains a circular stabilization ring; multiple airfoil blades with an external end of each blade attached to the interior of the circular stabilization ring; a central hub connected to the interior end of each blade, where the airfoil blades rotate around the central hub; a drive shaft that extends from the central hub such that it rotates as the central hub turns; an electric generator that is powered by the drive shaft, comprising multiple magnets circularly attached around drive shaft, and multiple magnetic coils arranged within the housing in close proximity to the magnets so that electricity is generated upon rotation of the magnets. 
     In other aspects, the invention relates to a bank of modular wind turbines, comprising: multiple squared shaped turbine housings that each contain a circular stabilization ring, where the turbine housings a connected together to form a bank of housings; multiple airfoil blades with an external end of each blade attached to the interior of the circular stabilization rings; a central hub connected to the interior end of each blade, where the airfoil blades rotate around the central hub; a drive shaft that extends from the central hub such that it rotates as the central hub turns; and an electric generator that is powered by the drive shaft, comprising multiple magnets circularly attached around drive shaft, and multiple magnetic coils arranged within the housing in close proximity to the magnets so that electricity is generated upon rotation of the magnets. 
     In other aspects, the invention relates to a bank of modular wind turbines, comprising: multiple hexagonally shaped turbine housings that each contain a circular stabilization ring, where the turbine housings a connected together to form a bank of housings; multiple airfoil blades with an external end of each blade attached to the interior of the circular stabilization rings; a central hub connected to the interior end of each blade, where the airfoil blades rotate around the central hub; a drive shaft that extends from the central hub such that it rotates as the central hub turns; and an electric generator that is powered by the drive shaft, comprising multiple magnets circularly attached around drive shaft, and multiple magnetic coils arranged within the housing in close proximity to the magnets so that electricity is generated upon rotation of the magnets. 
     Other aspects and advantages of the invention will be apparent from the following description and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       It should be noted that identical features in different drawings are shown with the same reference numeral. 
         FIG. 1  is an end view of the modular wind turbine generator and fan case in accordance with one embodiment of the present invention. 
         FIG. 2  is a cross-sectional view of  FIG. 1 . 
         FIG. 3  is a view of a main rotor used in the generator section without the magnets in accordance with one embodiment of the present invention. 
         FIG. 4  is a cross-sectional view of  FIG. 3 . 
         FIG. 5  is a view of a multi blade wind turbine fan that drives the direct displacement generator in accordance with one embodiment of the present invention. 
         FIG. 6  is a cross-sectional view of  FIG. 5 . 
         FIG. 7  is a cross-sectional view of a single wind turbine blade airfoil design in  FIG. 5  in accordance with one embodiment of the present invention. 
         FIG. 8  is an end view of the stator used to hold the spools of magnetic wire in accordance with one embodiment of the present invention. 
         FIG. 9  is a cross-sectional view of  FIG. 8 . 
         FIG. 10  is an exploded view of the locking mechanism holding the spools into the stator in accordance with one embodiment of the present invention. 
         FIG. 11  is an end view of the initial rotor without magnets for the generator in accordance with one embodiment of the present invention. 
         FIG. 12  is a cross-sectional view of  FIG. 11 . 
         FIG. 13  is an end view of the last rotor without magnets for the generator in accordance with one embodiment of the present invention. 
         FIG. 14  is a cross-sectional view of  FIG. 13 . 
         FIG. 15  is a view of a main drive shaft of the modular wind turbine fan and generator in accordance with one embodiment of the present invention. 
         FIG. 16  is an end view from the fan side of  FIG. 15 . 
         FIG. 17  is an end view from the non-fan side of  FIG. 15 . 
         FIG. 18  is a non-fan end cap holding the bearing and seal in accordance with one embodiment of the present invention. 
         FIG. 19  is a side view of  FIG. 18  showing the locking attachment and seal groove. 
         FIG. 20  is a back side view of  FIG. 18  showing the spanner wrench holes. 
         FIG. 21  is a cross-sectional view of  FIG. 18  showing internal design. 
         FIG. 22  is a fan end cap holding the bearings, seal and drive shaft in accordance with one embodiment of the present invention. 
         FIG. 23  is a side view of  FIG. 22  showing the locking attachment tab and the seal groove. 
         FIG. 24  is a back view of  FIG. 22  showing the spanner wrench holes. 
         FIG. 25  is a cross-sectional view of  FIG. 22 . 
         FIG. 26  is a view of a hexagonal end cap holding the Fan Turbine Case into the modular hexagonal housing in accordance with one embodiment of the present invention. 
         FIG. 27  is a side view of  FIG. 26 . 
         FIG. 28  is a cross-sectional view of  FIG. 26  showing the inlet design. 
         FIG. 29  is an end view of the spool which holds the magnetic accordance with one embodiment of the present invention. 
         FIG. 30  is a side view of  FIG. 29 . 
         FIG. 31  is a back end view of  FIG. 29 . 
         FIG. 32  is a square end cap holding the Fan Turbine Case into the modular square housing in accordance with one embodiment of the present invention. 
         FIG. 33  is a side view of  FIG. 32 . 
         FIG. 34  is a cross-sectional view of  FIG. 32  showing the inlet design. 
         FIG. 35  is a main rotor with the rare earth magnets assembled in accordance with one embodiment of the present invention. 
         FIG. 36  is a cross-sectional view of the main rotor in accordance with one embodiment of the present invention. 
         FIG. 37  is an end view of the stator assembly with the magnetic wire spools mounted in accordance with one embodiment of the present invention. 
         FIG. 38  is a cross-sectional view of  FIG. 37 . 
         FIG. 39  is a cross-sectional view of the assembly of the generator. 
         FIG. 40  is an exploded view of  FIG. 39  detailing the wire spools, rotors, stator and magnets. 
         FIG. 41  is a cross-section of the Micro Wind Turbine fan and generator assembly in accordance with one embodiment of the present invention. 
         FIG. 42  is a view of a hexagonal modular case in accordance with one embodiment of the present invention. 
         FIG. 43  is a cross-sectional view of  FIG. 42 . 
         FIG. 44  is a view of a square modular case in accordance with one embodiment of the present invention. 
         FIG. 45  is a cross-sectional view of  FIG. 44 . 
         FIG. 46  is a view of a modular linear case connector in accordance with one embodiment of the present invention. 
         FIG. 47  is a side view of  FIG. 46 . 
         FIG. 48  is a view of a stator with integral coils in accordance with one embodiment of the present invention. 
         FIG. 49  is a cross-sectional view of  FIG. 48 . 
         FIG. 50  is a cross-sectional view of the assembly of the generator with integrated coils in accordance with one embodiment of the present invention. 
         FIG. 51  is an exploded view of  FIG. 50 . 
         FIG. 52  is a view of a square modular micro wind turbine arrangement in accordance with one embodiment of the present invention. 
         FIG. 53  is a view of a hexagon modular micro wind turbine arrangement in accordance with one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention provides a modular small low cost wind turbine generator that affords substantially increased energy production with the ability to integrate into existing structures in the rural, suburban, urban and highly dense cities. The micro wind turbines can be easily connected to other micro wind turbines to form a larger generation panel similar to solar panels. These panels of wind turbines can be located at the edge of any building structure such as walls, fences, decks, roof tops, roof peaks or in a standalone system. 
     The ability to connect multiple modular wind turbines improves the overall capture of wind currents. Less wind current escapes the micro wind turbine design as compared to small to larger designs and improves the overall effectiveness of each adjacent micro wind turbine. An example is holding a hand into the wind has relative little resistance, however, holding a plywood panel against the same wind current will generally knock down the individual holding the panel in the wind. Multiple micro wind turbines enhance the power generation performance significantly. 
     The micro wind turbine fan is constructed to be sustainable in high wind currents due to the design of the wind turbine blades and housing. The blades attach to the outer housing eliminating the bending and fracture effects of individual blades during high wind currents. The blade design also works in low wind currents in the range of 2-4 mph due to the rotational twist and concave nature of the airfoil design. The housing surrounding the fan blades also increases the performance of the airfoils by not allowing wind current to escape off the tips of the turbine blades. The wind turbine blade airfoil is designed with a low pressure side which improves the performance of the turbine blades causing the blades to spin faster in the rotational axis overcoming the power generation system and the friction produced by the bearings. 
     The inlet housings for the micro wind turbine compacts the air increasing the velocity of the air and density of the air flowing through the micro wind turbine fan blades. This compression increases the overall performance of each micro wind turbine generator. 
     The modular design of the micro wind turbine allows multiple wind turbines to be connected either in a large grid pattern or in a chain of micro wind turbines behind one another or in combination with both grid pattern and a chain configuration. This design allows the micro wind turbines to be placed in and around any structure near the power consumption needs. 
     The micro wind turbine has multiple (more than two) power generators in some embodiments. Each power generator can produce substantial energy. Due to the design of the power generators and the permanent magnets, the design adds efficiencies in the power output. Maintaining close proximity of adjacent magnets adds to the power generated within each magnetic wire coil set increasing individual power generating unit output to increase the total power output. The micro wind turbine generating units may be installed in a sealed housing allowing for implementation in high humidity and severe weather conditions. 
     One embodiment of the generator core  77  ( FIG. 39 ) or  95  ( FIG. 50 ) is mounted in the generator case  3  ( FIG. 1 ). The turbine case housing  11  ( FIG. 2 ) is optionally mounted in a modular assembly case consisting of hexagonal modular case  90  ( FIG. 42 ) or square modular case  91  ( FIG. 44 ). The turbine case housing  11  ( FIG. 2 ) can be directly integrated into another shape case or structure. 
     One embodiment of the hexagonal modular case  90  ( FIG. 42 ) or the square modular case  91  ( FIG. 44 ) can be connected together using the dovetail  80  ( FIGS. 42 &amp; 44 ) mating with attached cases via the dovetail slot  85  ( FIGS. 42 &amp; 44 ) in order to form a larger array structure of micro wind turbines. 
     One embodiment of the hexagonal modular case  90  ( FIG. 42 ) or the square modular case  91  ( FIG. 44 ) can be connected in a linear chain using the modular linear case connector  92  ( FIG. 46 ) by attaching the modular cases using the modular case attachment tab  62  ( FIGS. 42 ,  44  and  46 ) in order to form a structure to collect more power from stronger wind current conditions. 
     One embodiment of the generator core  95  ( FIG. 50 ) is an assembly of main draft shaft  50 , end cap with shaft seal  58 , two ABEC bearings  74 , two snap rings  75 , rotor end assembly with drive slots  78 , one or more stator with integrated coils  94 , one or more main rotor assembly  72 , rotor end assembly with drive slots  79 , drive key  50  ( FIG. 39 ), and an end bearing cap with seal  51 . 
     One embodiment of the generator core  77  ( FIG. 39 ) is an assembly of main draft shaft  50 , end cap with shaft seal  58 , two ABEC bearings  74 , two snap rings  75 , rotor end assembly with drive slots  78 , one or more stator assemblies  73 , one or more main rotor assembly  72 , rotor end assembly with drive slots  79 , drive key  50 , and an end bearing cap with seal  51 . 
     One embodiment of the stator with integrated coils  94  ( FIG. 48 ) is the stator alignment slots  37 , the wiring slot  36 , and the magnetic wire coiled  96  integrated internally to the stator material. The number of magnetic wire coils  96  contained within stator follows the ratio of magnets to coils shown in the chart below for a three phase design: 
                                     Coils   Magnets   Coils/Phase                    3    4   1        6    8   2        9   12   3       12   16   4       15   20   5                    
One embodiment of the stator assembly  73  ( FIG. 37 ) is the stator  35  and the magnetic wire winding spool  69  and the magnetic wire. The ratio of magnetic wire winding spools to the number of magnets is shown in the above chart for a three phase design. One embodiment of the main rotor assembly  72  ( FIG. 35 ) is the main rotor  12  and the permanent magnets. The ratio of magnetic wire spools to the number of magnets is shown in the above chart for a three phase design.
 
     One embodiment of the modular square end cap  70  ( FIG. 32 ) is the four sided shape of the design, modular case attachment tabs  62 , the modular hub  64 , the wind turbine case face  65  and the air compression bore  63 . The air compression bore  63  increases the velocity of the air flowing into the micro wind turbine which increases the forces needed to turn the wind turbine fan and blades  24  ( FIG. 5 ). 
     One embodiment of the magnetic wire winding spool  69  ( FIG. 30 ) is the spool winding bore  69 , the spool winding tray  89 , the spool locking surface  67  and the spool winding orientation notch  68 . Magnetic wire is wound around the magnetic wire winding spool  69  and then inserted into the stator assembly  73  ( FIG. 37 ). The number if magnetic wires wound around the spool identify the amount of voltage derived from each of the spools. 
     One embodiment of the modular hexagon end cap  61  ( FIG. 26 ) is the six sided shape of the design, modular case attachment tabs  62 , the modular hub  64 , the wind turbine case face  65  and the air compression bore  63 . The air compression bore  63  increases the velocity of the air flowing into the micro wind turbine which increases the forces needed to turn the wind turbine fan and blades  24  ( FIG. 5 ). 
     One embodiment of the end cap with shaft seal  58  ( FIG. 24 ) is the main drive shaft bore  59 , the spanner wrench holes  55 , the locking attachment tab  52 , the seal groove  54  ( FIG. 25 ), the stator face  53 , the rotor clearance  57 , the ABEC bearing mount  56 , and the main drive shaft seal  60 . The end caps provide the necessary seals to allow the micro wind turbine to operate in humid/wet conditions. 
     One embodiment of the end bearing cap and seal  51  ( FIG. 18 ) is the spanner wrench holes  55 , the locking attachment tab  52 , the seal groove  54  ( FIG. 21 ), the stator face  53 , rotor clearance  57  and the ABEC bearing mount  56 . The end caps provide the necessary seals to allow the micro wind turbine to operate in humid/wet conditions. 
     One embodiment of the main drive shaft  50  ( FIG. 15 ) is the snap ring grooves  46 , the main drive keyway slot  47 , main drive shaft turbine blade mount  49  and the drive pin for the turbine blade fan  48 . 
     One embodiment of the rotor end with keys  45  ( FIG. 13 ) is the rotor drive key  13 , the rotor hub  14 , rotor bore  15 , master drive key slot  16  and the magnet pockets  17 . The ratio of magnetic wire winding spools to the number of magnets is shown in the chart above for a three phase design. 
     One embodiment of the rotor end with slots  44  ( FIG. 11 ) is the rotor bore  15 , master drive key slot  16 , magnet pockets  17  and the rotor drive slots. The ratio of magnetic wire winding spools to the number of magnets is shown in the chart above for a three phase design. 
     One embodiment of the stator  35  ( FIG. 8 ) is the wiring slot  36 , the stator alignment slot  37 , coil pocket  38 , stator bore  39  and the stator hub  40 . The ratio of coil pockets to the number of magnets is shown in the chart above for a three phase design. 
     One embodiment of the wind turbine fan with airfoil blades  24  ( FIG. 5 ) is the turbine blade hub  21 , turbine airfoil blades with rotational twist  22 , attachment pin  23 , nose cone  25 , main drive shaft hub  26  and the turbine blade stabilizer ring  20 . The turbine blade stabilizer ring  20  has several effects on the wind turbine fan: 1) during high wind current conditions the ends of the fan blades would normally deflect for which the stabilizer ring reduces the deflection and allows the wind turbine to operate in the higher wind conditions; 2) the stabilizer ring compresses the wind current through the wind turbine increasing the wind force applied to the turbine airfoil blades; 3) wind current normally leaving the ends of airfoils creates turbulence for which stabilizer ring eliminates and increases the performance of the airfoils. The nose cone  25  directs wind current around the turbine blade hub  21  and the generator core with power generators  77  ( FIG. 39 ). The turbine blade hub  21  covers the generator core  77  increasing the protection of the generator core  77  from the elements. 
     One embodiment of the turbine airfoil blades with rotational twist  22  ( FIG. 7 ) is the low pressure side of airfoil  30  which has the shape of the upper side of a wing and a high pressure side of airfoil  32  and the concave airfoil surface  31  collects the wind current to enable the rotation of the fan blades. As the turbine fan increases the rotational speed, the low pressure side of the airfoil  32  reduces the pressure allowing the turbine blades to rotate with increased velocity. The rotational twist enables the lower speed of the wind current at the turbine hub  21  with the higher speed of the wind at the turbine blade stabilizer ring  20 . 
     One embodiment of the main rotor  12  ( FIG. 3 ) is the rotor drive key  13 , the rotor hub  14 , rotor bore  15 , master drive key slot  16 , magnet pocket  17 , rotor drive slot  18  and the rotor magnet gap  19 . Combining magnets on both sides of the rotor reduces the functional space within the generator providing for more power generating units. The rotor magnet gap if reduced increases the overall efficiencies of the generating core by allowing adjacent magnets to increase the power to adjacent stator units. Increasing the gap reduces the effect of adjacent magnets to adjacent stator units. The rotor drive keys  13  drives adjacent rotors by inserting the key into the rotor drive slot  18  which relieves the stress on the single drive key  76 . 
     One embodiment of the turbine case housing  11  ( FIG. 2 ) is the generator case support  1 , the cowling  2 , generator case  3 , stator alignment key  4 , locking attachment key  5 , turbine blade shroud  6 , turbine case wire routing channel  7 , external wire routing channel  8 , internal write routing channel  9 , turbine case stop  10  and turbine case housing  11 . 
     An exemplary embodiment of the invention captures the energy of wind currents by utilizing multiple air foil blades in modular micro wind driven turbine that produces less than 1 kW of peak electrical power utilizing a series of permanent magnet direct drive generators that produces power that varies with wind speed. One embodiment of the modular micro wind turbines can be located adjacent to sides of buildings, building roofs, other vertical structures (fences), in line with wind generating currents or in a variable direction standalone structure. In one embodiment modular micro wind turbines are placed at a side of a building. En another embodiment modular micro wind turbines are placed along the top of a fence. In another embodiment modular micro wind turbines are placed at the edge or peak of a roof. One embodiment of the modular micro wind turbines can be integrated within a building structure to obscure viewing of the micro turbine. A modular micro wind turbine drives a series (three or more) of internal permanent magnet direct drive generators. The axis of rotation is horizontal to the wind current. The micro wind turbines can be installed in multiple directions to accept varying wind currents as changes in wind currents change over seasons and with weather conditions. The modular micro wind turbine operates within a range of low wind currents (2-4 mph) to extremely high wind currents (60+ mph). 
     Still other embodiments of the invention could be mounted on an aircraft or an automobile in order to provide localized power generation to onboard devices, etc. It is important to realize that other embodiments of the invention could be used as water driven turbines instead of wind. Such examples could be mounted on boats or similar structures where the turbines are exposed to fluid flow. 
     A micro wind turbine generator may be located in an urban community, attached to nearby structures such as a house, a deck, a fence, near the roof top or at the roof line to capture wind currents that are generated around and over normal urban structures. Micro wind turbines may be capable of being attached to other micro wind turbines similar to solar cells are attached to one another to create a solar panel. The micro wind turbine needed to be made modularized to be arranged in a pattern that would be acceptable in urban communities generally hidden from normal viewing. These micro wind turbines need to generate enough power to operate refrigerators, freezers, televisions, radios, provide backup power for home computers, charge cell phone batteries and operation of landline telephones. This type of system would not require commercial distribution and transmission lines but could be easily integrated within the consumer electrical systems. The micro wind turbines should be capable of operating in high and low wind conditions. The micro wind turbines should be easily maintained by the consumer and be inexpensive to install. 
     The micro wind turbine could be attached to commercial building structures to provide battery backup support systems for businesses, extending the life of their battery systems. In some cases the power could be extended for a duration that would allow the utility companies time to re-establish the distribution and transmission grid in the event of a power outage. 
     In other embodiments, a widely distributed power generation system could work in a fashion using the current distribution and transmission facilities in concert with micro wind turbines. Businesses and homes scattered throughout the country could be power generation units using the micro turbines. Each small power generation system would operate in a standalone environment and the excess power would be distributed to other consumers. If the individual power generation units did not supply enough energy then the system would consume power from the external power grid. This widely distributed system would be more secure than centralized power generation systems. When natural or man-made disasters occur, the widely distributed system allows the economy to continue to function normally. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed here. Accordingly, the scope of the invention should be limited only by the attached claims.