Abstract:
A wind turbine for generating electricity has been developed. The turbine includes a housing for securement to a support. A wheel is mounted within the housing and is rotatable about a horizontal axis. The wheel has an axle assembly and a number of blade assemblies affixed thereto. Each of the blade assemblies has a frame with a spaced-apart pair of uprights and a crosspiece connecting the uprights. Each of the blade assemblies also having a pair of movable blades positioned within the frame with each of the blades being hingedly fastened to a respective one of the uprights. A brake actuator assembly is associated with each of the blades for relieving pressure imparted by strong winds on the blades. A brake operator assembly, disposed principally within said axle assembly, synchronizes the movement of the blades. An electrical current generator is connected to the wheel so as to be powered thereby.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to fluid reaction surfaces and, more particularly to sustained ancillary movement of rotary working members, e.g., cyclic feathering, etc. 
       BACKGROUND OF THE INVENTION 
       [0002]    A wind turbine is a device that utilizes the wind to power a machine. If the turbine is connected directly to the machine, such as a pump or a millstone, the turbine is usually referred to as a windmill. If the turbine is connected to a generator which, in turn, supplies a machine with electrical power the turbine is often referred to as a wind generator. 
         [0003]    The most common wind turbine is one that rotates about a horizontal axis. Typical turbines of this type have a rotor shaft and an electrical generator positioned at the top of a tower and pointed into the wind. Small turbines are pointed by a wind vane whereas larger turbines generally use a wind sensor coupled with a motor. 
         [0004]    The speed at which a wind turbine rotates must be controlled. Most importantly, speed control permits the aerodynamic efficiency of the turbine to be optomized for use in light winds. Also, speed control keeps a generator within its torque limits. Of equal importance, speed control allows a wind turbine to be slowed in high winds to prevent it from exceeding its own structural limits and those of its supporting tower. Finally, limiting the rotational speed of a turbine reduces the noise that it emits. 
         [0005]    Speed control over a wind turbine is normally exerted by aerodynamic stalling and furling as well as electrical and mechanical braking. Stalling and furling, the preferred methods of slowing wind turbines, work by swiveling the turbine&#39;s blades so that either a flat side or an edge of the blades face into the wind. Electrical braking, however, requires the dumping of energy from a generator into a resistor bank, converting the kinetic energy of the turbine&#39;s rotation into heat and causing the turbine to slow down. Mechanical, drum, or disk brakes are often used to hold the turbine motionless for repair. Mechanical brakes are usually applied only after blade furling and electromagnetic braking have reduced turbine speed since mechanical brakes would wear quickly under typical loads. One major problem in designing wind turbines is getting them to slow quickly enough should a gust of wind cause sudden acceleration to unacceptable rotational speeds. 
       SUMMARY OF THE INVENTION 
       [0006]    In view of the problems associated with the known apparatus employed to control the speed of wind turbines, it is a principal object of the invention to provide a wind turbine whose speed is easily and automatically controlled. In the event of strong gusts, my wind turbine automatically slows down by feathering its blades in a synchronized manner thereby avoiding potentially damaging, over-speed conditions. 
         [0007]    It is an object of the invention to provide improved features and arrangements thereof in a wind turbine for the purpose described which is simple to construction, inexpensive to make, and dependable to use. 
         [0008]    Briefly, my wind turbine achieves its intended object by featuring a housing for securement to an above-ground support. A wheel is mounted within the housing and is rotatable about a horizontal axis. The wheel has an axle assembly and a number of blade assemblies affixed thereto. Each of the blade assemblies has a frame with a spaced-apart pair of uprights and a crosspiece connecting the uprights. Each of the blade assemblies also having a pair of movable blades positioned within the frame with each of the blades being hingedly fastened to a respective one of the uprights. A brake actuator assembly is associated with each of the blades for relieving pressure imparted by strong winds on the blades by allowing the blades to move on hinges. A brake operator assembly, disposed principally within said axle assembly, synchronizes the movement of the blades. An electrical current generator is connected to the wheel so as to be powered thereby. 
         [0009]    The foregoing and other objects, features, and advantages of my wind turbine will become apparent upon reviewing the following description of the turbine shown in the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    My wind turbine is described with reference to the accompanying drawings, in which: 
           [0011]      FIG. 1  is a perspective view of my wind turbine. 
           [0012]      FIG. 2  is a top view of the wind turbine of  FIG. 1 . 
           [0013]      FIG. 3  is a rear view of the wind turbine. 
           [0014]      FIG. 4  is a schematic view showing the relative positions of  FIGS. 4A and 4B   
           [0015]      FIG. 4A  is a top view of the right half of the drive shaft of the wind turbine with portions broken away to reveal details of the turbine blade feathering mechanism. 
           [0016]      FIG. 4B  is a top view of the left half of the drive shaft of the wind turbine with portions broken away to reveal details of the turbine blade feathering mechanism. 
           [0017]      FIG. 5  is an exploded, cross-sectional view of a gearbox that synchronizes the movement of the turbine blades on one side of the wind turbine. 
           [0018]      FIG. 6  is a cross-sectional view of a blade actuator that permits the feathering of turbine blades in response to strong winds. 
           [0019]      FIG. 7  is a side view of the wind turbine with portions broken away to reveal the turbine blades feathered in response to strong winds. 
       
    
    
       [0020]    The reference characters denote features consistently throughout the drawings. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    Referring now to the FIGS., my new, wind turbine is shown generally at  10 . Turbine  10  includes a housing  12  secured atop a support  14 . A wheel  16 , mounted within housing  12 , rotates about a horizontal axis when struck by passing winds W. Wheel  16  is connected to, and drives, an electrical current generator  18  positioned within housing  12 . To prevent wheel  16  from turning too fast, wheel  16  is outfitted with a number of brake actuator assemblies  20  that automatically feathers the paired blades  22  of each blade assembly  24  when such are struck by winds W that are too strong. 
         [0022]    Housing  12  includes a rectangular bottom wall  26  to the opposite sides of which a pair of side walls  28  is connected and extends upwardly. The front ends of side walls  28  slope upwardly and rearwardly from their junctions with bottom wall  26 . A front wall  30  is connected to front ends of both bottom wall  26  and side walls  28 . As shown, side walls  28  support front wall  30  so that it slopes upwardly and rearwardly at a shallow angle. The rear end of each of side walls  28  is provided with an upward extension  32  that serves as a rudder in winds W. 
         [0023]    Bottom wall  26  is connected by a swivel bearing  34  to the top of support  14 , a hollow post, that supports wind turbine  10  above the ground. Swivel bearing  34  is positioned midway between side walls  28  to achieve good side-to-side balance of turbine  10 . Additionally, swivel bearing  34  is positioned close enough to the front of housing  12  so that winds W will tend to swing extensions  32  downwind and cause front wall  30  to face directly into winds W. 
         [0024]    Swivel bearing  34  has an opening  36  in its center that permits a pair of electrical leads  38 , discussed below, to extend from generator  18  into support  14  and, then, to the ground in an enclosed manner. If desired, a swiveling electrical connector, similar to the alternator provided in an automobile, can be provided to leads  38  to prevent them from tangling as wind turbine  10  pivots on swivel bearing  34  in response to winds W. 
         [0025]    Wheel  16  is put together from several groups of working parts or assemblies. An axle assembly  40  attaches wheel  16  to housing  12  and permits wheel  16  to turn. A number of blade assemblies  24  radiate outwardly from axle assembly  40  to catch winds W. Each blade assembly  24  carries a pair of brake actuator assemblies  20  that automatically opens the associated blade assembly  24  to permit the passage of winds W when the speed of winds W is excessive. The brake actuator assemblies  20  are interconnected so as to work in unison by a brake operator assembly  42  mounted within axle assembly  40 . 
         [0026]    Axle assembly  40  includes a hollow body  44  whose opposed ends are sealed by hub caps  46 . Hollow body  44  comprises a tube  48  having a peripheral flange  50  surrounding each of its opposed, open ends. Each flange  50  is provided with a number of spaced-apart holes  52  sized for the passage of threaded fasteners  54  that connect a hub cap  46  to one end of tube  48 . Each hub cap  46  comprises a disk  56  with a number of holes  58  also sized to receive threaded fasteners  54 . Holes  58  are spaced around the periphery of disk  56  for registration with holes  52  in a flange  50 . A spindle  60  is affixed to, and extends outwardly from, the center of each disk  56 . Spindles  60  are adapted for positioning, and rotating, in journal bearings  62  affixed to side walls  28 . 
         [0027]    Four blade assemblies  24  are affixed to, and carried for rotation within, housing  12  by axle assembly  40 . Each blade assembly  24  includes a rectangular, blade flame  64  that carries a pair of movable blades  22  within its confines. A blade frame  64  has a pair of uprights  66  that at affixed at their inner ends to each of the opposite ends of tube  48 . Uprights  66  radiate outwardly from tube  48  and terminate at outer ends remote from tube  48 . The outer ends of uprights  66  are connected together by a crosspiece  68 . The crosspieces  68  are shown in the FIGS. to be about twice as long as uprights  66 , but can have any suitable dimensions. 
         [0028]    Each of blades  22  is formed of lightweight, yet durable, plastic or other suitable material. As shown, each blade  22  is rectangular in outline and is dimensioned to fill about one-half of the area bounded by frame  64 . The outside edge of each blade  22  is connected by a pair of hinges  70  to an adjacent upright  66  such that the blade  22  can “feather” or pivot on the upright  66 . (Together, a pair of blades  22  will swing open like barn doors when subjected to high winds W.) The inside edge of each blade  22  is positioned closely adjacent the inside edge of the adjacent blade  22  of a pair and roughly bisects its associated frame  64 . The top edge of each blade  22  is positioned close to a crosspiece  68  and the bottom edge of each blade  22  falls close to tube  48 . A small, rectangular window  72  is provided in each blade  22  proximate the bottom edge thereof. 
         [0029]    Each blade  22  is moved with a blade actuator assembly  20  that allows it to pivot downwind to relieve the pressure imparted by strong winds W and slow the turning of wheel  16 . Each actuator assembly  20  has a blade actuator  74  connected to an anchor bracket  76 . Each blade actuator  74  is carried by a blade  22  and each anchor bracket  76  is affixed to one of flanges  50 . 
         [0030]    Blade actuator  74  has a hollow body  78  from which an actuator arm  80  is urged outwardly by a compressed, coiled spring  82 . Body  78  is a tube  84  whose opposite ends are closed by caps  86  and  88  with cap  86  being provided with an outlet opening  90  at its center. A pair of pivot pins  92  is affixed to the middle of tube  84  and projects upwardly and downwardly therefrom. During the assembly of wind turbine  10 , pins  92  are set for rotation in close fitting sockets  94  located above and below window  72  in each of blades  22 . Actuator arm  80  has a rod  96  that slidably extends through opening  90 . A ring  98  is affixed to the outer end of rod  96  outside of body  78 . A biasing plate  100  is affixed to the inner end of rod  96  and is sized to slide within tube  84 . Spring  82  is disposed between biasing plate  100  and cap  98  to normally keep rod  96  extended from body  78 . 
         [0031]    The resiliency of springs  82  is important to the operation of wind turbine  10 . If spring  82  is highly resilient, blades  22  will be permitted to pivot in winds W of low speeds thereby wheel  16  to low speed operation. If spring  82  is relatively stiff, blades  22  will pivot only in strong winds W and wheel  16  will rotate at great rotational speeds. 
         [0032]    It is believed that springs  82  can be supplemented or replaced by other things. For example, pneumatic devices are well known in the shock absorber art for dampening the movement of springs such as the one shown at  82 . Pneumatic chambers also serve as substitutes for springs in some products. Similarly, resilient rubber and foam materials are excellent spring equivalents. All can be deployed in a blade actuator  74  to permit movement of actuator arm  80  in response to a force generated by winds W and, then, return arm  80  to its starting position when the force is gone. 
         [0033]    Four anchor brackets  76  are affixed to the inner surface of each flange  50 . Each of brackets  76  is generally triangular in shape and is provided with a hole  102  in its free corner remote from flange  50 . A pin or link  104  is passed through hole  102  and ring  98  to pivotally connect actuator arm  80  to axle assembly  40 . 
         [0034]    Brake operator assembly  42  has a pair of gear boxes  106  affixed within the opposite ends of tube  48 . A number of levers  108  radiate from each gear box  106  and engage the bottom edge of adjacent blades  22 . Gear boxes  106  are connected for synchronous operation by a connector shaft  110 . 
         [0035]    Each gear box  106  has a cover  112  including a cylinder  114  whose opposite ends are closed by plugs  116  and  118 . Cylinder  114  has four, radial openings  120  oriented 90° apart within which bushings  122  are set. A number of threaded bores  124  are provided in each end of cylinder  114  for receiving threaded fasteners  126  that releasably join plugs  116  and  118  to cylinder  114 . 
         [0036]    Plug  116  is circular in outline and is provided with a number of bores  128  around its periphery for the registration with bores  124  and the passage of fasteners  126 . Plug  116  has a central opening  130  with an enlarged, countersunk portion  132  at its inner side. Countersunk portion  132  is sized to receive both a weather-resistant seal  134  and a bushing  136 . 
         [0037]    Plug  118  is circular and is provided with a number of bores  138  around its periphery for registration with bores  124  and the passage of fasteners  126 . Additional, threaded bores  138  are provided in plug  118  for receiving threaded fasteners  140  that attach a gear box  106  to a disk  56 . Plug  118  has a central opening  142  that is sized to receive a bushing  144 . 
         [0038]    An actuator rod  146  extends through the center of each gear box  106 . Actuator rod  146  has a large-diameter, load-bearing portion  148  and a smaller-diameter, driving portion  150  affixed to, and extending from, one end of load-bearing portion  148 . One end of load-bearing portion  148  is snugly, yet rotatably, fitted within bushing  136 . The other end of load-bearing portion  148  is snugly, yet rotatably, fitted within bushing  144 . The inner end of driving portion  150  is affixed to load bearing portion  148  and is rotatably fitted within seal  134 . The outer end of driving portion  150  is rotatably fitted within central opening  130  and projects outwardly therefrom. The outer end of driving portion  150  has a grooved or splined surface  152  for engagement with one end of connector shaft  110 . 
         [0039]    Affixed to load-bearing portion  148  is a bevel gear  154 . The pitch surface shape and pitch angle of bevel gear  154  are a matter of design choice. However, bevel gear  154  has a preferred pitch angle of less than 90° and is, therefore, cone-shaped. This type of bevel gear has gear teeth  156  that teeth point outward. 
         [0040]    One of four, actuator pins  158  is snugly, yet ratatably, fitted within each of bushings  122 . Each actuator pin  158  has a grooved or splined surface  160  at its outer end for engagement with one of levers  108 . Also, each actuator pin  158  carries a miter gear  162  at its inner end for engagement with bevel gear  154 . Between its opposite ends, each actuator pin  158  carries a weatherproof seal  164 . 
         [0041]    Miter gears  162  are affixed to actuator pins  158  so as to rotate therewith. Miter gears  162  all have equal numbers of gear teeth  166 , that number being smaller than the number of gear teeth  156  and being a matter of design choice. The pitch surface shape and pitch angle of miter gears  162  correspond with that of bevel gear  154 . Teeth  166  mate with teeth  156  such that gears  162  and  154  rotate together on axes oriented at right angles to one another. 
         [0042]    Each of levers  108  includes a socket portion  168  for engagement with an actuator pin  158  and a bracket portion  170  for engagement with a blade  22 . Socket portion  168  is a tube sized to snugly receive an actuator pin  158 . The inner surface  172  of the tube is grooved or splined to grip the splined surface  160  of an actuator pin  158  received therein. Bracket portion  170  is U-shaped in cross section, having a cross member  174  and a pair of upright members  176  that are affixed to, and project outwardly from the opposite sides of cross member  174 . Upright members  176  are spaced widely enough apart to snugly receive the bottom edge of a blade  22  therebetween. 
         [0043]    Connector shaft  110  is a hollow pipe that extends through tube  48  to connect gear boxes  106  together. Connector shaft  110  has openings  178  at its opposite ends for receiving the driving portions  150  extending from gear boxes  106 . Openings  178  are grooved or splined around their peripheries so that rotational movement of actuator rods  146  is imparted to connector shaft  110  and vise versa. 
         [0044]    A power coupling  180  transmits kinetic energy from the rotating wheel  16  to the electrical generator  18 . Coupling  180  comprises a bevel gear  182  affixed to the outer end of one of spindles  60  so as to turn with the spindle  60 . A power transmission shaft  184 , suitably supported at an incline for rotation on the exterior of a side wall  28 , carries a miter gear  186  at its upper end that mates with bevel gear  182 . The shaft  184  carries another miter gear  188  at its lower end that mates with a bevel gear  190  carried on the outer end of a drive shaft  192  extending through side wall  28  from generator  18 . Thus, through gears  182 ,  186 ,  188  and  190 , the rotational movement of a spindle  60  is carried to drive shaft  192  causing generator  18  to produce an electrical current. 
         [0045]    The exact type of power coupling utilized with wind turbine  10  is not critical to the operation of wind turbine  10 . In this regard, it is believed that at least two other types of couplings can be used with equal facility. For example, a belt and pulley arrangement can be used instead of a gear drive. Additionally, a hydraulic pump can be used to circulate a pressurized liquid to perform work. A suitable pumping arrangement is described in a recently published patent application filed by me. 
         [0046]    The configuration of housing  12  and wheel  16  ensures that winds W only contact blade assemblies  24  extending upwardly from housing  12 , above side walls  28  and front wall  30  at a given point in time. Front wall  30  directs winds W upwardly so that they cannot contact blade assemblies  24  positioned between side walls  28  and reduce the angular momentum of wheel  16 . 
         [0047]    Wind turbine  10  operates automatically after its set up in a location where winds W blow with a sufficient consistency and velocity. With winds W blowing, extensions  32  serve to orient front wall  30  so that it faces directly into winds W. Winds W pass over front wall  30  and strike the blade assemblies  24  projecting above front wall  30 , thus rotating wheel  16  and driving generator  18  so as to produce an electrical current. The current made by generator  18  can be harnessed by remote electrical devices to do useful work. 
         [0048]    Should winds W have a velocity that is predetermined by an operator to be excessive or harmful to wind turbine  10 , springs  82  associated with the pair(s) of blades  22  receiving the most pressure from winds W will compress. The continued compression of these springs  82  will result in the pivoting movement of blades  22  on hinges  70 . The pivoting movement of the wind-blown blades  22  is, then, transmitted through levers  108  into the paired gearboxes  106 . Since all of blades  22  are connected together through gearboxes  106  and connector shaft  110 , the blades  22  not directly encountering winds W at a particular moment will pivot the same amount as windblown blades  22 . With the movement of all blades  22  being synchronized, wheel  16  remains balanced and vibration free as it rotates. 
         [0049]    As the velocity of winds W decrease, springs  82  drive actuator arms  80  to their fullest extents from hollow bodies  78 . In this state, the paired blades  22  of each blade assembly  24  are oriented in a coplanar configuration. Winds W striking blade assemblies  24  do so with optimum efficiency. In the event of a sudden surge in the velocity of winds W, however, brake actuator assemblies  20  instantaneously respond by feathering blades  22  to reduce their surface area exposed to winds Win the way that a clipper ship captain might take down some sails in a gale. Thus, wind turbine  10  is automatic in its operation and failsafe. 
         [0000]    Actuators bodies can be pneumatic rubber, have shock dampening ets. 
         [0050]    While wind turbine  10  has been described with a high degree of particularity, it will be appreciated by those skilled in the field that modifications can be made to it. For example, side walls  28  can be reinforced with the addition of braces to support a wheel of practically any size. Also, supplemental brakes of disk-, drum-, or caliper-type can be added to spindles  60  to lock wheel  16  in place for repairs or to further limit the speed of wheel  16  in response to hurricane-force winds W. Of course, the number and angular orientation of blade assemblies  24  on axle assembly  40  can be varied to increase or decrease the efficiency at which turbine  10  harnesses winds W. Therefore, it is to be understood that the present invention is not limited merely to wind turbine  10  described above, but encompasses any and all wind turbines within the scope of the following claims.