Abstract:
An apparatus uses mechanical means to allow low volume, intermittent air or water or other energy sources to provide electrical power through a power train connected to an electrical generator.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is related to commonly-owned U.S. Provisional Patent Application, Ser. No. 61/662,862 submitted 21 Jun. 2012 by Cahil C. Maloney, from which priority is hereby claimed, and which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The subject matter herein relates generally to apparatus and method for power generation, and more particularly to power generation using renewable energy sources such as low pressure compressed air and low volume water stream. 
     BACKGROUND OF THE INVENTION 
     Renewable energy sources that do not depend on photons from the sun or chemical processes utilize the mechanical power of moving masses. Among these, conventional hydroelectric power requires a large amount of water that is fast enough to turn the rotary blades of a turbine. Wind power requires strong wind to turn a wind turbine. Compressed air power requires a large amount of compressed air under high pressure, which when released, drives an air turbine that turns a generator. The foregoing are generally large industrial size machines that require large capital investment and are not adaptable for small size generators that supply power for one or a few households. 
     On the technical side, when a stream of water is small, or when the stream is intermittent, conventional hydroelectric power powered by hydro-turbines functions inefficiently or does not function at all. With regard to compressed air, when the flow of air is small and/or inconsistent, the conventional generators either do not work or work poorly. Therefore, there is a need for an apparatus and method to capture power sources, water, or compressed air that is small or inconsistent. The apparatus needs to be inexpensive and be able to supply power for one or a few households. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of a renewable energy power generating apparatus according to the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present disclosure provides methods and apparatus that are suitable for small scale power generation, capable of capturing and accumulating power from inconsistent or intermittent energy sources including water, wind, and/or compressed air. The power is accumulated and averaged by mechanical devices, and then efficiently converted to electricity. If needed, the electricity may be further accumulated in batteries and then discharged as needed. 
     In one embodiment of the present invention as shown in  FIG. 1 , a power generating apparatus  1  includes one or more drive units  3 ; an accelerating gear box unit  5  with an input  7  and an output  9 ; one or more coupling means  11  connecting the drive units  3  to the input of the gear box unit  5 ; and an electric generator  13  connected to the output  9  of the gear box unit  5 , wherein the drive unit  3  may be adapted to produce at an output speed of between one turn per minute and one turn per day. The electricity generated from the electric generator  13  may be fed into the input of an electrical unit  15 , which regulates the electricity, and output the electricity in a usable form. 
     In one aspect of the embodiment, the drive unit  3  includes a first drive arm  17  rigidly connected to an axel  19  at a first end  21  of the drive arm; and a compressed air driven power source  22  adapted to exert a force against a second end  23  of the drive arm  17 . The axel may be supported on the frame of the power generating apparatus  1  or otherwise mounted in a fixed axel bearing. As a result, the linear or nearly linear motion of the compressed air driven power source may be converted to angular motion at the axel. 
     The compressed air driven power source  22  may include an inflatable air bag  25  fitted inside a cylindrical hollow cylinder  27 . The air bag  25  may be adapted to move the second end  23  of the first drive arm when the air bag  25  is inflated, causing the drive arm to turn around the axel. The compressed air driven power source may also include a sealed air cylinder with piston. When compressed air is charged into the cylinder, the piston moves and pushes the end of the first drive arm. The compressed air power source may be connected to the second end  23  of the first drive arm via a rigid rod or a flexible cord depending on the configuration of the apparatus. 
     In another aspect of the embodiment, the drive unit  3  includes a second drive arm  29 . The first end  31  of the second drive arm  29  may be rigidly connected to the axel  19 , and the second end  33  of the second drive arm may be connected to a counter balance weight  35 . A weight load  37  may be connected to the second end  23  of the first drive arm via a cable  39  routed through one or more pulley wheels  41 ,  42 . The first drive arm  17  and the second drive arm  29  are about the same length. The weight load  37  may be about twice as heavy as the counter balance weight  35 . 
     When compressed air is charged into the compressed air driven power source  22 , the air bag  25  is inflated and raises the weight load  37 . The force pulling down on the second end  23  of the first drive arm is released. The counter balance weight  35  pulls down on the second end  33  of the second drive arm  29 , resulting in clockwise torque and rotary motion at the axel  19 , which may be accelerated through the accelerating gearbox unit, driving the electric generator  13 . 
     When compressed air is released from the air bag  25 , the weight load  37 , being heavier than the counter-balance weight  35 , pulls down the second end  23  of the first drive arm  17 , resulting in counter-clockwise torque and rotary motion at the axel, which may be accelerated through the accelerating gearbox unit  5 , driving the electric generator  13  to rotate in an opposite direction. 
     In some aspects of the embodiment, the compressed air for driving the air driven power source may be stored in a compressed air storage device. The compressed air may be produced by a wind-driven air compressor, an electric air compressor, or may be taken from some industrial waste compressed air source. 
     In another aspect of the embodiment, the drive unit  3  includes one or more micro-dam buoyancy engines (not shown), each including a water container and a floater movably placed inside the water container, the floater being connected to the coupling means. When water is charged into the container, the water raises the floater up by buoyancy force. When water is discharged from the container, the floater drops down with the water level. The up and down motion of the floater may be converted to rotary motion by drive arms, or cord and pulley wheel similar to the configuration described previously herein with air driven power sources. 
     With one air driven or water driven drive unit  3 , the output of the drive unit  3  may not be constant. The output changes directions, and the power level may be uneven. As a result, energy may be wasted because the gear boxes and the electric generator  13  need to change spin directions in every cycle. The power capacity of the gear box, electric generator  13 , and electric circuits are under-utilized because they need to accommodate the peak power, but the system does not run at peak power. Rather, the power level may be cyclically up and down. 
     To overcome these deficiencies, the power generating apparatus  1  may include more than one drive units  3 , each of which may be connected to a coupling means  9 . In some aspects of the embodiment, the coupling means  9  includes one or more overrunning clutches (not shown), allowing the gearbox and the electric generator  13  to turn at one direction only, and also allowing more than one drive units  3  to work harmoniously in the same system. 
     In some other aspects of the embodiment, the power generating apparatus  1  includes more than one drive units  3 , wherein the coupling means  9  includes a crankshaft (not shown), each of the drive units  3  being connected to a throw of the crankshaft, converting the reciprocating motion of the drive units  3  to rotating motion of the crankshaft. For example, the power generating apparatus  1  may include six drive units  3  working sequentially. They are able to produce a continuous and relatively smoother rotational output in a working principle similar to a 6-cylinder internal combustion engine. 
     In another aspect, the accelerator gear box unit  5  may include one or more pulley wheels and belts. The accelerator gear box unit  5  may also include more than one chain rings and chains. 
     The accelerator gear box unit  5  may include one or more fixed-ratio linear helical gearboxes connected in series. The accelerator gear box unit  5  may also include a combination of pulley wheels, belts, chain rings, chains, and helical gearboxes. 
     In yet another aspect, the electrical unit  15  of the power generating apparatus  1  may include a power conditioner  43 , an input of the power conditioner being connected to an output of the electric generator  13 , and an output of the power conditioner being connected to a battery device  45 , the power conditioner being adapted to charge the battery device. 
     In a further aspect, the power generating apparatus  1  may include an inverter  47 , an input of the inverter being connected to an output terminal of the battery device  45 , and power output of the inverter  47  being provided for household electric use or for being sent to the electric grid. 
     The invention may be further understood by description of a exemplary implementation. A power generating apparatus  1  has a fixed frame (not shown). The drive unit  3  includes an axel  19  supported on a axel bearing fixed on the frame. The axel is connected to a first drive arm  17  and a second drive arm  29 , each of which may be about seven feet long and of a rigid material, for example a steel beam. The first drive arm  17  is connected to a weight load  37  through a steel cord  39  routed via a first pulley wheel  41  fixed on the floor and a second pulley wheel  42  at the top of the frame. A weight load  37  of about 600 pounds is connected at the end of the steel cord  39 . The weight load  37  is placed at the top of a compressed air driven power source  28 . A counter balance weight  35  of about 300 pounds is connected to the end  33  of the second drive arm  29 . 
     The compressed air driven power source  28  includes a vertical hollow cylinder  27  (about 8-foot high and 1.5-foot in diameter) and an inflatable airbag  25  placed inside the cylinder. At a resting state, the air bag  25  is deflated, and the weight load  37  is hung low inside the cylinder  27 . When the air bag  25  is inflated by a compressed air source, the air bag  25  produces 600 pounds of force to raise the weight load  37 . The counter balance weight  35  is in full force to pull the second end  33  of the second drive arm  29  down, producing 300 lb×7 ft=2,100 lb-ft of torque. As the air bag  25  is fully inflated, the weigh load  37  is raised to the top of the cylinder  27 , and the drive arms  17 ,  23  have been turned a certain angle in one direction. When the air bag  25  is deflated, the weight load  37  drops down with a 600-pound force pulling down the second end  23  of the first drive arm  17 . Because of the 300 lb counter balance weight  35  on the second drive arm  29  cancelling out 300 lb of the force, the net torque is (600−300) lb×7 ft=2,100 lb-ft, but at an opposite direction from the first half cycle. As the air bag  25  inflates and deflates in cycles, the drive arms are pulled up and down, turning the axel back and force. 
     In this exemplary, because there is only one drive unit  3 , the connecting means  9  does not include an overrunning clutch or crankshaft. The connecting means  9  is a fixed connecting plate connecting the axel of the drive arms to the input of the accelerating gearbox unit. The accelerator gearbox unit  5  includes a 26:1 linear gearbox  49 , a 50:1 linear gearbox  51 , and a 4:1 pulley wheel (not shown) combination connected in series. The entire accelerator gearbox unit  5  thus gives acceleration of 26×50×4=5,200 times. If the drive unit  3  produces a rotational speed of one rotation every minute, the electric generator  13  rotates at l×5,200=5,200 rpm. 
     The power of the system is calculated as follows. The airbag is inflated and deflated in one-minute cycles. The weight load is raised 7 feet in each cycle. The work is 600 lb×7 feet×4.45 Newton/lb×0.305 m/ft=5,698 Joules. Power=5,698 J/60 seconds=95 watts average. 
     In this exemplary system, a 12-volt permanent-magnet DC electric generator  13  was used, and the electric power produced was measured to reach 13 volts. A light bulb was connected to the electric output, and the light bulb was brightly lit when the power generating device was operating. 
     Persons of ordinary skill in the art will realize that the foregoing description is illustrative only and not in any way limiting. Other modifications and improvements will readily suggest themselves to such skilled persons having the benefit of this disclosure. 
     While embodiments and applications of this disclosure have been shown and described, it would be apparent to those skilled in the art that many more modifications and improvements than mentioned above are possible without departing from the inventive concepts herein. The disclosure, therefore, is not to be restricted except in the spirit of the appended claims.