Abstract:
A differential speed control apparatus is provided having an input shaft in connection with a transmission, a speed reducer, and a planetary gear unit acting in concert to generate a constant rotational output, which is transferred to an electrical generator. The apparatus controls and converts a varying input speed to a constant output speed through a feedback system to automatically adjust the transmission based upon rotational speed of the output shaft. This feedback system enables continuous adjustment of the transmission to produce a constant output where the input is variable.

Description:
RELATED APPLICATIONS 
     The present invention was first described in and claims the benefit of U.S. Provisional Application No. 61/790,740, filed 15 Mar. 2013, the entire disclosures of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a differential speed control that employs a feedback system in connection with an output shaft and a transmission to generate a constant output from a varying input. 
     BACKGROUND OF THE INVENTION 
     From the beginning of time, mankind has relied on various sources of energy to survive. These sources have included wood, coal, oil, wind-power, water-power, and nuclear energy to just name a few. As each form of energy was discovered, mankind continued on in the quest for the next, better form of energy. Some of these energy sources, such as wind-power and water-power, produce energy that is at different levels depending on the naturally occurring phenomenon. An example of this is a wind turbine, which obviously turns faster when the wind is blowing harder. However, this variable speed input results in a generator that turns at variable speed as well, thus producing voltage, current, and/or frequency levels that vary. This output power is then difficult or even impossible to use when powering conventional electrical items, as power spikes and sags result in equipment damage or failure. Accordingly, there exists a need for a means by which a constant rotational force can be provided to electrical generators regardless of the constant performance from a prime mover. The development of the apparatus fulfills this need. 
     The apparatus of the present invention controls and converts a varying input speed to a constant output speed through an electronic controller. It allows for driving an electrical generator at a constant speed to produce a stable output voltage. The input shaft of the apparatus is in connection with a transmission, a speed reducer, and a planetary gear unit acting in concert to generate a constant rotational output, which is transferred to the electrical generator. An encoder and speed control module are employed to create a feedback system to automatically adjust the transmission based upon rotational speed of the output shaft. This feedback system enables continuous adjustment of the transmission to produce a constant output where the input is variable. 
     Prior art in this field consist of power generator systems having engine throttles, transmission ratio controls, multiple shafts, and complex gearing systems. These prior art devices lack the utility of simplicity, effectiveness, and efficiency afforded by the present invention. Other prior art attempt to manipulate the input energy before being converted into work energy. It is, therefore, an objective of the present invention to provide a means to maintain a constant rotational output of a transmission being subjected to varying rotational inputs. It is a further objective of the present invention to continuously monitor and control the rotational output via a feedback system comprising the output shaft and planetary gearing of the transmission, regardless of the input. It is a further objective of the present invention to provide a differential speed control system that is simple, effective, and efficient. 
     SUMMARY OF THE INVENTION 
     The apparatus controls a speed, in revolutions per minute (RPM), of an electrical generator so that varying inputs to the generator can be used to produce a constant, stable output. An input shaft of the apparatus is used to transfer varying rotational energies from a rotary power source. The input shaft is in connection with a transmission, a speed reducer, and a planetary gear unit acting in concert to generate a constant rotational output, which is transferred to an electrical generator. A variator rod is provided with the apparatus to either increase or decrease an output shaft portion of the transmission, preferably by adjusting an angle of an internal swash plate portion of the transmission, thus increasing or decreasing the rotational speed of the electrical generator to which the output shaft is in connection with. 
     The shaft is equipped with a rotary encoder to communicate rotational speed to a speed control module, which is in communication with a positioning motor. The positioning motor manipulates the variator rod based upon inputs from the speed control module. The speed control module, the positioning motor, and the variator rod act in concert to provide a closed-loop control of the generator&#39;s speed. 
     Furthermore, the described features and advantages of the disclosure may be combined in various manners and embodiments as one skilled in the relevant art will recognize. The disclosure can be practiced without one (1) or more of the features and advantages described in a particular embodiment. 
     Further advantages of the present disclosure will become apparent from a consideration of the drawings and ensuing description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The advantages and features of the present disclosure will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which: 
         FIG. 1  is a block diagram of a differential speed control apparatus  10 , according to a preferred embodiment of the present invention. 
     
    
    
     DESCRIPTIVE KEY 
     
         
         
           
               10  differential speed control apparatus 
               15  platform 
               20  input shaft 
               30  transmission 
               40  reducer 
               50  planetary gear unit 
               60  encoder 
               70  speed control module 
               80  positioning motor 
               90  variator rod 
               100  tachometer 
               110  generator 
               112  wiring 
               115  output power 
               120  input power source 
           
         
       
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within  FIG. 1 . However, the invention is not limited to the described embodiment, and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items. 
     The present invention describes a differential speed control apparatus (herein described as the “apparatus”)  10 , which provides a means for controlling a speed, in RPM&#39;s, of an electrical generator  110  to produce output power  115  having a stable voltage. 
     Referring now to  FIG. 1 , a block diagram view of the apparatus  10 , according to the preferred embodiment of the present invention, is disclosed. The apparatus  10  includes an input shaft  20  which may be rotated via mechanical connection to various rotary power means such as a windmill, a water wheel, or the like. It is envisioned for the apparatus  10  to be sized and geared appropriately to enable a generator  110  to produce constant output power  115 . This output power  115  can then be utilized to supply electrical current to various items such as those used in a common household, an electric vehicle, or other similar device. It is also envisioned for the apparatus  10  to run continuously, based upon availability of the input power source  120 . 
     An embodiment of the apparatus  10  is illustrated here providing a transmission  30 , a speed reducer  40 , and a planetary gear unit  50 . The portions of the apparatus  10  are envisioned to be securely mounted to a base plate or platform  15  and designed to obtain a particular rotary speed (RPM) being required by the generator  110  in order to produce a particular voltage. The transmission  30  is preferably a hydrostatic unit which provides an externally adjustable speed variator rod  90 . The speed reducer  40  supplies the apparatus  10  with the necessary torque, and the planetary gear unit  50  supplies the apparatus  10  with needed speed. It is understood that the actual configurations and types of the speed reducer  40  and planetary gear unit  50  would be based upon space constraints and other mechanical factors, and as such should not be interpreted as a limiting factor of the apparatus  10 . 
     The apparatus  10  also comprises a rotary encoder  60 , which is envisioned to be a rotary shaft encoder  60 , and is installed upon a shaft portion between the planetary gear unit  50  and the generator  110 , where a tachometer is also placed  100 . Data from the encoder  60  is communicated to a speed control module  70  via wiring  112 , which in turn controls and powers a positioning motor  80  being mechanically connected to a variator rod portion  90  of the transmission  30 . The encoder  60  is envisioned to acquisition the revolutions per minute of the shaft portion and convert this to an analog signal, the frequency of which matches that of the revolutions per minute. This analog signal is transmitted, via the wiring, to the speed control module  70  to be processed and compared with a pre-set periodic cycle that is the preferred cycle for the generator  110 . The variator rod  90  acts to increase or decrease an output shaft portion of the transmission  30  and subsequently the rotational speed of the generator  110 . The variator rod  90  is envisioned to adjust an angle of an internal swash plate portion within the transmission  30  in a conventional manner. It is also envisioned that the positioning motor  80  be of a high torque type being capable of smooth clockwise and counterclockwise rotation, thereby providing bi-directional motioning of the variator rod  90 . Once the generator  110  reaches the set speed as determined by the speed control module  70 , the transmission  30  will maintain the constant output, thereby producing electricity having a consistent voltage. 
     The speed control module  70  receives data from the encoder  60  and causes the positioning motor  80  to adjust the variator rod  90 , thereby providing closed-loop control of the speed of the generator  110 . 
     It is envisioned that the gear-reduction function of the planetary gear unit  50  could be varied, or additional planetary gear units  50  could be added as required to increase and decrease the rotation speed of the generator  110  by a higher factor. 
     It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope. 
     The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the apparatus  10 , it would be configured as indicated in  FIG. 1 . 
     The method of installing and utilizing the apparatus  10  may be achieved by performing the following steps: acquiring the apparatus  10 ; utilizing the transmission  30  and a generator  110  being securely mounted to a base plate or platform  15 ; establishing mechanical communication between the output of the transmission  30  and the generator  110  via speed reducer  40  and a planetary gear unit  50  portions; enabling the encoder  60  to monitor the speed and provide a corresponding signal to the speed control module  70  via wiring  112 ; allowing the controller module to energize the positioning motor  80  to act upon the variator rod  90  causing the transmission  30  to speed up or down to maintain a constant output speed; enabling the generator  110  to rotate at a consistent speed (RPM) and produce electrical power having a consistent voltage; and, using the output power  115  produced by for use in powering various electrical devices as desired. 
     The foregoing descriptions of specific embodiments have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit to the precise forms disclosed and many modifications and variations are possible in light of the above teachings. The embodiments were chosen and described in order to best explain principles and practical application to enable others skilled in the art to best utilize the various embodiments with various modifications as are suited to the particular use contemplated.