Abstract:
A non linear torque altering transmission is used in combination with an input or output device having a pulsating torque cycle characteristic. The transmission has a gear train of cooperating gears that during each cycle produce a varying leverage effect. This varying leverage effect is matched to the input/output device to improve the performance thereof. This combination is beneficial with many devices including a reciprocating piston engine, an AC compressor and wind driven turbines.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application claims priority from U.S. provisional patent application Ser. No. 60/662,383 filed Mar. 17, 2005, the entirety of which is incorporated herein by reference. 
     
    
     FIELD OF INVENTION  
       [0002]     The present invention relates to improved performance of a device having a pulsing input or output such as combustion engines, AC generators, compressors and other cyclically varying devices.  
       BACKGROUND OF THE INVENTION  
       [0003]     Structures to enhance the performance of internal combustion engines continued to be proposed including my own designs as set forth in Canadian Patent 2,077,275, Canadian application 2,450,542 and PCT application PCT/CA2004/001989. These designs use a rotary design as opposed to a reciprocating piston engine, to alter the transfer of the combustion force of the engine to its output shaft. Rotary engines require significant changes to the accepted manufacturing process and have not been readily adopted.  
         [0004]     The present invention provides an intermediate solution that provides some of the advantages of my earlier structures for conventional cyclically varying input or output devices. This intermediate solution includes a SLT (Selective Leverage Technique) gear train that uses a well known leverage principle to improve the performance of engines, AC motors and generators, compressors etc.  
       SUMMARY OF THE INVENTION  
       [0005]     According to the present invention a non linear torque altering gear train is used in combination with a device having a pulsating torque cycle characteristic. The gear train comprises a gear train having a cyclic torque variation selected to cooperate with the pulsating torque characteristic of the device to improve the performance thereof by non linearly modifying during each cycle the net torque of the combination.  
         [0006]     According to an aspect of the invention the device is an input to the gear train.  
         [0007]     In a different aspect of the invention the gear train is an output of a piston type four stroke motor and said gear train increases the net torque output during the power stroke and decreases the net torque required during the combustion stroke. The motor may be a single cylinder or a multi-cylinder engine.  
         [0008]     In a preferred aspect of the invention the piston type engine is a two or four cylinder engine and preferably, the gear train is defined by 2 elliptical-like gears.  
         [0009]     In yet a further aspect of the invention the gears cooperate to provide a maximum increase in peak torque of at least 2.0.  
         [0010]     The device can also be a driven device and in this case the gear train modifies the input force to improve the output of the driven device. This has particular application with AC generators and piston type compressors.  
         [0011]     A further embodiment of the invention includes steam and wind turbines providing the input force for the gear train and a connected AC generator. The gear train is a varying speed cyclic transmission and the AC generator is driven at increased torque during part of its cycle to increase the power output. The gear train preferably includes two elliptical-like gears.  
         [0012]     In a further aspect of the invention the gear train is a varying speed cyclic transmission paired to cooperate with a cyclically varying torque requirement or torque output of the device.  
         [0013]     With the present invention, the gear train has a cyclically varying torque characteristic matched to a cyclically varying requirement or output of the device.  
         [0014]     The present invention is also directed to using a SLT gear train to cyclically vary torque characteristics to match a cyclically varying requirement or output of a device. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]     Preferred embodiments of the invention are shown in the drawings, wherein:  
         [0016]      FIG. 1  is a perspective view of the SLT gear train of two spur gears mounted with offset axis of rotation;  
         [0017]      FIG. 2  is a top view of the SLT gear train using two elliptical shape gears;  
         [0018]      FIG. 3  is a top view of the SLT gear train using two gears with three distinct gear segments;  
         [0019]      FIG. 4  is a top view of the SLT gear train using two gears having four distinct gear segments;  
         [0020]      FIG. 5  is a perspective view of the SLT gear train of  FIG. 1 ;  
         [0021]      FIGS. 6, 7 ,  8  and  9  are schematics of the SLT gear train used in combination with an output shaft of a piston type internal combustion engine;  
         [0022]      FIG. 10  shows the SLT gear train that includes additional gears to allow the same direction of rotation of the input shaft to the output shaft;  
         [0023]      FIG. 11  is a torque/degree of rotation graph; and  
         [0024]      FIG. 12  is a schematic showing the use of the SLT gear train attached to the output shaft of an AC motor. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]      FIGS. 1 through 4  show different SLT gear train arrangements where rotation of one of the gears at a constant input/output speed produces a cyclically varying at a speed of the other gear and cyclically varying torque characteristics. These SLT gear trains have particular application with a powered device having a cyclically varying characteristic or pulsating characteristic or with a driven device having a pulsating characteristic.  
         [0026]     The SLT gear train  10  of  FIG. 1  has two circular gears  11  and  12  secured with offset axis of rotations  13  and  14 . These gears are simple to make and are preferred for many of the application of the SLT gear train with a pulsating device.  
         [0027]     The SLT gear train  20  of  FIG. 2  has similar cyclically varying characteristics but uses elliptical-like gears  21  and  22  rotating about axes  23  and  24 . This SLT gear train and the gears of  FIG. 1  can be used with single or double piston engines or compressors to improve the output as will be discussed with respect to the later Figures.  
         [0028]     The SLT gear train  30  of  FIG. 3  has two gears  31  and  32  with each gear having three changing speed segments  33  located 120 degrees apart. This SLT gear train is useful with devices having a pulsing sequence every 120 degrees.  
         [0029]     The SLT gear train  40  of  FIG. 4  includes gears  41  and  42  with each gear having four gear segments  43 . This SLT gear train is useful with devices having a pulsing sequence every 90 degrees.  
         [0030]     Each of the SLT gear trains of  FIGS. 1 through 5  provides a changing mechanical advantage or “lever” during each cycle. This advantage is matched or paired with cyclically varying characteristics of a driven or a drive device.  
         [0031]      FIG. 5  is a sectional view of a SLT gear train  50  having gears  52  and  54 . Gear  52  is rotated by drive shaft  51  such as an output shaft of an engine. Gear  54  is driven by gear  52  and rotates the new output shaft  53 . The SLT gear train of  FIG. 5  is advantageous with a two cylinder engine. The gears are elliptical-like, rotating around focal point with parameters: A=distance between centers, a=ellipse axis, c=ellipse focal distance.  
         [0032]     FIGS.  6  to  9  show the SLT gear train  60  paired with a one cylinder assembly  61 , crankshaft  62 , primary gear  63 , secondary gear  64  and output shaft  65 . These figures will also be explained relative to the graph of  FIG. 11 .  
         [0033]     The cylinder assembly  61  of  FIG. 6  has the piston starting the combustion stroke after compression of working media. The force exerted on the piston is transmitted through the connecting rod and rotates the crankshaft  62 . During the next 180 degree shaft rotation, variable torque is produced as generally shown on  FIG. 11 ,  
         [0034]     Curve  111  indicates maximum torque being produced at about 90 degree shaft rotation. From  FIG. 6  it can be understood that, if engine shaft  62  with gear  63  rotates clockwise, the torque at shaft  64  is increased due to the multiplying or leverage affect produced by the gears  63  and  64 . The maximum leverage occurs at 90 degree engine shaft and gear  63  key position (assuming that ellipse bigger axis “a”  FIG. 5  is perpendicular to key axis) is vertical.  
         [0035]     The cyclically varying gear multiplier or leverage is varied from 1.2 to 2 (90 degree) and then back to 1.2; but depending on ellipse parameters, these numbers could vary. With 180 degree rotation of engine shaft  62 , secondary shaft  65  rotation is less than 180 degree, and for those particular parameters equal to 110 degrees. With analysis of curve  112   FIG. 11  shows that maximum torque is produced during maximum gears leverage and in this particular case average torque magnification is approximately 60%.  
         [0036]      FIG. 7  shows gears position after combustion and before the exhaust stroke. During exhaust rotation (inertia) of secondary shaft  5  is pushing gases out of cylinder with higher speed and torque, because gear ratio allows to reduce energy required for exhaust.  
         [0037]      FIG. 8  shows gears position after exhaust before suction. During suction the suction stroke the gear ratio is working as a disadvantage and in this example requires 60% more energy for suction.  
         [0038]      FIG. 9  shows gears position after suction. During compression inertia of shaft  5  continues to provide the necessary force for compression. The gear ratio is now favorable and 60% less energy for compression is required.  
         [0039]     FIGS.  6  to  9  provide an explanation with respect to a four stroke engine, however this advantage can also be used for two stroke engines.  
         [0040]     For two cylinder four stroke engines with gears as described in  FIGS. 1 and 5 , the average leverage is between 50 and 75%.  
         [0041]     It is important for efficiency of the present method to find point of engine maximum torque and key the leading gear of the SET gear train to provide the cyclically varying mechanical advantage.  
         [0042]     In some cases direction of rotation and alignment  5  of the SLT gear train output shaft with the original engine output shaft may be necessary or desired.  FIG. 10  shows one for this purpose. In this case engine shaft  101  coupled with coupling  102  to external/internal primary shaft  103  having special gear  104  connected to satellite shaft  106  having special gear  105  and regular gear  107  transmitting rotation to regular gear  108  and shaft  109  which is aligned with original engine shaft/crankshaft. This arrangement could be incorporated into the engine, into a stationary housing or into a clutch.  
         [0043]     In preliminary tests of a two cylinder engine using the present invention, the average torque increase is approximately 50% and with the same rpm (rotation per minute) allows 50% engine power increase. Similar or increased benefits may be realized for 4, 6 and 8 cylinder engines.  
         [0044]     For increased understanding the following specific examples are provided. With a four cylinder engine, combustion is performed every 180 degree (four stroke) and the configuration of gears pitch line as shown in  FIG. 2  is advantageous. In this case leading special gear keyway alignment should be around 55 degrees clockwise or counterclockwise depending of direction of rotation (for maximum gear ratio 2) and not 90 degrees as on  FIG. 6 . In case of six cylinder engines, a special gear is shown on  FIG. 3 , having three equal sections every 120 degrees. Keyway angle deviation in this case is around 35 degrees. In case of an eight cylinder engine special gear is shown on  FIG. 4 , having four equal sections every 90 degrees, with keyway angle deviation in this case should be around 27 degrees.  
         [0045]     In some conditions for six and eight cylinder engines it is more economical to have extra pair of regular gears placed before pair of special gears multiplying engine rotational speed (rpm) in such way that leading special gear  FIG. 2  makes 180 degree rotation for 120/90 degree of engine shaft rotation with regular gears ratio 1.5/2 accordingly. After special gears could be placed another pair of gears to reverse multiplication in case of requirement. For a single cylinder engine, the speed can be reduced by pair of regular gears with ratio 2, in combination with the SLT gear train of  FIG. 1 .  
         [0046]      FIG. 12  illustrates the desired selective cyclical amplification of a force to improve the performance of an AC motor. An average AC motor force Fav is shown relative to the modified output force  1204 . The output force created using the combination of the present invention is curve  1204  with average force (and corresponding torque) F* for a driven by AC motor device.  
         [0047]      FIG. 12  shows example of SLT effect when adding device having two special gears connected to output shaft of single phase AC motor. Special gear  1201  is connected to AC motor shaft in such way that it creates a maximum torque for driven device connected to special gear  1202  when it required,  FIG. 12  shows induction curve * and current curve I and force curve F as a result of a load to AC motor. Without SLT device  FIG. 12  shows average motor force Fav and  1204  is actual force curve created by SLT device with average force (and corresponding torque) F* for driven device. If driven device is pulsing energy device (for example piston compressor) positive effect will be even greater if this device is aligned properly.  
         [0048]     In case of AC generator, using SLT device, connected to its shaft, and driven by turbine or other source (engine, wind turbine and etc.) it will supply, if properly aligned, higher torque to rotor when required by load. Without load rotor will have maximum speed variation and with load increase this variation becomes negligent. Special gears  FIG. 2  are recommended.  
         [0049]     If the driven device is a pulsing driven device (for example a piston compressor) the positive effect will be even greater if this device is aligned properly. In case of an AC generator, using the SLT gear train connected to its shaft, and driven by turbine or other input source (engine, wind turbine and etc.) it will supply, if properly aligned, higher torque to the rotor when required by the load. Without load, the rotor will have maximum speed variation and with load the speed variation becomes negligent.  
         [0050]     The timed mechanical advantage of the present system has been particularly described with respect to modifying the output of a pulsating drive device but it is also useful altering the input to a driven device such as a piston compressor, an AC generator or other pulsating devices having changing torque characteristics.  
         [0051]     Although preferred embodiments of the invention have been described herein in detail it is understood that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.