The present invention relates to internal combustion engine structures and, more particularly, pertains to an oscillating lever arm engine for generating rotation torque through the oscillating movement of lever arms.
The use of many different types of internal combustion engine structures is known in the prior art. More specifically, internal combustion engine structures to convert rotary to reciprocating motion heretofore devised and utilized are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements.
Known prior art internal combustion engine structures include those disclosed in U.S. Pat. No. 5,255,572; U.S. Pat. No. 5,113,808; U.S. Pat. No. 5,067,456; U.S. Pat. No. 5,060,609; and U.S. Pat. No. 4,352,343.
While these devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not disclose an oscillating lever arm engine for generating rotational torque through the oscillating movement of a lever arm which includes an elongated cylinder having a pair of pistons oppositely disposed within the cylinder, coupled together by a connecting rod with at least one lever arm pivotally mounted to the connecting rod between the pistons and also pivotally mounted at a medial portion thereof the exterior cylinder, wherein oscillating of the lever arm in response to the piston movement is translated into rotational movement of an adjacent flywheel.
Furthermore, the prior examples of oscillating piston devices, including pumps and compressors, do not take advantage of the possibilities for applying their advantages to two-cycle engines where there is a need to remove oil contamination presently used in two-cycle fuels. Additionally, it has gone completely unappreciated the possibilities for utilizing the advantages of an oscillating piston engine for supercharging a two-cycle engine or increasing the volumetric efficiency of the fuel/air charge delivered to the combustion chamber. In these respects, the oscillating lever arm engine according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in so doing provides an apparatus primarily developed for the purpose of generating rotational torque through the oscillating movement of only one lever arm.
The present invention is related to U.S. Pat. No. 5,884,590, issued Mar. 23, 1999, titled “Two-Stroke Engine,” and U.S. Pat. No. 5,572,904, titled “Oscillatory Lever Arm Engine”, by the same inventor. These two previous patents similarly describe a lever arm engine with oscillating pistons generally of the type disclosed herein. U.S. Pat. Nos. 5,884,590 and 5,572,904 are hereby incorporated by reference as though fully set forth herein.
Similar to the general concept presented in the embodiments disclosed in the previous U.S. Pat. No. 5,884,590, the present invention generally comprises an engine for generating rotational torque through the oscillating movement of a single lever arm. The inventive device includes an elongated cylinder having first and second opposed cylinder heads. A pair of pistons are oppositely disposed within the cylinder and coupled together by a connecting rod. A single lever arm is pivotally mounted at a first end thereof to the connecting rod between the pistons. The lever arm is also pivotally mounted at a medial portion thereof exterior of the cylinder to a mounting plate. A flywheel is rotatably mounted to the mounting plate and engages a second end of the lever arm, whereby oscillation of the lever arm in response to piston movement is translated into rotational movement of the flywheel.
The present invention teaches a new oscillating lever arm engine apparatus and method which has many of the advantages of the internal combustion engine structures mentioned heretofore and many novel features that result in an oscillating lever arm engine which are not anticipated, or implied by any of the prior art internal combustion engine structures.
The present invention further teaches an oscillating piston engine for use in two-cycle operation in which the crankshaft is isolated from the intake charge so that the fuel charge need not contain lubricating oil.
The present invention also teaches a two-cycle engine with the possibility of supercharging, in which the intake air charge is greater than that of the swept volume of the working piston delivered to the combustion space throughout each operating cycle.
The present invention further teaches the simplicity of a single lever oscillating piston reciprocating device which eliminates piston side thrust that may be employed as a pump or compressor. The device may be employed as an internal combustion engine pump or compressor. When used in the application of an internal combustion engine, the lever system provides high torque, even at low RPM.
The present invention is an oscillating lever arm internal combustion engine which is capable of running on a variety of different fuels (e.g., gasoline, diesel, alcohol, propane or hydrogen). Furthermore, this device which is very compact and lightweight, is inexpensive to manufacture when considering both material used and labor for assembly.
The present invention overcomes the drawbacks of the lever arm engine disclosed in U.S. Pat. No. 5,884,590.
The various features of novelty which characterize the invention, are pointed out with particularity in the claims annexed to, and forming a part of, this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
The description of the preferred embodiment shown in the figures of drawing is shown only diagrammatically. However, it will be understood by those skilled in the art how to select from among available design choices to construct the claimed device from these teachings. Further, for greater detail of the particular working structures that may be used in carrying out the claimed invention, reference may be made to applicant's U.S. Pat. No. 5,884,590 which is incorporated herein as if fully set forth.
In summary, the present invention is a two-cycle engine comprising an elongate cylinder block having opposing first and second coaxial cylinders; a piston assembly designed to slide within said cylinder block in an oscillating manner, said piston assembly having a first piston and a second piston, said first piston and a second piston fixedly coupled to and diametrically opposed; a first cylinder head coupled to the end of said first cylinder, and a second cylinder head coupled to the end of said second cylinder; said piston assembly defining a pumping space between said first piston and the interior of said first cylinder head and also defining a combustion space between said second piston and the interior of said second cylinder head; a transfer duct for providing fluid communication between said pumping space and said combustion space, said transfer duct providing a pressurized intake charge from said pumping space to said combustion space; a connecting rod extending between said first and said second pistons; a housing for storing a lubricating liquid (oil); a crankshaft positioned within said housing, said crankshaft rotatably movable; means affixed to said connecting rod for converting the oscillating motion of said first and second pistons into rotary motion of the crankshaft; one-way valve means in said first cylinder head for controlling the flow of an intake charge into said pumping space; a first lifter valve means in said second cylinder head for controlling the flow of an exhaust charge from said combustion space to ambient air external to said cylinder block; a second lifter valve means in said second cylinder head for controlling the flow of said intake charge from said transfer duct; means for introducing a fuel charge into said combustion chamber; ignition means located in said second cylinder for igniting a fuel charge; a plurality of cams located on the perimeter of said crankshaft, said cams communicating with a lifting rod which causes a rocker arm to control the operation of said first and second lifter valve means; and exhaust means in fluid communication with said combustion space, whereby oscillation of said coupled pistons draws an intake charge into said pumping space and then forces said intake charge from said pumping space through said duct means to said combustion space, wherein said second piston compresses said charge, and upon ignition, said ignited charge drives said second piston forceably, turning said crankshaft and wherein said means for converting the oscillation of said pistons to rotary motion of a single crankshaft, comprises a lever arm, rotatably and slidably mounted to said cylinder block.
Referring now to
A plurality of cooling channels 99 are designed to permit the closed-loop circulation of a liquid (e.g., air, or a water and antifreeze solution) to assist in cooling the two-cycle engine.
The piston assembly 32 includes a first piston 18 and a second piston 17 fixedly coupled to each other and diametrically opposed to each other, mounted within the first and second coaxial cylinders 8, 7, respectively. A connecting rod 36 extends between the first piston 18 and the second piston 17 to connect the pistons 18, 17 together. The pistons 18, 17 are designed to slide within the cylinder block 11 in an oscillating manner.
A first cylinder head 50 is coupled to the end of the first coaxial cylinder 8, and a second cylinder head 52 is coupled to the end of the second coaxial cylinder 7. The oscillating piston assembly 32 defines a pumping space 24 between the first piston 18 and the interior of the first cylinder head 50 and also defines a combustion space 19 between the second piston 17 and the interior of the second cylinder head 52.
A transfer duct 20 provides fluid communication between the pumping space 24 and the combustion space 19, the transfer duct 20 provides a means for delivering a pressurized intake charge from the pumping space 24 to the combustion space 19.
The lower half of the cylinder block 11 includes a housing 98. The crankshaft assembly 13, including a flywheel 10, is rotatably mounted within the housing 98. A plurality of cams 29 are fixed to the perimeter of the flywheel 10. The operation and purpose of the cams 29 will be more fully disclosed hereafter.
The tracking pin 38 is affixed to flywheel 10 and communicates with slot 14 on lever arm 15. Lever arm 15 includes the slot 14 at the lower end, and a pinned connection 16 to connecting rod 36 at its opposite end. As the crankshaft assembly 13 rotates, the flywheel 10 rotates, and lever arm 15 rocks about the fulcrum pivot 12 which is rigidly affixed to the cylinder block 11. The lever arm 15 is further slotted in the area of the fulcrum pivot 12 to permit the necessary longitudinal movement of the lever arm 15 with respect to the fulcrum pivot 12. In this way, oscillatory motion of pistons 18, 17, which are rigidly connected to connecting rod 36, is achieved as the crankshaft and flywheel 10 rotate.
Another function of the housing 98 is to store a lubricating liquid (oil). The movement of lever arm 15 delivers a controlled amount of lubricating oil to the inner walls of the cylinder block 11 to allow the smooth operation of the pistons 18, 17 by reducing the friction between the perimeter of the pistons 18, 17 and the inner walls of the first and second coaxial cylinders 8, 7.
The crankshaft assembly 13 extends through the housing to a point outside of the housing. The crankshaft assembly 13 is designed to deliver the rotational energy developed by the subject engine to an external source (e.g., for connection to a transmission, cutting blades or similar items that will produce work). In one embodiment of the present invention the rotational energy of the crankshaft 13 is utilized to drive a twin-cylinder compressor 60. The operation of the twin-cylinder compressor 60 will be more fully disclosed hereafter.
A first lifter valve means 22 in the second cylinder head 52 controls the flow of exhaust from the combustion space 19 to ambient air external the cylinder block 11. In a preferred embodiment the first lifter valve means 22 is positioned away from the cylinder wall to prevent the escape of lubrication oil. A second lifter valve means 21 in the second cylinder head 52 controls the flow of the intake charge from the transfer duct 20.
A means for introducing a fuel charge communicates with the combustion space 19 for delivering a fuel charge into the combustion space 19. The present invention may use gasoline, diesel, or hydrogen as a fuel charge. If the engine is designed to operate on gasoline, then the fuel charge will consist of gasoline, and the delivery means may be a fuel injector 27. A means for igniting the fuel charge also communicates with the combustion space 19. Again, if the engine is designed to run on gasoline, the igniting means would include a sparkplug 28. If the engine is designed to run on diesel the igniting means would be the heat of compression formed within the combustion space 19.
The plurality of cams 29 located on the perimeter of the flywheel 10 are designed to move the lifting rod 30 as the flywheel 10 rotates which in turn causes the rocker arm 23 to control the operation of the first and second lifter valve means, 22 and 21 respectively. The cams 29 are spaced precisely on the perimeter of the flywheel 13 to open and close the lifter valves means 22, 21 in synchronization with the piston assembly 32 to provide the intake charge or remove the exhaust at the proper time in order to allow the engine to operate.
This type of engine utilizing only a single lever arm 15 as shown herein is employed in novel embodiments which will be later described in detail. The present invention uses opposing pistons 18, 17 of different diameter. In a preferred embodiment, the first piston or “pump piston” 18 functions as a pump to supply an intake charge to transfer duct 20 and then through the second lifter valve means 21 to the combustion space 19 proximate a second or combustion piston 17 (sometimes referred to as the “working piston”) to provide two-cycle operation. The diameter of the pumping piston 18 is preferably larger than the diameter of the working piston 17. Because of the larger displacement of the pump utilizing the pump piston 18, together with its inherent volumetric efficiency, a greater amount of intake charge is provided to the combustion space 19 above the combustion piston 17 than can ordinarily be achieved by a crankshaft-scavenged two-cycle engine. In this configuration, the two-cycle engine may employ either diesel or electric spark ignition and may utilize either direct fuel injection or carburetion.
The delivery of the intake charge into the combustion chamber 19 is controlled by the second lifter valve means 21. In a preferred embodiment, the first lifter valve means 22 and the second lifter valve means 21 are poppet valves controlled by a rocker arm 23. The shape and position of the rocker arm 23 along with the number of cams 29 determine the valve lift, and when and how quickly the lifter valves means 22, 21 are opened. The control of the exhaust may be accomplished by the first lifter valve means 22.
Air/fuel intake to the combustion side of the engine may be achieved through the use of an injector 27. It will be readily appreciated that because the flow of fuel/air mixture is isolated from the crankcase and the spaces on the other side of the pistons that there is no need to add lubricating oil to the air/fuel mixture. This is an important advantage of the present invention. The various crankcase components are preferably lubricated by means well-known in the art of internal combustion engines, such as the means utilized in conventional four-cycle engines.
The operation of the two-stroke engine will be described with reference to
Referring now to
In one embodiment, the pistons 18, 17 are of different diameter to increase the volumetric efficiency and, thus, provide a greater intake charge to the combustion space 19. A one-way valve may be included between the first pumping space 24 and the transfer duct 20 so that the intake charge will travel only in the direction into the transfer duct 20 and away from the pumping space 24. The exhaust means is preferably an exhaust port controlled by the first lifter valve means 22 in the second cylinder head 52. The first lifter valve means 22 may advantageously be timed to open while the second lifter valve means 21 is open and the pumping piston 17 is supplying an intake charge to the combustion space 19 through the transfer duct 20 in order to more efficiently remove exhaust gases from the combustion chamber 19. The first lifter valve means 22 may also be timed to close prior to the second lifter valve means 21 closing while the pumping piston 17 is supplying an intake charge through the transfer duct 20 to provide a greater intake charge to the combustion space 19. At approximately the pistons 18, 17 furthest point of travel to the right, both the first lifter valve means 22 and second lifter valve means 21 are closed.
Referring again to
Referring now to
The operation, and in particular, the timing of the opening and closing of the first lifter valve means 22 and second lifter valve means 21 is controlled by the height, number and spacing of the cams 29 on the flywheel 10. The operation of the first lifter valve means 22 and the second lifter valve means 21 is also dictated by the shape of rocker arm 23. Every time a cam 29 engages the lifter 30, the second lifter valve means 21 opens and the first lifter valve means 22 closes; after the cam 29 ceases engagement of the lifter 30, the first lifter valve means 22 closes and the second lifter valve means 21 opens.
Referring now to
Mounted above the housing 63 is an elongate cylinder block 67 having opposing first 68 and second 69 coaxial cylinders. A first cylinder head 70 is coupled to the end of the first cylinder 68, and a second cylinder head 71 is coupled to the end of said second cylinder 69.
A piston assembly 72 is designed to slide within the cylinder block 67 in an oscillating manner, the piston assembly 72 having a first piston 53 and a second piston 51 where the pistons are fixedly coupled to and diametrically opposed to one another.
A connecting rod 73 extends between the first 53 and the second 51 pistons so that the first 53 and second 51 pistons move in synchronization with each other. The piston assembly 72 defines a first pumping space 74 between the first piston 53 and the interior of the first cylinder head 70 and also defines a second pumping space 75 between the second piston 51 and the interior of the second cylinder head 71.
The first inlet port 59 communicates with the first pumping space 74 via the first one-way inlet valve 54 and the first exhaust port 62 communicates with the first pumping space 74 via the first one-way exhaust valve 55.
The second inlet port 58 communicates with the second pumping space 75 via the second one-way inlet valve 56 and the second exhaust port 61 communicates with the second pumping space 75 via the second one-way exhaust valve 57.
A lever arm 76 having a first end and a second end connects at the first end to the mid-point of the connecting rod 73, the second end of the lever arm 76 including a slot 77 extends through a side of the cylinder block 67 and into the housing 63 so that the slot 77 can communicate with a guide pin 78 on the flywheel 64. The flywheel 64, guide pin 78, slot 77, lever arm 76 and connecting rod 73 are designed to convert the rotational movement of the crankshaft 66 into oscillating movement of the piston assembly 72.
The exhaust valves 55, 57 work in concert with the oscillation of the piston assembly 72 to provide a pressurized fluid source. When the first piston 53 moves towards the first cylinder head 70 the volume of the first pumping space 74 is reduced and the fluid pressure is increased within the first pumping space 74. Simultaneously the second piston 51 moves with the first piston 53 and the second piston 51 moves away from the second cylinder head 71 thereby increasing the volume of second pumping space 75. The volume of the pumping spaces 74, 75 are constantly changing by the substantially simultaneous operation of the inlet valves 54, 56 and the exhaust valves 55, 57 such that first inlet valve 54 closes preventing fluid movement from the first inlet port 59 while the first exhaust valve 55 opens thereby allowing fluid movement out of the first pumping space 74. The second piston 51 moves away from the second cylinder head 71 thereby increasing the volume of second pumping space 75 by closing second exhaust valve 57 thereby preventing any fluid movement through the second exhaust port 61 while opening the second inlet valve 56 thereby allowing fluid to move into the second pumping space 75. When the pistons 51, 53 reach their maximum movement in one direction, they begin to move in the opposite direction. This change in direction increases the volume of the first pumping space 74 and decreases the volume of the second pumping space 75, simultaneously closing the first exhaust valve 55 while opening the first inlet valve 54, allowing the first piston 53 to draw in fluid through the first inlet port 59, and closing the second inlet valve 56 while opening the second exhaust valve 57. This allows fluid to escape from the second pumping space 75 and provides a relatively high fluid pressure at the second exhaust port 61.
The exhaust valves 55, 57 may be connected together in order to provide a more powerful pumping action than a single-piston pump having a similar displacement. The means to do so would be known to one of ordinary skill in the art of compressors.
In another embodiment of the compressor 60 the inlet valves 54, 56 and the exhaust valves 55, 57 may be mechanically connected with each other and directly or indirectly connected to the lever arm 76 for precise timing of their respective movements.
An electric motor or a combustion engine may be used as the driving force for the compressor. The driving force may be applied to the portion of the crankshaft 66 that is external to the housing 63 in providing the rotational energy needed to turn the crankshaft 66 and thus oscillate the pistons 51, 53.
By the mechanical relations disclosed herein, it will be appreciated that the present invention contains improvements over the prior art. The present device provides an operating mechanism for a two-cycle internal combustion engine in which the crankshaft is isolated from the fuel charge so that the fuel need not contain lubricating oil. This provides the advantage of greater power and reduced environmental pollution from the exhaust. In addition, this two-cycle engine may include supercharging through the use of independently-timed exhaust valves and a pumping piston which has an operating volume greater than that of the combustion piston. Even without the use of valve timing that would permit supercharging, the present device permits greater power output due to increased fuel charge provided by the intake pumping means having an enlarged swept volume. These many advantages provide a great advancement over prior art engines which are not capable of achieving the same results.
It should be understood that the above description discloses specific embodiments of the present invention and are for purposes of illustration only. There may be other modifications and changes obvious to those of ordinary skill in the art that fall within the scope of the present invention which should be limited only by the following claims and their legal equivalents.
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