1. Field
The present invention relates to combustion engines, more specifically, an internal combustion free-piston engine.
2. Description of Related Art
Conventional internal combustion engines today consume vast amounts of fuel and do not harness the maximum potential of the amount of energy created by combustion. Thus creating a loss of use of the potential energy and wasting fuel. The traditional internal combustion rotary engine relies on the Revelutions Per Minute (RPM) for idle and increasing horsepower and torque. As a four-stroke engine introduces fuel and air into a cylinder, the RPM of the engine directly affects the amount of time the combustion cycle has before it is exhausted from the cylinder. At higher RPMs todays internal combustion rotary engines do not have enough air or time to completely combust the fuel therefore exhausting un-burnt fuel and carbon from the cylinders into the exhaust, creating the necessity of a catalytic convertor for further burning emissions out of the exhaust gases. Pollution has always been an issue when referring to the internal combustion engine along with the excessive amounts of fuel required to power them. These issues have forced humanity to search for cleaner burning and a more abundant renewable fuel source. Even as today's engine operates at idle, waiting to be utilized, it is consuming fuel, therefore wasting fuel. Conventional engines do not have the ability to fluctuate compression when desired nor can they create more torque when required.
Considering prior art, a multiple of different internal combustion engines and methods for controlling the combustion cycle have been invented solving various issues with said conventional engines, for example see U.S. Pat. Nos. 692,218, 4,539,946, 6,722,322, 7,194,989, 7,823,546, 8,215,112, 8,662,029, 8,746,200, 8,757,126, and 8,997,699.
Prior art in U.S. Pat. No. 692,218 is a free-piston explosive engine that consists principally of a valve mechanism for controlling the speed of the engine and regulating the supply of air and fuel to the cylinder as well as an effective means for returning the piston on the return stroke. It also provides a means of making the engine self-starting.
In U.S. Pat. No. 4,539,946 a “Method of Controlling the Combustion Cycle in a Combustion Engine” that regulates the amount of fuel that is drawn into the engine and retains a certain amount to be compressed and used while a portion flows out without being compressed.
U.S. Pat. No. 6,722,322 an “Internal Combustion Engine” issued on Apr. 17, 2002 is an engine having at least one cylinder with two cylinder heads interconnected by one cavity. It states the engine cylinder configuration substantially increases the volume to enhance efficiency.
An “Energy Efficient Clean Burning Two-stroke Internal Combustion Engine” issued Mar. 27, 2007, U.S. Pat. No. 7,194,989 is a precision cast engine having a piston unit and a rotor unit to translate linear thrust from the piston unit into rotary power.
U.S. Pat. No. 7,823,546 entitled “Super Charged Engine” issued Nov. 2, 2010 is an engine with an output shaft extending through the engine block and generally parallel to the piston, the engine includes a boost piston cylinder integral to the cylinder, and a boost piston for producing compressed air so as to supercharge the engine.
A “Free Piston Stirling Engine”, U.S. Pat. No. 8,215,112, is a free piston sterling engine comprising a power piston fitted into a cylinder and further includes; a support structure carrying moving magnets for linear alternator; and a passive structure that at normal operating power and frequency produces a restoring force on the piston in the absence of contact with the cylinder.
Another example in U.S. Pat. No. 8,662,029 is a linear combustion engine having a cylinder with a combustion section in the center portion of the cylinder and a pair of opposed piston assemblies adapted to move linearly within the cylinder.
In U.S. Pat. No. 8,746,200 a “Reciprocating Piston Internal Combustion Engine with Mass Balancing Device” relates to a reciprocating-piston internal combustion engine having at least one engine cylinder and piston oscillating therein and having a balancing mass which is driven by a crankshaft.
Issued Jun. 24, 2014, U.S. Pat. No. 8,757,126 is a non-reciprocating piston engine with pistons that follow a circular motion and respective cylinders follow a counter-circular motion relative to the pistons, such that each piston follows a linear path relative to the respective cylinder and at least a top surface of each piston remains within the cylinder throughout engine operation resulting in a stroke length four times the radius of the circular motion.
U.S. Pat. No. 8,997,699 is a linear free piston combustion engine with indirect work extraction via gas linkage having a cylinder with two opposed free pistons disposed therein that form a combustion section in a center of the cylinder with each piston having a front face and back face, where two opposed extractor pistons in their own cylinders at opposite ends of the free piston cylinder and two gas linkages and each extractor piston is connected to a rotary electromagnetic machine.
After acknowledging prior art, it is desirable to provide an engine that overcomes the issues mentioned above that uses less fuel and more completely combusts the fuel creating higher efficiency and less pollution by controlling the length of the combustion cycle. By providing an engine that can utilize various combustible fuels, does not idle, is not rotary, has fewer parts, is more cost effective to manufacture, and harnesses and stores the maximum amount of potential energy until needed, it is evident the efficiency will surpass that of the conventional internal combustion engine; which is currently around 35%-40%. It is also desirable to provide an engine that doesn't require a compression stroke to complete a cycle and stores the energy created by combustion until needed, therefore allowing the engine components to last longer because of less wear and tear and having more time to cool in between cycles.
The present invention is an internal combustion free-piston engine and is laid out in a linear design. The engine is comprised of multiple cylinders with three acting pistons per each combustion chamber. The first cylinder having a head with provisions for air/fuel, spark, and controlled exhaust valve introduction. The combustion chamber is located within the first cylinder and above a first piston being the combustion piston that is affixed to a main shaft. Where the main shaft is also a rack containing an air chamber that has an opening in the top of the combustion piston an opening in the bottom of the main shaft. The air chamber is used for transporting air into the combustion chamber during the combustion cycle. Beneath the combustion piston and inside the main shaft is the air chamber and a second stationary piston, with the air chamber creating a second cylinder interiorly of the first cylinder, so that when combustion takes place, air inside the air chamber is forced up into and out the combustion piston into the combustion chamber. Also located exteriorly to a third cylinder being the oil cylinder is an energy storage device being a spring. The energy storing device can be a compression, torsion, or extension spring. There is at least one energy storing spring per engine and springs can also be arranged in multiples per engine. The stationary piston has a through hole that's′ first opening is in its piston head and the distal opening is at its bottom that is open to outside air so that air can be replenished into the air chamber as the combustion piston ascends upward while the spring is utilizing stored energy and forcing the piston toward the head. At the bottom of the main shaft is a third piston being the oiling piston that serves as a positive displacement pump distributing oil throughout the engine during the combustion cycle. As the energy stored from combustion on the spring is required for work, the oiling piston, now moving upward, siphons oil into the oil cylinder. The main shaft also being a rack rotates a pinion affixed to an internal sprag clutch that is affixed to jackshaft extending out of the engine as the combustion piston is thrust downward during combustion; compressing, extending, or torqueing the spring, and the jackshaft is locked via braking system in the downward position until energy is required. As energy is required, the brake system is released and work can be performed. Multiple engines can be run together as one unit on the same drive shaft.
The current invention is a linear internal combustion free-piston engine. It's preferred embodiments are comprised of multiple cylinders and three acting pistons per each combustion chamber. Referring to
Toward the bottom of said combustion cylinder 10 is an emergency relief vent 25 utilized to allow air beneath the combustion piston 15 to flow freely in and out of the combustion cylinder 10 during the combustion cycle and utilization of the stored energy cycle. The emergency relief vent 25 is also used to eliminate the possibility of an explosion and over stressing of the compression spring 23 if the combustion chamber 19 is over-fueled forcing the combustion piston 15 beyond its normal operating stroke, therefore allowing gases to escape the bottom of the combustion cylinder 10. A wire mesh filter 39 is provided to prevent oil from escaping the emergency relief vent 25 but allowing air to escape.
Depicted in
Now referring to
In
Another preferred embodiment is a means for the exhaust pressure to be channeled from the controlled exhaust valve 14 into a chamber (not shown) that forces air pressure to build in a compressor (not shown). As the compressor reaches the desired pressure the exhaust gases are released to outside air. The compressed air is then used to force an air/fuel mixture (not shown) into the combustion chamber 19 at a desired PSI and is controlled electronically by way of solenoid (not shown).
Having clearly and concisely described the preferred embodiments that comprise the present invention, I will briefly explain the process of how the preferred embodiments function in the present invention. With the aforementioned combustion piston 15 having tension on it creating compression provided by the compression spring 23, extension spring 23a, or torsion spring 23b and in its upward most position near the head 11, an air/fuel mixture is pressurized into the combustion chamber 19 by way of solenoid to the desired compression ratio. Also controlled via solenoid, the igniter 13 is sparked beginning the combustion cycle forcing the combustion piston 15, main shaft 16 also being a rack 29, and oiling piston 26 all being one unit, downward. Therefore the air chamber 17 with open check valve 18a is thrusting additional air up through the combustion piston 15 into the air jackets 43 out into the combustion chamber 19 as the main shaft 16 is forced down by combustion onto the stationary piston 24 with check valves 18b and 18c in the stationary piston 24 being closed. Forcing additional air into the combustion chamber 19 during the combustion cycle causes a more complete burn of the fuel and helps maintain a static pressure after the combustion piston 15 has finished its downward stroke. Combustion also forces the spring retainer 22, 22a or 22b to compress, extend or torque the compression spring 23, extension spring 23a or torsion spring 23b and at the same time forces the oiling piston 26 to plunge deeper into the oil cylinder 27 sending oil through both oil outlets 30a and 30b and open check valves 18d and 18e disbursing lubricant through the oil jackets 40a and 40b to the engine components. Additionally as combustion forces the combustion piston 15 and the main shaft 16 also being a rack 29 downward, the pinion 21 is affixed to an internal sprag clutch 41 which is affixed to the jackshaft 36 that allows for slip and the jackshaft 36 does not rotate. The main shaft 16 is stabilized by an idler 35 that is affixed to an idler support shaft 45 and the rack 29 guided by being in contact with the said pinion 21 keeping the entire main shaft 16 unit square within the combustion cylinder 10 during all movement. With the said jackshaft 36 extending out of the combustion cylinder 10, in
It should be noted that this engine can be assembled in multiple sequences depending upon application. For example the compression spring 23 could also be located interiorly in the air chamber 17 in which case the said spring retainer 22 would be omitted and the bottom of the combustion piston 15 would act as a spring retainer. It should also be noted that multiple compression springs 23, extension springs 23a, or torsion springs 23b can be used and arranged around the exterior of the oil cylinder 27 but housed by the body 28 and so on. Additionally, other attributes of the present invention that should be noted are its ability to self-start and to use the compression spring 23, extension spring 23a, or torsion spring 23b to create tension on the combustion piston 15 allowing the air/fuel mixture to be pressurized into the combustion chamber 19 to a desired PSI and eliminating the compression stroke. Furthermore this engine does not idle, and by adding additional air into the combustion chamber 19 during the combustion cycle, the length of the combustion cycle is directly affected creating more efficient and complete fuel combustion. The design of the current invention allows for a longer combustion piston 15 stroke providing the ability to harness additional energy per combustion cycle, and while the combustion may be hotter, storing the energy on the compression spring 23, extension spring 23a, or torsion spring 23b allows additional time for cooling, and the compression spring 23, extension spring 23a, or torsion spring 23b can be adjusted for more or less torque if desired.
While the present invention has been explained by reference to the preferred embodiments described above, it will be appreciated that these embodiments are only examples provided to illustrate the present invention and are not meant to be restrictive on the spirit and scope of the present invention. This invention should be determined from the general principles and spirit of the invention as described above. Variations and modifications which are obvious to those skilled in the art including improvements made on the basis of the present invention, should be considered as falling within the scope of the present invention. Furthermore, it should be appreciated that the present invention can be assembled in multiple sequences and can be utilized in many applications, including but not limited to multiple engines married utilizing stored energy on a single shaft as one unit.
This application claims priority from U.S. Provisional Patent Application No. 61/990,215 filed May 8, 2014 with the United States Patent and Trademark Office. The disclosure of which is incorporated herein.
Number | Name | Date | Kind |
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3853100 | Braun | Dec 1974 | A |
9016256 | Hamby | Apr 2015 | B2 |
20100275884 | Gray, Jr. | Nov 2010 | A1 |
Number | Date | Country | |
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20160326953 A1 | Nov 2016 | US |
Number | Date | Country | |
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61990215 | May 2014 | US |