The present invention relates to internal combustion engines. In an internal combustion engine, the basic functionality includes: (1) the intake of a fuel-air mixture into a combustion chamber; (2) the compression of the fuel-air mixture; (3) the ignition of the fuel-air mixture; and (4) the expansion of the ignited mixture and exhausting of the combustion gases. The resultant release of energy in the form of expanding gas is used to power various mechanical devices, including vehicles.
A reciprocating internal combustion engine is perhaps the most common form of internal combustion engine. In a reciprocating internal combustion engine, the reciprocating motion of a piston in a cylinder results in the compression of the fuel-air mixture and the expansion of combustion gases. The energy is transformed from linear motion into rotational motion through connection of the piston to a crankshaft.
Most modern vehicle engines currently use a piston-cylinder arrangement in what is referred to as a four-stroke combustion cycle, comprised of (1) an intake stroke, (2) a compression stroke, (3) a combustion stroke, and (4) an exhaust stroke. In a four-stroke combustion cycle using a typical piston-cylinder arrangement, the piston starts at the top of the combustion chamber (i.e., the cylinder), and an intake valve opens. The piston moves downwardly within the cylinder, and the fuel-air mixture is drawn into the cylinder through the intake valve, completing the intake stroke. The piston then moves back upwardly to compress the fuel-air mixture until reaching the top of the stroke, completing the compression stroke. When the piston reaches the top of the stroke, the spark plug ignites the compressed fuel-air mixture, resulting in a controlled explosion that drives the piston downwardly, completing the combustion stroke. Finally, once the piston reaches the bottom of its stroke, an exhaust valve opens, and combustion gases are forced out of the cylinder by the upward movement of the piston back to the top of its stroke, completing the exhaust stroke and readying the piston for a subsequent combustion cycle.
Although common in vehicles, a reciprocating internal combustion engine using a four-stroke combustion cycle does have some disadvantages. As a result, other engines have been developed that use the same basic combustion principles with some variation. For example, in an internal combustion engine using a two-stroke combustion cycle, the intake and exhaust valves are eliminated. Instead, intake and exhaust ports are located on opposite sides of the cylinder. After each expansion stroke, combustion gases under pressure exit the cylinder through the exhaust port, and a fuel-air mixture is drawn in through the intake port. Although there is only one expansion cycle per crankshaft revolution, a two-cycle engine is must less efficient than a four-cycle engine.
Another reciprocating internal combustion engine is a diesel engine, which can have a four-stroke or a two-stroke combustion cycle. Unlike the above-described engines, however, a diesel engine draws in and compresses only air in the cylinder. This air is compressed by the piston to more than 450 psi, resulting in an air temperature of about 900-1100° F. At the bottom of the compression stroke, diesel fuel is injected into the cylinder, and the temperature of the air within the cylinder is sufficient to cause ignition of the fuel-air mixture without the need for a spark plug.
In any event, a reciprocating internal combustion engine has its disadvantages. The piston has a significant mass and thus inertia, which can cause vibration during motion and limits the maximum rotational speed of the crank shaft. Furthermore, such engines have relatively low mechanical and fuel efficiencies.
As a result of such disadvantages, some attempts have been made to propose alternate combustion engine designs. Perhaps the most well-known and commercially successful of these alternate designs is the Wankel or rotary piston engine. The Wankel engine has a quasi-triangular rotating piston that moves along an eccentric path to rotate the crankshaft. Rather than using inlet and exhaust valves, the edges of the rotating piston open and close ports in the wall of the combustion chamber. In other words, intake and exhaust timing are controlled solely by the motion of the rotor.
As the piston of the Wankel engine rotates, seals mounted at its three corners continuously sweep along the wall of the combustion chamber. The enclosed volumes formed between the piston and the wall increase and decrease through each revolution of the piston. A fuel-air mixture is drawn into an enclosed volume, compressed by the rotation of the piston that decreases the enclosed volume, and then ignited with the combustion gases being accommodated by and expelled through the expansion of the enclosed volume. In short, a complete four-stroke combustion cycle is achieved, but since there is no reciprocating motion, higher rotational speeds are possible.
The most pronounced disadvantage of a Wankel or rotary piston engine is the difficulty in adequately sealing the enclosed spaces between the piston and the wall of the combustion chamber that increase and decrease through each revolution of the piston. If these enclosed spaces are allowed to communicate with another, the engine cannot properly function.
Since development of the Wankel engine, some attempts have been made to address such shortcomings of a Wankel or rotary piston engine. For example, U.S. Pat. No. 5,415,141 describes and claims an engine that has a central rotor and a plurality of radially sliding vanes. The vanes rotate clockwise with the rotor to form enclosed volumes between the vanes, the side walls of the combustion chamber, and the rotor. These enclosed volumes decrease and increase in volume throughout the combustion cycle, with the fuel-air mixture being drawn into an enclosed volume, compressed by the rotation of the rotor and associated vane, and then ignited with the combustion gases being accommodated by and expelled through the expansion of the enclosed volume. Nevertheless, as with a Wankel engine, such a design still suffers from the problem of adequate sealing of the enclosed volumes from one another. Furthermore, the drag of the vanes along the wall of the combustion chamber reduces power and fuel efficiency.
As another alternative, U.S. Pat. No. 6,796,285 describes and claims an internal combustion engine that has a torque wheel mounted for rotation within the central cavity defined by a housing and driving a crankshaft. The torque wheel includes a plurality of separate arms in a spaced arrangement about the center of the torque wheel, thereby defining corresponding volumes between the respective arms. Positioned within these volumes are substantially identical combustion gates. As the torque wheel rotates, the combustion gates are moved through an elliptical path. Air is drawn into the central cavity of the housing, and fuel is introduced into the central cavity of the housing to create a fuel/air mixture in one of the volumes between the respective arms of said torque wheel and adjacent one of the combustion gates. This fuel/air mixture is then compressed during the continuing rotation of the torque wheel by the pivoting and outward movement of the combustion gate. The fuel/air mixture is then ignited, causing a rapid expansion of combustion gases and imparting a torque that causes continued rotation of the torque wheel. The combustion gate then pivots and moves inwardly toward the center of the torque wheel, allowing the combustion gases to expand, and then pivots and move outwardly again, forcing the combustion gases through an exhaust outlet.
Nevertheless, there remains a need for a durable, fuel-efficient internal combustion engine that can rotate faster than common gas-powered engines, while maintaining a constant rotational speed with a high power output to weight ratio.
An internal combustion engine made in accordance with the present invention includes a front housing (or engine block) that defines one or more generally wedge-shaped combustion chambers. The internal combustion engine further includes a second, rear housing that defines an internal cavity in which a wheel is mounted for rotation. This wheel is mounted on a crankshaft that extends through both the front and rear housings of the engine and is supported by a series of bearings.
Arranged inside each combustion chamber is a gate. These gates are also generally wedge-shaped, but become narrower as the respective combustion chamber widens. In other words, the widest portion of each gate is positioned within and essentially fills the narrowest portion of the respective combustion chamber. It is contemplated and preferred that a series of seals is arranged around the perimeter of each gate such that they substantially form a seal between the gate and the respective combustion chamber.
Each gate in the engine includes a corresponding gate control assembly. Each gate control assembly includes a control shaft which is connected to a respective gate and defines a pivot point for rotation of the gate. Each control shaft extends rearward and is supported by a series of bearings. At the distal end of each control shaft, there is an L-shaped control arm having a first end and second end. The first end is integral with or attached to the control shaft, while the second end extends into the rear housing.
The front face of the wheel, which is mounted for rotation within an internal cavity defined by the rear housing, defines a generally elliptical cam-cutout in its surface. Mounted to the second ends of the respective L-shaped control arms are one or more roller bearings which engage and ride in the elliptical cam-cutout. In this regard, it is contemplated that the elliptical cam-cutout has a stair-step cross-section for receiving a pair of roller bearings. By constructing the elliptical cam-cutout with such a stair-step cross-section, one roller bearing abuts a lower side wall of the elliptical cam-cutout while another roller bearing abuts an upper side wall of the elliptical cutout. The movement of the gate control assemblies within and with respect to the elliptical cam-cutout controls the movement and operation of the gates within the respective combustion chambers.
In the internal combustion engine, two cylinder heads are attached to opposite sides of the housing. Each head defines two ports for each combustion chamber: an intake port for drawing a fuel-air mixture into the combustion chamber, and an exhaust port for exhausting combustion gases. Furthermore, each cylinder head also includes a sparkplug, which is preferably controlled by an electronic spark control system.
The internal combustion engine operates on a four-stroke cycle. First, as an electronic starter turns the crankshaft and wheel, the elliptical cam-cutout causes the control arms to start moving. As a particular gate rotates to maximize the volume of the combustion chamber, the intake valve is opening. Thus, a fuel/air mixture is drawn into the combustion chamber between the gate and the wall of the housing. Then, as the wheel continues to turn, the elliptical cam-cutout acts on the control assembly to rotate the gate outwardly, compressing the air/fuel mixture within the combustion chamber between the gate and the wall of the housing. The fuel/air mixture is then ignited by a sparkplug. The ignition of the compressed fuel/air mixture causes a rapid expansion of combustion gases, imparting a force on the gate, and thus the wheel, as the wheel continues to rotate. Finally, the gate then begins to again rotate inwardly, minimizing the volume between the gate and the wall of the housing. An exhaust valve then opens, such that this rotation of the gate forces the combustion gases through the exhaust port.
Referring first to
Returning to the front housing 13, arranged inside each combustion chamber 26a, 26b is a gate 5a, 5b. As illustrated in
Referring still to
Referring now to
Referring now to
Referring now to
Referring still to the right side of the exemplary engine 100 and the gate 5a, in
During the rotation of the wheel 1 illustrated in
The internal combustion engine 100 constructed in accordance with the above specification avoids the problems of common reciprocating motion, piston-type engines and those of rotary combustion engines. Unlike a reciprocating motion, piston-type engine, minimal fuel and air for each combustion cycle is needed since it is not necessary to force a piston a substantial vertical distance within a cylinder. Rather, since the wheel 1 has a substantial mass and inertia, a relatively small combustion is sufficient to drive the wheel 1.
Furthermore, when a piston-cylinder arrangement is used, an offset crankshaft is necessary for transforming the energy from linear motion into rotational motion, resulting in a loss of efficiency. Similarly, a rotary piston engine requires an offset crankshaft due to the eccentric movement of the rotary piston within the combustion chamber. The wheel 1 of the engine 100 of the present invention is directly secured to the crankshaft 11 so there is no transformation of energy. The crankshaft 11 rotates with the wheel 1. In this regard, it is preferred that the engine 100 of the present invention be run at a constant rotational speed (RPM) in conjunction with a transmission designed to control the output speed.
Also, as a further refinement, it should be noted that in the embodiment illustrated in
As yet another refinement, during operation, the exemplary engine 100 may be cooled by either air or liquid by passing through channels (not shown) defined by the cylinder heads 6a, 6b and/or the front housing 13.
One of ordinary skill in the art will recognize that additional embodiments are also possible without departing from the teachings of the present invention. This detailed description, and particularly the specific details of the exemplary embodiment disclosed therein, is given primarily for clarity of understanding, and no unnecessary limitations are to be understood therefrom, for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without departing from the spirit or scope of the invention.
This application claims priority to U.S. Provisional Patent Application No. 60/779,338, filed Mar. 3, 2006, the entire disclosure of which is incorporated herein by reference.
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Number | Date | Country | |
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20070204831 A1 | Sep 2007 | US |
Number | Date | Country | |
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60779338 | Mar 2006 | US |