Compound expansion engine

Abstract

An improved reciprocating engine with compound expansion suitable for power generation and in particular a reciprocating engine with compound, or secondary, expansion, especially suited for the direct injection of fuel and oxidizer for higher efficiency, carbon sequestration, and Nox reduction in large displacement combustion engines.

Description

[0001] TITLE: COMPOUND EXPANSION ENGINE CROSS REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U. S. Provisional Application Serial No.

[0003] 63 / 710,373, entitled “COMPOUND EXPANSION ENGINE WITH CERAMIC COMBUSTION CHAMBER,” filed October 22, 2024, and U. S. Provisional Application Serial No. 63 / 829,416, entitled “COMPOUND EXPANSION ENGINE WITH VARIABLE VALVE TIMING,” filed June 24, 2025, both of which arc incorporated herein by reference.

[0004] BACKGROUND OF THE INVENTION

[0005] 1. Field of the Invention

[0006] The present invention relates to an improved method of power generation, and in particular, a reciprocating engine with compound, or secondary, expansion, especially suited for the direct injection of fuel and oxidizer in large displacement combustion engines.

[0007] 2. Discussion of Related Art

[0008] Broadly speaking, in the present day, there are three different types of combustion engines that satisfy a majority of the power generation needs of the world's population. These include the purely rotational mechanism of the turbine engine, and the two reciprocating mechanisms of the diesel engine and the four-stroke internal combustion engine. There are several other combustion engines that exist, such as the two-stroke engine and the Wankel rotary engine. However, these designs have never risen to the ranks of usage like the other three, primarily due to difficulties related to scaling and lubrication and emission controls.

[0009] In the present day, there is considerable discussion about the electrification of fossil-fired vehicles, such as automobiles, shipping trucks, and buses. Advances in electrochemical storage using batteries are touted as justification for someday making all of our vehicles powered by electric motors. Also, fuel cells that convert hydrogen gas directly into electricity are being pursued as an alternative to fossil-fired combustion engines. Although there is promise for the electrification of the lower powered vehicles with shorter range, it is less likely that the high powered long-range transportation systems, such as large ocean-going ships, will benefit from electrification.

[0010] While we look to the future of electrification, it is evident that the high-load and long-endurance power needs in certain areas of industry cannot be met with foreseeable types of electrification. Examples include trans-oceanic shipping and large generator sets (1 to 20 megawatt) used to power cities and datacenters for the growing power needs of Al (Artificial Intelligence). According to experts, these areas of power consumption and demand will continue to require the type of power density and endurance available from the combustion of liquid or gaseous fuels (whether fossil from the ground or synthetically derived).

[0011] If one looks back at the changes in power systems used to propel the larges ocean-going ships, they’ would sec how sails replaced oars, then steam engines replaced sails, then steam turbines replaced reciprocating steam engines, then fossil-fueled combustion engines replaced steam driven turbines, with the current state-of-the-art being fossil-fueled reciprocating internal combustion reciprocating engines connected to a generator (often referred to as a gen-set) powering electric motor propeller “pods.” According to this inventor, there is an opportunity to look back at the epitome of the reciprocating steam era, in particular, to the compound expansion engines, which harnessed a large amount of the potential work energy- from the steam.

[0012] A key factor in making the engines for large ocean-going ships more efficient is harnessing the energy from the wasted energy contained in the combustion exhaust gases. This concept is not new and often referred to as a 5-cycle engine where the exhaust gas from a conventional 4-stoke engine is routed to a piston cylinder arrangement to exert additional work on a crankshaft.

[0013] An important thread in the discussion of converting our energy needs away from fossil fuels is the subject of energy storage. With the use of renewable energy sources such as wind and solar there is a great need to store electrical power that is generated during peak generating periods, such as when the wind blows or the sun shines, for use when wind does not blow or the sun does not shine. In fact, the problem of energy storage is seen as paramount to the ability to convert from fossil fuels to renewable energy.

[0014] The ability to produce and store hydrogen gas under pressure, by electrolysis with electrical current generated from wind and solar, is touted as a leading option for the energy storage to convert our world from dependence on fossil fuels.

[0015] There are various methods presently available for the production of rotational energy. These various designs all have their benefits and shortcomings. The invention described in this patent application is well-suited to increase the efficiency of internal combustion engines using a fuel and oxidizer to convert chemical energy to rotational energy to conduct work, whether directly for moving vehicles or equipment or the generation of electricity. The present invention is designed to provide additional options for power generation compared to other presently available alternatives, and is particularly important for the improvement in quality and cost benefits to the consumer. SUMMARY

[0016] Other objects and advantages of the present invention will become apparent from the following detailed description when viewed in conjunction with the accompanying drawings, which set forth certain embodiments of the invention.

[0017] The present invention is directed to an improved power generation engine that includes a secondary expansion (or compound expansion) of the combustion gases in a reciprocating engine device which at least partially overcomes the disadvantages of existing systems or provides the consumer with a useful or commercial choice.

[0018] In some embodiments, a piston engine includes a primary combustion piston and a primary combustion expansion cylinder and a secondary piston and a secondary expansion cylinder. Although the two described pistons could drive a conventional crankshaft, a preferred embodiment is configured to drive journal-less camcrank devices (that is, a crankshaft that uses rolling-element bearings (such as ball or roller bearings). In accordance with a disclosed embodiment, the journal-less camcrank assembly is described in detail in a prior patent application publication, see U. S. Patent Application Publication Number 2014 / 0224116, with a current improved design disclosed in a US Patent Application Serial No. 19 / 300,927, filed August 15, 2025, both of which are incorporated herein by reference.

[0019] Briefly, and with reference to Figures 12A to 12F, operation of the valved-piston assembly 101 disclosed in US Patent Application Serial No. 19 / 300,927 is shown via a series of drawings describing the sequence of events occurring with the activation of a valved-piston assembly 101 relative to the 360-degree rotation of two camcrank assemblies 102, 103 (that is, the actuator) connected to the valved-piston assembly 101 such that the valved-piston assembly 101 drives two camcrank assemblies 2, 3 that rotates the drive shaft 119 that ultimately drivers a mechanical system requiring rotational power. It should be appreciated that only the power-band 106 drives the shaft 119 via the power camcrank 102. The exhaust-band 108 only activates the exhaust valve assembly 104 that is part of the valved-piston assembly 101. While the valved-piston assembly 101 of US Patent Application Serial No. 19 / 300,927 differs from the piston engine of tire present disclosure, the operation of the camcrank assembly is similar in the compound expansion engine described below.

[0020] The first camcrank assembly is the “power-camcrank assembly” 102, and the second camcrank assembly is the “exhaust-camcrank assembly” 103, which is 15-degrees in advance rotational angle relative to the power-camcrank assembly 102. It should be noted that the drawings shown in Figures 12A through 12F are for describing the operation, including how the forces are transmitted, and are not literal descriptions or representations of how the actuation mechanisms would be manufactured.

[0021] Figure 12A shows the power-camcrank assembly 102 engaged to a centrally located exhaust-valve assembly 104 of the valved-piston assembly 101 via a flexible power-band 106 that is firmly connected to the exhaust-valve assembly 104 at the exhaust-valve fixation point 107. Also shown is an exhaust-camcrank assembly 103 engaged to the main piston body 105 via a flexible exhaust-band 108 that is firmly connected to the main piston body 105 at the piston-body fixation point 109. Both the exhaust-valve assembly 104 and the main piston body 105 are part of the same valved-piston assembly 101. It is noted that the flexible exhaust-band 108 slips through the exhaust-valve assembly 104 at an exhaust- valve assembly seal bushing 1 4b in the exhaust valve assembly 104 to allow free movement of the flexible exhaust-band 108 and a perfect seal via seal bushing 104b, and both the flexible power-band 106 and the flexible exhaustband 108 are allowed free movement and a perfect seal via seal bushings 110a and 110b, respectively (note: this is for illustration purposes to communicate the operation of the valved-piston mechanism and not for actual production of the product). It should be noted Figures 12A to 12F show a single flexible power-band 106 for the purpose of simplifying the disclosure.

[0022] Figure 12A shows the power-camcrank assembly 102 and valved-piston assembly 101 at 0-degrees rotation (bottom-dead-center “BDC”) of the 360-degrees rotation. In accordance with the present valved-piston assembly, bottom-dead-center of the powercamcrank assembly 102 is the beginning of the power stroke.

[0023] It is further shown in Figure 12A that the valved-piston assembly 101 is installed in a cylinder 111 with a cylinder-plate assembly 112 on one end 111 a of the cylinder 111 and an atmospheric opening port 113 on the other end 111b of the cylinder 111. On the cylinder-plate assembly 112, there is a fuel-intake -port 114, an oxidizer-intake-port 116, and a sparkplug 115. It is noted that the flexible power-band 106 slips through the powerband bushing 110a, and the flexible exhaust-band 108 slips through the power-band seal bushing 110b and the exhaust-valve assembly seal bushing 104b, to allow a free movement of the flexible power-band 106 and the flexible exhaust-band 108 and a perfect seal (note: this is for illustration purposes to communicate the operation of the valved-piston mechanism and not for actual production of the product).

[0024] Figure 12A further shows the power-band idler assembly 117, which guides the flexible power-band 106 and provides a fixed and non-restrictive pivot point for motion of the flexible power-band 106. Also shown is the exhaust-band idler assembly 118, which guides the flexible exhaust-band 108 and provides a fixed and non-restrictive pivot point for motion of the flexible exhaust-band 108. Also shown in Figure 12A is the set of releasable-and-adjustable-band-anchor-points 127 that are individually connected to both the flexible power-band 106 and the flexible exhaust-band 108, that can be either mechanically or electronically activated to adjust position, tension, or fixation in a constant, variable, or intermittent manner.

[0025] Figure 12A further shows the power-camcrank assembly 102, that is mounted on a drive shaft 119, in the forefront. A second camcrank assembly, the exhaust-camcrank assembly 103, is shown mounted on the same drive shaft 119, however, the exhaustcamcrank assembly 103 is mounted immediately behind the power-camcrank assembly 102. Again, for the purpose of the description of how the present valved piston works, the exhaust-camcrank assembly 103 is 15-degrees in advance rotational angle compared to the power-camcrank assembly 102, although the degree of advance or retardation on either camcrank assembly can be adjusted to various settings depending on the desired timing arrangements.

[0026] Both the power camcrank assembly 102 and the exhaust-camcrank assembly 103 are not fixedly attached to the flexible membranes, that is, the flexible power-band 106 and the flexible exhaust-band 108, respectively. The connecting membranes, the flexible power-band 106 and the flexible exhaust-band 108, only engage their respective camcrank assemblies 102, 103 if there is pulling tension in the respective flexible membranes defined by the flexible power-band 106 and the flexible exhaust-band 108 they will each respectively engage the camcrank mechanism. There are bearing surfaces on the power-camcrank-bearing 120 and the exhaust camcrank-bearing 121, that allow free unrestricted rotation of the power camcrank-ring 122 and the exhaust camcrank-ring 123.

[0027] Figure 12A shows the initiation of the power stroke stage of the valved-piston assembly 101, occurring at or approximately bottom-dead-center (BDC), or 0-degrees, of the power-camcrank assembly 102 rotation. At this stage of the cycle, the sparkplug 115 has just ignited a fuel / oxidizer mixture and combustion gas 124 is expanding. The surfaces that are contacted by the combustion gases, including all surfaces of the valved-piston assembly 101, the cylinder 111 and the cylinder-plate assembly 112, could be made in a manner to minimize heat transfer, either with coatings, air pockets, or made of /

[0028] thermally insulating material such as a ceramic materials, that minimized heat transfer from combustion surfaces.

[0029] Referring now to Figure 12B, the power-camcrank assembly 102 is shown at 90-degrees clockwise rotation from bottom-dead-center. The valved-piston assembly 101 is approximately half-way through the power stroke and the combustion gas 124 is causing work to be done at the drive shaft 119. The exhaust-valve assembly 104 is closed due to closing force caused by combustion gas 124 pressure on the frontal piston-body surface area 125 portion of the valved-piston assembly 101 causing tension in flexible powerband 106 connected to the power-camcrank assembly 102. It should be appreciated that in the disclosed embodiment, the frontal piston-body surface area 125, is about four times greater that the frontal exhaust-valve surface area 126, with tension on the flexible power-band (and no tension or slack 108’ on the exhaust-band 108), resulting in a net resultant force that forcibly closes the main piston body 105 against the exhaust- alve assembly 104, preventing combustion gas 124 from escaping.

[0030] Figure 12C shows the power-camcrank assembly at 15-degrees before top-deadcenter (TDC). At this position, the exhaust-camcrank assembly 103 has reached topdead-center, and full tension has been transferred from the flexible power-band 106 to the flexible exhaust-band 108, causing the main piston body 105 to stop further travel in the direction of the power stroke. At approximately this point in the travel of the valved-piston assembly 101, there is a transfer of tension from the flexible power-band 106 to the flexible exhaust-band 108 and power-band slack 106’ is beginning to occur in the flexible power-band 106, and the exhaust-valve assembly 104 is free to open.

[0031] Figure 12D shows the power-camcrank assembly 102 at 180-degrees, top-deadcenter (TDC) of tire power-camcrank assembly 102 rotation. At this position, the exhaust-camcrank assembly 103 is 15-degrees in advance of the power-camcrank assembly 102, and full tension is in the flexible exhaust-band 108, pulling on the main piston body 105 and fully? opening the exhaust-valve assembly 104 by separating the exhaust valve plate 126’ and the exhaust valve seat 126” of the exhaust-valve assembly 104 from the piston body bottom plate 125’ and the piston body exhaust valve seat 125” of the main piston body 105 to create a passageway' for the exhaust gas 124, pulling the entire valved-piston assembly 101 down, and exhausting combustion gas 124 from the cylinder 111. Because the power-camcrank assembly 102 rotation is behind the rotation of the exhaust-camcrank assembly 103, there is slack in the flexible power-band 106.

[0032] Figure 12E shows the exhaust-camcrank assembly 103 at approximately 315- degrees. At approximately this position, due to the increased speed of the power-camcrank assembly 102 (due to its longer stroke), the exhaust- valve assembly 104 has “caught up” to the piston-body 105 portion of the valved-piston assembly 101, seamlessly transferring tension from the flexible exhaust-band 108 to the flexible powerband 106, which causes the exhaust-valve assembly 104 to close against the main piston body 105 and make a positive seal. At this point all, or at least a majority, of the combustion gas 124 has been exhausted. At this point, and during the remaining distance of the downward stroke, fuel 114’ and oxidizer 116’ can be injected and compressed for the next power stroke. Because the flexible power-band 106 is advancing the movement of the valved-piston assembly 101, by means of the advancing power-camcrank assembly 102, there is slack 108’ beginning to form in the flexible exhaust-band 108.

[0033] At this point of the downward stroke of the valved-piston assembly 101, at approximately 315-degrees, the valved-piston assembly 101 is approaching the cylinderplate assembly 112 with a potentially high velocity. So far in this example of the sequence of events there has not been described a mechanism that would prevent the valved-piston assembly 101 from unrestrained impact with the cylinder-plate assembly 112, other than the injection of fuel 114’ and oxidizer 116’. In the event the fuel 114’ and / or oxidizer 116’ are compressed gas, the further compression of the gas(cs) after injection would create a counter force, or impact buffer, to prevent detrimental impact of the valved-piston assembly 1 against the cylinder-plate assembly 112. The precise timing of the injection of fuel 114’ and / or oxidizer 116’, and their ignition, could eliminate detrimental impact between the valved-piston assembly 101 and the cylinder-plate assembly 112 (for example, in the case of a diesel-like combustion, where oxidizer 116’ (in the form of compressed air or nearly pure oxygen) was injected at 315-dcgrces rotation then further compressed to a high pressure-temperature, where upon injection of the fuel 114’ results in spontaneous ignition of the fuel causing a violent explosion (combustion commencing the power stroke) that prevents the valved-piston assembly 101 from impacting the cylinder plate). In this case, the energy from the momentum of the rapidly moving valved-piston assembly 101 is conserved, that is, the energy of the rapidly moving valved-piston assembly 101 is converted from kinetic energy to the potential energy of the compressed fuel 114’ and oxidizer 116’, contributing to the efficiency of the engine. The same example can be made with the injection of any oxidizer 116’ and fuel 114’ combinations, including air / liquid-gasoline, or air / combustible-gas combination. Advances in the electronically controlled common rail and direct injection of internal combustion engines, with electronic position sensors (not shown in drawings) mounted directly on the valved-piston assembly 101, would allow for controlling the timing of combustion to prevent detrimental impact of the valved-piston assembly 101 with the cylinder-plate assembly 112, in the manner described above.

[0034] Figure 12F shows the exhaust-camcrank assembly 103 at 360-degrees (or 0-degrees). At this position, the power-camcrank assembly 102 is 15-degrees behind in rotation, and full tension is in the flexible power-band 106. Fuel 114’ and oxidizer 116’ have been injected, and with a spark from the sparkplug 115, the next power stroke as shown in Figure 12A, is ready to commence, at or around bottom-dead-center of the stroke of the power-camcrank assembly 102. Because the flexible power-band 106 is in contact and advancing the movement of the valved-piston assembly 101, there is slack 108’ in the flexible exhaust-band 8.

[0035] Manufacturers of large displacement engines, such as Wartsilla, Caterpillar, and Cummins, are all working toward providing large displacement engines with multi-fuel capability. In some cases, large displacement engines are configured to run on one particular type of fuel, such as liquid fossil fuel, but include everything in place to switch to renewable fuels as supplies change. This is a practical approach because they can expect the supply of traditional fuels such as liquid and gaseous fossil fuels to change rapidly. Also, they can expect the advent, availability, and use of more carbon neutral fuels (such as bio-derived oils or methanol), or zero carbon fuels (such as hydrogen or ammonia) could become competitively priced, or required by regulation.

[0036] The option of someday’ using electrolyzer-generated and stored green hydrogen and oxygen (no air, no NOx) for large grid-tied ICE (internal combustion engine) generator-sets should come with opportunities for new ideas for engine platforms, instead of just modifying existing platforms. The fact that hydrogen and oxygen would be delivered to the ICE as high-pressure gas could be one reason to make changes to the normal 2 or 4-stroke platform, namely, by eliminating the intake stroke.

[0037] Recently, Porsche filed a patent for a "three-stroke internal combustion engine," see U. S. Patent Application Publication Number 2024 / 0301817. Whether or not this engine is actually built, it shows there are still ongoing efforts to increase efficiency with modifications to existing platforms. Examples of the language used by this world-class company are as follows: "There is a constant effort to optimize the operation of combustion machines in view of continuously increasing requirements to improve energy efficiency and other operational aspects of combustion machines modern combustion machines." And, since the first practical applications of the Otto and Diesel cycles in internal combustion engines, engineers the world over have struggled to improve the power-to- weight ratio and / or fuel efficiency of such engines.

[0038] The industrial revolution coincided with the advent of steam power. Piston type steam engines have no cooling system because the steam temperature is within operation limits of the materials of construction, and the steam acts as a coolant as it expands. Heat produced from friction during engine operation is conducted away by the steam itself, as it cools during expansion.

[0039] Piston type steam engines were configured with compound secondary, and tertiary expansion chambers, to improve efficiency. The use of steam also allowed the use of condensers to increase efficiency by creating a low-pressure area downstream (vacuum downstream of the turbine, in the case of a steam turbine), and recycle the water for reuse in the evaporation cycle. In the Applicant’s opinion, the design information disclosed in this application has direct application for not only increasing the efficiency of an engine system, by condensing all of the combustion gases, but also the opportunity to achieve near 100 percent recycling (or sequestration) of the combustion gases from an internal combustion engine, whether that is in the form of condensed and recycled water or carbon dioxide, as described in a patent application by the inventor, see Figures 9 and 10 of U. S. Utility Patent Application Serial No. 19 / 300,927, filed August 15, 2025. In other words, the development of a closed-loop internal combustion engine system with zero exhaust (emissions).

[0040] It appears that the world is poised to bring gigawatts of solar or wind-powered electrolyzers online to produce green hydrogen and oxygen (in many cases the oxygen is vented - which is a waste). Some of this hydrogen and oxygen can be stored and later used for power production.

[0041] There are potential benefits of powering combustion engines with direct injection of fuel pure oxygen, sometimes referred to as “oxy-fucl” combustion. In the case of burning hydrocarbon fuel or methanol, this would have the benefit of not generating nitrous oxide in the high temperature high pressure combustion. The present invention provides a suitable combustion chamber for extracting energy from this highly explosive mixture of fuel and pure oxygen.

[0042] The use of high temperature materials, such as ceramics or high nickel-chromium alloys, could allow for the combustion of fuel and pure oxygen (with or without cooling). Energy from the combustion products (water vapor, or a combination of water vapor and carbon dioxide)) could be harnessed in a compound expansion to increase efficiency (with no need for cooling). Adding a condenser into the combustion / steam cycle would increase the efficiency of the engine, and could recycle water for reuse, possibly back into an electrolyzer. This type of hydrogen-oxygen combustion system could be used for larger stationary generator sets.

[0043] Super High Tensile Strength of Steel

[0044] Another part of the disclosure that forms part of the invention disclosed herein is the design configuration of a flexible steel power band. The Applicant has discovered that a very strong flexible power band can be made by "wrapping" thin gauge steel strips around two bushings. The strips are not bonded together, but allowed to slip past each other freely.

[0045] An example of a high-strength steel is a steel designated as HY-80, or "High Yield 80,000psi" (550 MPa), developed as part of the United States nuclear submarine program. An interesting phenomenon observed by the Applicant is the routinely measured tensile strength of fine steel wire at over 6,900 MPa (1,000,000 psi). It is also commonplace to find piano wire with tensile strengths up to 3,000 MPa (435,000 psi).

[0046] This invention, using the flexible steel bands in pure tension, takes advantage of the phenomenon of thin gauge super high tensile strength steel. The flexible power band design used for the large displacement internal combustion engine of the invention has super high tensile strength, incredible ease of manufacturing, and is easily replaceable during a routine scheduled maintenance (with the free-spin characteristic of the Bandmotor, it would be possible to replace a band while the engine is running, in minutes).

[0047] There could be concerns about high cycle fatigue effects on a steel band used to transmit power. However, there are many examples of serpentine belts used to transmit power that have high life expectancy and the same load characteristics would apply to the flexible bands made of high tensile composite materials. In the Applicant's opinion, a flexible band (steel or composite) could be designed to have a predictable and reasonably long life expectancy.

[0048] With the foregoing mind, in one aspect a compounding expansion engine includes an inner piston, functioning as a primary combustion piston, contained within an inner cylinder sleeve, functioning as a primary combustion expansion cylinder, the inner piston is connected to an inner drive rod by an inner piston attachment pin. The compound expansion engine also includes an outer piston, functioning as a secondary piston, outside a circumference of the inner cylinder sleeve, functioning as a secondary expansion cylinder, the outer piston is contained within an outer cylinder, functioning as a secondary expansion cylinder. A head assembly covers the inner cylinder sleeve and the outer cylinder. The inner piston and the outer piston are connected to a crankshaft respectively via an inner power band and at least one outer power band to produce rotating power output.

[0049] In some embodiments a combustion chamber of the inner piston and the inner cylinder sleeve are connected by a gas channel to the outer cylinder to allow hot expanding combustion gas to travel from the inner cylinder sleeve to the outer cylinder producing force on the outer piston.

[0050] In some embodiments an inner valve mechanism allows containment and release of the hot expanding combustion gas between the inner cylinder sleeve to the outer cylinder.

[0051] In some embodiments the outer cylinder is connected by a gas channel to the outer cylinder allowing hot expanding combustion gas to travel from the outer second cylinder to an exhaust manifold to be ejected.

[0052] In some embodiments an outer valve mechanism allows containment and release of the expanded combustion gas between tire second outer cylinder to the exhaust manifold.

[0053] In some embodiments the head assembly includes a cylinder head, a manifold cover positioned to cover the inner cylinder sleeve and the outer cylinder, the manifold cover includes an inner poppet valve in communication with the inner cylinder sleeve, an outer poppet valve in communication with the outer cylinder, a fuel injector, a spark plug, an oxidizer injector, and an exhaust manifold port.

[0054] In some embodiments the inner piston transmits power to a power output shaft through an inner drive rod that is engaged with the inner power band and an inner camcrank, and the outer piston transmits power to the power output shaft through two outer drive rods that are engaged with the at least one outer power band and outer camcranks.

[0055] In some embodiments the engagement of the inner drive rod to the inner powerband occurs through a power band trolley that is mounted with trolley guide rails, the engagement of the outer drive rods to the at least one outer power band occurs through a power band trolley that is mounted with trolley guide rails. In some embodiments an inner piston attachment pin connects the inner piston to an inner drive rod.

[0056] In some embodiments an outer piston attachment pin connects the outer piston to an outer drive rod.

[0057] In some embodiments the opposite ends of the inner power band and the at least one outer power band are connected to fixed stationary power band mounting blocks.

[0058] In some embodiments the head assembly comprises a disk valve head assembly. In some embodiments the disk valve head assembly comprises a disk valve with an arrangement of radial ports on the disk valve, a fixed disk plate, and a disk valve head, wherein the arrangement of radial ports on the disk valve provides for both transfer of hot expanding combustion gas from the inner cylinder sleeve to the outer cylinder, and discharge of spent combustion gases out of the outer cylinder into an exhaust manifold.

[0059] In some embodiments the radial ports comprise inner disk ports and outer disk ports, the inner disk ports and the outer disk ports are aligned in sequence with corresponding ports in the fixed disk plate.

[0060] In some embodiments a cam driven mechanism is used to open and close the disk valve.

[0061] In some embodiments the cam drive mechanism includes a cam lobe installed on a power output shaft, a rocker arm assembly, a cable with cable guides, and a return spring, the cable is attached to a disk valve stanchion at a stanchion fixture point, the cable is attached to the rocker arm assembly and a rocker arm fixture point, and a return spring is attached to a fixed fixture point on an engine body.

[0062] In some embodiments a secondary inner piston connected to the inner piston via an inner continuous drive rod and a secondary outer piston connected to the inner piston via outer continuous drive rod.

[0063] In some embodiments the inner power band and / or the at least one outer powerband comprise thin gauge steel strip wrapped around two bushings.

[0064] In some embodiments each thin gauge steel strip is,5mm thick.

[0065] In some embodiments the the inner power band and / or the outer power bands comprise multiple layers of thin steel strip.

[0066] In some embodiments the rotating power output is directed to a shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figures 1 through 11 are a series of drawings describing components of a compound expansion engine with variable compression and timing.

[0068] Figure 1 is an isometric view showing in inner and outer pistons connected to drive rods to transmit power to a camcrank with conventional poppet style valves for transferring and exhausting combustion gases.

[0069] Figure 2 shows a top view of the components described in Figure 1.

[0070] Figure 3 shows a side view of the components described in Figure 1, with a top view of the camcrank, trolley, and trolley guide mechanisms.

[0071] Figure 4A illustrates an event of the engine operating cycle at 1 -degree, when ignition occurs in the combustion chamber of the inner piston, and the exhaust phase is just beginning in the outer piston cylinder.

[0072] Figure 4B illustrates an event of the engine operating cycle at 90-degrees, when the inner piston is halfway through the power stroke, and the outer piston is halfway through the exhaust stroke.

[0073] Figure 4C illustrates an event of the engine operating cycle at 181 -degrees, when the inner piston is at the bottom of the power stroke, and the outer piston is at the top of the exhaust stroke.

[0074] Figure 4D illustrates an event of the engine operating cycle at 270-degrees, when the inner piston is moving up and displacing hot combustion gas through the open valve into the secondary cylinder. The hot pressurized gas from the inner cylinder sleeve is driving the outer piston downward.

[0075] Figure 411 illustrates an event of the engine operating cycle at approximately 340-degrees, where the inner valves have closed. Compression of tire remaining gas within the combustion chamber above the inner piston is increasing, and the fuel / oxidizer is being injected. Outer valves are just beginning to open to allow the expanded exhaust gases to escape into the exhaust manifold.

[0076] Figure 5 shows the arrangement of a disk style valve for both the transfer of hot combustion gases out of the inner cylinder sleeve into the outer cylinder, and for exhausting the combustion gases out of the outer cylinder into the exhaust manifold Figure 5A is an exploded view of the disk valve head assembly showing the a fixed disk plate and the disk valve shown in Figure 5

[0077] Figure 6A shows the position of the perforated disk valve during the power stroke of the inner piston, where the inner valve ports between the inner and outer cylinder are in the closed position. During the power stroke, the outer ports between the outer cylinder and the exhaust manifold are open, allowing exhaust of the spent combustion gases.

[0078] Figure 6B shows the position of the perforated disk valve during the gas transferstroke of the inner piston, where the inner valve ports between the inner and outer cylinder are in the open position. During the gas transfer stroke, the outer ports between the outer cylinder and the exhaust manifold or closed, allowing the hot combustion gases to exert force on the outer piston.

[0079] Figure 7 shows the cam driven mechanism used to open and close the disk valve, including a cam lobe installed on the maid shaft, a rocker arm assembly, a cable with cable guides, and a spring return.

[0080] Figure 8 shows an arrangement of opposed cylinders, where the continuous drive rods eliminate the need for the trolley mechanism.

[0081] Figure 9 shows a means of varying the time of the TDC (top-dead-center) of the inner piston relative to the BDC (bottom-dead-center) of the outer piston, and vice versa.

[0082] Figure 10 shows the design and means of manufacturing of a very strong flexible steel power band.

[0083] Figure 11 shows a preferred embodiment of a camcrank using multiple standard roller bearings.

[0084] Figures 12A to 12F disclose operation of a valved-piston assembly disclosed in Applicant’s US Patent Application Serial No. 19 / 300,927 describing the sequence of events resulting in the 360-degree rotation of two camcrank assemblies. DETAILED DESCRIPTION

[0085] The detailed embodiments of the present invention are disclosed herein. It should be understood, however, that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the details disclosed herein are not to be interpreted as limiting, but merely as a basis for teaching one skilled in the art how to make and / or use the invention.

[0086] The description of the compounding band motor at least partially relies on reference to the journal-less camcrank assembly described in detail in a prior patent application, see U. S. Patent Application Publication Number 2014 / 0224116, which is incorporated herein by reference. In this prior patent application, a camcrank assembly is engaged by a flexible membrane that transmits power to the camcrank mechanism by a pulling tension. It is further described that the connecting membrane is not fixedly attached to the camcrank assembly, but rather the connecting membrane only engages the camcrank assembly if there is a force in the flexible membrane (due to a combustion event) that causes the camcrank to move.

[0087] Figures 1 through 11 are a series of drawings describing components of a compounding expansion engine with variable compression and timing.

[0088] Referring to Figures 1, 2, and 3, an inner piston 1, functioning as a primary combustion piston, contained within an inner cylinder sleeve (also referred to herein as the primary combustion expansion cylinder) 2, functioning as a primary combustion expansion cylinder, of a compounding expansion engine is disclosed. The inner piston 1 is connected to an inner drive rod 3 by means of an inner piston attachment pin 4. The inner piston 1 is contained between the inner cylinder sleeve 2 and the base plate 18. The top of the inner cylinder sleeve 2 is covered by a head assembly that is discussed below in greater detail. Figure 1 shows the inner piston 1 at the zero-degree rotation mark, which is TDC (top-dead-center) of the inner piston 1 firing stroke. As shown, there is an outer piston 5 that is 180-degrees of rotation from the position of the inner piston 1.

[0089] As shown in Figures 1 and 2, outside the circumference of the inner cylinder sleeve 2, functioning as a secondary expansion cylinder, is a second piston referred to as the outer piston 4, functioning as a secondary piston. As the outer piston 4 is positioned about the inner cylinder sleeve 2, the outer piston 4 is annular in shape. The outer piston 4 is contained within the outer cylinder 6 and base plate 18. The top of the outer cylinder 6 is covered by a head assembly that is discussed below in greater detail. The outer piston 5 is connected to outer drive rods 7 by outer piston attachment pins 8. Both the inner piston 1 and the outer piston 5 transmit power to a power output shaft 11. As is conventional in the art, the base plate 18 includes apertures for the passage of the inner-drive rod 3 and the outer drive rods 7

[0090] As shown in Figures 1 and 2, the inner piston 1 transmits power to the power output shaft 11 through the inner drive rod 3 that is engaged and coupled with an inner-power band 10 and inner camcrank 9. The engagement of the inner drive rod 3 to the inner power band 10 occurs through a power band trolley 15 that is mounted with trolley guide rails 16. In particular, a first end 10a of the inner power band 10 is connected to the power band trolley 15, while a opposite second end 10b of the inner power band 10 is connected to a power band mounting block 14. The remainder of the inner powerband rides over the inner camcrank 9 and rotates the camcrank 9 as the inner drive rod 3 moves up and down.

[0091] As shown in Figures 1 and 2, the outer piston 5 transmits power to the power output shaft 11 through two outer drive rods 7 that are engaged with separate outer power bands 13 and outer camcranks 12. The engagement of the outer drive rods 7 to the outer power bands 13 occurs through a power band trolley 15 that is mounted with trolley guide rails 16. In particular, first ends 13a of the outer power bands 13 are connected to the power band trolley 15, while opposite second ends 13b of the outer power band 13 are connected to power band mounting blocks 14. The remainder of the outer power bands 13 rides over the outer camcranks 12 and rotate the camcranks 12 as the outer drive rods 7 moves up and down.

[0092] It should be noted that inner and outer camcranks are offset relative to the poweroutput shaft in a manner providing for continuous rotation of the power output shaft. It should also be noted that the inner and outer camcranks are journal-less camcranks as discussed above with reference to Figure 12A through 12F, and include outer rings that are allowed to rotate relative to the central portion thereof that is connected to the power output shaft.

[0093] Transmission of power via a flexible membrane and camcrank to an output shaft is performed in the manner described in U. S. Patent Application Publication Number-2014 / 0224116, which is incorporated herein by reference.

[0094] Figure 1 is an exploded view of a portion of the trolley guide rails 17 showing the containment of the power band trolley 15. The opposite end of the inner power band 10 and the outer power bands 13 are connected to fix stationary power band mounting blocks 14. Further shown in Figure 1 is a head assembly covering the inner cylinder sleeve 2 and the outer cylinder 6. The head assembly comprises a cylinder head 19, a manifold cover 20, an inner poppet valves 21 in communication with the inner cylinder sleeve 2, outer poppet valves 22 in communication with the outer cylinder 6, a fuel injector 23, a spark plug 24, an oxidizer injector 25, and an exhaust manifold port 26. Further descriptions of the operation of these components is provided below with reference to Figure 4A, 4B, 4C, 4D, and 4E in the following figures.

[0095] The actuation mechanisms of valves shown in Figures 1, 2, and 3 for the inner poppet valves 21 and the outer poppet valves 22 can be a hydraulic, pneumatic, or direct mechanical system actuated by either cams or electronic actuation. In the preferred embodiment, they would be electronically controlled electro-pneumatic actuators for precise and variable valve open-close timing.

[0096] Figure 2 shows a top view of the components described in Figure 1 with the inner-piston 1 at TDC (top dead center). The view of the power band trolleys 15 is shown in hidden lines. Hidden lines are appropriate because the power band trolleys are hidden behind the trolley guide rails 16.

[0097] Figure 3 shows a side view of the components described in Figures 1 and 2, with the inner piston 1 at TDC (top dead center). The side view is shown with a section of the trolley guide rail removed to show the power band trolley 15.

[0098] Referring to Figures 4A, 4B, 4C, 4D, and 4E, the engine operating cycle of the combustion, power expansion, and exhaust of the compound expansion engine are described. It should be noted that the opening and closing of the inner poppet valves 21 and the outer poppet valves 22 can be adjusted to optimize flow and efficiency of the engine, and the following examples provided in Figures 4A through 4E are for the cursory explanation of the operation of the invention.

[0099] Figure 4A illustrates an event of the engine operating cycle at 1 -degree of rotation, immediately past top-dead-center, immediately after ignition of the fuel-oxidizer mixture in the combustion chamber 27 of the inner piston 1, and the exhaust phase is just beginning in the outer piston cylinder 6. With the inner poppet valves 21 closed, the hot expanding combustion gas 28 is producing a force on the inner piston 1 driving it downward. The downward force exerted on the inner piston 1 by the hot expanding combustion gas 28 will drive the outer piston 5 upward (by means of the common connection to the power output shaft 11 (not shown in Figure 4A).

[0100] It is noted that the combustion chamber 27 can be configured with advanced high temperature materials such as ceramics or nickel-chromium containing alloys to withstand the high temperature and desirable heat transfer characteristics required for super high temperature combustion resulting from super high compression or injection and combustion using highly concentrated oxidizer (such as nearly pure oxygen).

[0101] As further shown in Figure 4A, at the 1-degree rotation point, the outer poppet valve 22 is just beginning to open, which will allow the exhaust of spent ignition combustion gas 29, as shown in Figure 4B.

[0102] Figure 4B illustrates an event of the engine operating cycle at 90-degrees of rotation, when the inner piston 1 is halfway through the power stroke, and the outer piston 5 is halfway through the exhaust stroke. The hot expanding combustion gas 28 continues to exert force on the inner piston 1 pushing it downward, and by means of the common connection to the power output shaft 11 (not shown in Figure 4B), the outer piston 5 continues to force the spent combustion gas 29 out of the outer cylinder 6. The spent combustion gas 29 is forced out of the outer cylinder 6, past the outer poppet valves 22 (which are now in the fully open position), into the exhaust manifold 30, and then finally out of the exhaust manifold port 26.

[0103] Figure 4C illustrates an event of the engine operating cycle at 181 -degrees of rotation, when the inner piston 1 is 1-degree past the bottom-dead-center of the power stroke, and the outer piston 5 is at the 1 -degree past the top-dead-center of its exhaust stroke. As shown by the arrows, the direction of the inner piston 1 and outer piston 5 have changed direction of movement. At this point, all of the spent combustion gas 29 has been exhausted and the outer poppet valves 22 have completely closed. The inner poppet valves 21 are just beginning to open to begin the next sequence of phase of the engine operating cycle, as shown in Figure 4D.

[0104] Figure 4D illustrates an event of the engine operating cycle at 270-degrees, when the inner piston 1 is moving up and displacing hot expanding combustion gas 28 through the open inner poppet valve 21 into the secondary cylinder 6. The hot expanding combustion gas 28 drives the outer piston 5 downward exerting work energy to the power output shaft 11 (not shown in Figure 4D).

[0105] Figure 4E illustrates an event in the engine operating cycle at approximately 340-degrees. At this point, the inner poppet valves 21 have closed. With the inner poppet valves 21 closed and the inner piston 1 moving upward, there is a compression by the inner piston 1 of the remaining gas within the combustion chamber 27 and immediately above the inner piston 1 (which would be considered a spent combustion gas 29). At some point near top-dead-center of the inner piston 1, fuel / oxidizer 23 are injected, as shown by the arrows 32, followed by spark ignition 33 from the spark plug 24 (or by spontaneous stratified ignition similar to the ignition that occurs in a diesel engine, if the design of the compression and temperature conditions creates this condition). At a tuning point near this part of the operating cycle, just immediately after the inner poppet valves 21 close, the outer poppet valves 22 begin to open allowing the outer piston 5 to begin exhausting the spent combustion gas 29, and the operating cycle, as described in Figure 4A, begins anew.

[0106] Figure 5 shows an embodiment of a compound expansion engine employing a disk style valve for both the transfer of hot combustion gases out of the inner cylinder sleeve into the outer cylinder, and for exhausting the combustion gases out of the outercylinder into the exhaust manifold. Referring to Figure 5 an isometric view of the disk valve head assembly 34, which includes a disk valve 35, a fixed disk plate 36, and a disk valve head 37 and head bolt holes 37’, is provided. The arrangement of radial ports on the disk valve 35 provides for both the transfer of hot expanding combustion gas 28 from the inner cylinder sleeve 2 to the outer cylinder 6, and the discharge of the spent combustion gases 29 out of the outer cylinder 6 into the exhaust manifold 30, as will be explained.

[0107] Figure 5A provides an exploded view of the disk style valve, including the disk valve 35 and the fixed disk plate 36. Figure 5A shows the placement of port openings on the disk valve 35, including the inner disk ports 38 and the outer disk ports 39. Figure 5A also shows the placement of the corresponding port openings on the fixed disk plate 36, including the fixed disk inner ports 38’ and the fixed disk outer ports 39’. Together with what is shown in Figure 5, and later with the descriptions provided in Figures 6A and 6B, the purpose and operations of the disk valve components are described.

[0108] Referring back to Figure 5, the disk valve 35 has two radial sets of ports, including the inner disk ports 38 and the outer disk ports 39. Both the inner disk ports 38 and the outer disk ports 39 are aligned in sequence with corresponding ports in the fixed disk plate 36 (further described in Figures 6A and 6B). While the fixed disk plate 36 is stationary, the disk valve 35 rotates between an “open” and “closed” position by means of a disk valve stanchion 40 that is forcibly rotated by a cam mechanism (further described in Figure 7).

[0109] For clarification, by reference to Figures 5, 6A, 6B, and 7, the disk valve assembly 35 has two positions, including (1) outer disk port 39 open for flow between the outer cylinder 6 and exhaust manifold 30, with inner disk ports 38 closed to flow, and (2) inner disk port 38 open for flow between the inner cylinder sleeve 2 and outer cylinder 6, with outer disk ports 39 closed to flow. The two positions are described in more detail in Figures 6A and 613, respectively.

[0110] With reference to Figures 6A and 6B, as previously described in the prior paragraph, there are two positions of the disk valve head assembly 34. Figure 6A shows the first position, Position 1: outer disk port 39 open for flow between the outer cylinder 6 and exhaust manifold 30, with inner disk ports 38 closed to flow. Figure 6B shows the second position, Position 2: inner disk port 38 open for flow between the inner cylindersleeve 2 and outer cylinder 6, with outer disk ports 39 closed to flow.

[0111] Figure 6A shows a cross-section of the operation characteristic of the disk valve head assembly 34 m “Position 1.” Shown in Figure 6A is the fixed disk plate 36, with two radial sets of port openings, including the fixed disk inner ports 38’, and the fixed disk outer ports 39’. Both the fixed disk inner ports 38’ and the fixed disk outer ports 39’, coincide with the ports on the disk valve head assembly 34, namely, the inner disk ports 38 and the outer disk ports 39.

[0112] While it can be seen in Figure 6A that there is an alignment of the outer disk port 39 with the fixed disk outer port 39’, there is no alignment of the inner disk port 38 (note, no callout for the inner disk port 38 is shown in Figure 6A because in is hidden by the rotation of the disk valve 35, but will appear in the description of Position 2 described in Figure 6B). The inner disk port 38 is sealed against the sealing surface 42 of the fixed disk plate 36. In this sequence of the engine cycle (sec Figures 4A and 4B), the pressure of the hot expanding combustion gases 28, exerts pressure on disk valve 35, which presses it against the sealing surface 42 of the fixed disk plate 36, creating a positive seal and maintaining high compression in the combustion chamber 27. To allow this seal to take place between the disk valve 35 and the sealing surface 43 of the fixed disk plate 36, the disk valve 35 is allowed to “float” freely approximately 1mm, to allow it to press against the sealing surface 43.

[0113] As shown in Figure 6A the alignment of the outer disk port 39 with the fixed disk outer port 39’, allows the spent combustion gases 29 to escape out past the fixed outer port 39’, then through the outer disk port 39, then through heat exhaust port 41, into the exhaust manifold 30, the finally out to the atmosphere (or post exhaust treatment) through the exhaust manifold port 26.

[0114] Figure 6B shows a cross-section of the operation characteristic of the disk valve head assembly 34 in “Position 2”. Position 2 is achieved by rotating the disk valve 35, approximately 12 degrees (which can vary depending on port spacing), by means of an actuator (not shown). Figure 7 shows a cam driven actuator to rotate the disk valve 35. The actuator mechanism (not shown in Figures 6A or 6B) could be hydraulically, pneumatically, or electronically (electromechanical), or a cam driven actuator.

[0115] Position 2, shown in Figure 6B, the inner disk ports 38 of the disk valve 35 are in line with the fixed disk inner ports 38’ of the fixed disk plate 36. While it can be seen in Figure 6B that there is an ahgnment of the inner disk port 38 with the fixed disk inner port 38’, there is no ahgnment of the outer disk port 39 (note, no callout for the outer disk port 39 is shown in Figure 6B because in is hidden by the rotation of the disk valve 35, which is converse to the position description provided for Position 1 described in Figure 6A). The outer disk port 39, and the disk valve 35, is sealed against the scaling surface 43 of the disk valve head 37. In this sequence of the. engine cycle (sec Figures 4D), the pressure of the hot expanding combustion gases 28, exerts pressure on disk valve 35, which presses it against the sealing surface 43 of the disk valve head 37, creating a positive seal and maintaining higher compression in the outer cylinder 6 to allow further expansion of the hot expanding combustion gases 28. To allow this seal to take place between the disk valve 35 and the sealing surface 43 of the disk valve head 37, the. disk valve 35 is allowed to “float” freely approximately 1mm, to allow it to press against the sealing surface 43.

[0116] The sequence of events of the combustion and exhaust cycle described in Figures 4A, 4B, 4C, 4D, and 4E are essentially the same as would apply to the optional disk valve head assembly 34 operation (with the exception that the valve opening and closing cannot be time separately.

[0117] Figure 7 shows the cam driven mechanism used to open and close the disk valve 35, including a cam lobe 44 installed on the power output shaft 11, a rocker arm assembly 45, a cable 46 with cable guides 47, and a return spring 48. The cable 46 is attached to the disk valve stanchion 40 at a stanchion fixture point 51. The cable 46 is attached to the rocker arm assembly 45 and the rocker arm fixture point 50. The return spring 48 is attached to a fixed fixture point 51 on the engine body.

[0118] Figure 8 shows a further embodiment including an arrangement of horizontally opposed cylinders 52A and 52B, where the inner continuous drive rod 53 and the outer continuous drive rods 54 eliminate the need for the trolley and guide mechanisms.

[0119] Referring to Figures 8 an inner piston 1A contained within an inner cylinder sleeve 2A of a compounding expansion engine is disclosed. The inner piston 1A is connected to an inner continuous drive rod 53 by means of an inner piston attachment pin 4A. Figure 8 shows the inner piston 1A at the zero-degree rotation mark, which is TDC (top-dead-center) of the inner piston 1 A firing stroke. As shown, there is an outer piston 5A that is 180-degrees of rotation from the position of the inner piston 1A.

[0120] Referring to Figures 8, there is an inner piston IB contained within an inner cylinder sleeve 2B. The inner piston IB is connected to an inner continuous drive rod 53 by means of an inner piston attachment pin 4B, with the opposite end of the continuous drive rod 53 connected to the inner piston 1 A by means of the an inner piston attachment pin 4A. Figure 8 shows the inner piston IB at the 180-degree rotation mark, which is BDC (bottom-dead-center) of the inner piston IB exhaust stroke. As shown, there is an outer piston 5B that is 180-degrees of rotation from the position of the inner piston 1 A.

[0121] By comparison to the firing sequence shown in Figures 4A through 4E, the combustion sequence can be ascertained for the horizontally opposed arrangement shown in Figure 8. The horizontally opposed piston arrangement shown in Figure 8 results in an extreme power density internal combustion engine option that is highly desirable in many applications, including power generator sets and engine changeouts for large ocean-going vessels. It is noted that the horizontally opposed piston arrangement shown in Figure 8 would include additional arrangements of traditional crankshaft / connecting rod mechanisms, camcrank / powerband mechanisms, not shown in the Figure 8 drawing.

[0122] Figure 9 shows a means of varying the rotation angle of the TDC (top-dead-center) of the outer piston 5 relative to the BDC (bottom-dead-center) of the inner piston 1, and vice versa. The real-time adjustability of the timing of the two pistons can be used for optimization of gas flow and increased efficiency.

[0123] Figure 9 shows an arrangement of where the position of the band mounting block 14 relative to the position of the outer camcrank 12 and the outer drive rod 7 influences the timing of TDC (top-dead-center) of the outer piston 5 (not shown in Figure 9). Figure 9 show’s the timing TDC of the outer piston 5 can be varied and adjusted by rotating the position of the band mounting block 14 between a zero setting 55 and maximum setting 56. Figure 9 shows an adjustment range of 12-degrees between a zero point 57 and a maximum point 58 on the TDC of the outer piston 5 relative to the BDC of inner piston 1.

[0124] This is an important factor for optimizing the energy efficiency of using the spent gases from the inner cylinder sleeve 2 to do work on the secondary outer piston 5. It appears that having the TDC of the outer piston 5 advanced about 12-degrees ahead of the BDC of the inner piston 1 allows for more efficient work to be done because there is an immediate downward motion of the outer piston 5 after it comes out of its direction transition.

[0125] Figure 10A, 10B, and IOC show the design of a very strong flexible power band for the inner power band 10 and the outer power band 13. Figure 10A, 10B, and IOC show how the inventor has determined that a very strong flexible power band can be made by "wrapping" thin gauge steel strip 59 (.5mm thick for example, see Figure 10 A) around two bushings 60 (see Figure 10B). Figure 10A shows a flexible power band made of multiple layers of thin steel strip 59, where the number of thin steel strip 59 material can be variable 59A. In the example shown in Figure 10B, there is Imeter between the two bushings 60. Both the top group 61 and the bottom group 62 form a "band" made up of 26 each 25mm wide thin steel strips 59 at,5mm thickness each, to make each the top group 61 and the bottom group a total of 13mm thick. The.5mm thick steel strips 59 are not bonded together, but allowed to slip past each other freely. As shown in Figure 10C, the entire assembly is then formed around a diameter mandrel tool 63 (not overly plastically formed and limited cold working) and then crimped 64 to form one of the inner or outer power band 10, 13 approximately 26mm by 25mm in cross section.

[0126] Figure 11 shows a preferred embodiment of a ball-bearing camcrank mechanism (instead of a bushing type camcrank, see items 9 and 12 in Figure 3 for a bushing type camcrank). In this embodiment, a camcrank center plate 65 is fixed to the main drive shaft (not shown) and a camcrank outer ring 69 is positioned around the camcrank center plate 65 for movement relative thereto. In particular, the camcrank center plate 65 includes an outer wall 65a having a first transverse dimension 65b defining the largest distance from one side of the outer wall 65a to another side of the outer wall 65a. The camcrank outer ring 69 is annular and includes an inner first wall 69a and outer second wall 69b, wherein the inner first wall 69a has a second diameter 69c that is greater than the first transverse dimension 65b defined by the camcrank center plate 65. The outer second wall 69b of the camcrank outer ring 69 has a third diameter 69d that is larger than either the first transverse dimension 65b or the second diameter 69c.

[0127] The camcrank center plate 65 is fixed to the center portions 66 of a plurality of roller bearing assemblies 67. The center portions 66 are pivot pins that are fixedly attached to the camcrank center plate 65, and about which the outer portions 68 of the roller bearing assemblies 67 rotate. The outer portion 68 of each of the roller bearing assemblies 68 is in contact with the camcrank outer ring 69, which allows free rotation of the outer ring 69, as described in the operation of the camcrank mechanism, as described in U. S. Patent Application Publication Number 2014 / 0224116.

[0128] In compliance with the statute, the invention has been described in language more or less specific to structural or methodical features. It is to be understood that the invention is not limited to specific features shown or described since the means herein described comprises preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the description and claims appropriately interpreted by those skilled in the art.

Claims

CLAIMS:

1. A compounding expansion engine, comprising:an inner piston, functioning as a primary combustion piston, contained within an inner cylinder sleeve, functioning as a primary combustion expansion cylinder, the inner piston is connected to an inner drive rod by an inner piston attachment pin.an outer piston, functioning as a secondary piston, outside a circumference of the inner cylinder sleeve, functioning as a secondary expansion cylinder, the outer piston is contained within an outer cylinder, functioning as a secondary expansion cylinder; and a head assembly covering the inner cylinder sleeve and the outer cylinder; the inner piston and the outer piston are connected to a crankshaft respectively via an inner power band and at least one outer power band to produce rotating power output.

2. The compounding expansion engine according to claim 1, wherein a combustion chamber of the inner piston and the inner cylinder sleeve are connected by a gas channel to the outer cylinder to allow hot expanding combustion gas to travel from the inner cylinder sleeve to the outer cylinder producing force on the outer piston.

3. The compounding expansion engine according to claim 2, further including an inner valve mechanism allowing containment and release of the hot expanding combustion gas between the inner cylinder sleeve to the outer cylinder.

4. The compounding expansion engine according to claim 3, wherein the outer cylinder is connected by a gas channel to the outer cylinder allowing hot expanding combustion gas to travel from the outer second cylinder to an exhaust manifold to be ejected.

5. The compounding expansion engine according to claim 4, wherein an outer valve mechanism allows containment and release of the expanded combustion gas between the second outer cylinder to the exhaust manifold.

6. The compounding expansion engine according to claim 1, wherein the head assembly includes a cylinder head, a manifold cover positioned to cover the inner cylinder sleeve and the outer cylinder, the manifold cover includes an inner poppet valve incommunication with the inner cylinder sleeve, an outer poppet valve in communication with the outer cylinder, a fuel injector, a spark plug, an oxidizer injector, and an exhaust manifold port.

7. The compounding expansion engine according to claim 1, wherein the inner piston transmits power to a power output shaft through an inner drive rod that is engaged with the inner power band and an inner camcrank, and the outer piston transmits power to the power output shaft through two outer drive rods that are engaged with the at least one outer power band and outer camcranks.

8. The compounding expansion engine according to claim 7, wherein the engagement of the inner drive rod to the inner power band occurs through a power band trolley that is mounted with trolley guide rails, the engagement of the outer drive rods to the at least one outer power band occurs through a power band trolley that is mounted with trolley guide rails.

9. The compounding expansion engine according to claim 1, wherein an inner piston attachment pin connects the inner piston to an inner drive rod.

10. The compounding expansion engine according to claim 1, wherein an outerpiston attachment pin connects the outer piston to an outer drive rod.

11. The compounding expansion engine according to claim 1, wherein opposite ends of the inner power band and the at least one outer power band are connected to fixed stationary power band mounting blocks.

12. The compounding expansion engine according to claim 11, wherein the head assembly comprises a disk valve head assembly.

13. The compounding expansion engine according to claim 12, wherein the disk valve head assembly comprises a disk valve with an arrangement of radial ports on the disk valve, a fixed disk plate, and a disk valve head, wherein the arrangement of radial ports on the disk valve provides for both transfer of hot expanding combustion gas from the inner cylinder sleeve to the outer cylinder, and discharge of spent combustion gasesout of the outer cylinder into an exhaust manifold.

14. The compounding expansion engine according to claim 13, wherein radial ports comprise inner disk ports and outer disk ports, the inner disk ports and the outer disk ports are aligned in sequence with corresponding ports in the fixed disk plate.

15. The compounding expansion engine according to claim 13, further including a cam driven mechanism used to open and close the disk valve.

16. The compounding expansion engine according to claim 15, wherein the cam drive mechanism includes a cam lobe installed on a power output shaft, a rocker arm assembly, a cable with cable guides, and a return spring, the cable is attached to a disk valve stanchion at a stanchion fixture point, the cable is attached to the rocker arm assembly and a rocker arm fixture point, and a return spring is attached to a fixed fixture point on an engine body.

17. The compounding expansion engine according to claim 1, further including a secondary inner piston connected to the inner piston via an inner continuous drive rod and a secondary outer piston connected to the inner piston via outer continuous drive rod.

18. The compounding expansion engine according to claim 1, wherein the inner power band and / or the at least one outer power band comprise thin gauge steel strip wrapped around two bushings.

19. The compounding expansion engine according to claim 18, wherein each thin gauge steel strip is.5mm thick.

20. The compounding expansion engine according to claim 19, wherein the inner power band and / or the outer power bands comprise multiple layers of thin steel strip.

21. The compounding expansion engine according to claim 1, wherein the rotating power output is directed to a shaft.

22. The compounding expansion engine according to claim 1, wherein the inner piston and the outer piston transmit power to a power output shaft via respective camcranks, each of the camcranks includes a camcrank center plate fixed to the power output shaft, and the camcrank center plate is fixed to a center portion 66 of roller bearing assemblies, an outer portion of the roller bearing assembly is in contact with a camcrank outer ring, which allows free rotation of the outer ring.

Images