CROSS REFERENCE fOOlj This PCT application claims tJhe benefit ofPCT application No. PCT/US2 14/0 5560, filed on April 25, 21)14.

BACKGROUND

[fl©2| The internal combustion engine generally refers to a type of engine, in which the combustion of a fuel occurs with art oxidizer in a combustion chamber. The oxidizer is typically air. The fuels commonly include hydrocarbons, and are derived ftom fossil fuels such as diesei, gasoline and petroleum gas. The expansion of the high-iemperature and high- pressure gases produced by the combustion exerts direct force to mechanical components such as pistons, turbine blades, nozzles and the like, thereby moving these components. In short, engines are configured to transform chemical energy into mechanical energy.

| 03j Most internal combustion engines that are designed for gasoline use can run on natural gas, hydrogen gas or liquefied petroleum: gases. Liquid and gaseous biofnels such as ethanol and biodiesel can also be used. Biodiese! is produced from crops that

yield triglycerides such as soybean oil. So called producer gas, which is made from biomass, can also be used. Examples of next-generation fuels include shale gas, which may offer a low-cost energy solution with eco-fnend!y chemical reaction.

|t¾) j In view of ever increasing needs for energy saving and eco-frtendlitiess as well as the drive t o reduce dependency on foreign-produced oil, designs of highly efficient engines arc desired to utilize new types of fuels at their foil potential,

BRIEF D ESC I PTl ON OF THE DRAWINGS

[ «5j FJG. 1 illustrates an example of the conventional four-cycle process.

|0©6J FIG. 2 illustrates the structure of an example of the rotary synchronized combustion engine according to an embodiment,

(007) FIG. 3 is a block diagram illustrating a system including the .rotary synchronized combustion engine according to an embodiment.

i |0©8] FIGS. 4 A 4H illustrate key steps of the process of the rotary synchronized combustion engine according to an embodiment.

f(M)9| FIG. 5 illustrates an example in which a fourth wing section is provided to engage with the second wing section and a fifth wing section is provided to engage with the third wing section.

{001l){ FIGS. 6A - 6E illustrate the structure of another example of the rotary synchronized combustion engine according to an embodiment.

[001.1] FIG. 7A illustrates a perspective view of a 3D configuration of the first wing section integrated around the first shaft and the second wing section integrated around the second shaft, wherein the first wing section and the second wing section are oriented substantially orthogonal to each other.

10012 _. 1 FIG. 7B is a schematic drawing of the configuration illustrated in FIG. 7A, when viewed along the vertical direction.

(0013) FIG, SA illustrates a perspective view of another 3D configuration of the structure that is the same as the structure illustrated in FIGS. 7A and IB, wherein the first wing section and the second wing section are rotated to the configuration corresponding to the configuration illustrated in FIG. 4D.

(0014 _. 1 FIG- 8B is a schematic drawing of the configuration illustrated in FIG. A, when viewed along the vertical direction.

These drawings are provided to assist m understanding of the embodiments of the rotary synchronized combustion engine as described in detail below. In particular, the relative spacing, positioning, sizing and dimensions of various elements illustrated in the drawings are not drawn to scale. Those of ordinary skill in the art will appreciate that a number of alternative configurations exist but are omitted herein for clarity*,

DETAILED DESCRIPTION

|001$1 In a typical internal combustion engine, the combustion is intermittent as exemplified by the four-cycle, two-cycle or six-cycle process. FIG. 1 illustrates an example of the conventional four-cycle process in which four basic steps are repeated with two revolutions of the engine. These four steps are: (A) intake step, (B) compression step, (C) power step, and (D) exhaust step.

[0016] in F G. 1 , the rotational .movement generated by a crankshaft 104 actuates the linear movement of a piston 108 via a connecting rod 106, The initial rotational movement may be driven by a starter motor, for example, in the intake step A, the piston SOS moves downward in a cylinder 1 12, which forms a. combustion chamber, to maximize the volume within the cylinder 112 above the piston 108, thereby creating a low pressure therein. An inlet valve 1 16 opens by a cam lobe 120 pressing down a valve stem 124, while an outlet valve I 18 is closed. A mixture of fuel and air is sucked into the combustion chamber by atmospheric or greater pressure into the cylinder 1.1.2 where the pressure is low. The inlet valve 1 .16 closes at the end of this step.

M* 17 f in the compression step B, the inlet val ve 1 1 and the outlet valve 1 18 are closed, and die piston 108 moves upward in the cylinder 11.2 to minimize the volume within the cylinder 1 12 above the piston 108, thereby compressing the air-fuel mixture therein. During this compression process, pressure, temperature and the density of the air- fuel mixture increase,

[0018] in the power step€, the piston 108 is close to the top of the cylinder 1 12, and the air- fuel mixture is compressed to the minimum volume and ignited by a spark plug 128, The expansion of gases by the combustion of the air-fuel mixture pushes the piston 108 and the connecting rod 1 6 downward in the cylinder .1 12, producing power to rotate the crankshaft 104.

[0019] in the exhaust step D, the piston 1 18 moves upward from the position where the maximum volume within the cylinder 112 above th piston i IS is created, and the outlet valve 118 opens to allow the exhaust gases to escape the cylinder 112. At the end of this step, the outlet valve 1 18 closes, the inlet valve 1. 1.4 opens, and the sequence of the steps A - D repeats in the next cycle.

[0020] In the four-cycle process of a conventional internal combustion engine as depicted above, the four steps are carried out sequentially, and the conversion between the rotational movement of the crankshaft and the linear movement of the piston is repeated for transmission of the power generated by the combustion, Thus, the efficiency is inherently low. in view of the problems associated with the fundamental engine mechanism, the present document describes a new type of engine that enables power transmission between rotational movements without involving linear movements. The engine structure is configured to allow for only rotational movement of the parts, including reversibie rotational movements, and to synchronize multiple combustions within a cycle. Details of such rotary synchronized combustion engines according to present embodiments are explained below with reference to the subsequent drawings.

[0021 J FIGS. 2A - 2.E illustrate the structure of an example of the rotary synchronized combustion engine according to an embodiment, separately illustrating a front view in FIG. 2A, a side view in FIG. 2B, a cross-sectional view in FIG. 2C with respect to the plane indicated by dash-dot line a - a' in FIG, 2A, a top view in FIG. 2D, and a cross-sectional view in FIG. 2E with respect die plane indicated by dash-dot line b ~ b ^* in FIG. 2C. The internal parts of the engine are accommodated in a housing 200, which has a shape of enveloping a combination of three cylinders, which have substant ially the same dimensions, merged side-by-side to overlap partial iy with each adjacent one by keeping the three top surfaces level as well as the bottom surfaces level. The housing 200 has a side section, which is formed uniformly along the vertical direction, and top and bottom sections in the horizoiual direction. Each of the side section, the top section and the side section has an internal surface and an external surface . A first cylindrical section 204- 1 that is a center section of the housing 200 and a second cylindrical section 204-2 and a third cylindrical section 204-3 of the bousing 200 have respective cylindrical axes, each of which is an axis of symmetry of the cylinder. The vertical direction V and the horizontal direction H are indicated in the inset of FIG. 2A. Along the axes of symmetry, first, second and third shafts 208- 1 , 208-2 and 208-3 are provided, respectively. Thus, these shafts are provided in alignment and in parallel with each other, vertically penetrating through the housing 200. The housing 200 is attached with eight ducts 212-1, 212-2 ... and 212-8 communicating with the inside of the housing 200, each duct being for use for passing an air-fuel mixture or exhaust gases. All the eight ducts 212- 1, 212-2 ... and 212-8 are seen in the cross sectional view in FIG. 2C; the four ducts 212-1, 212-2, 212-5 and 212-7 provided in the front side section of the housing 200 are seen in the front view in FIG. 2A. The first and second duets 21 2-1 and 212-2 are attached to the front side section of the first cylindrical section 204-1 of the housing 200; and the third and fourth ducts 212-3 and 212-4 are attached to the back side section of the first cylindrical section 204-1 of the housing 200. The fifth duct 212-5 is attached to the front side section of the second cylindrical section 204-2 of the housing 200; and the sixth duct 212-6 is attached to the back side section of the second cylindrical section 204-2 of the housing 200. The seventh duct 212-7 is attached to the front side section of the third cylindrical section 204-3 of the housing 200; and the eighth duct 212-8 is attached to the back side section of the third cylindrical section 204-3 of the housing 200. Two spark plugs 216- 1 and 216-2 are provided to the first cylindrical section 204- 1 of the housing 200 for igniting the air-fuel mixture in two open sections, respectively, in the first cylindrical section 204-1 of the housing 200, These two spark lugs 216-1 and 216-2 may be attached to the top section of the first cylindrical section 214-1 as exemplified in FIGS. 2A and 2D; alternatively, one of them may be attached to the top section and the other may be attached to the bottom section, or both of them may be attached to the bottom section of the first cylindrical section 204- L

[0022] Each shaft is provided along the cylindrical axis of each cylindrical section of the housing 200, and a wing section is integrativel attached around each shaft. Specifically, as seen in the cross sectional view in the FIG. 2C, the first cylindrical section 204- 1 accommodates a first wing section 220-1 integratively attached around the first shaft 208-1 , the second cylindrical section 204-2 accommodates second wing section 220-2 integratively attached around the second shaft 208-2, and the third cylindrical section 204-3 accommodates a third wing section 220-3 integratively attached around the third shaft 208-3. Each wing section is configured to he vertically uniform along the shaft, a illustrated in FIG. 2E, which illustrates the vertical cross-sectional shape of the first wing section 220-1 and the first shaft 208-1 with respect to the plane indicated by b - b' in FIG. 2C. Only the shaft and the wing section are illustrated in FIG. 2E for clarity, by omitting the outlines of the housing 200 and the other parts.

[0023] Each wing section is configured so that the first wing section 220-1 engages with the second wing section 220-2 at one side and the third wing section 220-3 at the other side to dri e the axial rotation of the second wing section 220-2 and the third wing section 220-3 when the first wing section 220- 1 axia!ly rotates with the rotation of the first shaft 208- 1. An example is illustrated in FIG. 2C, where in the horizontal cross-sectional shape of each wing section is configured to be symmetric with respect to a vertical plane including the center axis of the shaft and to have two edge portions, each edge portion spanning along a part of the internal side surface of the corresponding cylindrical section of the housing 200. Both edge portions of each wing section are configured to be in contact with the internal side surface of the corresponding cylindrical section of the housing 200, and yet able to rotate freel within the corresponding cylindrical section of the housing 200. Lubrication oil or any other suitable materia! or technique may be used for that purpose. Each edge portion is configured io be wider than the portion near and around the shaft.

{0024] FIG. 3 is a block diagram illustrating a system including the rotary synchronized combustion engine according to an embodiment The reference numerals for the engine parts are the same as those used in FIG. 2, and omitted in FIG. 3 for clarity. The system includes various units additional to the engine unit to enable the engine process. A controller 300 including a CPU and/or a computer program may be co tipied to various parts of the engine to control associated functions. For example, the controller 300 is coupled to the eight ducts 212-1 , 212-2 .. . and 212-8 to control the input and output timings, pressure and other parameters associated with the air-fuel mixture and exhaust gases. One or more of the ducts 212-1, 212-2 . .. and 212-8 may include one or more valves, respectively, the open/close of which may also he controlled by the controller 300. The conn-oiler 300 is further coupled to the spark plugs 216-1 and 216-2 to control the ignition timings. The first shaft 208- 1 may be coupled to a starter motor 304 that drives the initial rotation of the first shaft 208-1. Instead of using a starter motor, the initial rotation may be driven manually or by other means as configured by those skilled in the art. The second shaft 208-2 and the third shaft 208-3 are coupled to mechanical parts 308 and 312, respectively, to transmit power in the form of the rotational energy of the second and third shafts 208-2 and 208-3 to the mechanical parts 308 and 312, respectively. The first shaft 208-1 is coupled to a mechanical part 316 to transmit power in the form of the rotational energy of the first shaft 208-, i to the mechanical part 316 once the engine process started.

[0025] FIGS. 4 A - 4H illustrate sequential steps of the engine process of the rotary synchronized combustion engine according to an embodiment. The reference numerals for the engine parts and other parts in the system are the same as those used in FIGS. 2 and 3, and tints omitted in FIGS. 4A - 4H.

[002t» _. | FIG . 4A illustrates a confi guration of the engine parts before starting, wherein the first wing section 220-1 is oriented substantiall orthogonal to the second wing section 220-2 and the third wing section 220-3, which are oriented substantially in parallel to each other. Here, the second wing section 220-2 is oriented so as to close the ducts 212-5 and 2 i 2-6 attached to the second cylindrical section 204-2, and the third wing section 220-3 is oriented so as to close the ducts 212-7 and 212-8 attached to the third cylindrical section 204-3, while the ducts 2.12-3 and 212-4 attached to the back side section of the first cylindrical section 204-1 communicate with an first open section 400- 1, and the ducts 212-1 and 212-2 attached to the front side section of the first cylindrical section 204-1 communicate with a second open section 400-2. Here, the first open section 400-1 and the second open section 400-2 are two open sections associated with the first wing section 200-1 , each open section surrounded by the first wing section 220-1 and the first cylindrical section 204- 1 of the housing 200.

[0027] FIG. 4B illustrates a configuration of the engine parts when the counter-clockwise rotation of the first wing section 220-1 is about to be started with the initial rotation of the first shaft 208-1 by the starter motor 304, tor example. The air-fuel mixture is injected as soon as the rotation starts so as to fill the first open section 400-1 and the second open section 400-2. The third duct 212-3 serves as an inlet to input the air-fuel mixture to the first open section 400- 1 , and the second duct 212-2 serves as an inlet to input the air-fuel mixture to the second open section 400-2. The fourth duct 212-4 and the first duct 212- 1 may be closed by- using respective valves 404- 1 and 404-2, so that the inputted air-fuel mixture does not escape through these ducts. The controller 300 may be configured to control the open/close of these valves. Alternatively to using valves, the rotation speed of the first wing section 220- i may be adjusted so that the first wing section 22.0- 1 rotates counter-clockwise fast enough to close the fourth duet 212-4 and first duct 212-1 before the inputted air-fuel mixture reaches these ducts to escape.

002-8] FIG. 4C illustrates a configuration of the engine parts, wherein the first wing section 220-1 has rotated counter-clockwise to reach the orientation to close the fourth duet 212-4 and first duct 212-1 , while the third duet 212-3 and the second duct 212-2 are still open as inlets for inputting the air-fuel mixture. Due to the fricfionai force between the first wing section 220- .1 and the second wing section 220-2, the second wing section 220-2 rotates clockwise. Similarly, due to the fiictiona! force between the first wing section 220- 1 and the third wing section 220-3, the third wing section 220-3 rotates clockwise. As mentioned earlier with reference to (C) of PIG. 2, the edge portions of each wing section are configured to be wider than the portion near and around the shaft. Therefore, in the configuration of FIG . 4C, the volume of the first open section 400-1 is reduced by the amount of a firs t projection 408-1 , which is a portion of the edge portion of the second wing section 220-2, the portion projecting into the first open section 400-1 . Similarly, the volume of the second open section 400-2 is reduced by the amount of a second projection 408-2, which is a portion of the edge portion of the third wing section 220-3, the portion projecting into the second open section 400-2. in spite of the reduced volume of each of the open sections 400- 1 and 400-2, the air- fuel mixture may be controlled, to keep entering the open sections 400-1 and 400-2 by adjusting the external pressure to he higher than inside the open sections 400-1 and 400-2. Here, the controller 300 including a CPU and/or a computer program ma be configured to control the input and output timings, pressiife and other parameters associated with the air- fuel mix ture. Accordingly, the density of the air-fuel mixture in the open sections 400-1 and 400-2 can be maintained or controlled to even increase instead of decrease. At the same time, the first open section 400-1 starts overlapping with a third open section 400-3, which is one of the open sections associated with the second wing section 220-2 and surrounded by the second wing section 220-2 and the second cylindrical section 204-2 of the housing 200.

Through the overlap portion 412-1, some of the air-fuel mixture is channeled from the first open section 400- i to the third open section 400-3. Similarly, the second open section 400-2 starts overlapping with a fourth open section 400-4, which is one of the open sections associated with the third wing section 220-3 and surrounded by the third wing section 220-3 and the third cylindrical section 204-3 of the housing 200, Through the overlap portion 412-2, some of the ai -fuel mixture is channeled from the second open section 400-2 to the fourth open section 400-4.

[0029] FIG, 4D illustrates a configuration of the engine parts, wherein the first wing section 220- i has further rotated counter-clockwise, and the second and third wing sections 220-2 and 220-3 have further rotated clockwise, until the first projection 408-1 touches the first wing section 220- 1 to close the channel between the first open section 400-1 and the third open section 400-3, and the second projection 408-2 touches the first wing section 220-1 to close the channel between the second open section 400-2 and the fourth open section 400-4, The air-fuel mixture may still be inputted through the third and first ducts 21 -3 and 212- L to fill the first and second open sections 400-1 and 400-2 by using a higher externa! pressure than the pressure inside the first and second open sections 400-1 and 400-2. Additionally, the air-fuel mixture in the third open section 400-3 ma be transferred to the second open section 400-2, and the air-fuel mixture in the fourth open section 400-4 may be transferred to the first open section 400- 1 , as indicated by solid arrow Sines in FIG. 4D. As a result, the air- fuel mixture is collected only in the first and second open sections 400-1 and 400-2 associated with the first wing sections 220- 1. Therefore, the system configuration according to the present embodiment allows for efficient use of the air-fuel mixture, by minimizing the escape thereof from the system. The transfer mechanism may be configured by using additional duets allowing for the channeling between, the fifth duct 212-5 and the second duet 212-2 and between die eight-duct 212-8 and the third duct 212-3, wherein the channeling timings ma be controlled by the controller 300 via opening and closing of associated valves. Any technique for transferring the air-fuel mixture with precise timings can he utilized as conceived, by a person of ordinary skill in the art.

10030} FIG. 4E illustrates a con figuration of the engine parts, wherein the first wing section 220-1 has further rotated counter-clockwise to orient substantially orthogonal to the second wing section 220-2 and the third wing section 220-3, which are oriented substantially in alignment with each other. Here, the first wing section 220- 1 is oriented so as to close the first. - fourth ducts 21 - 1 - 212-4 attached to the first cylindrical section 204- 1. The first open section 400-1 is closed by a first edge portion 416-1 of the second wing section 220-2; and the second open section 400-2 is closed by a second edge portion 416-2 of the third wing section 220-3, Each edge portion is configured to cylindrically span along a part of the internal side surface of the cylindrical section of the housing 200, in which the edge portion is located. Thus, in the configuration of FIG. 4E, the first edge portion 416-1 projects into the first open section 400-1 and closes the first open section 400-1 to have the minimum volume among all possible volumes. Similarly, the second edge portion 416-2 projects into the second open section 400-2 and doses the second open section 400-2 to have the minimum volume among all possible volumes. Due to the transfer of tiie air-fuel mixture indicated in FIG. 4D, the amount of the air- fuel mixture in the first and second open sections 400- 1 and 400-2 in FIG, 4E is substantially the same as the total amount injected into the first - fourth open section 400- 1 - 400-4 indicated in. FIG. 4 ^' D. The air-fuel mixture is thus compressed within the smallest possible volume, giving rise to the highest density in the configuration of FIG. 4E among all possible configurations. That is, the air-fuel mixture inputted inside the housing 200 is collected in the two open sections associated with the first wing section 220-1 , and compressed when each of the two open section has a minimum volume.

(0031] FIG. 4F illustrates a configuration of the engine parts, wherein the compressed air- fuel mixture in the first and second open section 400-1 and 400-2 gets ignited by the spark plugs 216-1 and 216-2, respectively. The timings of ignition may be controlled by the controller 300. The expansion of gases by the combustion of the air-fuel mixture produces power to push further the counter-clockwise rotation of the first wing section 220-1, which engages the second and third wing sections 220-2 and 220-3 to drive the clockwise rotation thereof. As a result, the first, second and third shafts 208- 1, 208-2 and 208-3 axtally rotate individually, thereby transmitting power in the form of the rotational power to external parts to he utilized for performing various functions. It should he noted that the engine parts in this example are configured to have two synchronized combustions that can produce larger energy at once than in the case of sequential combustions. This scenario is analogous to having a two-cylinder engine as opposed to having a one-cylinder engine.

[00321 FIG. 4G illustrates a configuration of the engine parts, wherein the first wing section 220-1 has further rotated to the orientation where the first wing section 220- i closes the third dtsct 212-3 and the second duct 212-2, while the first open section 400-1 communicates with the first duet 212- 1 and the second open section 400-2 communicates with the fourt duct 212-4 for allowing the exhaust gases to escape. The high internal pressure after the combustion will naturally push out the exhaust gases. Alternatively, the external pressure ma he adjusted to he lower than the internal pressure to suck out. the exhaust gases. The controller 300 may be configured to control the timings, pressure and other parameters associated with the exhaust gases.

[0033] FIG. 4H illustrates a configuration of the engine parts, wherein the first wing section 220-1 has further rotated to the orientation where the first wing section 220- ^' ! still closes the third duct 212-3 and the second duct 21 -2, the first open section 400-1 still communicates with the first duet 212-1, and the second open section 400-2 still communicates with the fourth duct 212-4. It is indicated in this figure that almost: all the exhaust gases have been outpurted from the first and second open sections 400-1 and 400-2 through the first duct and the fourth duct, respectively, and a fresh air-fuel mixture is ready to be inputted through the third duet 212-3 and the second duct 212-2,

[0034] After the configuration illustrated in PIG. 4H, the first, second and third wing sections 220-1 , 220-2 and 220-3 further rotate to assume the configuration illustrated in FIG. 4B, where the air-fuel mixture is inputted to the first and second open sections 400-1 and 400-2, and the process depicted in FIG. 4S ----- 4H repeats.

[0035J As explained with reference to FIGS. 4A— 4H above, the expansion of gases by the combustion of the air-fuel mixture produces power to push further the counter-clockwise rotation of the -first wing section 220-1 , which engages the second and third wing sections 220-2 and 220-3 to drive the clockwise rotation thereof. As a result, the first, second and third shafts 208- 1 , 208-2 and 208-3 axially rotate individually, thereby transmitting power in the form of the rotational energy to external parts to he utilized for performing various functions. In a conventional internal combustion engine such as illustrated in FIG. 1, the expansion of gases by the combustion of the air-fuel mixture pushes the piston 1 8 and the connecting rod 1 6 downward in the cylinder .1 12, producing power to rotate the crankshaft 104, whereby the power is transmitted to external parts oniy through one transmission path, and both linear and rotational motions are involved. In contrast, in the present rotary synchronized combustion engine, the first, second and third shafts 208-1 , 208-2 and 208-3 axially rotate individually, thereby transmitting power in the form of the rotational energy through three different transmission paths.

[0036] it is possible to increase the number of power transmission paths by providing one or more additional wing sections with respective additional shafts. FIG. 5 illustrates an example in which a fourth wing section 220-4 is provided to engage with the second wing section 220- 2 and a fifth wing section 220-5 is provided to engage with the third wing section 220-3. ^" The axial rotation of the first wing section 220- i drives the axial rotation of the second w ng section 220-2, which in turn drives the axial rotation of the fourth wing section. Similarly, the axial rotation of the first wing section 220-1 drives the axial rotation of the third wing section 220-3, which in turn drives the axial rotation of the fifth wing section 220-5. The one or more wing sections may be sequentially engaged with the second wing section 220-2, the third wing section 220-3 or both. The number of additional wing sec tions on the left may he the same as or different from the number of additional wing sections on the right. The total number of additional wing sections can be determined according to the needed number of power transmission paths and the needed power amounts transmitted through respective transmission paths.

[0037] A conventional internal combustion engine such as illustrated in FIG. I. operates to sequen tially perform the steps in the cycle. In contrast, in the present rotary synchronized combustion engine, the compressed air-fuel mixture in two combustion chambers, i.e., the first open section 400- 1 and the second open section 400-2, are ignited simultaneously by the two spark plugs 216-1 and 216-2, respectively, as illustrated in FIG. 4F. Therefore, the engine parts are configured to have two synchronized combustions that can produce larger energy at once than in the case of conventional sequential combustions. This scenario is analogous to having a two-c linder engine as opposed to having a one-cylinder engine.

f(M>38] In the present example of the rotary synchronized combustion engine, the engine parts are configured to have two open sections for combustion. However, it is possible to

configure the wing sections 220-1, 220-2 and 220-3 to have three or more open sections to compress the air-fuel mixture, thereby providing three or more combustion chambers. The number of ducts and the shape of each wing section need to be configured so that the air-fuel mixture does not leak to unwanted open sections and does not mix with the exhaust gases in any open, section of the housing. Furthermore, multiple spark plugs need to he respectively provided to simultaneously ignite the air-fuel mixture in the multiple open sections for synchronized combustions. This scenario is analogous to having a multiple-cylinder engine as opposed to having a one-cylinder engine.

[0039] in view of the above possible variations, the rotary synchronized combustion engine having multiple power transmission paths and multiple combustion chambers may be configured by including: a housing; multiple shafts provided in alignment and in parallel with each other, vertically penetrating through the housing; multiple wing sections integratively attached around the multiple shafts, respectively, and configured to engage with one or two adjacent wing sections to drive axial rotation, wherein a horizontal cross-sectional shape of each, wing section is configured to have at least two edge portions, each edge portion

configured t o span along and in contact with a part of an internal surface of the housing during the axial rotation; and multiple ducts attached to the housing and communicating with inside of the housing, each duct being for use for passing an air- fuel mixture or exhaust gases, wherein at least four of the multiple ducts are configured to communicate with at least two open sections associated with a first wing section of the plurality of wing sections. The air- fuel mixture is collected in the at least two open sections inside the housing, and the collected air-fuel mixture is compressed and ignited for combustion when each of the at least t wo open sections has a minimum volume. Accordingly, the chemical energy generated by the combustion is used to drive the axial rotation of each of the multiple wing sections, thereby indi vidually rotating the multiple shafts to transmit power.

[0040] hi the case of a conventional internal combustion engine such as illustrated in FIG. .1„ the expansion of gases by tie combustion of the air-fuel mixture pushes the piston 108 and the connecting rod 106 downward in the cylinder 1 12, producing power to rotate the crankshaft: 104. That is, in the conventional case, the original chemical energy generated by the combustion first drives the linear motion, which is then transformed to the rotational motion of the crankshaft 104. In contrast, in the present rotary synchronized combustion engine, the original chemicai energy generated by the combustion i transformed directly to rotational energy for rotating multiple wing sections attached to respective shafts. Therefore, higher efficiency can be achieved by using the present engine than the conventional engine, since the process of energy transformation has fewer steps, involving fewer parts.

[9041 j I the preset rotary synchronized combustion engine, the number of power transmission, paths can easily be increased by adding wing sections to be drive by the combustion in the center section, i.e. , in the open sections associated with the first wing section. Additionally, the number of combustion chambers can also be increased by increasing the number of open sections associated with each wing sections, thereby increasing the power analogously to having a multiple-cylinder engine.

10042} in the process illustrated in FIGS, 4A - 4H, the initial rotation of the first wing section 220- 1 is started counter-clockwise to subsequently repeat the counter-clockwise rotation of the first wing section 220-1 and the clockwise rotation of the second and third wing sections 220-2 and 220-3. Due to the symmetric configuration of the engine parts at rest, as illustrated in FIG, 4 A, the initial rotation of the first wing section 220- 1 can be started clockwise to subsequently repeat the clockwise rotation of the first wing section 220- 1 and the counterclockwise rotation of the second and third wing sections 220-2 and 220-3. That is, the rotation motion of each shaft is reversible in the present rotary synchronized combustion engine.

109 3] FIGS. 6 A - 6E illustrate the structure of another example of the rotary synchronized combustion engine according to an embodiment, separately illustrating a front view in FIG. 6A, a side view in FIG. 68, cross-sectional view in FIG. 6C with respect to the plane indicated by dash-dot line c - c ^* in FIG. 6A, a top view in FIG. 6D, and a cross-sectional view in FIG. 6E with respect the plane indicated by dash-dot line d - d' in FIG. 6C. The internal parts of the engine are accommodated in a housing 600, which has a shape of enveloping a combination of three ellipsoids, which have substantially the same dimensions, merged side-by-side to overlap partially with each adjacent one. It should be understood by those skilled in the art that ellipsoidal shapes generally include a substantially spherical shape, which is used to illustrate the present example in FIG, 6A -· 6E and later drawings. The housing 600 has an internal surface and an external surface. A first ellipsoidal section 604-1 thai is a center section of the housing 600, a second ellipsoidal section 604-2 and a third ellipsoidal section 604-3 of the housing 600 have respective ellipsoidal axes. Each ellipsoidal section has a pair of equal semi-axes in the horizontal plane and a third semi-axis which is an axis of symmetry in the vertical direction. Thus, the horizontal cross-sectional shape of each ellipsoidal section o the housing 600 is substantially a circle, merged side-by-side to overlap with each adjacent one. The ellipsoid can he prolate, i.e., elongated along the vertical direction, oblate, i.e., elongated along all the horizontal directions, or spherical. The vertical direction V and the horizontal direction H are indicated in the inset of FIG. 6 A. Along the axes of symmetry, first, second and third shafts 608-1 , 608-2 and 608-3 are provided, respectively. Thus, these shafts are provided in alignment and in parallel with each other, vertically penetrating through the housing 600. The housing 600 i attached with eight ducts 612-1 , 612-2 , .. and. 612-8 communicating with the inside of the housing 600, each duct being for use for passing an air -feci mixture or exhaust gases. All the eight ducts 12 - 1 , 612- 2 . .. and 612-8 are seen in the cross-sectional view in FIG. 6€; the four ducts 612-1 , 612-2, 612-5 and 612-7 pro vided in the front section of the housing 600 are seen in the front view in FIG. 6A. The first and second ducts 612- 1 and 612-2 are attached to the front sectio of the first ellipsoidal section 604-1 of the housing 600; and the third and fourth ducts 612-3 and 612-4 arc attached to the hack section of the first dlipsoidai section 604-1 of the housing 600. The fifth d uct 612-5 is attached to the front section of the second ellipsoidal section 604-2 of the housing 600; and the sixth duct 12-6 is attached to the back section of the second ellipsoidal section 604-2 of the housing 600. The seventh duct 612-7 is attached to the front section of the third ellipsoidal section 604-3 of the housing 600; and the eighth duct 61 2-8 is attached to the back section of the third ellipsoidal section 604-3 of the housing 600, Two spark plugs 61 -1 and 616-2 are provided to the first ellipsoidal section 604- ! of the housing 600 for igniting the air-fuel mixture in two open sections, respecti vely, in the first ellipsoidal section 604- 1 of the housing 600. These two spark plugs 616-1 and 616-2 may be atiaciied to the top section of the first ellipsoidal section 1 - 1 as exemplified in FIGS. 6A and 6D; alternatively, one of them may be attached to the top section and the other may be attached to the bottom section, or both of them ma be attached to the bottom section of the fi st ellipsoidal section 604- 1. [0044 _. As seen in the cross-sectional view in the FIG. 6C, the first ellipsoidal section 604-1 accommodates a first wing section 620- i integrative!y attached around the first shaft 608-1 , the second ellipsoidal section 604-2 accommodates a second wing section 620-2 integratively attached around the second shaft 608-2, and the third ellipsoidal section 604-3 accommodates a third wing section 620-3 integrati vei attached around the third shaft 608-3. Each wing section is formed contbrmal to the eiiipsoidai shape having an axis of symmetry along the vertical direction, i.e., alon the center axis of the corresponding shaft, as illustrated in FIG. 6E, which illustrates the vertical cross-sectional shape of the first wing section 620- ί and the first shaft 608-1 with respect to the plane indicated by d - d' in FIG. 6C. Only the shaft and the wing section are illustrated in FIG. 6E for clarity, by omitting the outlines of the housing 600 and the other parts,

J0 45] Each wing section is configured so that the first wing section 620-1 engages wit the second wing section 620-2 at one side and the third wing section 620-3 at the other side to drive the axial rotation of the second wing section 620-2 and the third wing section 620-3 when the first wing section 620- 1 axially rotates with the rotation of the first shaft 608- 1. As seen in FIG, 6C, the horizontal cross-sectional shape of each wing section projected on the plane indicated by the tine c-e ^" in FIG. 6A is configured to be symmetric with respect to a vertical plane including the center axis of the shaft and to have two edge portions, each edge portion spanning along a part of the internal surface of the corresponding ellipsoidal section of the housing 600. Both edge portions of each wing section are configured to be in contact with the internal surface of the corresponding ellipsoidal section of the housing 600, and yet ab!e to rotate freely within the corresponding cylindrical section of the housing 600, Lubrication oil or any other suitable material or technique may be used for that purpose. The edge portion of the cross-sectional shape of each wing section is configured to be wider than the portion near and around the shaft,

[0046] Examples of shapes and configurations of the wing sections of the structure in FIGS. 6A - 6E are further explained with reference to subsequent drawings in FIGS. 7A, 7B, 8A and 8B. FIG, 7 A illustrates a perspective view ⁷ of a 3D configuration of the first wing section 620- .1 integrated around the first shaft 608-1 and the second wing section 620-2 integrated around the second shaft 608-2, wherein the first wing section 620-1 and the second wing section 620-2 are oriented substantially orthogonal to each other. The third wing section 620- 3 is omitted in FIG. 7A for simplicity; however, it should be assumed that the third wing section 620-3 is provided on the right: side of and engaged wi h the first wing section 620- 1 in this figure, and is oriented in the same direction as the second wing section 620-2. FIG. 7B is a schematic drawing of the configuration illustrated in FIG. 7 A, when viewed along the vertical direction. In both FIGS. 7A and 7B, the outline of the first ellipsoidal section 604-1 of the housing 600 and the second ellipsoidal section 604-2 of the housing 600 are iii ustrated in dashed lines. This configuration in FIGS. 7A and 7B corresponds to the configuration illustrated in FIG. 4E. In the previous example illustrated in FIG. 4E, eac wing section is formed uniformly along the vertical direction, whereas in the present example illustrated in FIG. 7 A and 7B, each wing section is formed non-unifonnly along the vertical direction.

100 } The body shape of each wing section is explained below with reference to the second wing section 620-2 in FIGS. 7A and 7B, The second wing section 620-2, as well a each of the other wing sections, has a body shape which is defined by a first surface 700, a second surface 704 and a third surface 708, each of which is a curved surface- The first surface 700 is formed conformal to the internal surface of the second ellipsoidal section 604-2 of the housing 600. The first and second surfaces 704 and 708 have substantially the same curved shapes and are symmetric to each other with respect to a vertical plane including the center axis of the second shaft 608-2, i.e., the axis of symmetry of the second ellipsoidal section 604-2. The horizontal cross-sectional shape, projected on a horizontal plane orthogonal to the vertical axis, i.e., the axis of symmetry of the second ellipsoidal section 604-2, of each of the first and second surfaces 704 and 708 varies depending on the vertical position of the horizontal plane. The horizontal cross-sectional shapes 704- A and 70S-A, projected on the horizontal plane across the center of the vertical axis, of the second surface 704 and the third surface 708, respectively, are schematically illustrated in FIG. 7B . That is, in the example illustrated in FIGS. 7 A and 7B, the horizontal, cross-sectional shape of the second wing section 620-2 projected on the horizontal plane across the center of the vertical axi is similar to the shape described in the previous example of FIGS. 2A - 2E and 4 A - 4H. Specifically, the horizontal cross-sectional shape of the second wing section 620-2 is configured to be symmetric with respect to a vertical plane including the center axis of the second shaft 608-2 and to ha ve two edge portions, each edge portion spanning along a part of the internal surface of the second ellipsoidal section 604-2 of the housing 600. Both edge portions of the second wing section 620-2 are configured to be in contact with the internal surface of the second ellipsoidal section 604-2 of the housing 600, and yet able to rotate freely therein. Each edge portion is configured to be wider than the portion near and around the shaft. As the position mo ves away from the center of the vertical axis, the horizontal cross-sectional shape of each of the each wing section changes, whereby each, of the first and second surfaces 704 and 708 is formed to have a curved surface surrounded by a continuous ridge. In FIG. 7B, these ridges of the first and second surfaces 704 and 70S are schematically depicted b the curves 704-B and 708-B, respectively.

[0048] FIG. 8 A. illustrates a perspective view of another 3D configuration of the structure thai is the same as the structure illustrated in FIGS. 7A and ?B, wherein the first wing section 620-1 and the second wing section 620-2 are rotated to the configuration corresponding to the configuration illustrated in FIG. 4D. The third wing section 620-3 is omitted in FIG. 8A for simplicity; however, it should be assumed that the third wing section 620-3 is provided on the right side of the first wing section 620-1 in this figure and is oriented in the same direction as the second wing section 620-2. FIG. SB is a schematic drawing of the configuration illustrated in FIG. 8A, when viewed along the vertical direction, in FIG. 8B, the outlines of the first ellipsoidal section 604-1 of the housing 600 and the second ellipsoidal section 604-2 of the housing 600 are illustrated in dashed tines. The horizontal cross-sectional shapes 704- A and 708-A, projected on the horizontal plane across the center of the vertical axis, of the second surface 704 and the third surface 708, respectively, are schematically illustrated in FIG, SB. Also in FK3.8B, the ridges of the first and second surfaces 704 and 70S are schematically depicted by the curves 704-B and 708-B, respectively.

[9049] The engine process similar to the engine process illustrated in FIGS. 4A - 4H can he carried out by using the engine structure illustrated in FIGS. 6A - FIG. 8A, where the wing sections are configured to engage with one or two adjacent wing sections to drive axial rotation, wherein a horizontal cross-sectional shape of each wing section is configured to have at least two edge portions, each edge portion configured to span along and in contact with a part of the internal surface of the housing during the axial rotation. In the earlier example, the housing has a shape of e veloping a combination of multiple cylinders, which have substantially the same dimensions, merged side-by-side to overlap partially with each adjacent one by keeping respective top surfaces level as well as respective bottom surfaces level, and each wing section is formed vertically uniform along the shaft. On the other hand, in the later example, the housing has a shape of enveloping a combination of multiple ellipsoids, which have substantially the same dimensions, merged side-by-side to overlap partially with each adjacent one. The body shape of the wing section is defined b the first, second and third surfaces. The first surface is formed confbrma! to the internal surface of the housing, and the second and third surfaces are formed to be symmetric to each other with respect to a vertical plane including the center axi of the corresponding shaft, i.e. _f the axis of symmetry of the ellipsoid. Each of the second and third surface is formed to have a curved surface surrounded by a continuous ridge, whereby the air- fuel mixture is collected in at least two open sections associated with the first wing section in the housing, and the collected air- fuel mixture is compressed and ignited for combustion when each of the at least two open sections has a mini mum vol me to generate chemical energy to drive the axial rotation of each of the multiple wing sections.

[0050] While this document contains many specifics, these should not be construed as limitations on the scope of an invention or of what, may be claimed, hut. rather as descriptions of features specific to particular embodiments of the invention. Certain features that are described in this document in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described above as acting in certain combinations and even initially claimed a such, one or more feature from claimed combination can in sonic cases be exercised from the combination, and the claimed combination may be directed to a subcombination or a variation of a subcombination.