Abstract:
A rotary engine includes a first rotary unit operable to provides a first phase of compression to a fresh air charge drawn in through an inlet port to the first rotary unit. A second rotary unit in communication with the first rotary unit through a first passage, the second rotary unit operable to provide a second phase of compression to the first phase of compression, a combustion phase and a first phase of expansion, the second rotary unit in communication with the first rotary unit through a second passage such that the first rotary unit provides a second phase of expansion to the first phase of expansion and an exhaust phase that exhausts the first rotary unit via an exhaust port. A first fuel injector is in communication with the second rotary unit operable to initiate the combustion phase and a second fuel injector is in communication with the first rotary unit operable to selectively initiate augmented operation.

Description:
BACKGROUND 
     Engines typically compress air or other gaseous oxidizers prior to adding fuel and ignition to produce power. When positive displacement compression is physically separate from the power producing feature there is often unused remaining compressed air. Many examples of engines with separable positive displacement compression systems exist. One example can be conceptualized from a Wankel engine. The Wankel engine, invented by German engineer Felix Wankel is a type of internal combustion engine which uses a rotary design. Its cycle takes place in a space between the inside of an oval-like epitrochoid-shaped housing and a rotor that is similar in shape to a Reuleaux triangle but with sides that are somewhat flatter. This design delivers smooth high-rpm power from a compact size. Since its introduction, the engine has been commonly referred to as the rotary engine. An improvement on the rotary engine uses one rotor as a compressor to provide compressed air to a second rotor. The compressed air is then further compressed in the second rotor in advance of combustion. In some embodiments the exhaust of the second rotor is returned to the expanding section of the compressor rotor, thereby providing power recovery and increasing efficiency. This configuration has been referred to as a compound rotary engine. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a - 1   f  are a graphical representation of a first rotor section and a second rotor section in a non afterburning mode. 
         FIGS. 2   a - 2   g  are graphical representations of a first rotor section and a second rotor section in an afterburning mode where the first rotor section has an injector. 
         FIGS. 3   a - 3   g  are graphical representations of a first rotor section and a second rotor section in an afterburning mode where the second passageway has a passageway injector. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1   a - 1   e  represent a non-limiting embodiment of a compound rotary engine  60 . The compound rotary engine  60  has a first rotary unit  10  coupled with a second rotary unit  20 . A compressed air charge  53  is communicated via passageway  30  from the first rotary unit  10  to the second rotary unit  20 . A second rotary unit exhaust  58  from the second rotary unit  20  is communicated to the first rotary unit  10  via passageway  32 . Additionally, the second rotary unit  20  has an injector  70  in communication with the second chamber  24 . In this configuration, the first rotary unit  10  operates as a supercharger and as an additional expander of the second rotary unit exhaust  58  second rotary unit 
     Referring to  FIG. 1   a , a fresh air charge  50  is drawn in through an inlet port  18  into a first rotary unit  10 . 
     Referring to  FIG. 1   b , the first rotor  12  compresses the fresh air charge  50  (not shown) into a compressed air charge  53 . The compressed air charge  53  reaches a pressure that overcomes the spring force that normally keeps the first passageway check valve  31  closed. Once opened, the compressed air charge  53  flows into the second rotary unit  20 . In another non-limiting embodiment, the check valve is omitted. In additional non-limiting embodiments, the passageways may include valves controlled by electronically activated motors (not shown). 
     Referring to  FIG. 1   c , the second rotor  22  further compresses the compressed air charge  53  (not shown) into a compound compressed air charge  52 . A compound compressed air charge  52  is a compressed air charge  53  which is then further compressed in the second rotor in advance of combustion. 
     Referring to  FIG. 1   d , the second rotor  22 , near or at top dead center, and the second chamber  24 , at or near minimal working volume, is injected with fuel  42  via an injector  70 . The fuel  42  may be a light fuel (e.g., natural gas, gasoline, hydrogen), or a heavy fuel (e.g., JP-8, JP-4, diesel and others). A mixture of the compound compressed air charge  52  and the fuel  42  is then combusted. Combustion can be initiated via auto ignition (diesel) or spark ignition (not shown). 
     Referring to  FIG. 1   e , the second rotary unit exhaust  58  leaves the second rotary unit  20  via a second passageway  32 . The pressure of the second rotary unit exhaust  58  overcomes the spring force that normally keeps the second passageway check valve  34  closed. The second rotary unit exhaust  58  enters the first rotary unit  10 . In another non-limiting embodiment the check valve is omitted. The second rotary unit exhaust  58  further expands, asserting pressure on the rotor face  13 , thereby causing the first rotor  12  to rotate and drive a common shaft (not shown). 
     Referring to  FIG. 1   f , the second rotary unit exhaust  58  exits the first rotary unit  10  via an exhaust port  19 . The force behind this action is that the second rotary unit exhaust  58  is at a higher pressure than the ambient atmosphere. 
     The common shaft of the first and second rotors  12 , 22  (not shown) completes three crank revolutions for each complete rotor  12 ,  22  revolution. Each rotor face  13  completes a cycle in every revolution. There are two rotors  12 , 22 , for a total of six rotor faces  13 , thereby allowing the engine  60  to produce significant power within a relatively small displacement. 
     The terms augmentation, augmenter, and/or augmenting are used to describe the process where a remaining compressed air charge  51  ( FIGS. 2   f  and  3   f ) from the first rotary unit  10  and fuel  42  are combusted in the first rotary unit  10  to augment the engine power. When positive displacement compression is physically separate from the power producing feature there is often unused remaining compressed air. It is this unused remaining compressed air that is referred to as the remaining compressed air charge  51 . It is this remaining compressed air charge  51  that is mixed with fuel  42  and an second rotary unitexhaust  58  from the second rotary unit  20 . This mixture is combusted in the first chamber  14  of the first rotary unit  10 . The mixture is ignited either via auto ignition (diesel) or with a spark. Otherwise the majority of the work done to compress this remaining compressed air charge  51  would be lost when it is exhausted. The fuel  42  may be introduced into the second passageway  32  between the two rotary units  10 , 20 . Alternatively, the fuel  42  may be introduced into the first rotor  12  directly. This augmented combustion can be selectively activated and de-activated throughout the compound rotary engine&#39;s  60  mission. 
       FIGS. 2   a - 2   g  are one non-limiting embodiment of an augmented mode compound rotary engine  60 . The augmented mode compound rotary engine  60  has a first rotary unit  10  coupled with a second rotary unit  20 . A compressed air charge  53  is communicated from the first rotary unit  10  to the second rotary unit  20  via passageway  30 . A second rotary unit exhaust  58  is communicated from the second rotary unit  20  to the first rotary unit  10  via passageway  32 . The first rotary unit  10  has a first injector  70  in communication with the chamber of the first rotor  12 . The second rotary unit  20  has a second injector  71  in communication with the chamber of the second rotor  22 . 
     Referring to  FIG. 2   a , a fresh air charge  50  is drawn in through an inlet port  18  into a first rotary unit  10 . As the volume in the chamber increases, a partial vacuum, or lower pressure than ambient environment, is created and the higher pressure from the ambient environment forces in the fresh air charge  50 . 
     Referring to  FIG. 2   b , the first rotor  12  compresses the fresh air charge  50  (not shown) into a compressed air charge  53 . The compressed air charge  53  reaches a pressure that overcomes the spring force that normally keeps the first passageway check valve  31  closed. Once opened, the compressed air charge  53  flows into the second rotary unit  20 . In another non limiting embodiment the check valve is omitted. 
     Referring to  FIG. 2   c , the second rotor  22  further compresses the compressed air charge  53  (not shown) into a compound compressed air charge  52 . A compound compressed air charge  52  is a compressed air charge  53  which is then further compressed in the second rotary unit  20  in advance of combustion. 
     Referring to  FIG. 2   d , the second rotor  22 , near or at top dead center, wherein the chamber of second rotor  22  is at or near minimal working volume, is injected with fuel  42  via the second injector  71 . Combustion can be initiated via auto ignition (diesel) or spark ignition (not shown). 
     Referring to  FIG. 2   e , the second rotary unit exhaust  58  leaves the second rotary unit  20  via a second passageway  32 . The pressure of the second rotary unit exhaust  58  overcomes the spring force that normally keeps the second passageway check valve  34  closed. Once opened, the second rotary unit exhaust  58  flows into the second rotary unit  20 . In another non limiting embodiment the second passageway check valve  34  is omitted. 
     Referring to  FIG. 2   f  the second rotary unit exhaust  58  enters the chamber of first rotor  12 . Here the second rotary unit exhaust  58  mixes with and further compresses the remaining compressed air charge  51 . The remaining compressed air charge  51  is the portion of compressed air charge  53  that is not transferred to the second rotary unit  20 , and thereby remains in the rotary first rotary unit  10 . The first injector  70  injects fuel  42  to form a combustible mixture. Either through auto ignition (diesel) or spark ignition (not shown), the combustible mixture combusts. Alternatively the remaining compressed air charge may be mixed with fuel injected at the injector  71  to form a combustible mixture. The combustible mixture is combusted either through auto ignition (diesel) or spark ignition (not shown), prior to mixing with the second rotary unit exhaust  58 . In either variant, the first rotary unit exhaust  54  continues to further expand, asserting pressure on the rotor face  13 , thereby causing the rotor  12  to rotate and drive a common shaft (not shown). 
     Referring to  FIG. 2   g , the first rotary unit exhaust  54  exits the first rotary unit  10  via an exhaust port  19 . The force behind this action is that the first rotary unit exhaust  54  is at a higher pressure than the ambient atmosphere. 
     It should be noted that this secondary combustion can be selectively activated and de-activated throughout the compound rotary engine&#39;s  60  mission. The compound rotary engine  60  simultaneously offers high power density (number of horsepower or fractional horsepower per pound of engine weight) and low fuel consumption resulting in a comparably smaller power plant envelope. This rotary engine  60  can be utilized for various commercial, industrial, compact portable power generation, and aerospace applications. 
       FIG. 3   a - 3   g  represents a non-limiting embodiment of an augmented compound rotary engine  60 . The augmented compound rotary engine  60  has a first rotary unit  10  coupled with a second rotary unit  20 . A compressed air charge  53  is communicated from the first rotary unit  10  to the second rotary unit  20  via passageway  30 . The second rotary unit exhaust  58  is communicated from the second rotary unit  20  to the first rotary unit  10  via passageway  32 . The second rotary unit  20  has the injector  71  in communication with the second chamber  24  of second rotor  22 . The second passageway  32  is in communication with an additional injector  73 . 
     Referring to  FIG. 3   a , a fresh air charge  50  is drawn in through an inlet port  18  into the first rotary unit  10 . As the volume in the chamber increases, a partial vacuum, or lower pressure than ambient environment, is created and the higher pressure from the ambient environment forces the fresh air charge  50  in. 
     Referring to  FIG. 3   b , the first rotor  12  compresses the fresh air charge  50  (not shown) into a compressed air charge  53 . The compressed air charge  53  reaches a pressure that overcomes the spring force that normally keeps the first passageway check valve  31  closed. Once opened, the compressed air charge  53  flows into the second rotary unit  20 . In another non limiting embodiment the first passageway check valve  31  is omitted. 
     Referring to  FIG. 3   c , there is shown the second rotor  22  further compressing the compressed air charge  53  (not shown) into a compound compressed air charge  52 . A compound compressed air charge  52  is a compressed air charge  53  which is then further compressed in the second rotor in advance of combustion. 
     Referring to  FIG. 3   d , the second rotor  22 , near or at top dead center, wherein the second chamber  24  is at or near minimal working volume, is injected with fuel  42  via the injector  71 . The mixture of the compound compressed air charge  52  and the fuel  42  is then combusted. Combustion can be initiated via auto ignition (diesel) or spark ignition (not shown). 
     Referring to  FIG. 3   e , the second rotary unit exhaust  58  leaves the second rotary unit  20  via a second passageway  32 . The pressure of the second rotary unit exhaust  58  reaches a pressure that overcomes the spring force that normally keeps the second passageway check valve  34  closed. In another non limiting embodiment the second passageway check valve  34  is omitted. 
     Referring to  FIG. 3   f , the second rotary unit exhaust  58  enters the first rotary unit  10  first chamber  14 . Here the second rotary unit exhaust  58  mixes with fuel  42  injected via the injector  73  and further compresses the remaining compressed air charge  51 . The remaining compressed air charge  51  is the portion of compressed air charge  53  that is not transferred to the second rotary unit  20 , and thereby remains in the rotary first rotary unit  10 . The mixture is combusted either through auto ignition (diesel) or spark ignition (not shown). In either variant, the first rotary unit exhaust  54  continues to further expand, asserting pressure on the rotor face  13 , thereby causing the rotor  12  to rotate and drive a common shaft (not shown). 
     Referring to  FIG. 3   g , the first rotary unit exhaust  54  leaves the first rotary unit  10  via an exhaust port  19 . The force behind this action is that the first rotary unit exhaust  54  is at a higher pressure than the ambient atmosphere. 
     It should be noted that this secondary combustion afterburning mode can be selectively activated and de activated throughout the engine&#39;s mission. The compound rotary engine  60  simultaneously offers high power density and low fuel consumption for various commercial, industrial, compact portable power generation, and aerospace applications. 
     When referring to either the first or second passageway check valves  31  and  34  respectively, the term check valve is noted to be a generic term. This term can encompass a solenoid type valve, a spring type valve, a reed type valve, or any other valve that permits flow in one direction. Additionally, as previously stated, these valves can be omitted. 
     When referring to the injector  70 ,  71  and  73 , it should be noted that the term injector is a generic term. The injector used in communication with the chambers  14 ,  24  of the first and second rotor  12 ,  22  respectively, and in communication with the second passageway  32  may be of many different types. They may be mechanically controlled via spring force to set popping pressures. They may be electronically controlled via solenoids to activate fuel atomization. They may have various spray patterns to direct the fuel in the most efficient mixing methods. 
     When referring to the chamber of the first rotor  12 , it can also be referred to as a first chamber. When referring to the chamber of the second rotor  22 , it can also be referred to as a second chamber. 
     When referring to all Figures, it should be noted that the rotors  12 , 22  are physically present in each of their respective rotary units  12 , 20  at all times. In order to draw the reader&#39;s attention to the rotary unit  10 , 20  where an action or process is being described, only those rotors  12 , 22  are represented in their respective Figures. 
     The use of the terms “a” and “an” and “the” and similar references in the context of description (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or specifically contradicted by context. The modifier “about”, used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity). All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. It should be appreciated that relative positional terms such as “forward,” “aft,” “upper,” “lower,” “above,” “below,” and the like are with reference to the normal operational attitude of the vehicle and should not be considered otherwise limiting. 
     Although the different non-limiting embodiments have specific illustrated components, the embodiments of this invention are not limited to those particular combinations. It is possible to use some of the components or features from any of the non-limiting embodiments in combination with features or components from any of the other non-limiting embodiments. 
     It should be appreciated that like reference numerals identify corresponding or similar elements throughout the several drawings. It should also be appreciated that although a particular component arrangement is disclosed in the illustrated embodiment, other arrangements will benefit herefrom. 
     Although particular step sequences are shown, described, and claimed, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated and will still benefit from the present disclosure. 
     The foregoing description is exemplary rather than defined by the limitations within. Various non-limiting embodiments are disclosed herein, however, one of ordinary skill in the art would recognize that various modifications and variations in light of the above teachings will fall within the scope of the appended claims. It is therefore to be appreciated that within the scope of the appended claims, the disclosure may be practiced other than as specifically described. For that reason the appended claims should be studied to determine true scope and content.