Abstract:
The split-chamber rotary engine includes a rotary power module having a case with a circular rotor installed therein. At least one, and preferably two or more combustion chambers are formed peripherally in the rotor. The generally circular rotor cavity of the case includes at least one, and preferably two or more, peripheral expansion chambers. A corresponding number of reciprocating compressor modules are installed upon the case, with the compressor module axis being aligned generally tangentially to the rotor periphery. The compressor module includes concentric reciprocating pistons and valves that compress the air charge and transfer the compressed charge to the rotary power module for power production. The compressor module is driven purely by combustion gas pressure acting upon its inboard piston. No mechanical linkage exists from power module to compressor module. The engine may include multiple rotor and case rows, as desired.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to internal combustion engines, and particularly to a split-chamber rotary engine that combines mechanically independent rotary and reciprocating features, including a rotary power module with one or more reciprocating compressor modules. 
     2. Description of the Related Art 
     Innumerable different configurations of internal combustion engines and expansion motors have been developed in the past. The reciprocating piston internal combustion engine commonly known as the piston engine in its various forms (e.g., two-stroke and four-stroke spark, diesel ignition, etc.) has been accepted overwhelmingly as the engine configuration of choice for nearly all stationary and mobile applications. The refinement of the reciprocating piston engine since its inception has resulted in such engines developing smooth power and having great reliability, in most cases, as well as being simple to operate during normal use. 
     Nonetheless, the reciprocating piston internal combustion engine principle, by its nature, is not particularly efficient. The major problem is that this engine configuration combines the function of an air compressor for drawing in and compressing the intake charge and expelling the exhaust gases with the function of an expansion motor for using the power produced by the combustion of the air and fuel mixture in a single chamber. The air compression function is reasonably efficient, as the piston force and compression requirement are well matched with one another during the compression stroke. 
     However, the power stroke of the reciprocating piston engine is relatively inefficient. This is due to the basic design of the mechanism, which causes the expansive force of the heated combustible mixture to develop its greatest force at very nearly the top position of the piston, called top dead center. When the piston is at top dead center, the torque arm defined by the crankshaft throw is zero, and thus no torque is developed, regardless of the force developed upon the piston in the combustion chamber. As the crankshaft rotates, the torque arm increases from zero to a maximum at 90 degrees from top dead center. However, here the piston is at mid-stroke and the energy of the mixture is about half-spent. Also, friction between the sides of the piston and its piston rings and the cylinder wall is at its greatest at this point, due to the angular offset of the connecting rod. The overall result is an engine configuration that is not optimized for efficiency. 
     In response to the above considerations, other internal combustion engine configurations have been developed, the majority of these being of the rotary type. Among the rotary internal combustion engines the most successful is the Wankel engine. The classic Wankel configuration with two chamber lobes and a three-sided rotor develops relatively low torque at high rpm, requiring torque multiplication and speed reduction in the form of transmissions, gear reduction differentials, etc. While the modern reciprocating engine also develops its maximum torque at relatively high rpm in order to overcome some of the inefficiencies noted further above, the need for much higher rpm for the production of reasonable torque output is a negative characteristic of the Wankel type rotary engine. 
     A number of variations of rotary configuration internal combustion engines have been developed in the past, as noted further above. An example of such is found in Japanese Patent No. 63-285,224, published on Nov. 22, 1988. This reference describes (according to the drawings and English abstract) a rotary engine having a case with a cam-shaped rotor therein. The case includes radially sliding vanes therein for defining the internal operating volumes of the engine. Conventional poppet intake and exhaust valves are provided. 
     Japanese Patent No. 1-080,721, published on Mar. 27, 1989, describes (according to the drawings and English abstract) another rotary engine having cam-shaped rotors therein with radially sliding vanes extending through the peripheral wall of the stationary case. 
     Japanese Patent No. 2-049,927, published on Feb. 20, 1990, describes (according to the drawings and English abstract) another rotary engine having radially sliding vanes extending through the peripheral wall of the stationary case, with the inner tips of the vanes bearing against the periphery of the non-circular rotor within the case. 
     French Patent No. 2,643,945, published on Sep. 7, 1990, describes (according to the drawings and English abstract) a rotary engine with two laterally joined chambers, each having a rotor with radially extending vanes therein. One rotor and chamber acts as a compressor, with the compressed charge passing to the second rotor via a periodically opened passage timed to permit the flow from compressor to combustion chamber at the proper time. 
     German Patent No. 4,029,144, published on Mar. 12, 1992, describes (according to the drawings and English abstract) a rotary engine having a case with a circular internal volume and a smaller diameter rotor eccentrically installed therein. The rotor has a series of radially extending and retracting vanes to define a series of variable volume working chambers between the outer circumference of the rotor and the inner circumference of the case. 
     None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a rotary engine solving the aforementioned problems is desired. 
     SUMMARY OF THE INVENTION 
     The split-chamber rotary engine includes a case having a rotor cavity with at least one combustion chamber and at least one expansion chamber therein, and a rotary power module having a rotor and at least one peripheral combustion chamber formed therein. The rotor preferably includes two or more such chambers evenly distributed for balance purposes and to increase the number of power events per revolution. At least one reciprocating compressor module communicates with the combustion chamber of the case and rotor, with the compressor module including a series of concentric pistons and valves that serve to draw in and compress intake air and transfer that intake charge to the combustion chamber defined by the periphery of the rotor and the inboard end of the compressor module piston assembly extending into a combustion chamber piston passage in the case. Thus, the rotary engine has a split combustion chamber, with approximately half of the chamber contained within the rotor periphery, and the other portion of the chamber contained within the case adjacent to the inboard end of the compressor piston. 
     The compressor module of the engine communicates only pneumatically with the rotor, with all operation of the compressor module resulting from differential pressures developed in the compressor portion of the combustion chamber as the engine operates. No mechanical linkage exists between the moving parts of the compressor and rotor modules. The engine may be developed in a number of different configurations having single or multiple rotor combustion chambers and/or single or multiple compressor modules, as desired. 
     Because of the configuration of the split-chamber rotary engine, with its separate compression and power modules, multiple power events can occur with each rotation of the rotor, depending upon the number of combustion chambers built into the rotor and the number of compression modules provided, as well as the number of rotors in a multiple rotor configuration. This increases the torque output of the engine at relatively low rpm when compared to conventional engines. The ability to selectively engage a multiplicity of rotors and compressor modules besides selectively triggering combustion for the individual rotor chambers by simple control devices enable this engine to operate efficiently over a wide range of power demands, thus eliminating the need for mechanical gear boxes. 
     The split-chamber rotary engine has no wasted motion of reciprocating components and corresponding wasted fuel. The rotary engine is also highly resistant to detonation, as the opposing walls of the compression piston and rotor chamber are free to move and absorb shock waves. Fuel is introduced via a direct injection system at the combustion chamber, mixing with the air charge contained therein. These characteristics allow the use of fuels having relatively low octane or anti-knock ratings, as well as relatively heavy and low cost fuel oils, to operate the engine. Alternatively, one or more carburetors may be installed externally to the compressor, if some sacrifice of efficiency is acceptable. 
     The engine cannot reverse-fire due to the configuration of the combustion chamber(s) in the rotor and the placement of the compressor module and its combustion chamber relative to the exhaust port of the rotor case. As this engine configuration has no mechanical linkage between the rotor and the compressor module(s), the engine will also free wheel with little internal drag when loaded externally with no power requirement. The engine may be constructed in various sizes and scales, from very small units for powering model aircraft to motorcycles, automobiles, trucks, trains, earth moving machinery, helicopters, airplanes and very large units serving as stationary power plants, or for maritime use. 
     These and other features of the present invention will become readily apparent upon further review of the following specification and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first embodiment of a split-chamber rotary engine according to the present invention, showing its general configuration. 
         FIG. 2  is a broken away detailed perspective view of a portion of the rotor of the engine of  FIG. 1 , showing the rotor portion of the combustion chamber and the rotor seals. 
         FIG. 3  is a side elevation view in section of a single compressor module of the engine of  FIG. 1 , showing various internal details thereof. 
         FIG. 4A  is a side elevation view in section of a single compressor module rotary engine according to the present invention at the initiation of the combustion and power portion of the engine operating cycle. 
         FIG. 4B  is a side elevation view in section of the engine of  FIG. 4A , showing the progression of the power portion of the engine operating cycle. 
         FIG. 4C  is a side elevation view in section of the engine of  FIGS. 4A and 4B , showing the increasing size of the expansion chamber and the operation of the compressor module charging compressed air into the reservoir. 
         FIG. 4D  is a side elevation view in section of the engine of  FIGS. 4A through 4C , showing the further increase in volume of the expansion chamber and the operation of the compressor module drawing in fresh air for compression and charge of the next cycle, as the rotor vane approaches the exhaust port. 
         FIG. 5  is a schematic diagram of the pneumatic operating system for starting and controlling the power output of a split-chamber rotary engine according to the present invention. 
         FIG. 6  is an alternative embodiment of a split-chamber rotary engine according to the present invention, with the rotor incorporating three combustion chambers supplied by a single compressor module. 
         FIG. 7  is another alternative embodiment of a split-chamber rotary engine according to the present invention having two compressor modules and a rotor with three combustion chambers. 
         FIG. 8  is another alternative embodiment of a split-chamber rotary engine according to the present invention having three compressor modules and a rotor with four combustion chambers. 
     
    
    
     Similar reference characters denote corresponding features consistently throughout the attached drawings. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The rotary engine has a power module that comprises a rotor disposed within a case and at least one compression module that comprises a reciprocating piston assembly actuated by pneumatic or combustion pressure from the power module. The engine may have various embodiments that differ according to different numbers of combustion chambers within the rotor, different numbers of compression modules, and/or single or multiple rows of compression and power modules, as desired. 
       FIG. 1  provides a perspective view of a first embodiment of the engine  10   a , having a power module  12   a  with two identical compression or compressor modules  14 . Conventional spark plugs  16 , or glow plugs for starting in a diesel engine, are provided, with one spark plug or glow plug  16  located at the juncture of each compressor module with the rotor chamber within the power module  12   a , discussed further below. The power module  12   a  comprises a case  18   a  having a rotor therein, e.g. rotor  20   a , a portion of which is shown in  FIG. 2  of the drawings. 
     The rotor  20   a  of  FIG. 2  includes a combustion chamber portion  22  set into the peripheral portion of the rotor  20   a , with the leading end of the combustion chamber portion  22  defined by a rotor vane  24  disposed within a slot  26  formed in the rotor  20   a . The slot  26  includes a lower vane pressurizing passage  28  therein, which communicates pneumatically with the recessed face  30  of the rotor  20   a ; the face may be recessed on both sides of the rotor  20   a . The purpose of this vane pressurizing passage  28  is explained further below, in the description of the starting sequence. The slot  26 , and thus the vane  24 , is oriented along a secant of the generally circular rotor  20   a . The vane  24  includes two basic components  24   a  and  24   b , which can slide laterally relative to one another to completely fill and seal the width of the rotor chamber within the case  18   a.    
     The tip seal edge  32  of the rotor vane  24  is concave, and includes a cylindrical roller tip seal  34  residing therein, with the roller tip seal  34  rotating within the concave tip seal edge  32  of the vane  24  as the tip seal  34  bears against the case  18   a  wall during engine operation. The rotor  20   a  further includes a peripheral recess  36  through which combustion gases flow after the ignition event to an expansion chamber formed in the case wall, discussed in detail further below. 
       FIG. 3  of the drawings provides a cross sectional view of an exemplary compressor module  14 , showing its internal structure in detail. The compressor module  14  extends from a corresponding combustion chamber piston passage extending from the rotor chamber to the exterior of the case, e.g., case  18   b , as shown in drawing  FIGS. 4A through 4D  and discussed further below. The compressor module  14  includes an outer compressor cylinder  38  having a case attachment end  40  mechanically attached and sealed to the case  18   b  as shown e.g. in  FIG. 4A , and an opposite closed distal end  42 . A combustion piston sleeve  44  extends from the case attachment end  40  and resides within the piston passage of the case, as shown in e.g.  FIGS. 4A through 4D . The sleeve  44  includes at least one, and preferably a series of passages  46  in its inboard end, i.e., the end adjacent the rotor chamber of the case when the compressor module  14  is installed thereto. A combustion piston  48  reciprocates within the sleeve  44 , with the combustion piston  48  having a head  50  defining one end or wall of the combustion chamber. 
     A connecting rod  52  extends distally from the combustion piston  48 , and connects the combustion piston rigidly to a compressor piston assembly  54  disposed within the compressor module cylinder  38 . The connecting rod  52  has a hollow axial passage  56  to provide for the flow of intake gas from the distal portion of the cylinder  38  to the combustion chamber. Outlet ports  58  are provided through the wall of the combustion piston  48  to allow intake gas to flow from the axial passage  56  of the connecting rod  52 , through the sleeve passages  46 , and into the combustion chamber when the combustion piston  48  is position to align the ports or passages  46  and  58  during engine operation. 
     The connecting rod  52  passes through a divider  60  installed generally medially within the compressor cylinder  38 , with the divider  60  separating the interior volume of the cylinder  38  into a first volume  62  and a second volume  64 . The compressor piston assembly  54  is installed within the first volume  62 , and further separates that first volume into variable volume intake and compression volumes, respectively  66  and  68 . One or more intake passages  70  extend through the wall of the cylinder  38  into the intake volume  66 , between the divider  60  and compressor piston assembly  54 . The connecting rod  52  further includes one or more radial passages  72  extending through the wall thereof, allowing intake gases to pass through the hollow axial passage  56  of the connecting rod  52  and into the second volume  64  of the compressor module  14 . The gas flow route through the complete compressor module and engine is described in detail further below. 
     The compressor piston assembly  54  includes a plug  74  affixed and sealed to the distal end of the connecting rod or shaft  52 , with a hollow inner piston  76  affixed (e.g., threaded, etc.) and sealed to the plug  74 . The plug  74  has an open center to fit about the end of the connecting rod  52 , with the hollow interior of the inner piston  76  communicating with the hollow axial passage  56  of the rod or shaft  52 . A poppet valve  78  is installed concentrically within the inner piston  76 , with a spring  80  urging the valve  78  closed against the seat formed in the otherwise open head or crown  82  of the inner piston  76 . When the valve  78  is open, as shown in  FIG. 4C , the intake charge compressed within the compression volume  68  can flow through the center of the inner piston  76  and into the interior  56  of the connecting rod  52  for transfer to the combustion chamber, as discussed further below. 
     The inner piston  76  and its poppet valve  78  are surrounded concentrically by an outer sleeve  84  that slides within the cylinder  38  during the operational cycles of the engine. The outer sleeve  84  has limited axial motion relative to the inner piston  76 , and acts as another airflow control valve. When the inner piston  76  moves away from the distal end  42  of the cylinder, the outer sleeve  84  lags behind because of friction and a gap is opened between the head or crown  82  of the inner piston  76  and the head  86  of the outer sleeve  84 , as shown in  FIGS. 3 ,  4 A, and  4 D. This allows fluid (e.g., intake air) to flow from the intake volume  66  through a circumferential passage  88  between the inner piston  76  and the outer sleeve  84 , into the compression volume  68  of the cylinder  62 . 
       FIGS. 4A through 4D  provide cross sectional views of a second embodiment  10   b  of the engine, and show the general operating cycle of the engine. The engine  10   b  of  FIGS. 4A through 4D  functions essentially similarly to other engine configurations of the present invention but includes only a single compressor module  14  attached to a rotary power module  12   b . The rotor case  18   b  accordingly includes only a single combustion chamber piston passage  90   b  and combustion chamber  92   b  therein, with the combustion piston sleeve  44  and its piston  48  installed within the piston passage  90   b.    
     The rotor case  18   b  contains an internal rotor volume  94   b  therein, defined by a rotor chamber wall  96   b . The rotor volume  94   b  is generally circular, but includes an expansion chamber  98   b  extending from a point somewhat beyond the combustion chamber  92   b  to the exhaust passage or port  100   b . The number of case combustion chambers, expansion chambers, and exhaust ports correspond exactly to the number of compression modules  14  installed. 
       FIG. 4A  shows the rotor position at essentially the point of ignition and the beginning of the combustion event in the operating cycle. It will be seen in  FIG. 4A  that the combustion chamber  92   b  of the case  18   b  is aligned with the first of the two rotor combustion chamber portions  22   b  to form a complete combustion chamber for the ignition and initial fuel-air mixture combustion event. At this point, fuel is injected through the injector port  102  and the spark plug  16  is fired to ignite the fuel-air mixture in the combined combustion chamber comprising rotor chamber portion  22   b  and case chamber portion  92   b . Alternatively, the engine may use essentially a diesel system with autoignition after an initial glow plug startup is accomplished. As another alternative, the fuel may be introduced externally at the inlet port  70  of the compression module  14  and the injection system may be deleted, if an engine of somewhat lower efficiency is acceptable. 
       FIG. 4B  shows the position of the rotor  20   b  in the case  18   b  shortly after the ignition event, as the combustion gases are expanding. The force developed by the combustion process forces the combustion piston away from the rotor  20   b  and toward the distal closed end  42  of the compressor module  14 . This drives the compressor piston assembly  54  toward the distal end  42  of the compressor module, reducing the compression volume  68  and compressing the next intake charge therein. The force exerted upon the compressor piston causes a reaction to develop over the rotor, which, according to the second law of Newton, is equal and opposite to the force on the piston. This reaction force causes the rotor to gyrate in the opposite direction of the piston movement. 
     As the compressor piston assembly  54  is driven towards the distal end  42  of the compressor module, the compression volume  68  is reduced and the intake volume  66  is simultaneously increased, thus drawing a subsequent intake charge through the intake passages or ports  70 , as shown by the intake arrows. The passage between the sleeve  84  and inner piston  76  remains closed due to the relatively high pressure from the combustion piston  48  forcing the connecting rod or shaft  52  and its attached plug  74  and inner piston  76  into the compression volume  68 , while the increased pressure in the reduced compression volume  68  retards the motion of the sleeve  84  in that direction. The poppet valve  78  also remains closed against the inside of the head  82  of the inner piston  76  due to the pressure difference across the face of the poppet, thus compressing the next intake charge in the compression volume  68 . 
     Simultaneously with the above, the clockwise rotation of the rotor  20   b  from its position as shown in  FIG. 4A  results in the splitting of the two combustion chamber portions  22   b  and  92   b  from one another. It will be seen that in the rotor position shown in  FIG. 4B , there is little communication between the rotor combustion chamber portion  22   b  and the case combustion chamber portion  92   b.    
     As the compression piston assembly  54  is driven towards its maximally distal travel, the pressure within the compression volume  68  increases, overcoming the weak force of spring  80  and the pressure within the second volume  64  and causing the poppet valve  78  to open, as shown in  FIG. 4C . The opening of the poppet allows the compressed intake charge to flow through the top and into the interior of the inner piston  76  between the poppet valve  78  and the wall of the inner piston  76  to enter the hollow interior  56  of the connecting rod or shaft  52 . Sufficient clearance is provided along the skirt and base of the poppet valve  78  to provide for such flow. The intake charge then enters the second volume  64  of the compression module cylinder  38 , through the connecting rod ports or passages  72 . Charging of the second volume  64  continues until the forces that opened the poppet are reduced below the opening value. The poppet valve  78  closes, trapping the air contained within the compression volume  68 . 
     At this point in the operating cycle the residual combustion pressure within the case combustion chamber portion  92   b , which extends into the now open volume of the combustion piston sleeve  44 , is relatively low. This is because a substantial amount of gases from  92   b  have passed through the recess on the rotor into the expansion chamber  98   b . The pressure within the second volume  64  exceeds that in the combustion chamber portion  92   b . The trapped air within the compression volume  68  acts as an air spring, first absorbing the kinetic energy of the piston assembly, then pushing back the compression piston assembly  54  and all its associated parts. It will be noted that the diameter  106  of the combustion piston  48 , and thus its subtended area, is somewhat larger than the diameter  108  and corresponding subtended area of the connecting rod or shaft  52 . This results in the pressure within the second volume  64  acting upon the annulus of the larger diameter  106  of the combustion piston  48  to push the combustion piston  48  back into its sleeve  44  toward the combustion chamber portion  92   b.    
     As the above return of the combustion piston  48  toward the case combustion chamber portion  92   b  is occurring, the rotor  20   b  is continuing to rotate. The rotation is assisted by combustion gas expansion along the peripheral recess  36   b  of the rotor  20   b . Pressurized combustion gas flow extends in both directions between the rotor periphery and the case wall  96   b , but is blocked in the counterclockwise direction by a chamber vane  110  resiliently attached to and extending inwardly from the case wall  96   b . The chamber vane  110  is formed of a relatively thin, flexible metal, and includes a rotor contact edge  112  bearing against the peripheral surface of the rotor  20   b . Thus, combustion gas cannot pass along the peripheral recess  36   b  between the rotor periphery and the case wall  96   b  in a direction opposing rotation of the rotor. However, no such blocking vane is provided in the direction of rotation of the rotor, thus allowing combustion gas pressure to bear against the leading end  114  of the peripheral recess  36  to cause the rotor  20   b  to rotate in the desired clockwise direction. It will be noted that the first rotor vane  24  is extended into the expansion chamber  98   b  of the case  18   b . Centrifugal force is the primary means of rotor vane extension, but conventional springs or combustion or other gas pressure may be applied to the lower vane pressure passages  28  to extend the rotor vanes  24 , as required. 
       FIG. 4D  illustrates the results of the pressure in the second volume  64  pushing the combustion piston back toward the case combustion chamber portion  92   b . By this time, the combustion pressure in the case portion  92   b  of the combustion chamber has been reduced considerably due to the expanding gases flowing into the expansion chamber  98   b  through the rotor peripheral recess  36   b . This expansive flow continues to rotate the rotor  20   b  due to its pressure on the rotor vane  24 , i.e., the vane  24  to the upper right in  FIG. 4D . The combustion pressure cannot act in the opposite direction around the rotor  20   b  due to the rotor chamber vane  110 , as described further above. 
     As the pressure drops in the combustion chamber  92   b , the combustion piston  48  and thus its attached compressor piston assembly  54  are pushed back toward the case combustion chamber portion  92   b  due to the pressure in the second volume  64  acting upon the larger diameter  106  annulus of the combustion piston  48 , as described further above. This pressure also communicates with the hollow interior  56  of the connecting rod or shaft  52  by means of the connecting rod passages  72 . 
     As the combustion piston  48  and compressor piston assembly  54  travel toward the case  18   b , the space within the intake volume  66  is reduced as the compressor piston assembly  54  approaches the divider  60 . The greater air pressure within the intake volume  66  relative to the compression volume  68  at this point, along with the drag of the outer sleeve  84  within the cylinder  38 , causes the inner piston  76  to move away from the head or crown  86  of the outer sleeve  84 , thus opening the passage  88  between the inner piston  76  and its surrounding sleeve  84  to allow a new intake charge to flow from the intake volume  66  into the compression volume  68  of the compressor module  14 . 
     The cycle continues with the rotor  20   b  continuing to rotate, with vane  24  passing the exhaust port  100   b  and venting the expansion chamber  98   b  to the atmosphere. Next, the second combustion chamber portion  22   b  has rotated into alignment with the case combustion chamber portion  92   b  and the combustion piston  48  has reached the end of its travel toward the rotor combustion chamber portion  22   b , as shown by returning to  FIG. 4A . The compressed intake charge flows from the hollow axis  56  of the connecting rod  52 , outwardly through the combustion piston outlet ports  58  behind the combustion piston head  50 , through the transfer ports or passages  46  of the combustion piston sleeve  44  to bypass the piston head  50 , and back into the nose opening  104  of the combustion piston  48  through the forwardly disposed combustion piston ports  58  in front of the piston head  50 . As compressed air flows into the case combustion chamber  92   b , the pressure rises within this chamber and would push the piston  48  back, closing the passages  46  from the piston outlet ports  58  if allowed to actuate over the full face of the piston  50 . Thus, the nose of the piston  48  is reduced to fit a calculated orifice at the end of the combustion piston sleeve  44 . This calculated area is equivalent to the annular ring defined by the outer diameter of the combustion piston  48  and the hollow connecting rod  52 . The combustion chamber receives a full charge, whereupon a new ignition event occurs to continue the operation. 
     It will be seen that special consideration must be given to the starting sequence for the rotary engine, as merely rotating the rotor will not provide the energy needed to operate the compressor module  14  without ignition and combustion events occurring within the rotor case. Accordingly, an exemplary starting and operating system is illustrated in  FIG. 5  of the drawings, for a two compressor module engine embodiment  10   a . The starting system of  FIG. 5  is also an operating or control system, controlling various aspects of the engine during its operation. A motor  116  (electric, etc.) drives an air compressor  18  that draws air through a filtered inlet  120 , with the compressor  118  passing the air through a check valve  122  to fill an accumulator  124 . Alternatively, the engine  10   a ,  10   b , etc. could power the compressor  118  during engine operation, with air pressure stored after shutdown until the next starting operation. 
     Once sufficient pressure has been raised, a timer  126  actuates a first solenoid actuated pneumatic valve  128  that supplies pressurized air through a regulator  130  to a passage(s)  132  through the side of the case (shown in  FIG. 1 ). This pressurized air enters the rotor volume of the case between the case side plate and the recessed face  30  of the rotor (shown in  FIG. 2 ), to enter the lower vane pressure passages  28  of the rotor and push the vanes  24  outwardly against the chamber wall of the rotor for proper sealing. 
     When the pressure reaches a predetermined value, a pressure actuated switch or transducer  134  actuates a plurality of second solenoid pneumatic valves  136  to open those valves and allow pressurized air to pass to the dividers  60  of the two compressor modules  14  to drive blocking or stop pins  142  outwardly from the divider  60  toward the compression piston assembly  54 , thereby limiting movement of the compression piston assembly and its attached combustion piston  48  toward the combustion chamber portions of the case and rotor. Refer to  FIGS. 3 through 4D  for this operation. The pressurized air enters an inlet  138  in the divider  60 , and thence flows to a chamber(s)  140  in the divider in back of the stop pin(s)  142 . The pressurized air forces the blocking or stop pin(s)  142  outwardly, i.e., toward the compressor piston assembly  54 , thus limiting the travel of the assembly  54  and its attached connecting rod  52  and combustion piston  48  toward the combustion chamber portions  22 ( a, b , etc.) and  92 ( a, b , etc.). Thus, the combustion piston cannot travel inwardly toward the case until the stop pins  142  are released, which event does not occur until the compressor modules  14  are charged with an intake air charge as described further below. 
     As an aside to the above blocking or stop pin operation, this portion of the starting and operating or control system will be used during operation of the engine to selectively actuate one or more compressor module(s), as required to match power demand. This has the effect of disabling that compressor module to reduce the output (and fuel consumption) of the engine. Such a power limiting system is desirable when the engine is running at lighter loads, or when idling. 
     Returning to  FIG. 5 , pressure continues to build in the reservoir  124  due to the continued operation of the motor  116  and pump  118 . When full operating pressure is reached, the pressure switch  134  closes a second circuit to actuate a third pneumatic solenoid valve  144 . This valve  144  opens to allow pressurized air to flow through another check valve  146  to a second volume inlet passage  148  located in the divider  60 . The inlet passage  148  extends into the second volume  64  of the compressor module  14 , as shown in the sectional views of  FIGS. 3 through 4D . The high pressure within the second chamber or volume  64  acts on the annulus of the combustion piston  48 , pushing the piston  48  toward the combustion chamber portion  92   a  (or  92   b , etc.). As this occurs, the second pneumatic solenoid valves  136  serving to extend the compressor piston stop pins  142  are deactivated, allowing the stop pins  142  to retract in order to allow full travel of the compressor piston assembly  54 . When the combustion piston  48  reaches its maximum extension into the case combustion chamber portion  92 ( a, b , etc.), as shown in  FIG. 4A , the pressurized intake charge flows from the second volume  64  into the hollow axial passage  56  of the connecting rod  52 , and thence through the combustion piston outlet ports  58  in the nose of the piston  48  and the sleeve bypass or transfer passages  46  to enter the case combustion chamber portion  92   a ,  92   b , etc. 
     At this point, the pressurized air entering the case combustion chamber portion flows into either the rotor combustion chamber portion  22 ( a, b , etc.) if the two split chamber portions are aligned sufficiently closely with one another, or into one of the semicircumferential recesses  36  extending about the rotor, depending upon the position of the rotor within the case. Either way, the pressure causes the rotor to rotate within the case. When the rotor position is optimum for ignition, fuel is injected into the aligned combustion chamber portions and the ignition is actuated to start the engine. 
     The rotary engine may have any of a wide number of different embodiments, depending upon the number of compression modules and corresponding case configuration, the number of rotor combustion chambers and rotor vanes, and the number of rows of compression and power modules assembled together. The engine  10   a  of  FIGS. 1 ,  5 , and  7  incorporates two compression modules  14  and a three chamber rotor  20   a  therein, with the rotor  20   a  having a corresponding number of rotor vanes. It is preferable to have a different number of rotor combustion chambers and compression modules (and therefore case combustion chambers), in order to avoid a position of singularity during the starting phase, and to avoid simultaneous combustion events. It will be seen that the three rotor combustion chamber portions of the rotor  20   a  result in three power pulses for each of the two compression modules during each revolution of the rotor, i.e., six power events per revolution. This is equivalent to a twelve-cylinder four-stroke cycle (Otto cycle) engine. 
       FIG. 6  illustrates a cross sectional view of a rotary engine  10   c  having only a single compressor module  14  but including a rotor  20   a  with three combustion chamber portions and vanes. The case  18   b  may be the same as the case  20   b  illustrated in the sectional views of  FIGS. 4A through 4D  illustrating the operating principle of the engine, as only a single compression module  14  is used with this engine  10   c . Such an engine produces three power events per revolution, equivalent in number to a six-cylinder Otto cycle engine. 
       FIG. 8  provides a sectional view of a rotary engine  10   d  having three compressor modules evenly spaced about the power module  12   c . The power module  12   c  includes a rotor case  18   c  having three case combustion chamber portions  92   c , three expansion chambers  98   c , and three exhaust passages  100   c  therein, corresponding to the number of compression modules  14 . The rotor  20   c  includes four rotor combustion chamber portions  22   c  and corresponding vanes  24 . It will be seen that this configuration produces four power events for each of the three compression modules  14  per each revolution of the rotor  20   c , equivalent to the twelve power pulses produced by a twenty-four cylinder Otto cycle engine during each revolution. Thus, the more rotor combustion chamber portions and the more compression modules used in an embodiment of the present engine, the more power events per rotor revolution and the greater the torque. The result is a high torque, smooth running engine suitable for a vast number of different applications. 
     It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.