Abstract:
There is provided an internal combustion engine ( 10 ) having a housing ( 11,12,13 ) and a rotor arrangement ( 21,22,34 ) which is mounted for oscillating rotary movement within the housing. The housing provides at least one compression chamber ( 14 ) and at least one associated compression chamber ( 30 ) and the rotor provides piston means ( 23, 36 ) for each chamber. The rotor also has internal passage means for effecting selective communication between the compression and combustion chambers.

Description:
SUMMARY OF THE INVENTION 
     The present invention relates to internal combustion engines. 
     According to the present invention there is provided an internal combustion engine comprising a housing and a rotor mounted for oscillating rotary movement therein, the housing defining at least one compression chamber and at least one associated combustion chamber, the rotor defining for each chamber piston means for sealed sliding motion therein to constitute said oscillating rotary movement and the rotor providing internal passage means for effecting selective communication between the or each compression chamber and its associated combustion chamber. 
     Preferably each cylinder is part-toroidal and its associated piston means is correspondingly part-toroidal for sliding therein and ideally the cylinders are substantially circular in radial cross-section. 
     In preferred arrangements the rotor comprises a central shaft which extends through the housing and which is supported by means of bearings for rotation relative to the housing and also the housing provides inlet means incorporating one way valves for the passage of fuel mixture to the or each compression chamber and exhaust means for the passage of combustion products from the or each combustion chamber. 
     In one embodiment the housing provides a pair of identical compression chambers in a common plane, the two compression chambers being oppositely disposed and being separated by a pair of compression bulkheads which extend radially inwardly. Usually each compression bulkhead incorporates said inlet means. 
     With some of these arrangements said inlet means in each compression bulkhead comprises a radially extending inlet bore which terminates with a cross-bore which opens at one end into one of the compression chambers and at the other end into the other of the compression chambers, the one way valves being disposed in the cross bores to allow passage of fuel mixture only into the compression chambers. Preferably a pair of oppositely disposed compression pistons extend from a first central hub provided on the shaft, the central hub sealingly engaging and rotating relative to the pair of compression bulkheads and each compression piston dividing its compression chamber into first and second parts. 
     In certain arrangements the internal passage means comprising a through bore in each compression piston the through bore communicating with a radial bore extending inwardly through the piston and through the central hub to an axially extending bore in the shaft and also the ends of each through bore opening into the associated compression chamber each having a one way valve to allow passage of fuel mixture to the radial bore. 
     Conveniently the housing provides a pair of identical combustion chambers in single plane axially spaced from the common plane of the compression chambers, the two combustion chambers being oppositely disposed and being separated by a pair of identical combustion bulkheads which extend radially inwardly. Ideally the exhaust means comprises an exhaust passage extending substantially radially through the outer periphery of the housing and opening centrally into each combustion chamber. 
     With preferred arrangements a pair of oppositely disposed combustion pistons extend from a second central hub provided on the shaft, the second central hub sealingly engaging and rotating relative to the pair of combustion bulkheads and each combustion piston dividing its combustion chamber into two parts. In addition the internal passage means further comprises oppositely disposed radially extending openings from the axial bore in the shaft through the second central hub for selective communication with the respective combustion chambers depending on the position of the rotor. Preferably each radial opening in the second central hub opens centrally between the pair of combustion pistons. 
     In another embodiment the housing provides a compression chamber and an oppositely disposed combustion chamber in a common plane, the chambers being separated by a pair of identical bulkheads which extend radially inwardly. Usually the bulkheads each have an inlet passage opening into the compression chamber via a one way valve. 
     Preferably the rotor comprise a central shaft and a central hub which sealingly engages and rotates relative to the bulkheads, a compression piston extending from the central hub for sliding oscillation within the compression chamber and a combustion piston extending from the central hub for sliding oscillation within the combustion chamber. In one arrangement the compression piston has a through bore with a one way valve at each circumferential end, which through bore communicates with a radial bore which extends inwardly through the compression piston and through the central hub to the shaft where two radial passages extend through the central hub either to open into the respective combustion chambers or to be blocked by the respective bulkheads depending on the location of the rotor relative to the housing. 
     Ideally the housing further provides an exhaust opening from the combustion chamber, the opening being centrally disposed between the bulkheads. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Embodiments of the present invention will now be described in more detail. The description makes reference to the accompanying drawings in which: 
     FIG. 1 is an exploded perspective view of an internal combustion engine according to the present invention, 
     FIG. 2 is a vertical section through the engine of FIG. 1, 
     FIG. 3 is another vertical section through the engine of FIG. 1, perpendicular to that of FIG. 2, 
     FIG. 4 is a radial section taken on line IV—IV of FIG. 2, 
     FIGS. 5-10 are radial sections taken on line V—V with a combustion rotor in various positions in its cycle, 
     FIG. 11 is an exploded perspective view of an alternative internal combustion engine according to the present invention, 
     FIG. 12 is a vertical section through the engine of FIG. 11, and 
     FIG. 13 is a radial section on line XIII—XIII of FIG. 12, showing a rotor in one position of its cycle. 
     Referring first to FIGS. 1 to  11  there is provided an internal combustion engine  10  having a housing arrangement comprising a lower housing  11 , a central housing  12  and an upper housing  13 . The lower housing  11  and the upper housing  13  being securable to the central housing  12  by means of bolts, for example. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The upper housing  13  and one axial face of the central housing  12  define therebetween a pair of oppositely disposed compression chambers  14  separated from each other by a pair of oppositely disposed compression bulkheads  15 . The compression chambers  14  are part-toroidal in shape and, in this arrangement, are circular in radial cross-section. Each compression bulkhead has a circumferentially extending cross-bore  16  which communicates with the exterior of the housing by means of a radially extending bore  17 . Radially extending bore  17  may be fed with fuel/air mixture or simply air for compression in the compression chambers  14 . Each cross-bore  16  communicates with both compression chambers  14  by way of one way valves  18  which allow passage of mixture only into the compression chambers  14 . 
     The central part of the upper and central housings  13 ,  12 , between the compression chambers  14 , provide a pair of opposed circular bearing surfaces  19 , each incorporating a circular sealing element  20 . Between the bearing surfaces is disposed a central hub  21  which is mounted on an axially extending main shaft  22  which extends centrally through the engine. The central hub  21  is able to rotate between the bearing surfaces  19  and sealingly engages the pair of compression bulkheads  15 . Extending from the opposite sides of the central hub  21  are part-toroidal compression pistons  23 , each of which has a circular cross-section corresponding to the cross-section of the compression chambers  14  for rotary sliding movement therein about the central axis of the engine. 
     A circular seal  24  is provided at each circumferential end of each compression piston  23  for sealing said rotary sliding movement in the compression chambers  14 . The compression chambers  14  are, therefore, divided into opposed first compression chambers  14   a  and second compression chambers  14   b.  Each piston  23  has a circumferentially extending through-bore  25  which opens into adjacent first and second compression chambers  14   a ,  14   b  by way of one way valves  26  which allow passage of mixture only into the piston  23 . Each through-bore communicates with a radial bore  27  which extends through the piston  25 , through the central hub  21  and into an axial bore  28  provided in the main shaft  22 . 
     The lower housing  11  and the other axial face of the central housing  12  define therebetween a pair of oppositely disposed combustion chambers  30  separated from each other by a pair of oppositely disposed combustion bulkheads  31 . The combustion chambers  30  are part-toroidal in shape and, in this arrangement, are circular in radial cross-section. The central part of the lower and central housings  11 ,  12 , between the combustion chambers  30 , provide a pair of opposed circular bearing surfaces  32 , each incorporating a circular sealing element  33 . Between the bearing surfaces  32  is disposed a central hub  34  which is mounted on the main shaft  22 . The central hub  34  is able to rotate between the bearing surfaces  32  and sealingly engages the pair of combustion bulkheads, seals  35  being provided at both circumferential ends of each combustion bulkhead  31  for engagement with the central hub  34 . Extending from opposite sides of the central hub  34  are part-toroidal combustion pistons  36 , each of which has a circular cross-section corresponding to the cross-section of the combustion chambers  30  for rotary sliding movement therein about the central axis of the engine. 
     A circular seal  37  is provided at each circumferential end of each piston  36  for sealing said rotary sliding movement in the combustion chambers  30 . The combustion chambers  30  are, therefore, divided into opposed first combustion chambers  30   a  and second combustion chambers  30   b.    
     In the central hub there is a radial extending passage  38  which extends from the axial bore  28  in the main shaft  22  and opens midway between the two combustion pistons  36 . The circumferential distance between the pair of seals  35  in each bulkhead is greater than the circumferential length of the passage  38  where it opens at the radially outer surface of the central hub  34 . 
     Extending outwardly through the housing from each combustion chamber  30  is an exhaust opening  39  which is centrally disposed between the combustion bulkheads  31 . The main shaft  22 , central hubs  21 ,  34  and pistons  23 ,  36  together form a rotor which rotates as a single unit. 
     If the engine is to be run on petrol then an ignition means, such as a spark plug, will need to be provided perhaps in the circumferential end surfaces  40  of the combustion bulkheads  31 . The compression section can work on an air/fuel mixture ready for combustion or can work on an air mixture which will need fuel injection means to be provided in the combustion section. No specific details of this are provided but will be apparent to the skilled reader. If, however, the engine is to be run on diesel fuel then ignition means may not be necessary, the compression of the fuel mixture in the combustion chambers being sufficient to combust the fuel mixture in the known manner. 
     The operating cycle of the engine can now be described in more detail, looking initially at the compression chambers. Fuel/air mixture enters the engine by way of radial bores  17 . Assuming that the compression pistons  23  are moving in a clockwise direction fuel/air is drawn into the pair of first compression chambers  14   a  through the respective one way valves  18  in the compression bulkheads  15 . When the compression pistons  23  reach the clockwise end of their travel, which is determined by the compression ratio of the compression chambers  14 , they return in an anti-clockwise direction compress the mixture in the first compression chambers  14   a  which then passes through the respective one way valves  26  located in the pistons  23 . (Whilst this is occurring in first compression chambers  14   a,  mixture is being drawn into the second compression chambers  14   b ). The mixture passes into the bores  25 ,  27  in the pistons and into the axial bore  28  in the main shaft  22 . The mixture is temporarily held in these bores whilst the opening of each radial passage  38  of the central hub of the combustion section is disposed between the pair of seals  35  in the respective combustion bulkheads  31 , until it is required in a combustion chamber. The combined bores  25 ,  27 ,  28 ,  38  effectively act as a reservoir for compressed mixture, prior to use in a combustion chamber. 
     Turning now to the operation of the combustion chambers  30 , starting with FIG. 5 in which the radial passages  38  are blocked between the seals  35  of the compression bulkheads  31 . In this position the axial bore  28  of the shaft  22  and the bores  25 ,  27  in the compression pistons  23  are charged with fuel/air mixture and the second combustion chambers  30   b  hold the combustion products from a previous cycle. As the combustion pistons  36  move anti-clockwise, the radial passages  38  move past one of the seals  35  so as to open into the second combustion chambers  30   b  as shown in FIG.  6 . At this point the second combustion chambers  30   b  are about to open to the exhaust openings  39 . In FIG. 7 the exhaust is fully open and so is the passage  38 . Fresh fuel/air mixture drives out the exhaust products and the combustion pistons  36  are at the anti-clockwise end of their travel. 
     As the combustion pistons  36  return in a clockwise direction, the exhausts  39  and the radial passages  38  begin to close off as shown in FIG.  8 . When the exhausts  39  and the radial passages  38  no longer communicate with the second combustion chambers  30   b  then the mixture in the second combustion chambers  30   b  is compressed until the combustion pistons  36  reach the clockwise limit of their travel as shown in FIG.  9 . Ignition then occurs causing the mixture to combust and expand thus driving the pistons  36  back in an anti-clockwise direction as shown in FIG.  10 . Further anti-clockwise rotation returns the pistons  36  to the position shown in FIG.  5  and the engine enters another cycle. 
     It will, of course, be apparent to the skilled reader that a similar sequence of events is occurring in combustion chambers  30   a,  but at opposite times. In other words, combustion in the first combustion chambers  30   a  occurs at the rotor position shown in FIG. 7 whilst the second combustion chambers  30   b  are exhausting and a new charge of fuel/air mixture is entering the second combustion chambers  30   b.  The cycle for the first combustion chambers  30   a  can also be followed in FIGS. 5 to  10 . 
     The shaft  22  can then be linked to a suitable mechanism to produce a desired output. For example the shaft can be linked to a compressor. In one arrangement, the compressor could be constructed along similar principles to the compression part of the engine described above with the shaft  22  being extended and incorporating a further pair of part toroidal pistons for oscillating in a further pair of part toroidal cylinders. The further cylinders could incorporate bores  16 , 17  and one way valves  18  and the pistons could incorporate bores  25 ,  27  and one way valves  26  like in the engine compression stage. Air would be compressed and expelled through an axial bore in the shaft extension. 
     The above described engine is advantageous in that there is only one moving part, namely the unitised rotor, which oscillates about the central axis of the engine. Also, the compressed air/fuel mixture is transferred to the combustion chambers via internal passage means provided in the rotor. The above-described engine has natural dynamic equilibrium in that energy force in the engine has an equal and opposing force, except for gravity, such that there is no need to manufacture opposing forces or to counter-balance in order to gain equilibrium. 
     With the engines described herein, it is also possible to manufacture the circumferentially facing surfaces of the combustion pistons and bulkheads as concave surfaces, perhaps part-spherical, in order to improve combustion. 
     FIGS. 11 to  13  show an alternative arrangement of internal combustion engine  110  which is similar in many aspects of operation as that shown in FIGS. 1 to  10 . The engine  110  has an upper housing  111  and a lower housing  112  which are securable to each other by means of bolts, for example. The axially facing surfaces of the two housings define therebetween a compression chamber  113  and an oppositely disposed combustion chamber  114 . The compression chamber  113  and the combustion chamber  114  are separated from each other by a pair of bulkheads  115 . Both chambers  113  and  114  are part-toroidal in shape and, in this arrangement, are circular in radial cross section. 
     Each bulkhead  115  has an arcuate bore  116  extending from the exterior of the housing to each of the circumferential end faces of the combustion chamber  114 . Each arcuate bore  116  has a one-way valve  117  which allows passage of a suitable fuel/air mixture only into the compression chamber  113 . An exhaust opening  118  is provided in the housing and leads from the combustion chamber  114  at a location generally midway between the two bulkheads  115 . 
     The central part of the upper and lower housings  111 ,  112 , between the compression chamber  113  and the combustion chamber  114 , provide a pair of opposed circular bearing surfaces  119 , each incorporating a circular sealing element  120 . Between the bearing surfaces  119  is disposed a central hub  121  which is mounted on an axially extending main shaft  122  which extends centrally through the engine. The central hub  121  is able to rotate between the bearing surfaces  119  and sealingly engages the pair of bulkheads  115 , a seal  131  being provided at the circumferential end of each bulkhead adjacent the compression chamber  113  and another seal  132  being provided at the circumferential end of each bulkhead adjacent the combustion chamber  114 , the seals  131 ,  132  being provided for sealing engagement with the central hub  121 . 
     Extending from opposite sides of the central hub  121  are a part-toroidal compression piston  123  and a part-toroidal combustion piston  124 , each of which has a circular cross-section respectively corresponding to the compression chamber  113  and the combustion chamber  114  for rotary sliding movement therein about the central axis of the engine. A circular seal  125  is provided at the circumferential ends of each the compression piston  123  and the combustion chamber  124  for sealing said rotary sliding movement in the compression chamber  113  and the combustion chamber  14  respectively. The compression chamber  113  is, therefore, divided into fist and second compression chambers  113   a,    113   b  and the combustion chamber  114  is divided into first and second combustion chambers  114   a ,  114   b . A further circular seal element  133  is provided on the combustion piston  124 , midway between the seals  125 . The compression piston  123  and the combustion chamber  124 , the central hub  121  and the shaft  122  together form a rotor  134  which rotates as a single unit. 
     The compression piston  123  has a circumferentially extending through bore  126  which opens into the adjacent first and second compression chambers  113   a,    113   b  by way of one-way valves  127  which allow passage of mixture only into the compression piston  123 . The through bore  126  communicates with a radial bore  128  which extends through the central hub  121  and into an axial chamber  129  formed in the shaft  122 . Two angled radial bores  130  extend from the chamber  129  for communication with the respective combustion chambers  114   a,    114   b  or to be closed by the bulkheads  115  between the seals  131 ,  132  depending on the position of the rotor. 
     Although this description does not show the various positions of the rotor  134  during its cycle of operation, this will be apparent from the drawings and from a comparison with the engine shown in FIGS. 1 to  10 . Considering the first compression chamber  113   a,  as the rotor moves clockwise fuel/air mixture is drawn in through one way valve  117 . When the rotor  134  reaches the clockwise extent of its travel, it returns anti-clockwise to compress the mixture in the first compression chamber  113   a.  The compressed mixture can then pass through one-way valve  127  into the rotor  134 . The mixture is held in the rotor  134  until the left hand radial bore  130  clears the seal  132  in the left hand bulkhead. The mixture is then drawn into the first combustion chamber  114   a  and the combustion products from a previous combustion are expelled through the exhaust opening  118 . When the rotor reaches the end of its anti-clockwise travel it returns clockwise to close the exhaust, block the left hand radial bore  130  and compress the fuel/air mixture in the first combustion chamber  114   a.  At the clockwise limit of travel of the piston, the mixture in the first combustion chamber is ignited thus causing the rotor  134  to return in the anti-clockwise direction. A similar process is, of course, occurring in the second compression and combustion chambers  113   b,    114   b.    
     It will be appreciated that alternative shapes and configurations are possible with more compression/combustion chambers/pistons being included. Also the cross-sections of the part-toroidal pistons/chambers could be non-circular.