Abstract:
An internal combustion engine includes an insulated combustion chamber having a fuel mixture inlet and a spark plug nearby the inlet. A series of baffles is configured within the combustion chamber to absorb a shockwave caused by ignition of fuel mixture by the spark plug. A turbine receives reduced-pressure combustion gases from an exhaust-side of the baffles and there is a power takeoff at the turbine.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to internal combustion engines. More particularly, although not exclusively, the invention relates to a combustion engine having improved thermodynamic efficiency. 
     The inventor postulates that inefficiency in reciprocating piston internal combustion engines is caused mainly by heat loss. Heat losses are caused by the cooling system and other factors. The inventor therefore suggests that insulation is a solution to improved thermodynamic efficiency. A large variety of insulating materials are available. These include refractories, mineral wool blocks, silicate calcium slabs and mineral fibre tiles, which are very effective heat barriers. There is also the Linde type aspirating super insulator, which exhibits a heat conductivity of 0.0015-0.72 mW/m° C. and can be used in a temperature range of 240° C. to 1100° C. However, significant space is required to install these insulators and also, they are susceptible to damage caused by rubbing and high-speed contact. It is suggested therefore that traditional cylinder designs cannot be employed to achieve the desired insulating effects. The inventor suggests that such insulating materials cannot be used unless the combustion chamber is enlarged. 
     OBJECT OF THE INVENTION 
     It is an object of the present invention to overcome or substantially ameliorate the above disadvantages and/or more generally to provide and engine having improved thermodynamic efficiency. 
     SUMMARY OF THE INVENTION 
     There is disclosed herein an internal combustion engine comprising: 
     an insulated combustion chamber having a fuel mixture inlet and a spark plug nearby the inlet, 
     a series of baffles configured within the combustion chamber to absorb a shockwave caused by ignition of fuel mixture by the spark plug, 
     a turbine receiving reduced-pressure combustion gases from an exhaust-side of the baffles, and 
     a power takeoff at the turbine. 
     Preferably the power takeoff comprises a pulley. 
     Preferably the pulley belt-drives an oil pump. 
     Preferably the oil pump drives pressurised oil to a reservoir. 
     Preferably the reservoir comprises a piston, one side of which communicates with oil in the reservoir, and the other side of which communicates with combustion gases in the combustion chamber. 
     Preferably there is a high-pressure oil takeoff at the reservoir. 
     Preferably the turbine comprises a cylindrical housing having a rotor therein, the rotor having a hollow centre receiving exhaust gases from the combustion chamber and a number of radial passages extending from the hollow centre to a periphery of the rotor, the housing comprising an annular space about the rotor periphery with a plurality of buffers extending from the housing to the rotor periphery, the rotor also comprising a plurality of outlet passages extending inwardly from the rotor periphery to exhaust outlets, the rotor further comprising a flap at its periphery between each radial passage and outlet passage, the flaps adapted to close the radial passages upon interaction with the buffers as the rotor rotates. 
     Preferably the radial passages and outlet passages each comprise butterfly valves. 
     The preferred embodiment has an enlarged combustion chamber, typically being equal to two to four times the volume of a standard cylinder of an internal combustion engine. This is suggested to provide size sufficient for insulation of insulating materials. An equivalent amount of fuel required for each cycle of explosion or combustion in an ordinary engine is introduced to a single enlarged combustion chamber. 
     Having enlarged the combustion chamber, temperatures are reduced below 1000 C. and the above-mentioned Linde insulating materials can be used. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: 
     FIG. 1 is a schematic cross-sectional elevation of an engine, 
     FIG. 2 is a schematic cross-sectional elevation of a turbine forming part of the engine of FIG. 1, 
     FIG. 3 is a schematic cross-sectional elevation of the turbine taken at III—III in FIG. 2, 
     FIG. 4 depicts a sequence of positions of a rotor within the turbine of FIGS. 2 and 3, and 
     FIG. 5 is a schematic perspective cross-sectional illustration of parts of the turbine of FIGS. 2 to  4 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENT 
     In the accompanying drawings there is depicted schematically an engine  10 . Engine  10  comprises a combustion chamber  11 , typically fabricated from metal and having an internal insulation layer  12 . The material chosen for the insulation layer is typically a Linde type aspirating super insulator as noted above. Within the combustion chamber  11  there is a framework of baffles  13  comprising a series of plates having apertures  14  therethrough. The baffle plates are typically fabricated from heat resisting alloys or other material adapted to conduct heat away as shown at  15  in FIG.  1 . The baffles  13  function to absorb radiation in the form of heat produced by the combustion gases and to conduct heat to cool areas. 
     There is a carburettor  16  receiving fuel  17  and mixing it with air for delivery through inlet port  18  to the combustion chamber  11 . There is a spark plug  19  alongside the inlet port for igniting fuel mixture within the combustion chamber  11 . Attached at  20  to the combustion chamber  11  is a turbine  21  having a drive pulley  22  from which their extends drive belts  23  and  24 . Drive belt  23  drives an oil pump  25  which draws oil from an oil reservoir  26  for pressurised delivery via oil line  27  to an oil pressure chamber  28 . Oil pressure chamber  28  is mounted upon a spring  29  to a fixed surface  30 . There is a piston plate  31  upon the oil within the oil pressure chamber  28 . The other side of the piston plate  21  communicates via combustion gas line  32  with the combustion chamber  11 . That is, output power of the turbine  21  can be used to inject energy back into the combustion chamber. There is an oil outlet  33  beneath the piston plate  31  for delivering pressurised oil to ancillary equipment. This oil can also travel along a return path  34  to the oil reservoir  26  for re-pumping by the oil pump  25 . 
     As shown in FIGS. 2 and 3, the turbine  21  includes a housing  35  of substantially cylindrical form. Within the housing  35 , there is a rotor  36 . Surrounding the rotor  36  is an annulus  37 . The rotor  36  is mounted on a shaft (not shown) and has a hollow center/port  38  that receives combustion gas from the combustion chamber  11  via hollow center/port  38 . This pressurised gas passes outwardly along the radial passages  39  en route to the annulus  37 . Extending inwardly from the housing  35  are a number of buffers  40  having ramped faces  41  and flat faces  42 . Attached to the rotor  36  adjacent to each radial passage  39  is a flap  43 . Each flap  43  together with its associated flat face  42  defines a pressure chamber that can be closed by a butterfly valve  44  within the passage  39 . A number of exhaust passages  45  extend inwardly from the periphery of the rotor  36  and these carry exhaust gases away. The pressure in the hollow center/port  38  causes combustion gas to flow along each radial passage  39  to cause clockwise rotation of the rotor  36  due to gas—force exerted on each flap  43 . During clockwise rotation, spent gas at the other side of each flap  43  escapes via the exhaust passages  45 . When the flap encounters the ramped surface  41  of the next buffer  40 , it closes enabling rotation of the rotor  36  to continue. The flaps might be spring biased to re-open. The rotor  36  is connected to the drive pulley  22 . 
     The oil pressure chamber  28  acts as a pressure buffer device serving to alleviate excessive pressure. This device prevents explosive failure of the combustion chamber  11 . It further serves to stabilise pressure within the combustion chamber for delivery to the turbine  21 . It also serves as a standby hydraulic system for powering ancillary hydraulic equipment such as door closing devices, steering wheel retractors, seat belts, hydraulic suspension and the like. More importantly, when the internal combustion engine of the preferred embodiment is installed in a motor vehicle, the vehicle may come to a standstill without omission of exhaust gas for a short period of time before moving off at traffic lights for example. 
     The output of rotor  36  need not be reduced by a transmission gearbox. Output torque can be altered by varying the number of pressure chambers. That is, a multiple in-line arrangement of rotors  36  can be mounted on a common shaft. Each would have its own hollow center/port  38  and these can be operated individually or in unison, depending upon required output torque. There is an absence of combustion about the rotor itself. That is, the turbine cannot be considered to be of the traditional two or four-stroke design. 
     FIG. 4 depicts operational phases of a two-rotor engine. These will not be described in detail. Suffice to say that when the driving force of one rotor diminishes, the other rotor can compensate. To this end, when two rotors are mounted upon a common shaft, one would be angularly offset with respect to the other. 
     It should be appreciated that modifications and alterations obvious to those skilled in the art are not to be considered as beyond the scope of the present invention.