MXPA01002079A - Reciprocating machine with two sub-chambers - Google Patents

Abstract

A reciprocating machine includes a housing (12) and piston means (20) that are cyclically relatively displaceable along an axis (11) to define a variable volume working chamber (50). There is further provided air inlet means and fuel inlet means (100) admitting air and fuel to the working chamber for forming an ignitable mixture after compression of the air therein, and means to exhaust combustion products from the working chamber. The variable volume working chamber (50) includes at least two sub-chambers, a combustion chamber (54) and a main chamber (52) mutually displaced on the axis (11) and in communication at a cross section (53) at which gas in the combustion chamber (54) may expand at least partially laterally as it flows from the combustion chamber (54) into the main chamber (52). The air admission means, the exhaust means andthe chambers (52, 54) are arranged so that a swirl of gas is generated and maintained about the axis (11) in both chambers (52, 54) during operation of the machine. The combustion chamber (54) is sealed and defined laterally and at one end by integral heat resistant and/or low thermal conductivity wall structure (40) having a surrounding heat insulation jacket (48) and associated heat dissipation means (47, 49) arranged so that, during operation of the machine, the surfaces (42a, 44) of the wall structure bounding the combustion chamber are maintained at a temperature which is substantially higher than wall surfaces (31) bounding the main chamber (52).

Description

ALTERNATIVE MACHINE WITH TWO SUB-CAMERAS Field of the Invention This invention relates generally to 5 alternative machines, including those that can be operated as internal combustion engines, but in a particularly preferred embodiment relates to an improved sleeve valve engine. Field of the Invention 10 In recent decades, a substantial research effort has been made in the search for a commercially practical adiabatic engine. A useful reference on the subject is "The Adiabatic Engine", published by the "Society of Automotive Engineers (SAE), in 1984, as part of its Progress in Technology Series (No. 28). Most non-cooled adiabatic engines produced for research purposes under various programs make heavy use of ceramic insulating inserts, such as cylinder and combustion chamber liners, piston caps, sunroof, valve seats, valve housings and valve guides. These programs generally examined the viability of adiabatic engines lined with ceramics, and zirconia partially stabilized with yttria (PSZ) was considered as a particularly promising pottery for the purpose. Research programs contributed significantly to the advance of the design 1lUI IT < 1 l) 1 * -flWtr Éli »i 'i - i * - * - .. * .. *. ... "* &.!., A .- * .- .., *, *** .. * 4. engine, but the reality is that today, there is no successful adiabatic production engine. The main problems have included a short ceramic life, an inability to identify lubricants that had a satisfactory performance at the high temperatures involved, and the inability to obtain greater expansion energy within the cylinder and thus the need to extract energy from evacuation gases, by secondary expansion. Another problem was the substantial decrease in the volumetric efficiency of the cylinder due to the heating effect of the surfaces of the cylinder / combustion chambers or in the incoming air charge. Several contributors to the aforementioned publication including GM, Cummins and Komatsu, conclude that it is not possible to achieve a practical adiabatic motor operation without high evacuation gas temperatures, turbo charged or supercharged (preferably with intercooling) and secondary expanders. A design made by Kirloskar was based on vertically aligned cylinder fins and air cooling by convection, but achieved only a low level of adiabatic operation. At some previous time, the use of heat insulation members adjacent to the combustion space was proposed by Sir Harry Ricardo for several purposes trying to improve the performance of the engines at high i - 1., n. . »Ii * - tfraafamj jajg á velocity. In his classic text, "The High Speed Internal Combustion Engine," Fourth Ed. 1953 (Blackie &Son Glasgow), Ricardo suggests the use of a heat insulation member placed out of the path of incoming air. It suggests that such a member can easily be included in a swirling compression engine, and possibly in an induction swirling engine, of either a 4-stroke or 2-stroke sleeve type, but could only be adjusted with great difficulty or with breathing restrictions, in a 4-stroke open chamber spring valve motor. Ricardo mentions (on page 26 of the aforementioned text) that the heat insulated member has the functions of raising the compression temperature without reducing the density and, if properly positioned and provided, maintains the period of constant delay in terms of angle of crank, in this way allowing a fixed time of injection through the entire speed range. Ricardo also suggests that the heat-insulated member could also be useful because its surface temperature would be high enough to prevent the deposition of coal or ash, and that if it is placed in this way, the jet of fuel that collides with it , would completely eliminate the accumulation of deposits in this area, particularly when using fuels with a high ash content.

- - * •• - - - * - *, I ?. , - "TtiküifiMirirfl ffc nf -" ** - - * • ** "- • ~ - ^ - -'- - - *.» A *. * In Ricardo's text, you can also read the discussion, in pages 102-115, of a heat insulated member in the context of compression swirl compression chambers. A particular shape is illustrated in Figure 7.13 by means of an annular heat insulated liner for the wall of the combustion chamber, in the context of a sleeve valve combustion chamber. Without taking into account the presence of the lining, this illustration is typical of compression ignition engines, with sleeve valve, because the combustion chamber was formed in the so-called scrapping head by a cylindrical wall substantially smaller in diameter than the Main cylindrical wall guiding the piston and the valve sleeve. However, the arrangement shown in Figure 7.13 of Ricardo's text would not be practical, since one would expect that the differential expansion between the scrapping head body and the lining would cause practical difficulties as the operating temperatures varied. , leading to fatigue and / or mechanical and / or sealing failures. Then, a loss of heat insulation would result, due to the filling of annular space with soot and / or char. In compression-ignition engines of sleeve valves, the sleeves typically oscillate both longitudinally and circumferentially, and a common feature of the motors was the admission of the air in a form 'irrßai "*" -' • - '' - > * - * • - > - - «-« »*». «.. - ~ * a. .1 ^ v ^ ****, which generated a high velocity swirl of air in the chamber in this way improving mixing and combustion. Sir Harry Ricardo described typical swirl ratios for a 4-stroke operation (ie, a swirl RPM 5 relative to the crankshaft RPM), to obtain the highest average effective braking pressure and the lowest specific braking fuel consumption , in the order of 10. Ricardo also developed a series of cameras indirect injection combustion illustrated for example in its text mentioned above in Figures 7.7 and 7.10. Engines of the similar type are described in British Patent 1046104, in Japanese Patent Publication 62-051718 and in German Patent Publication 1476351. These systems are Indirect injection involved locate the eddies in the transient passage within the main chamber. Engines having smaller coaxial combustion chambers than the main chamber are described in US Patents 3815566 and 5778849 and in the Japanese Patent 5-157002. In the North American Patent 3815566, a perforated gate separates the chambers. It is an object of the invention to provide an internal combustion engine with improved thermal efficiency, and in one or more embodiments, to provide an adiabatic engine improved.

SUMMARY OF THE INVENTION The present invention provides an internal combustion engine that includes: a housing and piston means that cyclically move relatively along an axis to define a working chamber of variable volume; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two sub-chambers reciprocally displaced on the shaft and in communication with a cross section in which the gas can be expanded in a sub-chamber and at least partially and laterally as it flows from one sub-chamber to the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are arranged so that a swirl of gas is generated and maintained around the axis in both sub-chambers during the operation of the engine; and wherein one of the sub-chambers is sealed and defined laterally and at one end by the wall structure of low thermal conductivity and / or integral heat resistant, having a surrounding heat insulation envelope and associated heat dissipation means, < m i li. These are arranged so that, during the operation of the motor, the surfaces of the wall structure that join a sub-chamber are maintained at a temperature that is substantially higher than the surface temperature of the sub-chamber. wall that connect the other sub-chamber. Advantageously, the sub-chambers are arranged in such a way that the engine operates in a direct injection mode. The fuel intake means may include a fuel injector with a flow passage through the wall structure, but preferably include a fuel injector mounted intimately in a complementary opening or notch in the integral wall structure. The fuel injector preferably includes passages to cool their tips. The flow passage is advantageously accommodated to open in the working chamber at a radius that divides the sub-chamber into a central cylindrical portion and an annular outer portion, the portions of which have substantially equal volumes. Such a sub-chamber typically has an average width D and an average length L away from the cross-section where the gas can be expanded in one sub-chamber and at least partially and laterally as it flows from the sub-chamber into the other sub-chamber. The L / D ratio is preferably 0.9 or higher. In the simplest and most .. *.! ** .. * ». The sub-chamber is cylindrical with a diameter D and an axial length L. The cross-section preferably is equal to the sub-chamber or less. Passages or galleries may be provided in the main cylinder of the housing that extends around the other sub-chamber, to flow lubricant therethrough, whose lubricant is effective to reduce or control temperatures and / or temperature differences through or around the cylinder, while this is heated to a desired functional viscosity. The gas vortex in the other sub-chamber is preferably such that a surrounding swirl-cooler layer is formed therein, preferably effective to cool the end and peripheral walls of the other sub-chamber. Preferably, the gas vortex is such that the vortex ratio in the sub-chamber is at least 6: 1, and more preferably is in the range from about 10: 1 to about 25: 1. In the other sub-chamber, the swirl ratio is preferably at least 3: 1. The swirl of gas in a chamber may be such that there is a radial temperature gradient in the gas flow of a sub-chamber with a relatively hotter core and a relatively cooler periphery. 25 In a preferred embodiment, the means of admission aiaai-aia * Hta_1aí AIR METHOD and exhaust means include ports in the housing, and alternative sleeve valve means that control the ports. Such sub-chamber is then preferably placed within the scrapping head means opposed to the piston means. Preferably, the housing and the ports are such as to allow or minimize preheating of incoming air charges through the walls of the hot combustion chamber. Such housing may include respective cylindrical portions laterally defining the sub-chambers, and an annular shoulder between the cylindrical portions opposite the piston means. The shoulder preferably is provided by an annular head member, and the heat dissipating means may include annular neck means attached to the wall structure to reduce thermal conduction of the wall structure to the annular head member. Such shoulder and neck means are advantageously integrally formed with the wall structure defining the sub-chamber. Preferably, during operation, the motor exhibits at least an almost adiabatic operation. In an alternative embodiment such a sub-chamber is substantially defined within the piston means. Preferably, the sub-chambers are axially ^. «B ^ Mtiu '- ^ --- ^ - symmetrical in general shape around the axis, which is a generally longitudinal central line axis of such housing. The invention also provides, in another aspect, an internal combustion engine that includes: piston and housing means that can be moved relatively cyclically along an axis to define a working chamber of variable volume; means for admitting air and fuel to the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two subchambers reciprocally displaced on the axis and in communication with a cross section in which gas can be expanded in a sub-chamber at least partially and laterally as it flows from a sub-chamber inside the other sub-chamber; wherein a sub-chamber has an average width D and an average length L away from the cross-section, and the L / D ratio is 0.9 or greater; and wherein the air intake means includes intake ports, positioned and arranged to transfer a swirl to the gases in the chamber around the shaft, A * im íL.mr ~ * *? I.? * M ». *,,***, '1 ." . . * * * Including the laterally expanded gas flowing from one sub-chamber into the other sub-chamber where, during engine operation, a surrounding swirl-cooler layer is formed in the other sub-chamber and a swirling flow in the other sub-chamber. another sub-chamber. The vortex flow swirl ratio in the chamber is at least 6: 1, preferably in the range of 10: 1 to 25: 1. The invention further provides a method for operating an internal combustion engine at least almost adiabatically, which engine has a housing and piston means defining a working chamber, the method includes: cyclically and relatively displace the housing and the piston means along an axis to define a working chamber of variable volume; admit air and fuel to the working chamber; compress the air in the working chamber to form a combustible mixture; cause combustion of the compressed air / fuel mixture; evacuating the gases from the working chamber including causing the gases to expand at least partially and laterally as the gases flow from one sub-chamber of the working chamber into the other sub-chamber of the same; and generate and maintain a gas swirl around the axis in both sub-cameras while the motor is operating; wherein the wall surfaces joining a sub-chamber are maintained at a temperature substantially greater than a temperature of the wall surfaces joining the other sub-chamber. The fuel mixture can be ignited, for example, by a compression ignition, or by a spark plug ignition or discharge. Air and fuel can be mixed in the working chamber, either partially or totally outside the chamber. In general, the apparatus can perform a function other than that of an engine, for example, a pump or compressor. More generally, then, the invention provides an alternative machine, which includes: a housing and piston means that can be displaced cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting fluid in the working chamber; and means for evacuating fluid products from the working chamber; wherein the variable volume working chamber includes at least two sub-chambers reciprocally offset on the axis and in communication with a cross section in which the gas in a sub-chamber can expand at least partially laterally as it flows from one sub-chamber into the other sub-chamber; wherein the fluid intake means, the exhaust means and the sub-chambers are arranged so that a swirl of fluid is generated and maintained around the axis in both sub-chambers during the operation of the machine; and wherein one of the sub-chambers is defined laterally and at one end by means of heat dissipation associated with the wall structure arranged in such a way that, during the operation of the machine, the surfaces of the wall structure joining one of the sub-chambers are maintained at a temperature that is substantially greater than the wall surfaces that join the other sub-chamber. Any of the optional features and relevant preferred advantages, set forth above for the engine can also be included in the alternative machine. BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a cross-sectional view of the working end of an almost adiabatic diesel engine with ***. * * r ™? 'f - »*». .8Jtt.t, * - ttafaa. ... * i * Má9 v ± -? * a? 4-stroke single cylinder sleeve valves according to one embodiment of the present invention; Figures 2 and 3 are respective cross sections on lines 2-2 and 3-3 of Figure 1; Figure 4 is a fragmentary cross-section of the driving end of the engine of Figure 1 showing the piston and sleeve drive links; and Figures 5 to 8 are developed partial elevation views showing various relative positions of the entry and evacuation ports. Preferred Modes The diesel engine with single-cylinder 4-stroke sleeve valves illustrated is conventional to the extent that it includes a housing 12 consisting of a main cylinder 14 and a scrap head 16, a piston oscillating, and an annular valve sleeve 30 having a shaft 11 that forms an axis for the motor configuration. The valve sleeve 30 oscillates both axially and circumferentially along the inner surface 15 of the cylinder 14, while the piston 20 in turn oscillates axially in the defined space within the internal cylindrical surface 31 of the sleeve 30. The crown 21 of the piston approaches but does not touch the annular shoulder 41 of the scrapping head 16 (the minimum space is commonly referred to as the ascending movement height s), and the piston carries - • i - ** - ** - piston or sealing rings 23 for sealing the interface with the sleeve 30. That part of the scrapping head that leaves concentrically within the main cylinder 14 is separated from the surface 15 of the cylinder to define an annular notch 17 received by the oscillating sleeve. The interface between the sleeve and the scrap head in turn are sealed by a pair of rings 33 carried by the scrapping head just outside the shoulder 41. The crown 21 of the piston may include a heat insulation insert as is known . The oscillation of the piston with respect to the cylinder and the scrapping head is effective to define a working chamber 50 of variable volume sealed by the rings 23, 33 and composed of two sub-chambers 52, 54. The sub-chamber 54 may not be cylindrical or may be cylindrical. to be restricted in its mouth 53, but here a cylindrical sub-chamber is defined within the scrapping head 16 to be coaxial with the shaft 11, of a uniform diameter D and an axial length L. For direct injection, as illustrated in FIG. embodiment, mouth 53 typically has a cross section equal to the cross section of sub-chamber 54. For indirect injection the mouth will usually be smaller in its cross section than sub-chamber 54. Sub-chamber 52 is located between shoulder 41 and crown 2-1 of piston, and is limited by these surfaces and by the inner cylindrical face 31 of the valve sleeve 30, with this also having an axis 11 ? Jí "• '•'" < at- > -1"...,.. .u. ^ .A. **. **** ^ *. .. * * r ^? Jj ^^ ja ^ as its axis, as small as possible, the sub-chamber 52 has an axial extension equal to the height of upward movement S. It would be appreciated that the arrangement of the sub-chambers is such that the engine operates in a direct injection mode.Ascribing the conventional terminology, sub-chamber 52 hereinafter will be referred to as the main chamber 52, and the sub-chamber 54 as the combustion chamber 54, but it should be emphasized that the latter term does not suggest that the combustion is confined to the sub-chamber 54. Referring to Figure 4, the piston 20 is activated in the usual manner of the crankshaft 25 by means of the crank 26 and the connecting rod 27, the latter being pivotally attached to the piston by means of a piston stump 28. The crankshaft 25 is supported on the bearing 24, while the connecting rod 27 pivots on sleeve 29 of the bearing carried by crank 26. Sleeve 30 valve is activated from the crankshaft (not shown) by means of a sub-shaft 34, a bearing 34a, a crank 35, and a fixed pin 36 on the lower end of the sleeve fastened on the crank 35 by means of a spherically mounted bearing 37. The entrance and evacuation ports are accommodated around the main chamber 52 as radial openings of the cylinder 14. A preferred configuration is illustrated in Figure 3, and in Figures 5 to 8. These consist of a total of five similar equiangularly spaced ports. , comprising three ports 60, 61, 62, input, symmetrically on one side of a diametrical plane 63, and ports 64, 65 of evacuation on the other side of plane 63. Matching ports 70-75 are provided in the control sleeve 30 and the circumferential movement of the sleeve is such as to cause a fine initial opening of the inlet ports whereby the inlet air is directed obliquely into the main chamber 52 in the direction of arrows D in Figure 3 , and generates a high speed swirl effect around the axis 11 of the main chamber 52. The movement of the sleeve 30 in the direction of the arrow C will complete the opening of the input ports by matching the control ports 70, 71, 72 with the input ports 60, 61, 62, but the high speed swirl already generated around the main chamber 52 will be maintained during the entire operation cycle, both in the main chamber 52 and at a higher speed, in the combustion chamber 54, where the swirl is effective to improve the mixing, shorten the delay period of ignition, and facilitate the use of simple spray nozzles. A vortex generated by the oblique air intake is a known feature of the engines with sleeve valves, and the combustion chamber swirl ratios (ie, swirl RPM as compared to the * - -aJ -. * ^. ^ --.- ^, RPM of the crankshaft) in the order of 8 to 10 can typically be observed. However, in the context of the present invention, it is taught that the vortex can have important novel effects that will be described later. Other details related to the operation and configuration of the ports and the swirl proportions will be provided later in this description. The structure of the scrapping head 16 will now be described in greater detail. The main central component is an integral body 40 of a heat resistant material, preferably of relatively low thermal conductivity. Such a suitable material is made of stainless steel, but alternative materials may be used, for example, especially steel alloys containing nickel and / or chromium and ceramics. The body 40 has a relatively thin wall skirt portion 42 defining the combustion chamber 54, and an enlarged solid head 43 which closes at one end of the combustion chamber 54 and provides an end wall and / or surface 44 for the combustion chamber. At the other end of the body 40, around the open end of the combustion chamber 54, the body 40 has a flange 45 which provides the aforementioned shoulder 41 joining the main chamber 52 and thereby forming a head plate for the main chamber . The scrapping head 16 is completed by means of "* -" «* * Á < an outer annular head cap 18 and an intermediate mounting ring 19. As can be seen clearly in Figure 1, a radially inner portion of the head cap 18 is fixed to one end of the ring 19 and the other end of the ring 5 19 is fixed in turn to the head plate 45, both connections by means of respective rings of screws, or bolts 39. Alternatively, methods of assembling shrink or other well-known assembly methods should be used. The assembly is completed by securing the outside of the lid of head 18 on the end of the main cylinder 14. The arrangement is such that the head cap 18 and the ring 19 extend around the portions 42, 43 of the heat resistant body 40, and have matching outer cylindrical surfaces positioned to define a space 17. annular to receive the sleeve 30. The head cover 18 and the mounting ring 19 are typically formed of inexpensive casting materials such as aluminum or iron. The sealing rings 33 are respectively housed in the space between a peripheral groove in the head plate 45 and a flange of the head 45. mounting ring 19, and in a channel in the head plate 45. The passages or galleries 80 may be provided for circulating cooling fluid within the head cap 18 and a ring 19 but the means for dissipating heat from the heat resistant body 40 are such that restrict the flow of heat and thereby allow the inner surfaces 42a, 44 of the body 40 achieve a much higher equilibrium temperature than conventional in the combustion space of the scrapping head of the engines with sleeve valves. This objective is achieved in two ways. First, the head plate 45 is cut to a smaller diameter peripherally at 46 so that the main body of the head plate 45 is attached to the cylindrical body portion 42 only by a relatively narrow annular neck 47. Second, the cut to a smaller diameter 46 forms with the annular space 48, between the ring 19 and the cylindrical body portion 42, and the lower head 43, an insulating or curtain air envelope which is sucked out by a small annular space 49 which separates it. the solid head 43 of the body 40 resistant to the heat of the surrounding body of the scrapping head 16. Alternatively, the annular space 48 may be filled with a suitable high temperature insulation material to minimize the heat loss of radiative convection from the surface of body portion 42. The solid head portion 43 of the heat resistant body 40 is formed with an opening 82 with several steps to firmly seat and complement a fuel injector 100. In this way, the fuel injector 100 is intimately mounted in the opening 82 to be in an integral sense with the body 40. The tip - «MU» ». . . -, a, to ,, i .. ".aü -!; .., -.,. - *., -. **. *. ,., .- ^. a. . ... ....,., * ..? "ÍL < * m-.A. .% ¡2 * m ** ,. r1 :. ..rr **. ^ -. * .. * m.-aa - ^. i .., - ,. J. ..a 102 of the nozzle of the injector 100 may be flush with the end face 44 of the combustion chamber 54. Alternatively, it can be placed backward or forward of the end face 44. Preferably, the injector is provided with either standard internal cooling galleries, or alternate cooling passages in the solid head 43 of the heat resistant body 40 in order to protect the materials and tip passages at the high temperatures involved in this case. The tip 102 of the orifice, and the axis of the injector extending parallel to the main axis 11 of the system, centers on a radius that divides the combustion chamber 54 into an inner cylindrical portion and an outer annular portion having a substantially equal volume . It is considered to be a more favorable position for fuel injection than the conventional position favored by Ricardo, that is, with the axis of the injector as close as possible to the lateral cylindrical surface of the chamber to optimize air mixing and the fuel. It should be noted that the aforementioned passages or galleries 80 for circulating the cooling fluid within the head cap 18 and the ring 19 were provided in the prototype as a precautionary measure to ensure that the tips of the injectors do not overheat. Tests have shown that, in fact, the correction of the details in the design / selection of; (1) the injectors and their assembly within the body 40 resistant to heat; (2) the L / D ratio for the combustion chamber 54; (3) the design of the annular space 48 and the use or choice of insulation therein; and (4) the head cover 18 and the heat resistant body 40 will make it possible to exclude the cooling galleries 80. As will be discussed later, this allows the motor to be designed or operated without any specific cooling means at all other than the very small amount of heat naturally radiated or transmitted by convection from the external surfaces of the motor. Returning now to the operation of the engine, a compression or diesel 4-stroke ignition cycle is generally conventional in relation to the successive movements of the piston and the sequence of the opening and closing of the ports. The piston compresses the gases during the compression stroke, the fuel is injected and, after a period of delay, the combustion starts and the expansion stroke moves the piston downwards. In the upper dead center of the compression stroke, the piston ring 21 closes on the shoulder 41 but is separated from the height of upward movement, leaving the combustion chamber comprising mainly the combustion chamber 54, but also a minimalist main chamber 52. The second ascending time of the piston evacuates the gases through the ports 64, 65, controlling the opening of the port by a longitudinal movement of the sleeve 30 and closing the port by the circumferential movement of the sleeve, while the second downward movement sucks fresh air through ports 60, 61, 62: here, the opening of the port is controlled by a circumferential movement of the sleeve 30 and is closed by a longitudinal movement. Figures 5, 6, 7, and 8 are partial developed elevation views (double the size or scale of Figures 1 to 4) of the cylindrical interior surface 15 of the cylinder 14 and the outer surface of the sleeve 30 between the arrows Ei and E2 showing the relative positions of the evacuation port 64, and the entry port 62 and the movement of the evacuation port 74 and the entry port 72. Figure 5 is illustrated with a sleeve crank pin 36 in the Lower Dead Center position as shown in Figure 4. Figure 6 is illustrated with a 90 ° crank sleeve pin 36 after the Dead Center Lower . Figure 7 is illustrated with a sleeve crank pin 36 in the Upper Dead Center. Figure 8 is illustrated with a 90 ° sleeve crank pin 36 after the Upper Dead Center. In Figures 5 to 8, the sleeve ports 72 and 74 are shown in dotted or dashed lines while the barrel ports 62 and 64 are shown in solid or uninterrupted lines. The orbit or trajectory of movement of the sleeve and its ports is shown by the marked ellipses 130. The major axis of the ellipse 130 is, of course, twice the radius of the crank M (Figure 4) and the minor axis is determined by the relationship between, or the magnitudes of the crank radius M, the lateral distance N (Figure 4) between the axis of the main cylinder or the center line and the center line of the hemispherical bearing 37 and the outer radius of the sleeve 30. In the Figure 5, the sleeve inlet port 72 has the sloped "opening" edge uncovered from the cylinder barrel inlet port 62, resulting in an open port area 129. The lateral width X of the open area 129 increases rapidly due to the circumferential velocity component of the sleeve orbit 130 being at a maximum. Similarly, the lateral width Y J ikt '-' "• - *" "&" - - "* - ^ to ^^^^ of the open area 131 decreases rapidly, which results in a quick closing of the ports 64 and 74 of evacuation . In Figure 6 the sleeve inlet port 72 is almost in its closed position. The vertical height Z of the open area 132 decreases rapidly because the vertical velocity component of the sleeve orbit 130 is at a maximum. The evacuation ports 74 and 72 are closed. In Figure 7 all the ports are closed, the lower edges of the sleeve ports 72 and 74 have passed well above the sealing rings 33 of the scrapping head and the piston 20 is at or near the Upper Dead Center in the ignition time. In Figure 8, the lower edge of the sleeve evacuation port 74 has the upper edge of the cylinder barrel port 64 uncovered. The vertical height W of the open area 133 increases rapidly as the vertical velocity component of the sleeve orbit 130 once more has just reached a maximum value. Input ports 62 and 72 are closed. The illustrated preferred engine and its operation differ in important matters from a conventional sleeve valve engine. First, it is found that the main influence of the thermal resistance of the body 40 It is supported by its heat resistant material and its integral shape, and its isolation from the surrounding media, optimized by such devices as the narrow neck 47, the temperature gradients around the smaller diameter cut 46 and the space 48 cause a circulation of air within the envelope formed by these spaces, together with the side effects such as final losses on the face 44 and on the piston 21 and the influence of incoming fresh air, were combined to determine an equilibrium temperature for the surfaces 42a, 44 much higher than conventional. On the other hand, the temperature of the surfaces 42a, 44 is substantially higher than the temperature of the wall surface of the main chamber 52. In fact, it is believed that it is desirable that this temperature difference be in the range of 400 ° to 1000 ° C. A significant preferred element of the illustrated design facilitating combustion chamber performance is believed to be due to the integral assembly of the injector body in the solid heat resistant material of the body 40. The high temperature in the combustion chamber 54 also reduces further the "delay period" of the ignition, providing heat to quickly vaporize the injected fuel droplets. This effect increases the Known benefits of the swirl mentioned above by reducing the delay period and improving the rapid mixing of fuel and air. Additionally, it could be appreciated that this temperature differential can be maintained at even higher preferred values due to the lack of restriction in both the longitudinal and lateral expansion of the body portion 42. In particular, the body 40 is free to expand longitudinally outwardly to accommodate a longitudinal expansion of the portion 42 as the temperature of the inner surface 42a increases, while the space 49 around the body 40 likewise accommodates the lateral expansion. or radial. The space 49 will typically be about 0.2 mm, and the maximum radial expansion of the head portion 43 arises from the heated body portion 42 which it believes is somewhat less than the same. Second, as the expansion stroke begins, and the gas expands both downwardly and laterally within the main chamber 52 in the cross section 53 aligned with the shoulder 41, a substantial temperature differential between the combustion chamber 54 and the shoulder 41, in combination with the expansion of the gas and the swirling level of air or gas held around the common axis 11 of the chambers 52, 54 results in a layer ^ j Highly stable swirl limit of relatively cooler gases that follow the piston crown down adjacent the cylindrical wall 31 of the sleeve 30. It is believed that this is the explanation for the unusually low cylinder wall temperatures observed. On the other hand, the incoming air charge forming a spiral or swirl layer at a fairly high velocity within the orifice 31 in the main chamber 52 is believed to have a significant cooling effect on the surface 31 itself and also on the surface 31. the lower face 41 of the scrapping head 45, during the entry time. The temperature of the average external wall of uniform state of the cylinder 14 has been mediated at 100 ° C above the ambient temperature with the engine working at 7 bar bmep, the total absence of any forced fluid cooling either by water or air. This temperature rise is substantially independent of the speed of operation of the motor, an effect quite contrary to the observation with both conventional motors, and in the development of the adiabatic motors with ceramic. Perhaps, this arises from the expectations that, as the speed of operation of the engine increases, it would also increase the "cooling effect of entry" mentioned above. It is emphasized that the proposed mechanisms are simply believed to be a probable explanation of the i, f,. * - 'ffiffrf- 1 T -. -, * *. t. - You Ji &A? Ú »..". . . , I observed effect, but it is not stated that the low temperature of the cylinder wall observed is true or only arises from this mechanism. Other mechanisms may be involved. The swirl ratio in the combustion chamber of the illustrated engine has been measured to be in the region of 9: 2, but a swirl ratio in the combustion chamber greater than 6: 2 is considered, for example, in the range of 10 to 25: 1 or greater, it is desirable to improve the effects of the invention. This is, by convection, the measured value for the combustion chamber: it should be understood that the swirl ratio generated in the main chamber will be lower, inversely related to the ratio of the diameters of the chamber, although other effects will affect / have influence on the air velocity exact, especially on the adjacent end and peripheral surfaces. It is preferred that the swirl ratio in the main chamber 52 is at least 3: 1. Another effect of the swirl and a third difference of the conventional engines of this general type, which believed to arise from the swirl of air in combustion chamber 54 is a temperature gradient of a relatively hotter core at a relatively cooler periphery. You are not sure of the extent to which this effect occurs, if it occurs, but can also help maximize combustion chamber temperatures that i ^ i »• ti -aHÜ * - lHBaftfr -w? ^.-'- m -mit * - *. *,, .-, * ^ *, -, t * Újk * m- ** can achieve. A fourth difference is found in the proportions of combustion chamber 54. In Ricardo's book mentioned above, the ratio of length to diameter of the combustion chamber is recommended in the order of 0.842. All the production and research engines illustrated in the book have this ratio in the range of 0.76 to 0.88. In comparison, it is preferred that the ratio VD, where L is the axial length of the combustion chamber 54 and D is the uniform diameter of the combustion chamber 54, should be 0.9 or greater, preferably greater than 1.0 and advantageous and substantially greater, for example in the order of 2 to 4 or more. If the combustion chamber 54 becomes relatively elongated, it is believed that this improves the final cooling effect of the adjacent cylindrical surface 31 of the stable swirl layer. The areas of the end face 44 of the combustion chamber and of the confronted end surface of the crown 21 of the piston are reduced relative to the lateral surface area, so that the ultimate losses are diminished. On the other hand, the distance or "displacement" of fuel spray from the tip 102 of the injector can be reduced to less than L, whereby the lowermost portion of the air in the combustion chamber 54 remains colder. A higher L in relation to D also further reduces the initial heating effect of the Att. incoming air caused by contact with hot combustion chamber surfaces and subsequent reduction in volumetric efficiency. The cold temperature of the main cylindrical body, and the remaining environment is indicative of the almost adiabatic operation. There is no need for a conventional water or air cooling system and in fact none is provided. However, the low temperature of the system usually has another consequence: most common lubricating oils require a higher temperature than that found in the crankcase of this engine to achieve a correct functional viscosity. To solve this difficulty, the circulation of the crankcase lubricant is taken advantage of through passages or galleries 110 in the main cylinder 14 between the ports 60-62, 64, 65 of evacuation mainly to reduce the temperature difference between the ports input and evacuation that would otherwise result in excessive "non-round" distortion at the sleeve interfaces, although this last problem can of course be solved using a conventional circulating cooler. The secondary benefit of this configuration is heating the oil to achieve functional viscosity. - In general, it can be seen that the arrangement is designed to allow or not the minimum pre-heating of ^^^^ »* '-; ^ f £ _ incoming air charges through the walls of the hot combustion chamber. A well-known formula for the theoretical value of the indicated standard thermal air efficiency (ASTE) of an ideal diesel cycle is the following expression: ASTE = 1 - [. { T4 - T !} / k. { T3 - T2} ] where the constant k is the proportion of the specific heats, in this case it starts with being 1.4. The temperature parameters of this expression include the room temperature Ti, the temperature T2 at the end of the compression and immediately before the start of combustion, the combustion temperature T3, and the temperature T at the end of the expansion and at the beginning of the evacuation. For the illustrated engine at a minimum specific brake fuel consumption point (which here, as is typical, approximately matches the maximum brake manufacturing pressure) has been consistently measured during extensive tests, the evacuation temperature above the environmental, ie T4 - Ti, as typically in the range of 160 ° -200 ° C, while, T3 - T2 has been calculated by established methods at approximately 1900 ° C. With these values in the previous expression, the ASTE was calculated in the order of 93%. For a diesel engine of conventional production of a cylinder size similar to the prototype and operating at the same task point, the ASTE • jj ^ g calculated approximately 69%. At lower task points, the differences calculated in ASTE were even greater. One could appreciate the above discussion that the illustrated engine has a number of operational advantages, including, but not limited to the following: (i) Because the described properties of the body 40 resistant to heat and its environment, a high temperature is obtained of equilibrium operation in combustion chamber 54, and that the preceding heat losses, during and after combustion are reduced. As a further result, it is possible to achieve satisfactory operation with a compression ratio significantly lower than would otherwise be possible. (ii) There is a minimal loss of heat in the cylinder wall in the expansion stroke, an effect that is believed to arise under the high stable swirl and the lower temperature gas layer against the surface 31. (iii) There is also a minimal loss of heat during the compression stroke, which is believed to be due to the combined effect of the high swirl gas layer and the properties of the body 40 resistant to heat and its environment. (iv) The engine, in this way, exhibits an almost adiabatic operation and thus there is no need for a conventional water or air cooling system. A prototype engine has been designed and constructed as shown generally in Figures 1 through 4, and through testing has consistently operated on, or about 95% of the perfect adiabatic operation. The analysis of the test results clearly indicates that an operation close to the adiabatic operation can be achieved at 98%. Such an almost adiabatic operation has been achieved without the need for high operating temperatures for the pistons and cylinder walls; the turbocharged or supercharged; formation of compounds; saturation cycles; the use of ceramics; any specific or conventional means of cooling the barrel or cylinder head; or evacuation gas temperatures higher than normal and without secondary expanders. The absence of these characteristics, but the presence of an almost adiabatic operation, is contrary to the expectation as mentioned above. These results should be compared with a statement in the Diesel Engine Reference Book, eds. Challen & Baranescu, on p. 107 (2nd edition 1999) that dictates that "the use of an adiabatic motor would of course result in a very considerable increase in the evacuation temperature". (v) As a result of these effects, there is a close adherence to the parameters required for an optimal ASTE in the previous expression, that is, high T3 - T2 and low T4 - Ti. (vi) Because the design of the sleeve valve motor is adopted in preference to the spring valve motor, not only a high swirl ratio is achieved and maintained, but also a very high volumetric efficiency to be achieved and maintained of the high operating temperature of the combustion chamber 54. This latter effect is due to the fact that the incoming air charge does not effectively come into contact with the hot combustion chamber 54 until after the compression stroke has started, that is, after the closing of the inlet ports and that the air in the main chamber 52 starts to be transferred to the combustion chamber 54. (vii) The high known mechanical efficiencies of the sleeve valve motors are available to the system. (vm) By accommodating a thermal barrier around the combustion chamber 54, and having a cold main cylinder, the problems encountered in the adiabatic engine designs with known or proposed ceramic fittings are avoided or minimized as a result of the high temperatures in cylinders, piston and valves (typically 400 to 1000 ° C), piston rings and lubricants (typically up to approximately 500 ° C) and evacuation gas (up to 1000 ° C). .,. ' , (ix) By shortening the ignition delay period (as a result of the high swirl temperature in chamber 54), the overall duration of the combustion period is shortened, and combustion approaches closer to the constant volume (the ideal) instead of constant pressure. (x) The high swirl ratios that can be achieved by facilitating the use of simple spray nozzles in a high VD environment. (xi) All these effects combine to substantially raise the average effective braking pressure (bmep). (xii) High operating speeds are achieved. (xiii) In a conventional sleeve valve Cl engine as defined and developed by Ricardo and others, in many years, an increase in the air whirlpool ratio would automatically cause an increase in the rate of heat transfer, particularly away from the combustion chamber and would strongly reduce the possibility of an adiabatic operation. In the engine described here, the problem of fundamental design, compromise or nexus are eliminated, thereby allowing all the benefits that can be obtained from high air swirl ratios. Again, it is instructive to compare this result with other statements in "Diesel Engine Reference Book", in ? á ^ ect? ^? M ... ¿* i3tm ¿í t * «. a m ^^^ ??? m? _ ^^ ¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡^ ^ ^ ^ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^ [heat] lower ". (xiv) These benefits can be achieved without incurring the penalties that would otherwise arise from additions such as charged tube; supercharged; secondary expansion; saturation cycles or the use of ceramics or high surface temperatures or the main work chamber. In addition, a conventional cooling system that uses water or air is not required. Of course it should be understood by those skilled in the art of engines that the design of any particular engine according to the invention will require a set of compromises together with the preferred elements of the invention in order to achieve a given performance criterion. For example, the proportions of the combustion chamber 54, including its VD ratio, will be affected by its dimensional relationship to the dimensions of the main chamber 52 - both to determine the compression ratio and, along with the port design the proportions of swirl respectively for the two cameras. The value of / D also affects other parameters as mentioned above, as well as the position of the injectors. In an alternative embodiment, the camera 54 of ^ HHt combustion can be provided in the piston instead of the scrapping head. This would be less satisfactory, for example due to the increased weight of the piston, and to the displacement of the axis of the piston stump or alternatively the elongation of the piston, but these disadvantages would not be insurmountable if the application were guaranteed. Another disadvantage would be the need to provide a screen or guard to prevent contact between the lubricating oil and the heat-resistant body that defines the combustion chamber. In this alternative mode, it could be expected that the injector is still disposed within the scrapping head, or inside the head of the cylinder in a version with 2-stroke or 4-stroke high-valve ports. The illustrated engine is a compression or diesel ignition engine with 4-stroke sleeve valves. The concepts of the invention can also be applied to spark ignition engines of 4-stroke sleeve valves, 4-stroke spring valve motors, 2-stroke engines with sleeve valves, and / or spring valves and / or cylindrical ports controlled by the movement of pistons, or any of these engines with the combustion chamber mounted on the piston, and for any of these engines using a spark plug ignition or discharge with liquid fuel or gas or gas fuel with a gt ^^^^^? ^^^^? jgí ^^^^ * '- yftí ^ tói * ^ j! diesel pilot gas. It is also emphasized that the concepts of the invention can be combined in a single apparatus with variable timing sleeve valve arrangements of Australian patent 600913. Where spring valves are used instead of sleeve valves, an arrangement suitable for generating The desired shape of the vortex is illustrated in Figures 7.5 and 7.6 of the aforementioned text by Ricardo et al (Ps 100, 101 of the 4th ed.). It should be further emphasized that the invention is not confined to cases where the combustion chamber 54 is cylindrical. Any other functional configuration can be employed including arrangements with a restricted neck opening within the main chamber 52. Where this restriction was a significant proportion of the cross section, the engine can operate as an indirect injection engine. The invention of course extends to alternative machines having different functions from those of the engine functions, for example, compressors or pumps.

Claims (49)

1. CLAIMS 1. An internal combustion engine includes: a housing and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two mutually displaced sub-chambers on axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows from a sub-chamber within the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are arranged so that a swirl of gas around the shaft is generated and maintained in both sub-chambers during the operation of the engine; and wherein one of the sub-chambers is sealed and defined laterally and at one end by means of a wall structure. low thermal conductivity and / or integral heat resistant having an envelope isolated from surrounding heat and heat dissipation means accommodated - ~ - "->" - such that, during engine operation, the surfaces of the wall structure join one of the sub-chambers and are maintained at a temperature that is substantially greater than the wall surfaces that they unite the other sub-chamber.
2. 2. The internal combustion engine according to claim 1, wherein the sub-chambers are accommodated, whereby the engine operates in a direct injection mode.
3. 3. The internal combustion engine according to claim 1, wherein the sub-chambers are accommodated whereby the engine operates in an indirect injection mode.
4. The internal combustion engine according to claim 1, 2 or 3, wherein the combustion intake means includes a fuel injector mounted intimately in a notch or complementary opening in the integral wall structure.
5. The internal combustion engine according to claim 4, wherein the fuel injector includes a tip and a passage for cooling the tip.
6. The internal combustion engine according to any of the preceding claims, wherein the fuel intake means includes a flow passage accommodated to open in the working chamber to a radius that divides one of the sub-chambers into a cylindrical portion. central and an outer annular portion, whose portions have rrSÁm ifUrhl *. »» * JuftfeUa ... t »^ substantially equal volumes.
7. The internal combustion engine according to any of the preceding claims, wherein one of the sub-chambers has an average width D and an average length L away from the cross-section and the portion VD is 0.9 or greater.
8. The internal combustion engine according to claim 7, wherein one of the sub-chambers is cylindrical, having a diameter D and an axial length L.
9. 9. The internal combustion engine according to any of the preceding claims, where the cross section is equal to or less than one of the sub-chambers.
10. The internal combustion engine according to any of the preceding claims, wherein the wall structure is free to expand longitudinally and laterally with respect to the shaft sufficiently to accommodate the thermal expansion that arises from the temperature to the surfaces of the structure of wall that join one of the sub-chambers.
11. The internal combustion engine according to any of the preceding claims, operating including passages or galleries in a main cylinder of the housing extending around the other sub-chamber, for flow lubricant therethrough, which ^^ - tifc «-» --- '"-Jittitt? it ml? á lubricant with this is effective to reduce or control the temperatures and / or temperature differences through or around the cylinder while it is with this heated at a desired functional viscosity 12.
12. The internal combustion engine according to any of the preceding claims., wherein the swirl of gas in the other sub-chamber is such that it is formed therein in a relatively swirling surrounding chiller layer.
13. The internal combustion engine according to claim 12, wherein the colder binding layer is effective to cool both the end and peripheral walls of the other sub-chamber.
14. The internal combustion engine according to any of the preceding claims, wherein the gas vortex is such that the swirl ratio in one of the sub-chambers is at least 6: 1.
15. 15. The internal combustion engine according to claim 14, wherein the swirl ratio is in the range of about 10: 1 to about 25: 1.
16. The internal combustion engine according to any of the preceding claims, wherein the gas vortex is such that the swirl ratio in the other sub-chamber is at least 3: 1.
17. 17. The internal combustion engine according to '"•" »• - • ¡¡j ^ fc. ^^ g ^^ j ^ any of the preceding claims, wherein the gas vortex in one of the chambers is such that there is a radial temperature gradient in the gas flow of one of the sub-chambers with a relatively hotter core and a relatively colder periphery.
18. The internal combustion engine according to any of the preceding claims, wherein the air intake means and the exhaust means include ports in the housing and alternative sleeve valve means that control the ports.
19. 19. The internal combustion engine according to claim 18, wherein one of the sub-chambers is disposed within the scrap head means opposed to the piston means.
20. 20. The internal combustion engine according to claim 18 or 19, wherein the housing and the ports are such as to allow a minimum pre-heating or no pre-heating of incoming air charges by the combustion chamber walls. hot
21. 21. The internal combustion engine according to any of the preceding claims, wherein the housing includes respective cylindrical portions laterally defining the sub-chambers and an annular shoulder between the cylindrical portions opposite the piston means. * > - ** • * > < - • ijíí ^ r *? r *, mr ** M- & i j-fl & Fofc ».
22. 22. The internal combustion engine according to claim 21, wherein the shoulder is provided by an annular head member.
23. 23. The internal combustion engine according to claim 22, wherein the heat dissipating means includes annular neck means attached to the wall structure to reduce thermal conduction of the wall structure to the annular head member.
24. 24. The internal combustion engine according to claim 23, wherein the neck and shoulder means are integrally formed with a wall structure defining one of the sub-chambers.
25. 25. The internal combustion engine according to any of the preceding claims, exhibiting at least an almost adiabatic operation.
26. 26. The internal combustion engine according to any of the preceding claims, wherein one of the sub-chambers is substantially defined within the piston means.
27. 27. The internal combustion engine according to any of the preceding claims, wherein the sub-chambers are generally and axially symmetrical about the axis, which is generally a longitudinal centerline axis of the housing.
28. 28. The internal combustion engine according to any of the preceding claims, wherein the fuel mixture can be ignited with compression ignition.
29. 29. The internal combustion engine according to any of claims 1 to 27, wherein the fuel mixture can be ignited by a spark plug ignition or discharge.
30. 30. The internal combustion engine according to any of the preceding claims, wherein the air and fuel are substantially completely mixed in the working chamber.
31. 31. The internal combustion engine according to any of claims 1 to 29, wherein the air and fuel are mixed at least partially externally of the working chamber.
32. 32. An internal combustion engine including: a housing and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; where the variable volume work chamber ^^^ ¿*. . *** i? m.m *.,. a.ai.l.A .A. ** ? * * .. *. • ** - ***** '' includes at least two mutually displaced sub-chambers in axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows of one sub-camera inside the other sub-camera; wherein one of the sub-chamber has an average width D and an average length L away from the cross-section, and the VD ratio is 0.9 or greater; and wherein the air intake means includes positioned and accommodating ports of entry for imparting a swirl in the gases in the chamber around the shaft including the laterally expanding gas flowing from one of the sub-chambers within the other sub-chamber where a swirling chiller surrounding layer is formed during the operation of the motor in the other sub-chamber and a swirling flow in the other sub-chamber, the swirling ratio of the swirling flow in a chamber is at least 6: 1, and preferably it is in the range of 10: 1 to 25: 1. The internal combustion engine according to claim 32, wherein the colder attachment layer is effective to cool both the end and peripheral walls of the other sub-chamber. 34. A method for operating an internal combustion engine at least almost adiabatically, whose engine has a housing and piston means that define a chamber of '* - - -' - work, the method includes: cyclic and relatively displace the housing and the piston means along an axis to define a working chamber of variable volume; admit air and fuel into the working chamber; compress the air in the working chamber to form an ignition mixture; cause combustion of the compressed air / fuel mixture; evacuating gases from the working chamber including causing the gases to expand partially and laterally as the gases flow from one sub-chamber of the working chamber to the other sub-chamber of the same; and generating and maintaining a swirl of gas around the axis in both sub-chambers while the engine is in operation; wherein the wall surfaces joining a sub-chamber are maintained at a temperature that is substantially higher than the temperature of the wall surfaces joining the other sub-chamber. 35. An alternative machine, including: a housing and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting fluid in the working chamber; ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ ^ g ^ ¡t ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ evacuate fluid products from the working chamber; wherein the variable volume working chamber includes at least two sub-chambers initially displaced on the shaft and in communication with a cross section in which the gas in a sub-chamber can expand at least partially and laterally as it flows into one of the sub-cameras within the other sub-camera; wherein the fluid intake means, the exhaust means and the sub-chambers are arranged so that the swirl or fluid is generated and maintained around the axis in both sub-chambers during the operation of the machine; and wherein one of the sub-chambers is defined laterally and at one end by a wall structure with an associated heat dissipation means accommodated in such a way that, during the operation of the machine, the surfaces of the wall structure which join a of the sub-chambers are maintained at a temperature that is substantially higher than the temperature of the wall surfaces that join the other sub-chamber. 36. An internal combustion engine that includes: a housing-and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; - * 3- - iw. ^. . ** r & m. *: Íil ~ * Í * A. *. * means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two mutually displaced sub-chambers on axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows from a sub-chamber within the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are accommodated so that a swirl of gas around the gas in both sub-chambers is generated and maintained during the operation of the engine; and wherein the fuel intake means includes a flow passage accommodated to open within the working chamber at a radius that divides the sub-chamber into a central cylindrical portion and an annular outer portion, which portions have substantially equal volumes. 37. The internal combustion engine according to claim 36, wherein one of the sub-chambers has an average width D and an average length L away from the cross-section, and the ratio VD is 0.9 or greater. 38. The internal combustion engine according to claim 37, wherein one of the sub-chambers is cylindrical, of a diameter D and an axial length L. 39. The internal combustion engine according to any of the claims 36, 37 or 38, where the cross section is equal to or less than one of the sub-chambers. 40. An internal combustion engine that includes: a housing and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two mutually displaced sub-chambers on axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows from a sub-chamber within the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are arranged so that a gas swirl is generated and maintained around the gas in both sub-chambers during the operation of the engine; Y - "-" "* '' -" - "- - '• -" - ******** - * > * -. ** - * -. - -1- - * ^ wherein the gas vortex in the other sub-chamber is such that a relatively swirling surrounding cooler layer is formed therein. 41. The internal combustion engine according to claim 40, wherein the colder attachment layer is effective to cool both the end and peripheral walls of the other sub-chamber. 42. The internal combustion engine according to claim 40 or 41 wherein the gas vortex is such 10 that the swirl ratio in the other sub-chamber is at least 3: 1. 43. An internal combustion engine including: a housing and piston means displacing cyclically and relatively along an axis to define a variable volume working chamber; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two sub-chambers mutually displaced on axes and in communication with a cross section in which the gas in one of the sub-chambers can be expanded at least 25 partially and laterally as it flows from a sub-chamber inside the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are arranged so that a swirl of gas around the shaft is generated and maintained in both sub-chambers during the operation of the engine; and wherein the swirl of gas in one of the chambers is such that there is a radial temperature gradient in the gas flow of one of the sub-chambers, with a relatively hotter core and a relatively cooler periphery. 44. The internal combustion engine according to claim 43, wherein the gas swirl is such that the swirl ratio in the sub-chamber is at least 6: 1. 45. The internal combustion engine according to claim 44, wherein the swirl ratio is in the range of about 10: 1 to about 25: 1. 46. An internal combustion engine including: a housing and piston means that move cyclically and relatively along an axis to define a working chamber of variable volume; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; Y means for evacuating combustion products from the working chamber; wherein the variable volume working chamber includes at least two mutually displaced sub-chambers on axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows from a sub-chamber within the other sub-chamber; wherein the air intake means, the exhaust means and the sub-chambers are arranged so that a swirl of gas around the shaft is generated and maintained in both sub-chambers during the operation of the engine; and wherein one of the sub-chambers has an average width D and an average length L away from the cross-section, and the VD ratio is 0.9 or greater. 47. The internal combustion engine according to claim 46, wherein the sub-chamber is cylindrical, and has a diameter D and an axial length L. 48. The internal combustion engine according to any of claims 46 or 47, where the cross section is equal to or less than one of the sub-chambers. 49. An internal combustion engine that includes: a housing and piston means that move cyclically and relatively along an axis to define a variable volume work chamber; means for admitting air and fuel into the working chamber to form a combustible mixture after compression of the air therein; and means to evacuate combustion products from the working chamber; wherein the variable volume working chamber includes at least two mutually displaced sub-chambers on axes and in communication with a cross-section in which the gas in one of the sub-chambers can expand at least partially and laterally as it flows from a sub-chamber within the other sub-chamber; and wherein a chamber is defined by the free wall structure to expand longitudinally and laterally with respect to the axis sufficiently to accommodate the thermal expansion arising from the temperature of the surfaces of the wall structure joining said sub-chamber. ^ j ^^^^ gg ^ j ^^^^^^^^^^^^^^^^^^ g ^^ g SUMMARY OF THE INVENTION An alternative machine includes a housing (12) and piston means (20) that can be moved relatively cyclically along an axis (11) to define a working chamber of variable volume (50). In addition, air inlet means and fuel inlet means (100) are provided which provide air and fuel to the working chamber to form a combustible mixture after compression of the air therein, and means for evacuating the combustion products of the working chamber. The variable volume working chamber (50) includes at least two sub-chambers, a combustion chamber (54) and a main chamber (52) displaced reciprocally on the shaft (11) and in communication with a cross-section (53) in wherein the gas in the combustion chamber (54) may extend at least laterally in a partial manner as if it were flowing from the combustion chamber (54) into the main chamber (52). The air intake means, the exhaust means and the chambers (52, 54) are arranged so that a swirl of gas is generated and maintained around the axis (11) in both chambers (52, 54) during the operation of the machine. The combustion chamber (54) is sealed and defined laterally and at one end by the heat-resistant wall structure and / or low integral thermal conductivity (40) having a , isá. * - "- *** - J - *" - - *** "*** > ** wrapped in insulation to the surrounding heat (48) and associated heat dissipation means (47, 49) accommodated so that, during the operation of the machine, the surfaces (42a, 44) of the wall structure that join the combustion chamber are maintained at a temperature which is substantially greater than the wall surfaces (31) that join the main camera (52).