ENDOTHERMIC ROTARY ENGINE WITH TWO PARALLEL ROTATION AXES
The invention relates to an endothermic engine of the rotative mass type, particularly efficient for the optimal exploitation of the thrust stroke, generated by the firing of a combustible mixture, and by the other strokes of expansion and discharge of the burned gases, and wherein suction and compression of the combustible material are properly arranged, whereby the exploitation of the thrust results in a high power production relative to the minimal size of the engine and to its operative and constructive easiness, and besides to a reduced consumption of combustible material.
In the actual endothermic crank mechanism engines there are notoriously cylindrical pistons that can intake at most the same volume of mixture as the volume of greatest expansion of the burned gas, it being well-known that the suction stroke occurs in the same chamber that is then used for the expansion or usable phase of the engine.
Since, notoriously, the explosion and combustion of the compressed mixture determines a greater volume with respect to the volume of the same mixture before the blast, it is clear that in the actual alternative engines that use the same chamber both for suction and for expansion, not all the available pressure is exploited for the thrust, causing in effect, an inner loss of the usable work of the piston.
Furthermore, the pistons of the actual linear engines, acting alternatively along their axis, require a transformation of their alternative movement to a rotative movement with proper crank mechanisms, in order to exploit the strength produced on the rotative engine shaft, hence determining a further reduction of the available power.
Finally, the linear and axial arrangement of the pistons and of their sliding chambers of the actual endothermic engines not only requires the necessary presence of the above-mentioned crank mechanisms, but also determines their big bulk and consequent great size, with respect to usable volume of the expansion stroke, and leads to a structure necessarily steady, complex and heavy that further reduces their efficiency and practicality, still without eliminating vibrations and loudness of the actual engines.
Many studies and attempts at solutions improving the known alternative piston engines foresee the presence of a piston or mass, that is allowed to rotate in a cylindrical opening communicating with proper predefined suction, compression, firing and expansion spaces, so that a single rotative element can accomplish at the same time these strokes, passing, with its specific perimeter part, through each specific zone of the stator, thus eliminating any actual vain travel and giving directly the rotatory movement to the shaft of the engine.
All these rotative solutions have been revealed as scarcely useful in practice, mainly because of the difficulties of removal of the heat of the rotative piston, with consequent difficulty in adjusting its expansions and managing its sealing tightnesses with respect to the stator containing it, so as to avoid the dispersion of the combustible mixture and flue gases into the not relevant zones.
Also, the structure of the chamber of combustion in the actual rotating engines presents difficulties in coordinating their optimal form for the combustion with respect to the desired compression parameters.
Another great disadvantage of the rotating piston engines accomplished until now is that of having never foreseen an expansion opening having a bigger volume than the suction opening with the consequence that these endothermic engines do not exploit the greater volume of the expansion stroke and they do not improve the yield of the thrust stroke.
In order to overcome all these disadvantages and difficulties and thus making all the advantages of a rotating mass engine feasible, with respect to the known alternative mass engines, the Italian patent 1 250 184 dated April 3, 1995 has been lodged, in which a rotating mass engine is proposed, based on a stator having two centers of rotation, and on a rotor comprising two parts indicatively semi-cylindrical and rotating in the same direction, each on one of the two axes of the stator, such parts being linked to each other by means of a sluice board or slider that acts as a hinge between the two parts of the rotor and allows their mutual sliding and divergation during rotation.
According to this proposed solution, the rotating mass does not comprise any more a single block, but three different elements, that allow the accomplishment of different volumes in the zone of suction of the mixture and the zone of expansion of the burned gas , and thus allow a better and more complete exploitation of the combustion thrust.
Still according to this solution already proposed, a better gas-tightness is possible, since the packings are placed on cylindrical and flat surfaces that act on sealing surfaces and not on sealing lines any more, as in previous rotative engines.
The practical embodiment of this solution has, in fact, highlighted some mechanical and functional problems that have suggested a series of constructive improvements, which are the object of the present improved endothermic rotative engine.
The main object of this invention is still that of improving and optimizing the thermodynamical cycle of the endothermic rotative engines , reaching the ideal ratio between the volumes of the zone of expansion and the volumes of the other zones assigned to the other strokes of the cycle, in order to allow the greatest exploitation of the usable thrust of expansion and an optimal path of the flue gases , and the combustible mixture to be compressed and brought to the firing stroke .
A main innovative feature of this invention is that of introducing a cinematic arrangement based on a rotor comprising two semi-cylindrical parts and rotating in the same direction on two parallel rotation axes, with a hinging slider in between, then achieving with such rotor the better exploitation of the thrust during the usable expansion stroke, and the adjustment of the other strokes of suction, compression of the combustible material and discharge of the burned gases, wherein said rotor is held in a stator whose chamber presents two cylindrical openings intersecting each other, and on the flat cover walls of which the seats for the two parallel axes of the rotor are provided, and being provided with proper seats to feed and blast the combustible material and discharge the burned gases.
The other objects, already mentioned and pursued in the above- mentioned patent, relate to the constructive easiness, to the possibility of maximum cooling and better tightness of the packings, to the silence and to the absence of vibrations, which objects are better achieved in the present improved constructive solution, as well.
In particular, the present improvement pursues the object of making industrially feasible an embodiment of an endothermic rotative engine that is particularly able to exploit fully the power produced during the stroke of expansion, with respect to the different volumes of its zones of suction and compression, determining, under same supplied power, a minimal overall bulk of the engine.
Another object of this invention is that of assuring the best conditions of intaking the cooling air and of the combustible material, as an effect of the mutual movement of the parts of the rotor at a suction position prearranged on the stator.
A further object of this invention is that of optimizing the form and the volume of the combustion chamber, with respect to the thermo-dynamical yield that a rotating mass engine can allow.
Still another object of the present invention is that of allowing a proper scavenging and cooling stroke of the different zones of the engine during its usual working.
Another object of the invention is that of facilitating the most efficient arrangement of the tight packings between rotor and stator.
These particular objects and those already mentioned in the above-mentioned patent, the content of which being incorporated herein by reference, are in effect perfectly achieved with the improved endothermic rotative engine of the present invention, which, in the following, is described and illustrated in one
embodiment only exemplary and not limitative, shown in the drawings, in which:
Fig. 1 shows an exploded perspective view of the main components of the stator and the rotor that form an engine of the present invention;
Fig. 2 shows a cross-sectional view of the central part of the stator of the engine of Fig. 1, provided with its cover or back wall;
Fig. 3 shows a cross-sectional view of the same central part of the stator of Fig. 2 with the elements of the rotor of Fig. 1 housed therein;
Fig. 4 shows a perspective view of a rotating compression element that forms a part of the rotor of Figs . 1 and 3;
Fig. 5 shows a perspective view of a slider or hinging and sliding element between the compression element of Fig. 4 and the expansion element of Fig. 6 of the rotor of Fig. 1;
Fig. 6 shows a perspective view of an expansion rotating element of the rotor of Figs. 1 and 3, cooperating with the compression element of Fig. 4 and linked and hinged thereto by means of the slider of Fig. 5;
Fig. 7 shows a perspective view of the rotor completely assembled, comprising the compression rotating ele-
ment of Fig. 4 and the expansion rotating element of Fig. 6 joined and linked to each other by the slider of Fig. 5, the rotor being illustrated in its minimal bulk or closing condition;
Fig. 8 shows a perspective view of the rotor, similar to the perspective view of Fig. 7, but with its components arranged in the greatest bulk or opening condition, this condition being in this case illustrated with the rotor turned by about 180° with respect to the situation of Fig. 7;
Fig. 9 shows a perspective view of a rotating conduit for the discharge of the burned gases, whose rotary movement is provided by the rotary force of a main shaft of the engine;
Figs. 10 to 18
schematically show some aspects of the typical working strokes of a cycle of the engine at issue, the strokes being illustrated with the rotor moving anticlockwise for graphical practicality and for uniformity with the previous views of the components of the engine, wherein:
Fig. 10 shows the arrangement of the stator and the rotor at the moment of the firing, that starts the expansion or usable phase of the cycle;
Fig. 11 shows the arrangement at the moment immediately following the firing stroke;
Fig. 12 shows the arrangement in a middle moment of the expansion stroke;
Fig. 13 shows the arrangement at the moment of maximal expansion and exploitation of the burned gases;
Fig. 14 shows the arrangement at a middle moment of discharge of the burned gases and with the contemporary beginning of the new stroke of suction:
Fig. 15 shows the arrangement at the final moment of discharge of the burned gases and of scavenging of the engine with the air or fresh mixture previously sucked in;
Fig. 16 shows the arrangement at the moment immediately following the discharge stroke with the scavenging in the final stroke;
Fig. 17 shows the arrangement at an initial stroke of compression of the mixture;
Fig. 18 shows the arrangement at a final moment of the stroke of compression of the mixture that precedes its firing stroke and the beginning of a new cycle;
In all drawings, the same parts are represented or are understood as represented by the same reference number, while, for representation and interpretation practicality, the different elements are sometimes illustrated with full lines even when they overlap with other elements and should be represented with dotted lines.
According to the embodiment proposed in the different figures of the drawing, and in particular with reference to Fig. 1, the endothermic engine at issue is fundamentally formed by a stator A that is in turn formed by a central body Al, by a head cover wall A2 and by a back cover wall A3, while its rotor B, in turn, is formed by a rotating compression element B2, by an expansion rotating element BI and by a slider (or linear linking and hinging element) B3.
The central body Al of the stator is fundamentally formed by a pair of cylindrical hollows 1, 2, passing and intersecting each other, said hollows 1, 2 being aligned with vertical axes X and
Y parallel and spaced to each other by a distance 3, and with a common horizontal axis Z. The intersections between the axis X,
Y and the axis Z determine the longitudinal axes XZ and YZ , which are orthogonal to the axes X, Y, Z, are parallel to each other, and concentric to the respective cylindrical walls of the hollows 1, 2. The hollows 1, 2 are contained in a substantially double cylinder-shaped center annulus 4 provided with external cooling fins 5.
In the upper part of the central body Al, in a proper position of an upper part 4 ' of the annulus 4 , a hole 6 with an inner thread is provided for the housing of a spark plug or injector
7 (cf. Fig. 2), said hole 6 being allowed to communicate with an open compartment or combustion chamber 8 arranged between the hole 6 and the hollows 1, 2. The chamber 8 is shaped with a substantially rounded surface and opens toward the hollows 1, 2. The chamber 8 is placed substantially between the two vertical axes X, Y.
A chamfer 9 of the chamber 8 links and connects the combustion chamber 8 with the upper part of the hollow 2.
In the lower part of the central body Al, in a proper position of a lower part 4" of the annulus 4, a cylindrical exhaust port 10 is provided. The exhaust port is arranged at a side face of the annulus 4 and is connected with flares 11 that are open along the inner surface of the cylindrical hollow 1. The exhaust port 10 is arranged with an inclination β equal to about 20° with respect to the axis X of the hollow 1 (cf. Fig. 2).
The central body Al is completed by the presence of a series of holes 12, into which plugs and/or screws are applied, for steadily fixing the central body Al to the opposing head and back covers or walls A2 , A3.
The covers A2 , A3 are substantially formed by flat bodies externally finned, and are provided with opposing flat surfaces
20 and 40, respectively. The outer perimeter of the covers A2, A3 corresponds to the outer perimeter of the center annulus 4 of the central body Al , to which they are steadily fixed, for example by means of screws and/or plugs passing through holes
21 and 41, respectively, that are aligned to the holes 12 presenting themselves at the side faces of the central body Al .
Both covers A2 , A3, at their opposing surfaces 20, 40 contacting the central body Al , have a cylindrical groove or hollow 22 that is coaxial to the axis YZ, being thus concentric to the hollow 1 of the central body Al .
Each of the cylindrical grooves 22 determines, in its inner side (or better axial bottom) a circular surface 23 having a circumference equal to the inner diameter of the groove 22.
An axially raised portion or plane 24 is provided on a part of the surface 23, its edge being determined partially by the inside radius of the groove 22 and on its opposite side by a corresponding radius centered on the axis XZ of the hollow 1 of the central body Al.
A hole 25 that is preferentially tilted and provided with an inner flare 26, is provided on each of the raised portions 24 of the covers A2 , A3. The flare 26 is placed at the lower part of the covers A2, A3 and turns inwardly. The hole 25 is placed between the axes X, Y of the hollows 1, 2, constrained within the cylindrical part of the respective groove 22.
A cylindrical tang 27 projects from the raised portion 24. The tang or support 27 projects toward the inner side of the hollow 1 and is arranged concentrically to the axis XZ . Further, the tang 27 is provided with an axial hole 28 that communicates with the respective outer surfaces of the covers A2 , A3.
The covers A2, A3 each further comprise a cylindrical through hole 29 that is placed in such a position to be coaxial to the port 10 of the central body Al, and a through hole 30 shaped,
as shown, as a circular segment and intended to communicate with that zone of the hollow 1 that is near the flares 11 which communicate with the exhaust port 10 of the central body Al .
In particular, the circular segment shape of the hole 30 is determined by the necessity of facilitating at its best the exhaust stroke, during opening and closing thereof, regulated by the passage of particular points of the elements Bl, B2.
After having described the main components constituting the stator A of the engine at issue, the main components of the rotor B, which are to be housed in the hollows 1, 2 of the stator A, are hereinafter described.
As already mentioned, that rotor B substantially comprises the expansion rotating element Bl hinged by means of the slider B3 (or hinging or sliding element) .
The rotating compression element B2 is housed in the hollow 2 of the stator A, and is provided to rotate around the axis YZ of the stator A, this being meant to achieve the best compression of the mixture, before firing it in the combustion chamber 8.
The compression element B2 is formed by a circular segment outer surface wall 50 having a radius substantially identical to the radius of the hollow 2, and being supported by a pair of side walls 51, 52 that are linked on their respective outside surfaces, to a pair of rings 53 and 54, respectively.
Being placed outside the side walls 51, 52, the pair of rings 53, 54 presents a reciprocal distance that is equal to the width of the circular segment surface wall 50, which is, in turn, substantially identical to the width or depth of the central body Al, in the hollow 2 of which said compression element B2 is meant to rotate.
By application of the covers A2 , A3 to the sides of the central stator body Al, after introduction of the compression element B2 into the hollow 2, a consequent theoretical contact between the outside surfaces of the walls 51, 52 of the compression element B2 and the inside flat and opposing surfaces 20, 40 of the covers A2, A3 is reached, except for the foreseeable clearances for the application of the side tight sealing segments as already indicated in the previous Italian patent application.
By the application of the covers A2 , A3, further, the rings 53, 54 of the compression element B2 are inserted into the respective holes or cylindrical grooves 22 of the covers A2, A3 which have diameters corresponding thereto and being properly provided with antifriction and lubrificant means .
Within this embodiment, the compression element B2 is allowed to rotate inside the hollow 2 of the stator A, guiding its rings 53, 54 within the grooves 22 that engage them on the longitudinal axis YZ of the stator A. The side walls 51, 52 of the compression element B2 have an end provided with hinging loops 55, 56 that are linked to each other by an end portion 50' of the circular segment-shaped outside surface wall 50, and that are preferentially provided with bushes or antifriction bearings 57, 58.
The expansion rotating element Bl of the rotor B comprises a circular segment-shaped surface wall 60 having an outer radius substantially identical to the radius of the hollow 1 of the stator A, in which hollow 1 the element Bl is housed to rotate on its axis XZ , in order to assure the best tight conditions during the usable stroke of expansion.
The expansion rotating element Bl is to be connected to the compression element B2. The circular segment wall 60 has a width substantially identical to the width of the central body Al of the stator A. The segment wall 60 extends over a portion of the circumference of less than 180° and is provided with side surfaces 61 substantially plane and meant to slide on the flat surfaces 20, 40 of the stator covers A2 and A3, respectively, except for interposing of proper tight packings, as already specified in the previous Italian patent application (cf. Fig. 6).
Said side walls or surfaces 61 have a depressed zone 62 near a hub portion 63 through which a through hole 64 is provided, in which two portions 80', 80" of a main shaft 80 are keyed or otherwise fixed (cf. Fig. 7). The depressed zone 62 allows the walls 51, 52 of the compression element B2 to rotate without contacting neither of the element Bl and the walls 24 of the stator covers A2 , A3.
On the depressed zone 62, and in particular on both sides of the hub 63 of the side walls 61, a groove or further depression 65 with limited corner width is provided.
The hub 63 is further provided with, besides the through hole 64 able to house and steadily fix the main shaft 80, a radial shoulder 66 and a radial flat surface 67 that will be used as thrusting surfaces during the expansion stroke of the engine at issue.
The expansion rotating element Bl is completed by the presence of a radial through hole 68 which starts at the outer wall of the shoulder 66 of the hub 63, and reaches the outer side of the edge or circular segment wall 60. The through hole 68 has a rectangular cross section, with one of its inner surfaces aligned to the thrusting flat surface 67.
As already mentioned, the rotor B is completed by the presence of a slider B3 able to connect, hinge and make the compression element B2 interact with the expansion element Bl inside the stator A, so as to achieve the different strokes foreseen in the thermodynamic cycle of the engine at issue. The slider B3 is shown in detail in Fig. 5.
The slider B3 comprises a rod or shaft 70 having a rectangular cross section, or, in any case, a cross section substantially identical to the cross section of the through hole 68 provided in the expansion element Bl, and being provided with a T-shaped head 71. The width of the head 71 is identical to the width of the circular outer surface wall 50 of the compression element B2 and the circular segment surface wall 60 of the expansion element Bl. At the same end of the rod 70, but on the side opposite with respect to its longitudinal axis (rectangular portino), a pivot 72 is fixed, arranged parallel to the axis XY.
The lower end (portino) of the head 71 has a hollow partially cylindrical surface 74 that determines a cylindrical port 73 concentric to the pivot 72 and able to house the head surfaces of the loops 55, 56 at the side walls 51, 52 of the element B2. The port 73 achieves a gas tightness by means of proper tight sealing segments placed on the surface 74.
After having thus described the main components of the stator A and the rotor B, their assembly and interconnection procedure is hereafter summarized with particular reference to Figs . 7 and 8.
Firstly, the slider B3 is linked to the compression element B2 upon insertion of the two sides of the pivot 72 into the through holes of the loops 55, 56 of the side walls 51, 52 of the compression element B2.
In this way, the pivot 72 of the slider B3 hinges the loops 55, 56 of the compression element B2. The head portions of the loops 55, 56 are thus housed in the circular port 73, delimited by the pivot 72 and the cylindrical surface 74 of the head of the slider B3.
The assembly proceeds then with the insertion of the rod 70 of the slider B3 into the through hole port 68 of the element Bl, starting from the part of the flat surface 67.
Since the compression element B2 is already linked and hinged to the pivot 72 of the slider B3, it is clear, that through the slider B3, the expansion element Bl and the compression element B2 , besides being hinged to the pivot 72, are also allowed to
slide linearly to each other along the rod 70 of the slider B3, and so along the thrusting flat surface plane 67, till they reach their smallest bulk or closed condition, as illustrated in Fig. 7.
Furthermore, since the compression element B2 is forced to rotate on axis YZ , being forced by its cylindrical rings 53, 54 supported within the grooves 22 of the stator covers A2 , A3, the expansion element Bl is forced to rotate on the axis XZ because it is linked to the main shaft 80. The main shaft 80 is supported at the axial hole seats 28 of the stator covers A2, A3. Thus, a reciprocal relative rotating movement of the elements Bl, B2 is allowed by the contemporary or simultaneous translation of the slider B3, that moves its hinged pivot 72 along the axis of the through hole port 68, and the rotation of the element B2 on the pivot 72 of the slider B3.
This constraint among the elements Bl, B2, B3 induces the compression element B2 to rotate on its axis YZ, touching lightly with its outer surface wall 50 concentrically the cylindrical wall of the stator hollow 2, so as to achieve the compression of air or a combustible mixture that may be between them and that is, anyway, unable to escape.
Such compression is assured also by means of the radial contact of tight sealing means placed on the expansion element Bl and on the cylindrical wall of the stator hollow 1.
Furthermore, the rotating movement of the compression element B2 and the consequent displacement of the slider B3 are caused by the rotating movement of the expansion element Bl that is
forced to rotate on its axis X , as a consequence of the blast or ignition of the combustible mixture in the combustion chamber 8.
The expansion element Bl, at the beginning of the combustion, presents its minimal thrust flat surface 67 to the expanding combusting mixture, the minimal thrust flat surface being just sufficient to make it move. But with the fast development of the expansion, a force is immediately generated that forces the element Bl to turn in the only possible direction, presenting the gas thrust an increasing thrust surface 67, and, consequently, the expansion volume of the burned gases increases to completely obtain and use the power of the firing process.
As already mentioned, with the rotation of the expansion element Bl and with the constraint of the slider B3 that can only slide inside its guiding through hole 68 and that has to drag the hinged compression element B2, and with the constraints of the rotation axes XZ and YZ, a translation of the slider B3 is achieved, whereby a contemporary rotation and divergation (divarication) between the elements Bl and B2 rotating on their respective own axes XZ and YZ and a consequent series of strokes of expansion and compression of the combustible mixture inside the hollows 1, 2 of the stator A, forming main strokes of the gas engine, are made possible.
The stroke of the largest circumferential divergation or relative circumferential rotation between elements Bl and B2, as illustrated in Fig. 8, determines also the greatest suction volume of air or fresh mixture, to which is also relevant the position of the holes 25 provided on the covers A2, A3 of the
stator A and the position of the groove or depression 65 of the hub 63 present on the expansion element Bl.
The rotation of the compression element B2, besides along the cylindrical side of the hollow 2, where it carries out its specific task of compressing the mixture previously taken in, continues of course inside the area of the hollow 1, without touching its cylindrical wall that remains far apart.
In this stroke of rotation, the compression element B2 cooperates with the surface 67 of the element Bl, with the head 71 of the slider B3 and with the side walls of the hollow 1 of the stator A, for forming the expansion volume and for exhausting the burned gases that, by means of the flares 11 and the lateral draft through holes 30, are forced toward the exhaust port 10.
As a matter of fact, according to the proposed embodiment, the port 10 does not directly accomplish the task of exhausting the burned gases, but it houses a rotating conduit 90, that, as illustrated in Fig. 9, has holes 91, 92 in correspondence to the bored flares 11 and through holes 30 of the central block Al of the stator A, and able to be aligned with said flares and holes 11, 30, respectively, but only during the stroke of exhausting the burned gases, while in the other strokes, the conduit 90 is induced to turn so as to present its closed cylindrical surface adjacent to the holes.
The presence of the conduit 90, with its exhaust holes 91, 92, constitutes the exhaust valve of the engine at issue, thanks to
which the suction of the exhaust of the engine at issue is avoided.
The arrangement and adjustment of the holes 91, 92 of the conduit 90, in order to present them to the holes 11, 30 of the stator A for the desired exhaust stroke of burned gases , is achieved, for example, by means of a crown gear 93 driven by the main shaft 80, by interposing another crown gear, a belt or a chain, or any other element able to achieve the proper reduced rotation rate, so that the desired exhaust phasing is achieved.
After having thus described the main components of this invention, and after having explained one embodiment of its rotor B and of the arrangement of the rotor B with respect to the stator A, and after having illustrated their respective function, their operation is hereafter described, in particular with reference to Figs. 10 to 18, so as to verify that they comply with the specified objects of the invention.
With reference to Fig. 10, operation starts with the end portion 50' of the compression element B2 being placed near the chamfer 9, so as to facilitate the access of the combustible mixture into the combustion chamber 8 of the stator A; that means that the element B2 has already run along the whole cylindrical portion of the hollow 2 and has already brought the combustible mixture MC within chamber 8 to its greatest degree of compression.
According to the invention, when the compression element B2 reaches the edge of the chamfer 9 to the compression chamber 8, the spark plug 7 ignites its ignition spark, that fast but gradually fires the mixture MC, causing its expansion.
It can be noticed that the combustible mixture MC is compressed in the compression chamber 8 and is kept therein, both by the action of the end portion 50' of the cylindrical surface wall 50 of the compression element B2, and by the end of the surface wall 60 of the expansion element Bl, that is placed tight on the side surface of hollow 1, and also by the head 71 of the slider B3 that is interposed sealingly tight between the elements Bl and B2 , and that in that situation, induces the elements Bl, B2 to their largest circumferential divergation, corresponding to that illustrated in Fig. 8.
In the situation of Fig. 10, the suction holes 25 of the stator covers A2, A3 are placed over the depressed groove 65 of the expansion element Bl, allowing the flow of fresh mixture MF from the outside of the engine, and its expansion ME in any free space that the largest circumferential divergation between elements Bl, B2 provides within the hollows 1, 2, and so in any free space between the expansion element Bl and the compression element B2.
The combustion of the mixture MC in the chamber 8, as already mentioned, causes a gradual but fast combustion of all the mixture with the consequent thrust to the expansion element Bl, that is so induced to rotate toward the positions shown in Figs. 11 to 13, allowing the combusting mixture MS to reach its maximum usable thrust volume.
With reference to Fig. 11, it is highlighted that after having accomplished a rotation movement of the expansion element Bl equal to few degrees, its depressed groove 65 exits the zone of the suction hole 25, determining the end of stroke of suction of the fresh mixture MF, while the already intaken mixture ME remains free and keeps on expanding inside the free spaces of the hollows 1, 2. The mixture ME is, however, subject to a relative compression under effect of the reduction of the circumferential divergation between the elements Bl, B2, as can be inferred from Figs. 12 to 14.
From Fig. 11, it can also be inferred that the combusting mixture MS pushes on the shoulder surface 67 of the expansion element Bl, causing its usable rotation movement that is transferred to the main shaft 80, and forces also the compression element B2 to rotate through the slider B3 hinged by pivot 72 to element B2.
From Figs. 12 and 13 it can then be inferred that the expanded mixture ME helps in cooling the walls of the hollow 2, and the inner walls of the elements Bl, B2, said expanded mixture ME being gradually compressed corresponding to the increase of the volume of the combusting mixture MS.
In particular, Fig. 13 represents the maximum development of the stroke of expansion or usable thrust stroke of the combusting mixture MS, because, when continuing its rotation, the expansion element Bl meets the draft holes 11, 30 that connect to the hole 10, where the exhaust pipe 90 is open with its holes 91, 92 aligned with the draft holes 11, 30, so as to
begin the stroke of exhausting the burned gases, as represented in the following Figs. 14 and 15.
Fig. 14 represents the situation, in which the burned gases are reduced under environmental pressure, just before the hollows 1, 2 are connected because of the approaching of the end of the wall 50 at the chamfer 9.
As a matter of fact, as it can be inferred from the following Fig. 15, as the end of wall 50 goes beyond the edge of the chamfer 9, a direct passage, through the combustion chamber 8, between the wall of the hollow 2 and the wall of the hollow 1 is accomplished, determining thus the scavenging stroke, caused by the passage of the expanded mixture ME, already partially compressed but still fresh, from the hollow 2 toward the combustion chamber 8 and toward the following hollow 1.
The entry of the fresh gas into the expansion area of hollow 1 determines the complete discharge of the residual combustion material via the still open holes 91, 92 of the exhaust pipe 90.
With reference to Figs. 14 and 15, it can be noticed that in these strokes a new stroke of suction of fresh mixture MF begins, because of the fact that the hole or conduit 25 of the stator covers A2, A3 goes again over the depressed groove 65 of the element Bl.
Such superposition of the hole 25 over the groove 65 determines the opening thereof and the beginning of the suction stroke that can be adjusted according to their respective shapes and sizes .
The suction of the fresh mixture MF through the holes 25 of the covers A2, A3 is caused by the expansion of the closed space between the elements Bl, B2 of the engine, that switch from the undiverged condition of Fig. 7 to the diverged (open) condition of Fig. 8.
The forming of the suction volume MF occurs without possibility of communication with the hollows 1, 2, as can be seen in Figs. 14 to 17, assuring thus its maximum capacity and rapidity of accomplishment.
In particular, in Fig. 14, it is highlighted how the embodiments of the groove 65, not represented in Fig. 14 but shown in Fig. 6, and the shape of the contiguous portions of the hub portion 63 of the compression element Bl, and the inner portion of the end portion 50 of the element B2 cooperate to determine an initial suction volume practically equal to zero, for the maximum efficiency of the following suction stroke.
As a matter of fact, the hub portion 63 of the element Bl is engaged on the inner wall of end portion 50 of the suction element B2, in order to achieve a sufficient sealing tightness against the mentioned inner wall, to isolate the suction volume MF from the expanded mixture ME.
Finally, the potentiality of the suction stroke is determined by the concomitant conformation of the elements Bl, B2, B3 of the rotor B, according to what has been described above and illustrated in Figs. 14 to 17, achieving a sufficient isolation of the initial volume. Proceeding in the rotation of the expansion element Bl, the condition of Fig. 17 occurs, in which the end of the circular segmented arch-shaped wall 60 of the expansion element Bl contacts the wall of the hollow 1, thus closing any passage between the chamber of combustion 8 and that of expansion (hollow 1), while the wall 50 of the element B2 contacts the wall of the hollow 2, determining the complete closing of the volume of mixture under compression MC .
In this condition of Fig. 17, the mixture under compression MC contained in the hollow 2 begins to be compressed inside the chamber 8 by the arch wall 50 of the element B2, and the arch wall 60 of the element Bl, and by the head 71 of the slider B3.
Proceeding with the rotation of the expansion element Bl, under the effect of the acquired energy during the usable thrust stroke of the element Bl, the condition of Fig. 18 occurs, whereby the mixture MC is compressed more and more into the hollow 2 and into the communicating combustion chamber 8, while the strokes of expansion and of suction of the fresh air reach their maximum volumes as an effect of the largest divergation between the elements Bl, B2.
In the stroke of Fig. 18, the different sealing tights between the elements determining the initial suction volume MF open, determining the accomplishment of a single volume with the preexisting expanded mixture ME.
This volume ME continues its expansion under the effect of the reciprocal movement between the elements Bl, B2, B3, calling for more fresh mixture MF from the holes 25 of the covers A2 , A3, that are still in communication with the respective grooves 65 of the expansion element Bl, until the condition of Fig. 10 of a new cycle is reached.
Comparing the situation of Fig. 13, regarding the volume of maximum expansion MS, with the situation of Fig. 17, regarding the volume of maximum compression MC, it can be inferred also that the present solution of a rotative engine allows a better exploitation of the expansion thrust according to one of the specified objects.
It is apparent then that the suggested embodiment has a bulk and size that is minimal with respect to the power that it can produce, according to other specified objects. Also, the reciprocal movement of the expansion and compression elements Bl, B2 inside the sealing tights in the hollows 1, 2 supports to improve the suction of the fresh air, besides the scavenging and exhaust stroke, according to other specified objects.
Of course, the embodiment till now described and illustrated is to be understood, as already specified, to be purely exemplary and not limitative.
As a matter of fact, it is possible to feed the engine only with air and inject the combustible gas directly into the combustion chamber, as it is possible to replace the spark plug 7 with proper injectors near the chamfer 9, for a better nebuli- zation of the combustion gas .
It is, furthermore, possible to replace the described supporting system (tang 27) for the main shaft 80, placing it onto the outer surface of the head covers A2, A3, increasing consequently the diameter and the solidity of the shaft 80, as it is possible to change and adjust the strokes of the engine, adjusting the position of the different elements of the stator and the rotor.
It is then possible to determine the firmness and size of the volumes of suction, compression and expansion, both by changing the depth of the hollows 1, 2 of the stator A, and by modifying lightly the distance and/or the bending radius of the walls 50, 60 of the rotor B.
It is also possible to provide the different illustrated parts as single blocks or as different components properly and steadily linked to each other, as it is possible that the semi- cylindrical portion of the element Bl is provided in solid with the function of a hand wheel or with a hollow inside.
These and other similar modifications or adjustments are understood as belonging to the scope of protection as defined by the appended claims .