EP0627042A1

EP0627042A1 - Positive displacement machine with reciprocating and rotating pistons, particularly four-stroke engine.

Info

Publication number: EP0627042A1
Application number: EP93905403A
Authority: EP
Inventors: Roumen Antonov
Original assignee: Individual
Current assignee: ANTONOV ENGINE
Priority date: 1992-02-21
Filing date: 1993-02-18
Publication date: 1994-12-07
Anticipated expiration: 2013-02-18
Also published as: RU94038044A; JP3366635B2; JPH07504248A; ES2082634T3; ATE130397T1; FR2687728B1; CZ198394A3; US5419292A; RU2102612C1; KR100266999B1; FR2687728A1; BR9305927A; AU672389B2; TW252179B; CZ285414B6; DE69300818T2; WO1993017224A1; CA2130260A1; DE69300818D1; EP0627042B1

Abstract

PCT No. PCT/FR93/00162 Sec. 371 Date Aug. 2, 1994 Sec. 102(e) Date Aug. 15, 1994 PCT Filed Feb. 18, 1993 PCT Pub. No. WO93/17224 PCT Pub. Date Sep. 19, 1993.Four elements (9a, 9b, 11a, 11b) are mutually articulated as a parallelogram deformable according to four parallel axes (A1, . . . A4). A crank (31) causes a circular motion of a first co-ordination axis (K1) connected to one (9a) of the elements. Another element (11b) is articulated to the frame along a second co-ordination axis (K2). A variable volume chamber (17) is defined between the cylindrical surfaces (S1, . . . S4) whose axes (C1, . . . C4) intersect the longitudinal axes (Da, Db) of the first elements (9a, 9b). Distribution orifices (19, 21) are selectively open and obturated by the elements as a function of the angular position of the crank (31). A sparking-plug is provided. Each first element (9a, 9b) carries two cylindrical convex surfaces (S1, S2; S3, S4) the rigidely interconnected. Each cylindrical surface is in dynamic sealing relationship with a cylindrical surface belonging to the other element and whose axis (C1, . . . C4) instersects a same line (L14, L23) parallel to the longitudinal directions (Ea, Eb) of the second elements (11a, 11b). Utilization for easily constructing a rapid machine of the type four-stroke one-cycle per revolution and low relative speed of the dynamic sealing lines.

Description

Volumetric machine; with plunging pistons, in particular four-stroke engine.

The present invention relates to a volumetric machine in which swaying pistons define between them a variable volume chamber.

FR-A-2 651 019 discloses a volumetric machine comprising four elements connected in a deformable parallelogram. Each element comprises a convex cylindrical surface and a concave cylindrical surface, each centered on one of the articulation axes of the element, and cooperating in sealed manner with the concave cylindrical surface of one of the neighboring elements and respectively with the convex cylindrical surface of the other neighboring element. One of the axes of articulation of the parallelogram is fixed, and the opposite axis is animated in a circular movement. This simultaneously causes a variation of the angles at the top of the parallelogram and an oscillation of the parallelogram around its fixed axis. The variation of the angles of the parallelogram varies the volume of a chamber defined between the four convex cylindrical surfaces. The oscillation around the fixed axis allows this chamber to communicate selectively with an intake port and an exhaust port. This produces a heat engine performing the four times

(intake, compression, expansion, exhaust) in a single turn of the crank. This machine has the disadvantage of being relatively bulky for a given volume capacity, and of not allowing very high compression rates.

The construction of each element requires fairly high precision so that the seal is of good quality without the mechanical friction becoming prohibitive.

The object of the invention is to provide a volumetric machine which overcomes these drawbacks. • The invention thus relates to a volumetric machine comprising, between two opposite faces, flat and parallel, two first opposite elements articulated to two

REPLACEMENT SHEET second elements opposite along four axes of articulation perpendicular to said faces and arranged at the four vertices of a parallelogram each side of which constitutes the longitudinal axis of a respective one of the first and second elements, the elements carrying four convex cylindrical walls which define between them a variable volume chamber, the longitudinal axis of each first element being cut by the axes of two respective convex cylindrical walls, two lines oriented like the axes of the second elements being each cut by the axes of two respective convex cylindrical walls, the machine further comprising coordination means connected to two of the elements along two coordination axes, the coordination means comprising a crank type system connected to a control shaft and to one of these two elements for jointly oscillating the parallelogram between the flat faces while varying its angles at the top and correspondingly the volume of the chamber, distribution orifices being formed on at least one of the planar opposite faces to selectively communicate the chamber with an intake and an exhaust as a function of the angular position of the crank.

According to the invention, the machine is characterized in that each first element rigidly carries the two convex cylindrical walls whose axes intersect the longitudinal axis of this first element, in that each convex cylindrical wall forms with the convex cylindrical wall intersecting the same line, a pair of cylindrical walls belonging to different first elements, in that each first element comprises closing means extending between its two convex cylindrical walls, and in that the machine comprises dynamic sealing means between the convex cylindrical walls of the same pair. The main function of the second elements is to maintain a constant distance between the centers of the convex cylindrical walls of the same pair.

REPLACEMENT SHEET In other words, everything happens as if a deformable parallelogram connected the four axes of the four convex cylindrical walls. Thus, the distance between the convex cylindrical walls of the same pair is always the same, regardless of the configuration of the deformable parallelogram. This is what makes it possible to provide the dynamic sealing means, between the convex cylindrical walls of the same pair, although these are movable relative to one another. The convex cylindrical walls of different pairs and which are adjacent to each other along the periphery of the parallelogram are fixed relative to each other because they are carried by the same first element, and it is therefore easy to achieve a sealed connection between them thanks to the sealing means, which can be of static type.

There is therefore defined between the four convex cylindrical walls a chamber whose periphery is closed in a substantially sealed manner and whose volume varies according to the configuration of the parallelogram.

Preferably, the volumetric machine according to the invention is designed to operate as a four-stroke thermal engine, and it comprises in particular combustion initiator means positioned to correspond with the chamber at least when the latter is in a first volume position. minimal.

The machine according to the invention performs, like that of the prior art, the four times in a single crank turn. But its size is reduced, and there are only two dynamic seals around the chamber, between the convex cylindrical walls of the same pair. In addition, these seals can be reduced to a simple tangent contact between convex cylindrical walls, which is a particularly simple solution, and very reliable even at very high speeds. In particular, this kind of close relationship is unlikely to seize up. In addition, the relative velocity between the convex cylindrical walls of

REPLACEMENT SHEET same pair is particularly reduced, for a given speed of rotation of the crank.

One can also choose to interpose between the convex cylindrical walls of the same pair a sealing element such as a floating bar of generally biconcave shape, or even a sealing body fixed to a second element articulated to the first elements along two axes. of articulation corresponding with the axes of the cylindrical walls of the pair considered. Other features and advantages of the invention will emerge from the description below, relating to nonlimiting examples. In the accompanying drawings:

- Figure 1 is a view of an elementary machine according to the invention, along the plane I-I of Figure 3;

- Figure 2 is a partial sectional view along II-II of Figure 1;

- Figure 3 is a view of the machine in section along the line III-III of Figure 1;

- Figures, 5 and 7 are views similar to Figure 1, but showing the machine in three successive stages of its operation;

- Figure 6 is a schematic view illustrating one of the maximum volume positions of the chamber;

- Figures 8 and 9 are views corresponding to Figures 5 and 1 respectively, but with a different setting of the compression ratio;

- Figure 10 is a view similar to Figure 4 but corresponding to an alternative embodiment;

- Figures 11 to 13 are similar views at the bottom of Figures 1, 10 and 5 respectively, but relating to a second alternative embodiment;

- Figure 14 is a schematic view of the inner face of a cylinder head 4, according to a third alternative embodiment;

- Figure 15 is a partial sectional view of the machine along the line XV-XV of Figure 14;

REPLACEMENT SHEET - Figure 16 is a view similar to Figure 4 but relating to a fourth alternative embodiment;

- Figures 17 and 18 are two schematic views of a fifth variant of the invention in a position of maximum volume and respectively in a position of minimum volume;

- Figure 19 is a perspective view of a sealing body of the machine of Figures 17 and 18;

- Figure 20 is a schematic view of the four elements of a sixth version of the invention, '

- Figure 21 is a view similar to Figure 5, but relating to another embodiment;

- Figure 22 is a detail of Figure 21, on an enlarged scale; - Figure 23 is an exploded perspective view of a first element of Figure 21, and of certain parts which it carries, with sections and cutaway;

- Figure 24 is a sectional view along XXIV-XXIV of Figure 21;

- Figure 25 is a partial view of another embodiment of the first element; and

- Figure 26 is a view of the first element in section along the lines XXVIa-XXVIa at the top of the figure and XXVIb-XXVIb at the bottom of the figure.

FE OF REPLACEMENT We will now describe, with reference to FIGS. 1 and 2, as well as to the upper part of FIG. 3, a first example of an elementary machine according to the invention. A real machine can comprise a single elementary machine, or several elementary machines, for example two elementary machines 1 as shown in FIG. 3, where the elementary machine at the bottom corresponds to an alternative embodiment which will be described in detail below. As shown in the upper part of the figure

3, the machine comprises a casing 2 which defines for each elementary machine two flat and parallel faces 3a and 3b located opposite. The flat faces 3a are at least partly defined by two opposite cylinder heads 4 of the casing 2, while the two faces 3b are constituted by two opposite faces of an intermediate partition 6 placed at equal distance between the two faces 3a. The distance between each cylinder head 4 and the intermediate partition 6 is defined by a respective peripheral wall 7. A part 3c of the flat face 3a of the elementary machine from the top of FIG. 3 is defined by a turret 8, in the form of a plate, which is rotatably mounted in an appropriate recess of the corresponding cylinder head 4, for reasons which will appear more far.

The cylinder heads 4, the intermediate partition 6 and the peripheral walls 7 together form a frame for the machine. The turret 8 is movable relative to this frame,

REPLACEMENT SHEET but, as an element defining the volumes inside the machine, is considered to belong to the casing 2.

As shown in FIG. 1, each elementary machine 1 comprises, between the flat faces 3a and 3b, two first opposite elements 9a and 9b, and two second opposite elements 11a and 11b.

Each first element 9a or 9b is articulated to the two second elements 11a and 11b according to two distinct axes of articulation. There are therefore four distinct articulation axes, A1, A2, A3, A4, which are all mutually parallel and perpendicular to the plane faces 3a and 3b.

These four axes A1, A2, A3, A4 are arranged at the four vertices of a parallelogram. The longitudinal axis of each element 9a, 9b, 11a, 11b is called the side of the parallelogram, Da, Db, Ea, Eb, respectively, which joins the two axes of articulation of the element considered, for example the axes of articulation A1 and A2 for the first element 9a having the longitudinal axis Da.

FIG. 2 shows the structure of the articulation of axis A4 between the elements 9b and 11b. The end of the first element 9b is made with two parallel ears 12, forming a yoke, between which is engaged a single ear 13 of the second element 11b. A tubular axis 14 is fitted through the two ears 12 and the ear 13 to make the articulated connection.

Each first element 9a or 9b carries on its side facing the other first element, two convex cylindrical walls SI, S2, and respectively, S3, S4 defined by attached linings 16.

The axis C1, C2, C3 or C4 of each cylindrical wall SI, S2, S3 or S4 intersects the longitudinal axis Da o Db of the first element 9a or 9b of which the cylindrical wall is integral.

In addition, each cylindrical wall SI, - S4, forms with a cylindrical wall of the other first element, a pair of cylindrical walls whose axes

REPLACEMENT SHEET intersect the same line L14 or L23 parallel to the longitudinal axes Ea and Eb of the second elements 11a and 11b. Thus, the cylindrical walls SI and S4 together form a pair whose axes Cl and C4 intersect the same line L14 parallel to the axes Ea and Eb, and likewise, the walls S2 and S3 form a pair whose axes C2 and C3 intersect a same line L23 parallel to the longitudinal axes Ea and Eb.

It can therefore be seen that the axes Cl, C2, C3, C4 are at the four vertices of a second parallelogram whose sides C1 C2 and C3 C4 are always coincident with the longitudinal axes Da and Db of the first elements 9a and 9b and whose sides Cl C4 and C2 C3 (lines L14 and L23) are always parallel to the axes Ea and Eb.

In the example, the axes C1 and C2 are located between the axes A1 and A2 of the corresponding first element 9a, and the axes C3 and C4 are located between the axes A3 and A4 of the corresponding first element 9b. This is an advantageous practical arrangement, with all the cylindrical walls S1 ... S4 located between the second elements 11a and 11b.

In the example shown, each second element 11a, 11b has a curved shape which is concave towards the inside of the parallelogram in order, in particular in the extreme position shown in FIG. 1, to follow the contour of the cylindrical wall SI or S3 respectively which is then the closest. This minimizes congestion. This is also true for the walls S2 and S4 in another extreme position shown in FIG. 5. The four elements 9a, 9b, 11a, 11b are movable relative to each other, from the extreme position shown in the figure 1 and can thus take on different attitudes, some of which are shown in FIGS. 4, 5, 6 (schematic) and 7.

In the situation shown in Figure 4, a chamber 17 has formed between the first two elements 9a and 9b. The chamber 17 is delimited by the part of each cylindrical wall S1 ... S4 which is located inside the parallelogram Cl, C2, C3 _r C4, as well as by means of closure constituted by two concave cylindrical surfaces 18 each carried rigidly by one of the first elements 9a and 9b and connecting the two convex cylindrical walls SI and S2 or respectively S3 and S4 of the first element considered. Each concave cylindrical surface 18 is complementary to each of the convex cylindrical walls of the other first element. Thus, in the attitude represented in FIG. 1, the cylindrical wall S2 of the first element 9a fits into the concave surface 18 of the first element 9b, and the cylindrical wall S4 of the first element 9b fits into the concave surface 18 of the first element 9a, which brings the chamber to a substantially zero volume. The situation shown in Figure 1 corresponds to the end of the exhaust or the start of the intake. The cancellation of the volume of the chamber at this stage of the cycle makes it possible to completely exhaust the exhaust gases and to perfectly separate these from the gases which will be admitted for the following engine cycle. Returning to FIG. 4, the chamber 17 is further closed by dynamic sealing means. In the example, these dynamic sealing means reside in a choice of dimension: the radii RI, R2, R3, R4 of the convex cylindrical walls SI ... 4 are chosen so that the sum of the radii of the cylindrical walls of the same pair is equal to the distance between the axes of the cylindrical surfaces of the same pair.

In the example, the radii R1 ... R4 are equal to each other and equal to half the distance between the axes C1 and C4 or between the axes C2 and C3. Thus, the cylindrical walls of the same pair, SI and S4 or S2 and S3, are permanently in a close proximity relationship, which ensures a substantially sealed closure of the chamber 17. Furthermore, the chamber 17 is closed by the flat and parallel faces 3a and 3b (Figure 3), except in certain attitudes (Figures 4 and 6) where the chamber 17 communicates with an intake port 19 (Figure 4) or with an exhaust port 21 (Figure 6) . The orifices

REPLACEMENT SHEET intake 19 and exhaust 21 are formed through the rotary turret 8. They selectively communicate the chamber 17 with an intake 22, for example a carburetor, and respectively an exhaust 23. The turret 8 comprises a central hole 24 in which project the electrodes of a spark plug 25 screwed into the cylinder head 4. The central hole 24 further communicates the chamber 17 with a backpressure space 26 which is formed between a rear face of the turret 8 and the cylinder head 4. A seal 27 peripherally delimits the back-pressure space 26 and separates it from the inlet 19 and exhaust 21 orifices located radially outside. The periphery of the rotary turret 8 completely surrounds the chamber 17 in all the attitudes of the four elements 9a and 9b. Thus, the gap surrounding the turret 8 can never constitute a line of flight for the chamber 17. The pressure prevailing in the chamber 17, especially when the latter is strong, created in the back pressure space 26 against pressure which presses the turret 8 against the first elements 9a, 9b and presses them against the flat face 3b. This ensures sufficient sealing contact between the elements 9a, 9b and each of the plane faces 3a and 3b all around the chamber 17 whatever its configuration. ^" For the back pressure in space 26 to generate a pressing force greater than the pressure in chamber 17, it suffices that the area delimited by the seal 27 around the hole 24 is greater than the largest area that can have the chamber 17 when the latter is under pressure, that is to say essentially during the compression and expansion times.

As already indicated, the situation represented in FIG. 1 is a situation of minimum volume corresponding to the end of the exhaust and the start of the intake. In the situation shown in Figure 4, the chamber 17 has grown above the intake port 19. Consequently the chamber has sucked in fresh gas.

REPLACEMENT SHEET In the situation represented in FIG. 5 corresponding to the end of compression and the start of combustion, we are again in a situation of minimum volume in which the chamber 17 is isolated from the inlet 19 and exhaust 21 ports. and it communicates with the central hole 24 in which the electrodes of the spark plug are located. We see that in this situation of minimum volume the angles Ql and Q3 of the parallelogram adjacent to the axes Al and A3, which were acute in the exhaust end situation (Figure 1) became obtuse in the combustion start situation (Figure 5), and vice versa as regards the angles Q2 and Q4 adjacent to the axes A2 and A4.

Then, the chamber 17 expands again (FIG. 6) to achieve an engine time or gas expansion time, then comes to communicate with the exhaust orifice 21 until its volume becomes zero again as shown in FIG. figure 1.

It can be seen that the situations in FIG. 4 (intake) and in FIG. 6 (exhaust) correspond to substantially identical attitudes of the four elements 9a, 9b, lia, 11b with respect to each other. The fact that the chamber 17 communicates with the intake orifice 19 in the situation in FIG. 4 and with the exhaust orifice 21 in the situation in FIG. 6 is due to the fact that all of the four elements 9a, 9b, 11a, 11b is not in the same place in the space defined by the inner peripheral face of the peripheral wall 7. The movements of the elements 9a, 9b, 11a, 11b relative to each other as well as the movements of the assembly that they form inside the peripheral wall 7 are defined by coordination means which vary the position of a first coordination axis Kl, integral with the first element 9a, relative to a second axis of coordination K2 integral with the second element 11b. The second coordination axis K2 is the axis of a pivoting link 28 which connects the element 11b to the frame of the machine. The coordination axis K2 is located equidistant from the axes of articulation A1 and A4 of the second element 11b, and outside the parallelogram A1, A2, A3, A4.

The coordination axis K1 is the articulation axis between the element 9a and an eccentric pin 29 of a crank 31 pivotally mounted along an axis J relative to the frame of the machine. The coordination axis K1 is close to the articulation axis A2 by which the first element 9a is articulated with the second element 11a other than that to which the coordination axis K2 is linked. The coordination axes Kl and K2 are perpendicular to the faces 3a and 3b and therefore parallel to the other axes A1 ... A4, C1 ... C4.

Considering the line M (FIG. 1) passing through the axis J of rotation of the crank 31 and the coordination axis K2, the two positions of minimum volume of the chamber 17, which correspond to the extreme values for the angles of the parallelogram, are obtained when the first coordination axis Kl is located on the line M, between the axes K2 and J in Figure 1, or beyond the axis J in Figure 5. Indeed, it is in this position that the distance between the axes Kl and K2 is the smallest and respectively the largest, and consequently the angle Ql the smallest and respectively the largest.

The radius of gyration of the coordination axis K1, i.e. the distance between the axes J and K1, is smaller than the distance between the coordination axis K2 and the articulation axis A1 between the two elements 9a and 11b connected to the coordination axes Kl and K2. Thus, the rotations of the crank 31 produce angular back and forth 0 of the second element 11b around the pivoting link 28.

The crank is designed so that the position of the coordination axis Kl, in the first position of minimum volume (FIG. 5), corresponding to the start of combustion, is such that the volume of the chamber 17 in this position is non-zero and on the contrary corresponds to the compression ratio that we want to give to the machine, and so that the position of the coordination axis Kl in the second position of minimum volume or end of exhaust position, shown in Figure 1 is such that the volume of the chamber 17 is zero in this position. If it is assumed that the position of the coordination axis K2 is defined, the orientation of the line M passing through the coordination axis K2 and the position of the axis K1 on the first element 9a, the two aforementioned conditions give the two positions of the axis Kl on the line M to achieve the two positions of minimum volume of the chamber 17, and consequently give the position of the axis J located on the line M midway between the two positions of Kl.

In neither of the two minimum volume positions (FIGS. 1 and 5), the articulation axis A1 between the two elements 9a and 11b connected to the coordination means 28, 31, is located on the line M. Thus, in these positions the direction of pivoting of the second element 11b around the coordination axis K2 necessarily changes. If the axes Al and Kl passed together on the line M there would be indeterminacy on the direction of rotation of the second element 11b from this position.

However, in the first position of minimum volume (FIG. 5) corresponding to the start of combustion, the axis Al is not far from the line M. The angle B which separates the axes Kl and K2 seen from the axis Al is therefore close to 180 °. In addition, the directions F and G of rotation of the crank 31 and respectively of the element 11b from this position of minimum volume are the same. Given these conditions, a relatively small angular displacement of the crank 31 produces on the second element 11b a relatively large angular displacement, more than proportional to the ratio of the radii of gyration of the axes Kl and Al. In addition, like the axes Kl and K2 are both located outside the parallelogram, the angle B is much larger than the corresponding angle Ql, close to 120 ° in the example. Thus, the angular travel to be performed by the element 11b so that the parallelogram passes from the first position of minimum volume (FIG. 5) to the next position of maximum volume (FIG. 6) in which the parallelogram is a rectangle is about 30 °, therefore relatively small. It is therefore sufficient, for two cumulative reasons, a relatively short angular stroke of the crank 31 so that the element 11b performs around the axis K2 the rotation of about 30 ° which is necessary for the parallelogram Al, A2 , A3, A4 becomes a rectangle and therefore the chamber 17 reaches its maximum volume.

In the example shown, it suffices for the crank 31 to perform a rotation TD (FIG. 6) of approximately 75 ° so that the elements 9a, 9b, 11a, 11b pass from the first position of minimum volume (FIG. 5) at the next maximum volume position in which the parallelogram A1, A2, A3, A4 is a rectangle. We can still see that in the situation of the figure

7 corresponding to a 90 ° rotation of the crank 31 from the first position of minimum volume, the rectangular configuration of the parallelogram Al, A2, A3, A4 is clearly exceeded, that is to say that the angle Ql is already reduced to a value of around 75 °.

This is advantageous since the expansion of the gases can take place very quickly, for a given speed of rotation of the crank, and this minimizes the time during which the heat is evacuated by the metal walls, and consequently minimizes the heat losses.

The amplitude of the oscillating movement of the second element 11b is only about 90 ° between the two positions of minimum volume of the chamber 17 shown in Figures 1 and 5. This is obtained by giving the radius of gyration of the axis of articulation Al around the second coordination axis K2 a length that is sufficiently large with respect to the radius of gyration of the coordination axis Kl around the axis J of the crank 31.

FIG. 6 represents the situation of maximum volume of the chamber at the end of expansion, with display of the angle TD which has been traversed by the coordination axis K1 from the first position of minimum volume (start of combustion), and of the TE angle, about 105 ° which remains

REPLACEMENT SHEET to be covered up to the second minimum volume position, as well as the two angles UD and UE covered by the articulation axis A1 around the coordination axis K2. Thanks to the geometry chosen, the two angles TD and TE, which are very different from each other, produce for the axis A1 two respective displacement angles UD and UE substantially equal.

In the first position of minimum volume (FIG. 5) the pressure of the gases exerted on the element 9a has a resultant P which is exerted on the pin 29 of the crank 31 in a direction which is substantially tangential with respect to the circular trajectory of the axis Kl of the pin 29, and which is directed in the direction F of rotation of the crank 31. This result is therefore very effective in transmitting the engine torque to the crank 31 without producing parasitic forces in the mechanism . This is due to the low value of the angle V between the longitudinal axis Da of the element 9a, direction in which the resultant P is substantially perpendicular, and the line M which corresponds in this position to the direction of the lever arm of the crank 31. Another cause of the favorable application of the gas force on the crank 31 is the suitable direction chosen for the rotation of the crank 31. If one had chosen for the crank 31 a direction of rotation opposite of direction F, onctionnemen would also be possible since from the position of Figure 5 the chamber 17 would also increase in volume to return to the situation shown in Figure 4. May the transmission of force to the crank is would do so in an extremely indirect manner via the first element 9b, and the second element 11b operating in reversing lever pulling the element 9a to the left of FIG. 5.

As shown in Figure 3, the crank 31 is connected to an output shaft 30 to which can be connected, in a conventional manner, a flywheel and a multiple ratio transmission device to form a motor propulsion unit of a motor vehicle. Also

REPLACEMENT SHEET conventional, this flywheel, and / or the inertial load constituted by the vehicle, provide the crank 31 with the energy necessary to maintain the operation during the energy consuming phases (intake, compression, exhaust).

The crank 31 comprises two eccentric pins 32, one for each elementary machine 1, offset by 180 ° relative to each other around the axis J to cancel the main components of the inertial forces of each elementary machine 1 A more perfect cancellation is carried out if the two elementary machines 1 are entirely offset with respect to each other by 180 ° around the axis J so that all the movements in each elementary machine 1 are symmetrical with those in the other elementary machine 1 with respect to the J axis

(neglecting the axial offset of one machine relative to the other along the J axis).

The machine of FIGS. 1 to 6 comprises adjustment means making it possible to optimize its operation. In particular, the pivoting link 28 comprises a pin 32 (FIG. 1) around which the second element 11b pivots and which is carried by an eccentric 33 rotatably mounted in the frame. When, as shown in Figure 1, the eccentric 33 is oriented so that the pin 32 is as close as possible to the axis J of the crank 31, the angle B and therefore the angle Ql are also small as possible in the first position of minimum volume of chamber 17 (Figure 5). Consequently, the volume of the chamber 17 in the first position of minimum volume is as large as possible, which corresponds to the minimum compression ratio for the machine, since the maximum volume of the chamber 17, defined by the rectangular configuration of the parallelogram A1, A2, A3, A4 (FIG. 6), is independent of the position of the pin 32.

In the second position of minimum volume (FIG. 1), this position of the pin 32 again corresponds to the smallest possible value for the angle Q1, and

REPLACEMENT therefore at the smallest possible volume for the chamber 17, that is to say the zero volume in the example.

If, as shown in Figures 8 and 9, the eccentric 33 is rotated 180 ° so that the pin 32 is as far as possible from the axis J of the crank 31, the angle Ql in the first (Figure 8) and in the second (Figure 9) minimum volume position is increased. This corresponds to a reduction in the volume of the chamber 17 in the first position of minimum volume, and consequently to an increase in the compression ratio of the machine, and to an increase in the volume of the chamber 17 in the second position of minimum volume. (figure 8). This relatively unimportant increase can be considered a drawback since it shows a dead volume from which the exhaust gases cannot be mechanically removed.

The rotary adjustment of the eccentric 33 for adjusting the compression ratio of the machine can be carried out manually, even when running, or can be carried out automatically. For example the eccentric 33 can be connected to a device for measuring the depression in the inlet 22 to increase the compression rate when this depression is high (low absolute pressure) and to reduce the compression rate when the absolute pressure in admission 22 becomes stronger. Such an automatic adjustment would be particularly advantageous in the case of a supercharged engine.

As is known, it is advantageous to modify the timing of the distribution of a heat engine as a function of its operating parameters, in particular the speed of rotation and the load.

This is allowed according to the invention, by rotation of the turret 8 about the axis of the central hole 24. In the schematic example shown, this rotation is ensured by a pinion 34 meshing with a toothing 36 provided on a part of the periphery of the turret 8 (Figure 3).

REPLACEMENT SHEET It can be seen by observing FIG. 7 that if, from the position shown, the turret 8 had been rotated in the direction indicated by the arrows H, the exhaust orifice 21 would have been discovered earlier by the element 9a and therefore the chamber 17 would have communicated earlier with the exhaust. This corresponds to a condition sought when the engine rotation speed is higher. This angular offset will also place the intake orifice 19 in a position in which it will begin to communicate with the chamber 17 a little earlier before the end of the exhaust time, which is also sought for high speeds, in particular if, as shown in FIG 9 _r the volume of the chamber 17 in the second minimum-volume position is not zero: thus obtained, in known manner, a scavenging effect of the last flue gases to the exhaust by fresh gas coming in through the inlet.

The control of the angular position of the turret 8 can be manual or on the contrary automatic depending on the speed of rotation of the crank 31 and on the inlet pressure 22. The precise adjustments to be made as a function of these two parameters may be determined by the skilled person according to his usual knowledge. It should however be noted that taking into account the large cross-sections of gas passage, permitted by the invention, the advances at the opening of the orifices, and delays at their closing are less great than in conventional piston and cylinder engines. The engine cooling means, comprising for example various cavities 37 (FIG. 3) in the intermediate partition 6 and in the cylinder heads 4, nor the means of lubrication of the joints will not be described in detail either. There is shown in FIG. 10 and at the bottom of FIG. 3 a simplified version capable of operating without a lubrication circuit thanks to a supply of oil + petrol + air mixture 38 entering through a fitting.

REPLACEMENT SHEET inlet 39 in a part 40 of the peripheral space located between the elements 9a, 11a, 9b, 11b and the inner face of the peripheral wall 7 of the casing 2. The inlet orifice 19 is constituted by a non-recess crossing formed in the face 3a and through which the chamber 17 communicates selectively, during the admission time, with another part 41 of the aforementioned peripheral space.

In addition, the inner face of the peripheral wall 7 is profiled so as to be in quasi contact with the elements 9a ... 11b on the one hand in the vicinity of the articulation axis A1, the trajectory of which is circular around the axis. of coordination K2, and on the other hand in the vicinity of the diametrically opposite axis A3 on part of the trajectory of the latter. While the volume of the chamber 17 increases during the admission time, these two quasi-contacts, forming a sealing barrier, separate the regions 40 and 41 of the peripheral space from one another, and the volume of the region 41 decreases, which compresses the intake gas and drives it towards the chamber 17 through the orifice 19. This achieves a kind of forced admission, or even overfeeding of the chamber 17. We can become aware of the variation in volume of region 41 by comparing FIGS. 1 (start of admission) and 10 (admission in progress). It can be seen from FIGS. 5 and 7 that, during compression and expansion, the region 41 increases again in volume and the axis A3 clearly deviates from the inner peripheral face of the peripheral wall 7, which allows to region 41 to suck up gas from region 40.

According to the variant of Figure 10 and the bottom of Figure 3, the air-fuel-oil mixture bathes the entire mechanism located in the housing 2, which provides lubrication without separate lubrication circuit. In the example of FIGS. 11 to 13, which will only be described with regard to its differences from that of FIG. 10, the first element 9b opposite to that connected to the coordination means (crank 31) carries

REPLACEMENT SHEET rigidly two pallets 56, 57 adjacent each of one of the axes of articulation A3, A4 of this first element. The peripheral face of the inner peripheral wall 7 has two notches 58 and 59 whose profile corresponds to the envelope of the positions of the end of the pallets 56 and 57 during the admission time (FIG. 11: start of admission, Figure 12: end of admission).

In addition, during the admission time, the volume of the region 41 of the peripheral space of the casing, located between the two pallets 56 and 57 decreases very sharply. Its volume reduction can be equal for example to 650 cm3 for an engine whose chamber 17 has a maximum volume of 400 cm3. Thus, the element 9b forms with the peripheral wall 7 of the casing a mechanical compressor for boosting the engine.

Then, during the gas expansion time, the pallets 56 and 57 are offset from the walls of the notches 58 and 59, which allows the region 41 to suck up gas 38 entered by the connector 39 (as shown in Figure 10) . If the direction of rotation of the crank 31 were reversed, the pallets should be placed on the element 9a, in order to produce a region whose volume decreases during the admission time. But this would be less advantageous since it would be necessary to seal the bearings of the crank 31. In the example shown in FIGS. 14 and 15, the face 3a is entirely formed on the corresponding cylinder head 4 and the inlet 19 and exhaust ports 21 are therefore no longer adjustable around the axis of the central hole 24. There is provided in the face 3a a circular groove 42, for example centered around the axis of the hole 24. This groove is partially occupied by a flat ring 43 , having a radial slot 44. The ring 43 has an outside diameter substantially equal to the outside diameter of the groove 42. Its axial thickness and its radial width are respectively less than the axial depth and the radial width of the groove 42.

In addition, the position of the groove 42, the diameter of its radially outer edge 42b and the radial width

REPLACEMENT SHEET of the ring 43 are chosen so that the proximity lines 46 between the first elements 9a and 9b are located radially between the radially outer edge 42b of the groove 42 and the radially inner edge 43a of the ring 43, at least for the positions of the crank 31 for which the chamber 17 must be isolated from the peripheral space surrounding the elements inside the peripheral wall 7. In addition, the elements 9a and 9b are designed to, at least in such positions of the crank 31, completely cover the radially inner edge 43a of the ring 43 with the exception of the parts of this edge which are opposite the chamber 17. In other words, the edge 43a must not be visible by an observer placed in the peripheral space of the housing. Preferably, the slot 44 should not appear in this space either.

Thus, the high pressures of the chamber 17 penetrate into the groove 42 and cause, on the radially inner face 43a of the ring 43 a thrust directed radially outwards which presses the ring 43 in a substantially sealed manner against the radially outer edge 42b of the groove 42, as well as, on a rear face 43b of the ring 43, a thrust directed axially towards the elements 9a and 9b which provides a seal between the ring 43 and these elements.

The slot 44 of the ring 43 allows the ring 43 to increase in diameter and to bear against the radially outer edge 42b under the pressure of the gases exerted on its radially inner face 43a. As the proximity lines 46 between the elements 9a and 9b are always opposite the ring 43, the ring 43 prevents the gases from the chamber 17 from passing behind the proximity lines 46, therefore in the peripheral space, in s' escaping along the face 3a. In addition, the axial thrust on the ring 43 is transmitted by the ring 43 to the elements 9a and 9b and applies these against the face 3b which achieves a seal by contact between the face 3b and the elements 9a and 9b. This

REPLACEMENT SHEET prevents the gases from leaking from the chamber 17 towards the peripheral space along the face 3b.

An elastic element, such as a corrugated washer or the like, can be placed between the rear face 43b of the ring 43 and the bottom of the groove 42 to provide the initial support between the ring 43 and the elements 9a and 9b, and consequently prevent the gas from pressing the ring 43 against the bottom of the groove 42 instead of pressing it against the elements 9a and 9b. The total area of the rear face 43b of the ring 43 is chosen to be sufficient for the axial force generated by the gases on the ring 43 to be sufficient.

The example shown in FIG. 16 will only be described with regard to its differences from that of FIGS. 1 to 9.

The first elements 9a and 9b are extended and they have towards each other three convex cylindrical surfaces SI, S2, S5 and respectively S3, S4 and S6. The axes C5 and C6 of the surfaces S5 and S6 intersect the same line L56 located at equal distance between the lines L14 and L23, parallel to the latter. The surfaces S5 and S6 therefore form a pair of convex cylindrical walls which is located between the pair SI,, S4 and the pair S2, S3 already described. The radius R5 and R6 of the surfaces S5 and S6 is slightly smaller than the radii R1 ... R4, all equal, of the surfaces S1 ... S4. There is thus a slight clearance 47 between the surfaces S5 and S6. This play is without drawback because the two chambers 17 defined between the elements 9a and 9b on either side of the play 47 are always at the same pressure and at the same stage of the operating cycle in all the angular positions of the crank 31. The surfaces S5 and S6 can therefore be produced without any particular finish and in particular do not need to be produced on inserts 16 such as those carrying the surfaces SI ... S4.

REPLACEMENT SHEET A machine is thus produced in a very simple manner and in a reduced footprint, the volume capacity of which is double that of FIGS. 1 to 9.

As the amplitude of the movements of the chamber 17 which is closest to the coordination axis K2 is smaller than that of the other chamber 17 situated to the right of FIG. 16, the intake and exhaust ports may have a slightly different relative shape and layout for the two chambers (this is not shown).

In the example which is shown diagrammatically in FIGS. 17 to 19, the assembly formed by the four elements 9a, 9b, 11a and 11b is the same as in FIGS. 1 to 9, with two convex cylindrical walls SI, S2 and respectively S3, S4 on each of the first elements 9a and 9b. However, the dynamic sealing means between the convex cylindrical walls of the same pair SI and S4, and respectively S2 and S3, instead of being constituted by a simple proximity relationship, comprise, for each pair, a floating bar 48 having a Z-shaped profile, each base of which is terminated by a slightly re-entrant fin 49. Such a floating strip constitutes an easy approximation in place of a biconcave body which would have two opposite concave cylindrical faces matching the two convex cylindrical walls such that S2 and S3 to be sealed against each other. Each bar 48 is forced to center on the corresponding line L14 or L23 because the two regions of the bar located on either side of this line are wider than the distance remaining between the two cylindrical walls along this line.

Thus, each floating bar 48, which slides at the same time on the two cylindrical walls of the same pair, such as S2 and S3, which it makes watertight relative to each other, is always automatically positioned in a suitable manner for ensuring this seal, whatever the attitude of the four elements 9a, 9b, 11a and 11b with respect to each other.

REPLACEMENT SHEET As shown in FIG. 19, the floating bars 48 have, at each longitudinal end, in the extension of the bases of the Z, tongues 53 bent towards the interior of the chamber 17 in order to press tightly against the faces 3a and 3b of the housing. The embodiment of Figures 17 to 19 further differs from that of Figures 1 to 9 by its coordination means which include, in addition to the crank 31 connected to the motor shaft (not shown) a second crank 51 which is connected to the crank 31 by two gears 52 connected in cascade so that ^the second crank 51 has rotated at the same speed and in the opposite direction of the crank 31.

The crank 31 rotates the first coordination axis K1, which in this example coincides with the hinge axis A2. The second crank 51 rotates the second coordination axis K2 which, in this example, coincides with the articulation axis A4 opposite the axis A2. The coordination axes Kl and K2 are therefore symmetrical with respect to the center of the parallelogram Al, A2, A3, A4 which coincides with the axis of the hole 24 for the spark plug. The whole machine has symmetry with respect to this center, including the axes Jl and J2 of rotation of the cranks 31 and 51.

In FIG. 17, the machine is shown in a position of maximum volume of the chamber 17. The positions of minimum volume are obtained when the axes K1 and K2 are on the line N intersecting the axes J1 and J2. In Figure 18, the machine is shown in the vicinity of such a position of minimum volume.

By suitably choosing the distance between the axes Jl and J2 of the two cranks 31 and 51 as well as the radius of gyration of the axes Kl and K2 around the axes Jl and J2, the distance between the axes Kl and K2 is defined in each of the two positions of minimum volume of the chamber 17, and it is therefore possible, as in the modes

REPLACEMENT SHEET of previous embodiments that these two volumes are different.

During the operation, the center of the parallelogram Al A2 A3 A4 is stationary. Consequently, the movements of the four elements 9a, 9b, 11a, 11b are equivalent to reciprocating movements of the elements 9a and 9b relative to each other, with correlative pivoting movement of the elements 11a and 11b, and superimposed movement of oscillation of the assembly around the geometric axis passing through the center W.

A very good quality balancing can be achieved for all the inertial forces generated by this combination of movements by providing a machine comprising two elementary machines stacked one on the other (substantially as shown in FIG. 3) with between them a 180 ° offset from the crank angle 31.

In the example of FIGS. 17 to 19, as we have seen, the sealing bars 48 are stationary relative to the lines L14 and L23. The variant embodiment of FIG. 20 exploits this observation. The second elements are articulated to the first elements along the axes of the corresponding convex cylindrical walls S1 ... S4. In other words, the axes Al and Cl, ... A4 and C4 are two by two combined. Under these conditions, the longitudinal axis Ea or E of each second element 11a or 11b is merged with the line L23 or L14 respectively. Each dynamic sealing body 54 is therefore immobile with respect to one of the second elements 11a and 11b. This made it possible to produce a rigid connection between each sealing body 54 and a respective one of the second elements 11a and 11b. Each sealing body has a biconcave shape matching the two convex cylindrical walls between which it performs dynamic sealing. This makes it possible to produce a high quality seal between each sealing body 54 and the two cylindrical walls with which it cooperates,

REPLACEMENT SHEET suitable for example for operation according to the diesel cycle.

Furthermore, in the example of FIG. 20, the coordination axes Kl and K2 are each linked to one of the second elements 11a and 11b respectively, in positions symmetrical relative to the center W of the parallelogram λl, A2, A3 , A4. The axes Kl and K2 are rotated by two cranks such as 31 and 51 of Figures 17 and 18 symmetrical with respect to the center W and connected to each other to rotate in opposite directions.

The production of the machines according to the invention is particularly simple, the large functional surfaces can all be produced in a planar or cylindrical manner. The sealing relationships are carried out under zero or low load and wear and tear on the machine is therefore reduced. The speed of movement relative to the locations of the lines or sealing surfaces is remarkably low compared to the speed of rotation of the crank. In addition, a given crank rotation speed makes it possible to perform twice as many cycles per unit of time as a traditional piston and cylinder engine. One can thus envisage speeds of rotation double those of traditional motors, with consequently four times more cycles per unit of time. At such cycle speeds, the combustion and expansion times are very short and the thermal leaks particularly limited. For a given power, the double speed and the doubling of the number of cycles per turn of the crank allows in theory to have a volume capacity ("cubic capacity") four times lower, which limits the surfaces of thermal leaks and consequently limits still heat losses.

It will also be noted that the movement of the first and second elements 9a, 9b, 11a, 11b against the faces 3a and 3b is a swirling movement without stopping point, which is particularly favorable for achieving perfect lapping on these surfaces, making the surfaces in question particularly resistant to wear and

REPLACEMENT SHEET particularly waterproof by simple proximity. The large surface contact between the elements 9a and 9b and the faces 3a and 3b promotes the cooling of the elements 9a and 9b. In the example shown in FIGS. 21 to 24, the cylindrical walls SI to S4 are defined by shells 61 which, in each pair, are directly pressed against each other along a sealing line 60 forming one of the ends of the chamber 17. Each shell has a free inner edge 62 always situated in the chamber 17 and an outer edge 63 always situated outside of the chamber 17. The outer edge 63 is adjacent to a fixing region 64 of the shell 61 The region 64, always located outside the chamber 17, is fixed in leaktight manner to the first element 9a or 9b with which it is associated. Each first element therefore carries two shells 61 directed towards each other from their respective attachment region 64. From the attachment region 64, the shell 61, made for example of steel, floats by elastic bending. Its support against the other shell 61 of the same pair results from an elastic prestress during assembly. There is behind each shell 61 an intermediate space 66 which communicates with the chamber 17 through a slot 67 adjacent to the inner edge 62 of the shell. Thus, when the chamber 17 is occupied by pressurized gas, this gas passes into the intermediate space 66 to reinforce the mutual support of the two shells 61 of each pair. The rear faces of the shells 61 are permanently exposed over their entire length to the pressure of the chamber 17. On the other hand, their front faces, that is to say the cylindrical walls SI to S4, are not exposed to the pressure of the chamber 17 only over a reduced and variable length. So when room 17 has either of its two

REPLACEMENT SHEET minimum possible volumes (Figure 22), one of the cylindrical walls (SI) of each pair is exposed over practically its entire length to pressure in chamber 17 while the other cylindrical wall (S4) is not exposed to the pressure only over a short part of its length. Thus, the pressing force exerted on this wall S4 only partially compensates for the pressing force exerted on the rear face of the associated shell 61, which therefore bears strongly against the other shell. The latter does not flex excessively because the support takes place near its attachment region 64, therefore with a small bending moment.

On the contrary in the situation not shown where the volume of the chamber is substantially maximum, the force produced by the pressure is approximately the same on the two shells and they are therefore in equilibrium one against the other with a very small deformation compared to the state at rest. The deformation of the shells is therefore reduced in all cases. As shown in FIG. 24, each shell 61 comprises along each face 3a or 3b a lateral edge formed by an edge 68 defined by the corresponding cylindrical wall, such as S3, and a bevelled wall 69 forming an angle of approximately 45 ° with the cylindrical wall S3. When the shell 61 undergoes bending movements, the inner edge 62 and the edges 68, as well as the cylindrical wall which they frame, move relative to the body of the first corresponding element. The edge 68 is in mobile proximity relation. And substantially sealed with the adjacent face 3a or 3b. Thus, the gas located in the intermediate space 66 cannot easily leak as shown by the arrow 70 in FIG. 22.

As shown in Figure 24, each connecting wall 18 is integral with the body of the element (9a) which carries it. It is also terminated by two lateral edges 71 but these edges 71 have a certain

REPLACEMENT SHEET spacing relative to the faces 3a and 3b to avoid any friction.

On the side opposite to each edge 68, the intermediate space 66 is limited by a sealing segment 72 (FIG. 24) which is pressed in a mobile and sealed manner against the adjacent face 3a or 3b, by means of a prestressing spring. 73. Each segment .72 has a bevel face 74 which is parallel to the bevel face 69 of the shell 61 while having a certain distance from it. This beveled face 74, as well as a lateral face 76 and a rear face 77 of each segment, are subjected to the pressure prevailing in the intermediate space 66, which thus contributes to applying the segment 72 against the opposite face 3a or 3b and against a bearing face 78 of the body of the corresponding element, 9b in FIG. 24.

This double sealed support prevents the pressurized gas from escaping through a zone 79 located between the body of the first element 9a or 9b and each opposite face 3a or 3b.

As also shown in FIG. 23, each segment 72 and the associated spring 73 extend continuously between the two fixing regions 64 of the two shells 61 associated with the corresponding element 9a or 9b. The spring 73 can be constituted by a wavy elastic strip. Behind the connecting wall 18, the element 9a or 9b has, opposite each face 3a or 3b, a profiled groove 80 receiving the corresponding part of the length of the segment 72 and of the spring 73. This groove 80 communicates with the chamber 17 by the slots 67 between which it extends and also by the spacing existing between the edges 71 (FIG. 24) and the faces 3a and 3b. Thus, also in this region, the pressure applies the segments 72 against the faces 3a and 3b and against the bearing face 78 of the elements 9a and 9b. There is thus, between room 17 and regions 79, continuity

REPLACEMENT SHEET sealing over the entire length of the first elements 9a and 9b which is liable to be exposed to pressure.

In practice, in the vicinity of the fixing region 64 of each shell 61, we will choose to favor reliability and reduction of friction rather than perfect sealing because the leakage paths leading to this region are very complex and narrow, similar to labyrinths, and in any case only allow very low flow rates. We can further increase this labyrinth effect by providing roughness on the faces defining the intermediate spaces 66.

The embodiment which has just been described has the advantage of achieving controlled sealing conditions between the cylindrical walls SI to S4 and this in a manner largely independent of the state of wear of the engine and of the precision. of its component parts. In addition, the shells 61 dampen the vibrations of the first elements relative to each other, and prevent these vibrations from producing shocks between the cylindrical surfaces SI to S4. This greatly improves the longevity of these surfaces and contributes to the maintenance, over time, of the good quality of sealing along the lines 60.

In the embodiment of Figure 25, segments 81 have been added along the side edges of the shells 61, to further reduce the possibility of leakage along a path as illustrated by arrow 70 in Figure 22 The segment 72 subsists all along each first element 9a or 9b, as described with reference to FIGS. 21 to 24. Thus, as shown at the bottom of FIG. 26, along each face 3a or 3b, the intermediate space 66 is defined between the two segments 72 and 81. The pressure of the gases, assisted by a preloading spring 82, tends to separate the two segments from one another and

REPLACEMENT SHEET applying them sealingly against the face 78 of the body of the first element 9b and respectively against a sealing face 83 provided at the rear of the shell 61. In addition, the pressure, assisted by a similar prestressing spring 84 at the spring 73, permanently applies the segment 81 against the corresponding opposite face, 3b in FIG. 26. Along the connecting wall 18 (top of FIG. 26), the segment 72 remains alone. It is pushed by the gas pressure and prestressed by the springs 73 and 82 as described above.

Of course, the invention is in no way limited to the examples described and shown. In the example of FIG. 1, one could make the axis Kl and / or the axis K2 coincide with one and / or another of the articulation axes A1 ... A4.

One could, with reference to the upper part of FIG. 3, place the dispensing orifices 19 and 21 through the face 3b, for example in a fixed position, and replace the pivoting turret 8 by a non-rotating plate having the sole function of lean against the elements 9a and 9b under the action of pressure in the backpressure space 26. In the embodiment of Figures 14 and 15, one can place the groove 42 and the ring 43 in the face 3b to make the orifices 19 and 21 more conveniently through the face 3a, if it is desired in particular for the suction orifice to be a recess as shown in FIG. 10, which would then be formed in the face 3a only .

In the embodiment of FIGS. 17 to 19, there is no combination relationship between the floating bars 48 on the one hand and the coordination means produced in the form of two crankshafts 31 and 51 on the other hand: these two enhancements can be used independently of each other.

REPLACEMENT SHEET Similarly, in the example in FIG. 20, the means of coordination could be different.

The invention could be used to produce a compressor or a pump or else an expansion machine operating at two cycles per revolution, or even a two-stroke engine operating at two cycles per revolution. In these different cases, it will generally be arranged so that the two minimum volume positions correspond to identical volumes, so that the two cycles of each crank turn are identical.

REPLACEMENT SHEET

Claims

CLAIMS 1. Volumetric machine comprising, between two opposite faces (3a, 3b), planar and parallel, two opposite first elements (9a, 9b) articulated with two opposite second elements (11a, 11b) along four axes of articulation (Al, ... A4) perpendicular to said faces (3a, 3b) and arranged at the four vertices of a parallelogram each side of which (Da, Db, Ea, Eb) constitutes the longitudinal axis of the respective one of the first and second elements, the elements carrying four convex cylindrical walls (SI, ... S4) which define between them a chamber (17) with variable volume, the longitudinal axis (Da, Db) of each first element (9a, 9b) being cut by the axes (Cl, C2; C3, C4) of two respective convex cylindrical walls (SI, S2; S3, S4), two lines (L14, L23) oriented like the axes (Ea, Eb) of the second elements ( 11a, 11b) being each cut by the axes (Cl, C4; C2, C3) of two respective convex cylindrical walls (SI, S4; S 2, S3), the machine further comprising coordination means (28, 31) connected to two of the elements (9a, 11b) along two coordination axes (K1, K2), the coordination means comprising a crank type system (31) connected to a control shaft and to one (9a) of these two elements to jointly oscillate the parallelogram between the planar faces (3a, 3b) while varying its angles at the top and correspondingly the volume of the chamber (17), distribution orifices (19, 21) being formed on at least one of the planar facing faces (3a) to selectively communicate the chamber (17) with an inlet (22) and an exhaust (23) depending on the angular position of the crank (31), characterized in that each first element (9a, 9b) rigidly carries the two convex cylindrical walls whose axes (Cl C4) intersect the longitudinal axis (Da, Db) of this first element, in that each convex cylindrical wall forms e with the convex cylindrical wall whose axis intersects the same line (L14, L23) a pair (SI, S4; S2, S3) of cylindrical walls belonging to first elements (9a, 9b) different, in that each first element comprises closing means extending between its two convex cylindrical walls, and in that the machine comprises dynamic sealing means between the cylindrical walls (SI, S4; S2, S3) convex of the same pair.

2. Machine according to claim 1, characterized in that the dynamic sealing means comprise a proximity relationship between the cylindrical walls of a same pair.

3. Machine according to claim 1, characterized in that the dynamic sealing means comprise a floating body (48) mounted between the cylindrical walls (SI, S4, - S2, S3) of the same pair.

4. Machine according to claim 3, characterized in that the floating body (48) is a bar with a Z-profile.

5. Machine according to claim 1, characterized in that the dynamic sealing means comprise, for each second element, an intermediate body (54) having two faces which are in sealed contact each with one of the cylindrical walls (SI, S4; S2, S3) of the same pair.

6. Machine according to one of claims 1 to 4, characterized in that the closing means have towards the chamber a face (18) having a concave profile substantially complementary to that of the cylindrical walls (SI, S2, S3, S4) .

7. Machine according to one of claims 1 to 6, characterized in that the axes (C1 ... C4) of the convex cylindrical walls (S1 ... S4) coincide with the articulation axes (Al ... A4 ) between elements.

8. Machine according to claim 7, characterized in that the dynamic sealing means (54) are carried by the second elements (11a, 11b).

9. Machine according to one of claims 1 to 6, characterized in that the axes (C1 ... C4) of the convex cylindrical walls (S1 ... S4) are, on each axis longitudinal of the first element (9a, 9b), located between the two articulation axes (A1, A2; A3, A4) intersecting this longitudinal axis (Da, Db).

10. Machine according to one of claims 1 to 9, characterized in that at least part of the dispensing orifices (19, 21) has an adjustable position relative to a frame of the machine.

11. Machine according to claim 10, characterized in that the orifices (19, 21) are formed through a turret (8) adjustable by rotation, the outer periphery of which surrounds the chamber (17) in all the angular positions of the crank (31).

12. Machine according to one of claims 1 to 11, characterized by means for communicating the chamber with a rear face of a plate (8), the front face of which constitutes at least one part (3c) of one ( 3a) opposite faces, this plate having an independence from the frame allowing it to bear against the first elements (9a, 9b).

13. Machine according to one of claims 1 to

11, characterized in that one of the opposite faces, carried by a casing wall of the machine, has an annular groove (42) partially filled by a split ring (43), which is exposed from the gas at pressing forces directed towards the first elements (9a, 9b) and radially towards an outer peripheral edge (42b) of the groove (42), and which is capable of pressing tightly against the elements and against said edge external device under the action of these pressing forces.

14. Machine according to one of claims 1 to 12, characterized in that at least one of the cylindrical walls (S1-S4) is defined by a shell (61) which is resiliently biased towards the other cylindrical wall of the same pair, and in that a space (66) formed behind the shell (61) communicates with the chamber (17) so that the shell is further urged towards the other cylindrical wall of the same pair by the pressure of the gases reigning in the room.

15. Machine according to claim 14, characterized in that the shell (61) is fixed in a substantially sealed manner to one of the first elements (9a, 9b) in an external region (64) which is always located outside of the chamber (17) and in that an inner edge (62) of the shell (61), which is always located in the chamber (17), as well as two lateral edges (68) of the shell, have a freedom of displacement by bending of the shell.

16. Machine according to claim 14 characterized in that each first element (9a, 9b) comprises opposite each face opposite (3a _Λ 3b) sealing means (72, 81) which are put under pressure by the gas occupying the space (66) behind the shell (61).

17. Machine according to claim 16, characterized in that the sealing means comprise, opposite each face opposite, a sealing member (72) which extends all along the chamber between two fixing regions opposite (64) belonging to two shells (61) defining two cylindrical walls (SI, S2; S3, S4) of the same first element (9a, 9b)

18. Machine according to claim 16 or 17, characterized in that the sealing means comprise a sealing member (81) along each lateral edge of each shell (61).

19. Machine according to one of claims 14 to 17, characterized in that lateral edges (68) of the shell (61) are in sealing relation at least approximate with the facing faces (3a, 3b).

20. Machine according to one of claims 14 to 19, characterized in that the two cylindrical walls (SI, S4; S2, S3) of at least one of the pairs consist of two similar shells (61).

21. Machine according to one of claims 1 to 20, characterized in that the closing means between the two convex cylindrical walls of each first element (9a, 9b) have towards the other first element a corrugated wall defining at least one boss (S5, S6) between the two cylindrical walls.

22. Machine according to claim 21, characterized in that the boss is a third convex cylindrical wall (S5, S6) similar to the other two.

23. Machine according to one of claims 1 to 22, operating as a four-stroke heat engine, characterized in that it comprises combustion initiator means (25) positioned to correspond with the chamber (17) at least when it- this is in a first position of minimum volume.

24. Machine according to claim 23, characterized in that the coordination axes (Kl, K2) are located outside the parallelogram (Al, A2, A3, A4).

25. Machine according to claim 23 or 24, characterized in that the coordination means are connected to the elements so that the angular distance (TD) between two positions of the crank corresponding to the first position of minimum volume and respectively a first maximum volume position, ie less than 90 °.

26. Machine according to one of claims 23 to 25, characterized in that the coordination means are designed and connected to the elements so that the volume of the chamber (17) is greater in the first position of minimum volume than in a second position of minimum volume, performed at the end of a time exhaust during which the chamber (17) communicates with an exhaust port (21) forming part of the distribution orifices (19, 21).

27. Machine according to claim 26, characterized in that in the second position of minimum volume, the volume of the chamber (17) is substantially zero.

28. Machine according to one of claims 22 to 27, characterized in that the dispensing orifices comprise an inlet orifice (19) constituted by a recess made in at least one of the planar faces (3a, 3b) for selectively communicating the chamber (17) with a supply space (41) located along at least part of the outer periphery of the elements (9a, 9b, lia, 11b), in a casing (2) surrounding the elements, this space being connected to combustion gas supply means.

29. Machine according to claim 28, characterized in that the supply space (41) is delimited between two barriers (56, 57) spaced from one another in the peripheral direction of the casing and which realize, at less during an admission time, a quasi-sealing between the internal profile of the housing and the elements, in a region of the periphery of the housing which is chosen so that the supply space (41) reduces in volume when it communicates with the chamber (17).

30. Machine according to claim 29, characterized in that the casing has an internal profile of which certain regions (58, 59) correspond substantially to the envelope of the positions of two regions of the elements between which the supply space is delimited ( 41), the two barriers being produced by a proximity relationship between the two regions of the elements and the interior profile of the casing.

31. Machine according to claim 29, characterized in that the two regions of the elements are integral with the same element (9b), and in that the barriers comprise at least one pallet (56, 57) integral with this element or the casing, and a notch formed on the casing or respectively on this element, this notch having a profile corresponding to the envelope of the positions of the end of the pallet relative to the notch.

32. Machine according to one of claims 28 to 30, characterized in that the barriers separate the supply space from an entry space (40) with which the supply means (39) communicate.

33. Machine according to one of claims 30 to 32, characterized in that the supply means are means for supplying air-gasoline-oil mixture.

34. Machine according to one of claims 24 to 33, characterized in that the crank (31) is arranged so that in the first position of minimum volume the lever arm of the crank is oriented transversely to the direction of the force expansion (P) of the gas exerted on that (9a) of the two elements to which the crank (31) is connected, and moves in the direction (F) of this force (P).

35. Machine according to one of claims 1 to 34, characterized in that the coordination means (28) are adjustable to modify the volume of the chamber in one of the minimum volume positions, and thus adjust a compression ratio of the machine.

36. Machine according to one of claims 1 to 34, characterized in that the coordination means comprise, in addition to the crank type system (31) connected to one (9a) of the two aforementioned elements along a first of the axes of coordination, a pivoting link

(28) between the other (11b) of the two elements and a frame of the machine along a second (K2) of the coordination axes.

37. Machine according to claim 36, characterized in that the two elements to which the coordination means are connected, are, a first (9a) and one second elements (11b), and in that the distance between the second coordination axis (K2) and the articulation axis (Al) between the two elements (9a, 11b) is greater than the radius of the crank .

38. Machine according to claim 37, characterized in that the distance between the second coordination axis (K2) and the axis (J) of the crank (31) is little less than the sum of the distances separating from the axis d articulation of the two elements (Al), the second coordination axis (K2) on the one hand and the axis (J) of the crank on the other hand.

39. Machine according to claim 38, characterized in that in the first position of minimum volume, the articulation axis (Al) between the two elements (9a, 11b) is located between the two coordination axes (Kl, K2 ).

40. Machine according to one of claims 36 to 39, characterized in that it comprises means for adjusting the distance between the second coordination axis (K2) and the pivot axis of the crank (J) relative to the built.

41. Machine according to one of claims 1 to 35, characterized in that the coordination means comprise two systems of the crank type (31, 51) each connected to one of the two aforementioned elements.

42. Machine according to claim 41, characterized in that the two aforementioned elements are two opposite elements (11a, 11b).

43. Machine according to claim 41 to 42, characterized in that the two systems of the crank type are substantially identical (31, 51), interconnected to rotate at the same speed in opposite directions, and are, like the axes coordination (Kl, K2), symmetrical with respect to the center (W) of the parallelogram.