FR2680402A1 - Mechanism for reversible conversion of a uniform rotational movement into a sinusoidal (simple harmonic) reciprocating rectilinear motion of variable stroke, and engine including such a mechanism - Google Patents

Abstract

The mechanism according to the present invention includes a driveshaft (11), provided with at least one bore (20) which is offset by an amount x with respect to the axis of rotation of the driveshaft and which extends parallel in all planes, to the axis of the said driveshaft, a satellite gear (13), provided with a pinion of pitch-circle diameter (D/2) housed inside the bore of the driveshaft, synchronising means (33) housed, free to rotate, inside a casing and in which there rolls, without sliding, the satellite pinion in a synchronous fashion and in the opposite direction from the driveshaft, and a crank wrist (pin) (14) which is offset by the amount x with respect to the axis of rotation of the satellite gear which carries it, and which moves with a stroke C. Such a mechanism is characterised in that it is fitted with means for angular offset (41) designed to allow adjustment of the stroke of the crank pin. This mechanism associated with a combustion engine, for example, particularly makes it possible to adjust the stroke of the pistons during operation.

Description

REVERSIBLE TRANSFORMATION MECHANISM OF A ROTATION MOTION
UNIFORM IN A RECLINED SINUSOIDAL MOTION
WITH VARIABLE STROKE, AND MOTOR COMPRISING SUCH A MECHANISM
The present invention relates to a reversible transformation mechanism from a uniform rotational movement into a siniloidal reciprocating rectilinear movement with variable stroke, and to a motor comprising such a mechanism.

 I1 is already known of the so-called "h ypo c: yr: lodal" movement mechanisms, that is to say allowing the transformation of a uniform rotational movement into a rectilinear alternating sinusoidal movement and vice versa.

 Such a mechanism is described in particular by patent FR 2,034,244 and mainly comprises a drive shaft pierced with an eccentric bore of a value x relative to the axis of the drive shaft. In this eccentric bore rotates, without sliding, a satellite driven in rotation in the opposite direction of the motor shaft. This satellite is integral with an eccentric crankpin of the same value x which is driven in a reciprocating rectilinear movement when the motor shaft is driven in rotation, or vice versa.

 To obtain a rectilinear movement of the crankpin, it is imperative in particular that the eccentricity of the bore where the satellite is housed, is equal to the eccentricity of the crankpin relative to the axis of rotation of the satellite and that a mechanism for synchronization of the motor shaft and the satellite is provided, so that a pinion secured to the satellite, of a pitch diameter D / 2, rolls without sliding inside the timing mechanism of a pitch diameter D.

 Such a mechanism brings many advantages compared to known rod and crank systems. In particular, such a transmission has fewer parts moved radially, in motion.

 However, the mechanism according to this document still has many disadvantages. First of all, it comes in a non-compact form. Thus, some rooms must be opened to facilitate the installation of the satellite. Therefore, in operation, that is to say once closed, they are weakened and do not allow high rotational speeds. In addition, such mechanisms do not allow adjustment of the value of the crankpin stroke in operation.

 Another drawback of such a mechanism lies in the number of moving parts. I1 is, in fact, difficult to dynamically balance all of these parts, which leads to imbalances and therefore adversely affects proper operation at high speed. I1 thus appears premature wear, more particularly of the bearings, as well as pistons and cylinders generally associated with the movement of the crankpin, when this type of mechanism equips an engine.

 This is why, to date, no mechanism with hypocycloidal movement has been used for the production of an engine.

 The present invention aims to overcome all of these drawbacks and to create a compact hypocycloidal movement mechanism, dynamically balanced, which can be driven at high speed, reliable and whose crankpin stroke is easily adjustable in operation.

 When the crankpin of such a mechanism is associated with a pair of heat engine pistons, the adjustment of the crankpin stroke makes it possible to adjust the compression ratio of the associated engine.

 One of the aims of the present invention is to be able to make this adjustment during the operation of the engine.

To this end, the present invention relates to a mechanism for reversible transformation of a uniform rotational movement into a rectilinear alternating sinusoidal movement of the type comprising
- a drive shaft provided with at least one eccentric bore of a value x with respect to the axis of rotation of the drive shaft, said bore extending parallel, in all planes, to the axis of said drive shaft ,
- a satellite fitted with a pinion of pitch diameter D / 2, housed inside the bore of the motor shaft,
synchronization means having an internal pitch diameter D, housed, free to rotate, inside a casing and in which rolls without sliding the pinion of the satellite synchronously and in the opposite direction to the motor shaft, and
a crank pin offset by the value x with respect to the axis of rotation of the satellite which carries it, so as to effect a rectilinear sinusoidal reciprocating movement of stroke c during the rotation of said satellite, said mechanism being characterized in that it is provided with means for angular shifting of the synchronization means with respect to the casing, adapted to allow adjustment of the crankpin stroke.

 This mechanism thus presents a motor shaft provided with at least one eccentric bore in which rolls without sliding a satellite provided with an eccentric crank pin.

 The conditions for the hypocycloldal movement are therefore met. The crankpin then travels each time the motor shaft rotates a rectilinear sinusoidal return trip of given stroke c, of value equal to 4x.

 The mechanism according to the invention is further provided with means for angularly shifting the means for synchronizing the motor shaft relative to the casing, causing a variation in the crankpin stroke.

 Thus, by acting on the angular offset of the synchronization means relative to the casing, the variation of the crankpin stroke is caused. When the mechanism according to the invention is associated with the pistons of a heat engine, and more particularly when the crankpin of such a mechanism is associated with a pair of coaxial and opposite pistons, the variation in the stroke of the pistons results in a variation in the displacement, the volume of the combustion chamber and the compression ratio in the cylinders. In fact, by varying the stroke of the udder, we simultaneously shift in an identical manner for each of the cylinders, the top dead center and the bottom dead center. It is thus possible during the actual operation of the engine to adjust the compression ratio.

 Preferably, the angular offset of the synchronization means relative to the casing varies from 0 to 200. In this case, when the diameter of the piston has a value twice the stroke, this varies from 0.939 to 1 and a variation is caused compression ratio from 7 to 12, therefore practically from simple to double. In addition, the transverse displacement or swaying of the crank pin caused by this angular offset remains less than 0.345, that is to say slightly greater than one third of the diameter of the piston so that no oblique forces are created. not passing through the crankpin.

 One of the advantages of the present invention is that it causes, by means of small angular offsets, large variations in compression ratio.

 Advantageously, the angular offset means are formed by the cooperation of a helical thread of an endless screw, with a sector machined on the outside of the internal gear crown constituting the synchronization mechanism between the motor shaft and the satellite.

 It should be noted that the motor shaft according to the invention can (as a variant) be provided with two eccentric bores drilled in opposition at each of its ends.

Each of the bores receives a satellite carrying an eccentric pin. Each of the crankpins is connected to two coaxial and opposite pistons of a heat engine.

 Such an engine therefore comprises four cylinders mounted in opposition two by two. An output shaft takes up the power of the motor shaft. We could just as well associate another four-cylinder transmission with this output shaft. This constitutes a transmission unit comprising four cylinders and can be used alone or by two, or more, this depending on the desired power of the engine, the construction of which is thus modular.

 It should be noted that such a four-cylinder transmission unit has the advantage of being made more symmetrically and is therefore easier to balance dynamically and statically. The unit obtained is still very compact. The piston stroke is adjusted for the four cylinders simultaneously, using the same worm screw and a single ring gear.

 One of the advantages of the present invention lies in the fact that the speed of rotation of a motor associated with this mechanism is of the order of 12000 revolutions / min.

However, the linear speed of displacement of the piston in the cylinder remains low (of the order of 15 to 20 m / s) because the stroke is short, this mistletoe does not cause any heating or difficulty of specific adjustment.

 In addition, such a compact engine easily lends itself to the installation of sensors of all kinds, for example, of temperatures, of pressure, of exhaust gas analysis, etc., so that the assembly parameters influencing good combustion in the cylinders can be controlled by an associated calculation unit. This results in better efficiency, lower energy consumption and better combustion, therefore less pollution. In addition, such motors are very well balanced and have a very low wear rate, and therefore a longer service life.

 The implementation of the mechanism according to the invention provided with its means of adjusting the stroke of the crankpin can be carried out in association with any type of motor, in the construction of capsulism machines, pumps, compressors, etc.

Other objects, characteristics and advantages of the present invention will become apparent from the following description, with reference to the accompanying drawings in which
FIG. 1 is a perspective view showing a mechanism according to the invention without its protective casing,
FIG. 2 is a view in longitudinal section of the mechanism according to the invention,
FIG. 3 is a view according to arrow F in FIG. 1, showing the crankpin of a mechanism according to the invention associated with two rods of coaxial and opposite pistons,
FIGS. 4a to 4e are schematic views showing the variation of the stroke as a function of the angular offset,
FIG. 5 is a view similar to FIG. 2 showing a mechanism according to the invention, provided with two satellites in opposition at each of the ends of the motor shaft and,
- Figure 6 is a top view of the mechanism shown in Figure 5.

 According to the embodiment shown in Figures 1 to 3, the mechanism 10 according to the invention comprises in particular a motor shaft 11 and a satellite 13 provided with a crank pin 14. All of these elements are grouped in a protective casing 15 (figure 2).

 As illustrated in more detail in Figure 2, the diameter of the drive shaft decreases along its length.

 This tree thus has four main areas. A first zone of large diameter corresponding to a balancing mass 16 is called a balancing zone.

A second zone 17 of smaller diameter is called the satellite rotation drive zone. A third zone of even smaller diameter is a synchronization zone 18.

A fourth zone of reduced diameter is an exit zone 19 from the shaft.

 The motor shaft 11 has an axis of rotation A and is pierced with an eccentric bore 20 of a value x (FIG. 2), along its entire drive zone 17.

 This bore is preceded by a recess 21 in the balancing mass 16, and by a recess 22 in the synchronization zone 18. Each of the recesses is in alignment with the bore 20.

 As is more visible in Figure 1, the balancing mass 16 is an integral part of the drive shaft, and has a semi-annular shape.

 The drive zone 17 (FIG. 2) is supported freely in rotation relative to the casing 15 by a first ball bearing 23, a spacer 24 and a second roller bearing 25.

 The two bearings 23, 25 and the spacer 24 are held in position on the drive shaft 11 on one side by an annular shoulder 26 and on the other by a circlip (not shown) placed in a groove 27.

 At the synchronization zone 18, the motor shaft 11 rotates freely in rotation relative to the parts which surround it and relative to the satellite 13.

 The outlet zone 19 of the motor shaft 11 is kept free to rotate relative to the casing 15 which surrounds it by means of a bore provided with a needle bearing 28.

 The satellite 13 has a diameter which increases throughout its length.

 This satellite has an axis of rotation B and comprises the cylindrical crank pin 14 whose longitudinal axis C is eccentric with respect to the longitudinal axis of the satellite by the value x (not visible in FIG. 2). Carrying this crankpin and forming an integral part of the satellite 13, there is a balancing mass 40. As is better visible in FIG. 1, this mass 40 generally has the shape of a half-disc, and is adapted to always be placed in opposition with respect to the balancing mass 16 of the motor shaft.

 The satellite then comprises a drive zone 30, then a pinion 12 of pitch diameter D / 2 constituting an engagement zone 31. A ring 33 with internal toothing surrounds the pinion 12 which rolls without sliding in it. This crown has a primitive internal diameter D. The motor shaft is, in turn, free to rotate inside this crown. The crown 33 is also mounted to rotate freely relative to the casing 15, by virtue of a ball bearing 35.

 The crown 33 is, moreover, associated with an angular offset means 41 comprising a machined helical sector 36 of the hollow wheel type cut on the external diameter of the crown. Associated with this machined sector, there is an endless screw 37 carried by the casing and whose longitudinal axis is perpendicular to the longitudinal axis of the crown.

 The helical thread of the endless screw 37 is intended to cooperate with the helical thread of the machined sector 36. The reduction ratio between the worm and the machined sector 36 of the crown is preferably very high.

 The crank pin 14 (Figure 2) is, in turn, free to rotate, by means of a needle bearing 45, relative to a die 42 which surrounds it.

This die is free to slide between the two branches 46 and 47 of a slide 48 (Figure 3).

 The slide 48 is provided with two rods 49 and 50 which act as piston rods.

 As can be seen better in FIG. 3, the die 42 is not directly in contact with the transverse parts 61 and 62 of the slide 48. There is in fact a certain clearance between these parts 61 and 62 and the die 42.

 At the end of each of the rods 49 and 50 is fixed a plate 51 forming a piston.

 This piston is adapted to slide inside a cylinder 52 fixed to the casing 15.

 Two separating parts 53 delimit between the cylinder and the housing cooling chambers 61 with variable volume.

 A bore 54 is drilled in the center of each separation piece 53 and provided with oil recovery means 55.

 Each cylinder 52 is provided with a plurality of air introduction lights 56 arranged annularly at the base of the cylinder. Likewise, outlet lights 70 situated at the base of each cylinder 52 allow the cooling air to escape from the cooling chambers 61. Advantageously, the cooling chambers 61 of each cylinder are interconnected by a channel pressure balancing 71 (Figure 3).

 In known manner, such cylinders have a combustion chamber 95, a cylinder head 57 provided with two exhaust valves 58, 59, synchronized and a fuel injection system 60, for example electro-pneumatic. An overpressure pot P is placed near the lights 56.

 It should be noted that the casing 15 is in one piece.

The various elements housed inside it are made so that they can be put in place by sliding from one of the ends of the casing. A very compact mechanism is thus obtained.

 The operation of such a mechanism associated with a two-stroke engine, with two coaxial and opposite pistons is described below.

 As can be seen in more detail in FIG. 3, when a piston (in the example on the left) arrives at its maximum compression point, the two associated valves 58 and 59 are closed.

 After explosion of the mixture in the right cylinder (Figure 3), this left piston is pushed to the right at the bottom of the opposite cylinder. Therefore, as the pistons of each of the two cylinders are rigidly and coaxially connected by the rods 50 and 49, and are integral with the crank pin 14, via the slide 48, it follows that the right piston compresses the mixture contained in the corresponding right cylinder. In addition, the crank pin 14 performs a complete rectilinear sinusoidal path with the value of the stroke c equal to 4x.

 This implies a complete rotation of the satellite which itself causes a half-rotation of the motor shaft.

 Of course when the right piston (in Figure 3) has finished compressing the mixture contained in the corresponding cylinder, the explosion of this mixture will cause the same mechanism a half-rotation of the drive shaft.

 We thus transform a reciprocating rectilinear sinusoidal movement (movement of the crank pin) into a uniform circular movement (movement of the motor shaft). This using a very compact and dynamically balanced mechanism. Therefore, it does not create oscillations or oblique forces of the pistons in the cylinders and it does not create premature wear of these different elements.

 The angular offset device 41 operates in the manner described below.

 By rotation of the worm screw 37, during or outside of the operation of the motor, the toothed ring gear 33 is rotated, which shifts relative to its initial position in the casing.

This rotation of the crown takes place in solidarity with the satellite, which also shifts relative to the casing. However, this offset by an angle ck causes a variation in the value of the stroke c of the crankpin according to the following formula Cq Cm cos i where Cm is the value of the maximum stroke. Indeed and as is clearly visible in FIGS. 4a to 4e, it will be noted that the value of the stroke c, cl, c2, c3, c4, varies as a function of the angle of offset between the axis of rotation of the motor shaft (placed in
O) and the straight line YY 'on which the axis of the crankpin moves (successively placed in A, A1, A2, A3, A4), and whose axis of rotation coincides with the motor axis in O.

 It will be noted that in FIG. 4a and in all the following figures, the circle with the largest diameter D represents the internal pitch diameter of the ring gear.

The circle of diameter D / 2 represents the pitch diameter of the pinion, rolling without sliding inside the ring gear. Point A represents the axis of the crankpin.

 The variation in the crankpin stroke obtained results in a variation in the stroke of the pistons integral with this crankpin. I1 results for cylinders 52 whose internal displacement also varies as well as the volume of the compression chamber, a variation in the compression ratio of the engine.

This angular offset also causes a translation of the crankpin (see FIGS. 4a to 4e). The transverse displacement (L) or swaying of the crank pin according to the angle 0 <follows the following relation
L = Cm sinX
Therefore, when the angle <varies from O to 200, the maximum stroke varies from 1 to 0.939, while the transverse displacement varies from O to 0.342.

 In the preferential case where the piston has a maximum stroke equal to half the diameter of the piston and is associated with a heat engine, the volumetric ratio (compression ratio) varies from 7.91 to 1 per cent (= 200, and from 10 , 5 to 1 for G = 00, this taking into account the volume of the compression chamber originally fixed.

 In the case of a diesel engine, the compression ratio then varies from 18.6 to 1 for = 200, and from 45 to 1 for = = 00, this taking into account the volume of the compression chamber fixed to the origin.

 It should be noted that the variation of the piston stroke is carried out gradually, and that this variation is advantageously accompanied by a simultaneous and symmetrical change in the top dead center, and in the bottom dead center of each of the cylinders relative to the axis of rotation of the motor shaft.

 It should be noted that an angular offset varying from 0 to 900 causes a variation in the crankpin stroke from its maximum value to zero. However, such an offset of 900 is not advantageous for heat engines (it can be for hydraulic pumps, for example) insofar as it also causes a transverse displacement equal to the maximum value of the stroke. However, this would create much too large oblique forces, disproportionate wear of the parts and in the extreme (o (= 900) the compression ratio becomes zero.

 It will be noted that as long as one remains in small offset angles (0 to 20), this offset generates a transverse displacement (darting) of the crank pin which is absorbed by the clearance left between the transverse parts 61 and 62 of the slide and the die 42. In addition, this game makes it possible to compensate for any swaying which would be created by the wear of the synchronization mechanism.

 It will also be noted that the value of the stroke C depends directly on the offset x chosen at the origin. As can be seen in FIG. 4a, the maximum stroke Cm is equal to 4x. It is therefore very important to carefully choose the offset value x at the origin in order to allow a variation in the appropriate compression ratio.

 Given the excellent guidance of the pistons in the cylinders, it is possible to reduce the length of the piston skirt by about 2/3 of its traditional value. This reduces the possibility of wear and friction of this skirt.

 If we wanted to obtain the same result with a conventional rod and crankshaft system, it would be necessary to insert a stick between the rod and the rod on which the piston is fixed. Therefore, we would transfer the oscillations on the stock system and we would significantly increase the volume and inertia of the mechanical assembly.

In the engine according to the invention, the energy required for the compression phase of the opposite piston passes through the slide piece 48 without passing through the movement transformation system, which increases the overall efficiency and makes it possible to reduce the dimensions of the movement transformation mechanism.

 It will also be noted that compared to the connecting rod-crankshaft transformation system, the engine and satellite assembly is much more compact with equal maximum stroke, with a mass of the moving parts and a center of gravity which approaches the axis of rotation of the motor shaft.

 In operation, the reciprocating movement of the mobile assembly composed of the pair of pistons 51 and the rods 49 and 50 integral with the crank pin 14 are absorbed by the gas mattresses trapped in the compression chambers of the cylinders 52. This very considerably attenuates the vibrations of low and medium frequencies which arise in this set.

 The operation of the cylinders and pistons associated with the mechanism according to the invention is described below.

 Air for cooling the underside of the pistons is introduced through the ports 56 during part of the compression and expansion phase. During the scavenging phase of the burnt gases, air is also introduced through the ports 56 to allow the evacuation of these gases. In addition, of course, these lights 56 are adapted to allow the supply of combustion air to the cylinder.

All these air introductions are carried out using an electro-compressor group 90 consisting of a compressor 91 associated with an electric motor M of the centrifugal type with variable speed of rotation, which makes it possible to have a flow rate and a variable discharge pressure.

 To obtain this variation in the speed of rotation of the centrifugal compressor, it is driven by the electric motor M, of the asynchronous type with a short-circuited rotor. This electric motor is supplied with energy by alternating current produced by a static converter of frequencies 12 volts DC x volts AC in a frequency range located between 300 and 500 hertz.

 With this type of electro-compressor group, the heat engine according to the invention is perfectly supplied with air, whatever its function, at all engine rotation speeds and especially at start-up.

 In fact, from start-up, the motor M operates and allows the suction of ambient air (arrow A, FIG. 3) by the compressor 91. This compressed air is sent into the air introduction pipes 92. After passing through the suppression pots P, this air is introduced into the annular openings 56 of the cylinders.

 In addition, the fact of constructing engines with a piston stroke of between 0.6 and 0.4 of the diameter of the piston, with equivalent displacement makes it possible to reduce the times of sweeping of the burnt gases and transfer of the air supply. oxidizer.

 To further improve the transfer of the combustion air, the scavenging of the burnt gases and the supply of the cooling air, when the lights are opened, the overpressure pots P are placed as close as possible to the lights and are sized to generate pulsations of air reducing transfer times.

 The supply of fuel 60 to the cylinders is carried out by direct injection of the fuel into the cylinder by an electro-pneumatic system. The fuel is introduced in the form of aerosols, at the end of the scavenging of the burnt gases, after closing of the exhaust valves 58, 59, then of the ports 56. This thus eliminates any loss of fuel. However, this loss of fuel is the major drawback encountered in engines operating according to the two-stroke or semi-diesel cycle, since it is impossible to reconcile with the different regimes the correct filling of the cylinder or the good sweeping of the burnt gases.

 In addition, to minimize air pollution and fuel consumption, the engine settings according to the invention are made using numerous sensors associated with the parameters controlling good combustion and the management of engine power.

 All these parameters are memorized and analyzed by a calculation unit which acts on the various adjustment members in order to optimize the combustion and the efficiency of the thermodynamic cycle of the engine.

The computer thus receives information concerning the measurement
- atmospheric pressure,
- the ambient air temperature,
- air / oxidant pressure,
- the temperature of the combustion air,
- vehicle speed,
- the engine speed,
- engine power,
- from top dead center,
- the pressure of the combustion chamber,
- the temperature of the combustion chamber,
- the exhaust gas temperature,
- the temperature of the lubricating oil,
- the cooling air temperature, and concerning the analysis of exhaust gases.

All of this information is stored and analyzed to allow control of various settings, namely
- adjustment of the stroke and compression ratio,
- setting and dosing the fuel injection,
- setting the ignition advance,
- and the adjustment of the cooling air valves.

 In addition, the computer controls the frequency converter and therefore the power supply to the motor of the electrocompressor which modulates the pressure and the air flow delivered by the compressor.

 It will be noted that the computer can thus automatically control, during or outside the operation of the engine, the adjustment of the stroke of the crankpin (s).

 It should be noted that the arrangement of the coaxial and opposite cylinders, situated on either side of the movement transformation mechanism gives a very ventilated assembly which makes it possible to very easily evacuate the thermal energy of combustion which is not transformed. in mechanical energy.

 Although the mechanism for reversible transformation of a uniform rotational movement into a rectilinear reciprocating sinusoidal movement has been described, applied to a two-stroke heat engine or semi-d center of gravity of such a mechanism is naturally located very close to the axis of rotation of the motor shaft.

 It should also be noted that the power of the motor shaft 111 is taken up in a conventional manner by an output shaft 119 (FIG. 6). The transmission of movement between the motor shaft 111 and the output shaft 119 is achieved by a gear 180 housed in place of the spacer 24 of the first embodiment.

 In the context of this variant with two satellites 119, each of the spacers has been replaced by a gear 180 meshing with the output shaft 119 placed parallel to the motor shaft 111.

 It should be noted that such a power take-off in two symmetrical locations ensures better resumption of the movement of the motor shaft 111. As a variant, however, it is possible to take the movement of the motor shaft 111 at a single point .

 The movement transformation unit thus produced is adapted to be connected to four coaxial and opposite cylinders two by two or else to four pumping chambers of a pump ...

 Such units can be combined in order to create a motor (or a pump) comprising n modules. It is also possible to adapt the power of the motor (or of the pump) according to the work to be carried out, by engaging or disengaging a certain number of modules between them.

Whatever the embodiment used, the thermal engines produced according to the invention operate according to a four-stroke, or two-stroke cycle with crossed currents or two-stroke with equi-current scanning, or diesel, or semi-diesel and regardless of the cycle used, have the following advantages
- great simplicity of construction,
- perfect static and dynamic balancing of all moving parts,
- a significant reduction in friction losses of the pistons in the cylinders,
- a reduction in the linear speed of the pistons in the cylinders,
- transfer of energy from the compression phase by the piston connecting rod,
- transfer of useful energy only by the movement transformation system,
- a high rotation speed (12,000 rpm),
- a significant increase in mass power, of the order of 2 to 4.5 depending on the operating cycle (four-stroke or two-stroke),
- a significant improvement in the combustion cycle,
- a significant improvement in the overall efficiency of the engine (increase of at least 30 (which goes from 30 to 40-42%), only due to a reduction in friction),
- a significant reduction in fuel consumption and,
- a significant reduction in air pollution.

 Of course, the present invention is not limited to the embodiments described above. Thus, any angular offset device between the crown and the casing can be envisaged and not only a worm.

The various parts used can be made of any suitable material without departing from the scope of the invention.

Claims (20)

 1 / - Mechanism for reversible transformation of a uniform rotational movement into a rectilinear alternating sinusoidal movement of the type comprising  - a drive shaft (11, 111), provided with at least one bore (20, 120) offset by a value x relative to the axis of rotation of the drive shaft and extending parallel in all planes , to the axis of said drive shaft,  - a satellite (13, 113), fitted with a pinion of pitch diameter D / 2, housed inside the bore of the motor shaft,  - synchronization means (33, 133) having a primitive internal diameter D, housed, free to rotate, inside a casing and in which rolls without sliding the pinion of the satellite synchronously and in opposite direction to the drive shaft, and  - a crank pin (14, 114) offset from the value x with respect to the axis of rotation of the satellite which carries it, so as to effect a rectilinear sinusoidal reciprocating movement of stroke c during the rotation of said satellite, said mechanism being characterized in that it is provided with angular offset means (41, 141) of the synchronization means relative to the casing, adapted to allow adjustment of the crankpin stroke.  2 / - Mechanism according to claim 1, characterized in that said synchronization means (33, 133) are constituted by a crown with internal teeth, and in that the shifting means rotate the crown with internal teeth and the satellite relative to the housing.  3 / - Mechanism according to claim 1 or 2, characterized in that the internal gear ring is provided on its outer diameter with a helical sector (36, 136) of the hollow wheel type adapted to cooperate with a helical thread of a worm (37, 137).  4 / - Mechanism according to one of the preceding claims, characterized in that preferably the angle of offset between the crown and the casing relative to an initial position varies from 0 to 200.  5 / - Mechanism according to one of the preceding claims, characterized in that the drive shaft (111) is provided at each of its ends with an eccentric bore (120), each bore being drilled in opposition and receiving a satellite ( 113) fitted with a crank pin.  6 / - Mechanism according to one of the preceding claims, characterized in that the maximum stroke Cm is equal to 4x, where x is the offset value.  7 / - Motor of the type comprising at least one mechanism according to one of claims 1 to 6, characterized in that said crankpin (14, 114) is integral with a pair of opposite pistons (51, 151), mounted to slide in corresponding cylinders (52, 152).  8 / - Motor according to claim 7, characterized in that the value of the diameter of each piston is of the order of twice the value of its maximum stroke.  9 / - Engine according to claim 8, characterized in that the combustion cycle carried out in each cylinder is of the two-stroke type.  10 / - Engine according to one of claims 7 to 9, characterized in that each cylinder has a compression chamber (95) and a cylinder head (57), and is provided on its lower partle with a supply means air (56) and at least one exhaust valve (58, 59) housed in the cylinder head.  11 / - Motor according to claim 10, characterized in that the air supply means is an electro-compressor (91) of the centrifugal type driven by an asynchronous motor (M) medium frequency, supplied with electrical energy by a converter static frequency 12 volts DC x three-phase volts between 300 and 500 Hz.  12 / - Engine according to claim 10, characterized in that the air is introduced by a plurality of annular lights 56 arranged to allow the scanning of the exhaust gases contained in the cylinder.  13 / - Engine according to one of claims 10 to 12, characterized in that the air supply means operates continuously and is adapted to sweep the exhaust gases, supply the cylinder (52) and cool the piston ( 51) during part of the compression and expansion phase.  14 / - Motor according to claim 13, characterized in that it further comprises in the immediate vicinity of the lights (56), overpressure pots (P) adapted to generate pulsations of air in order to reduce the transfer times of burnt gases and combustion air.  15 / - Engine according to one of claims 7 to 14, characterized in that it further comprises a direct injection means (60) of the fuel in the cylinder.  16 / - Engine according to claim 15, characterized in that the injection means is an electro-pneumatic system.  17 / - Engine according to one of the preceding claims, characterized in that it is provided with means for optimizing the combustion of the mixture introduced inside the cylinders.  18 / - Motor according to claim 17, characterized in that the optimization means include in particular a plurality of sensors, a central computing unit and automatic adjustment means.  19 / - Motor according to claim 18, characterized in that said plurality of sensors includes measurement sensors  - atmospheric pressure,  - the ambient air temperature,  - air / oxidant pressure,  - the temperature of the combustion air,  - vehicle speed,  - the engine speed,  - engine power,  - from top dead center,  - pressure in the combustion chamber,  - the temperature of the combustion chamber,  - the exhaust gas temperature,  - the temperature of the lubricating oil,  - the cooling air temperature, and at least one exhaust gas analysis sensor (NOx, CO, C02).  20 / - Motor according to claim 18, characterized in that it comprises adjustment means  - the stroke and the compression ratio,  - the pressure of the combustion air,  - and metering the fuel injection,  - advance ignition, and  - cooling air valves.