FR2667650A1 - Combustion engine with rotary pistons - Google Patents

Abstract

Internal-combustion engine with rotary pistons including, in a cylinder (3), two half-rotors (4, 5) supporting the pistons (41, 51) and given an oscillatory movement which is superimposed on the uniform rotation of the drive shaft. It includes 2, 3, 4...n simultaneous ignition points distributed evenly about the cylinder, each half-rotor (4, 5) including 4, 6, 8...2n pistons (41, 51) so as to run through the four strokes of the cycle in 1/2, 1/3, 1/4...1/n revolutions, so that for one revolution of the rotor there are 16, 36, 64,...4n<2> ignitions.

Description

The object of the present invention is the new industrial product which constitutes an internal combustion engine with rotary pistons in which the pistons are animated with an oscillating movement superimposed on the uniform rotation of the motor shaft.

The interest of rotary piston engines is known compared to conventional engines, in particular with regard to efficiency and power. Among the known rotary piston engines, that which is the subject of French patent 2 138 581 has the advantage of allowing, with a single cylinder and four rotary pistons, operation comparable to that of a conventional eight-cylinder engine. Such a motor comprises, in a cylindrical stator, two animated half-rotors, in addition to the uniform rotational movement of the motor shaft, an oscillating movement allowing the pistons to approach and move away so as to complete the four strokes of the cycle of an internal combustion engine.Each half-rotor has two pistons arranged at 1800, and there is a single ignition point on the stator, the four strokes of the cycle being covered over one revolution of the rotor, which gives four ignitions per revolution.

The object of the present invention is to provide a rotary piston engine which is even more efficient than that which is the subject of this document, since it uses several ignition points and an even number of pistons greater than or equal to four, which has the effect of suppressing the radial forces and parasitic friction, and of balancing the forces of inertia.

The present invention thus relates to a rotary piston engine which is characterized in that it comprises 2, 3, 4, ... n simultaneous ignition points regularly distributed around the cylinder, each half-rotor comprising 4, 6 , 8, ... 2n pistons so that the four times of the cycle go through 1/2, 1/3, 1/4, ... 1 / n revolution, so that for one revolution of the rotor there is 16, 36, 64 ... 4n2 ignitions.

Thus, for an engine with two ignition points and four pistons, for which the cycle is covered in 1/2 turn, there are 16 ignitions per revolution.

According to the invention, the transmission ensuring the movement of the half-rotors (uniform rotation and oscillation) can be achieved by implementing non-constant velocity articulated joints, of the cardan type, or, variable-radius gears on one turn, associated with gears with 1, 2, ... n lobes.

In order to avoid any radial force on the half-rotors, they are driven, in accordance with the invention, by pinions located symmetrically with respect to the axis.

It should be noted that the transmission is preferably located on only one side of the engine so as to facilitate access, cooling and lubrication thereof.

The oscillating motion of the half-rotors produces inertial forces which increase rapidly with speed. On the other hand, the gases in the compression and expansion phases constitute an elastic coupling. The inertia-elasticity association induces a natural frequency, therefore a speed of rotation for which these forces are balanced and no longer have to be supported by the transmission.

The calculation shows that the adaptation speed is quite low, the oscillating masses cannot be reduced indefinitely. To increase this speed until it coincides with the cruising speed, it is advisable to add an additional elastic coupling which can be either mechanical (torsion spring, spiral spring or coil spring working in flexion), or constituted by pockets of gas whose volume varies.

Thus, by varying the average pressure in the gas pockets as a function of the load and of the speed of rotation, an elastic system with variable stiffness is obtained.

This pressure can be automatically adapted to the speed by simple electro-pneumatic regulation, the inertia forces being thus compensated over a wide range of speeds.

As the compression forces in the engine are predominant at start-up, they are advantageously reduced by closing the intake during cranking with the starter, the intake being reestablished when a certain speed is reached.

According to the invention, the movement arriving on several shafts surrounding the axis can be advantageously brought back to the axis formed by the output shaft by various pairs of gears constituting a gearbox.

Thus, according to an advantageous characteristic of the rotary piston engine according to the invention, the engine housing enclosing the transmission also contains the gearbox, the clutch then being transferred to the box outlet.

The seal between cylinder and rotors of the rotary piston engine according to the invention can be achieved by virtue of a small clearance over a fairly large length with expansion zones, however this solution has the drawback of creating risks of accidental contact of the cylinder. makes differences in expansion, deformation and wear of the bearings. Several types of solutions can then be implemented, among which
- lubrication or the use of a self-lubricating material such as impregnated frit
- the choice of materials supporting accidental contact without deterioration of the surface condition
- the choice of shapes making any accidental contact unlikely
- machining with sufficient clearance for the construction, this clearance being reduced by deposit during a special lapping
- recourse to a segmentation system using rolling segments.

Finally, the tightness can be improved without rotor / stator contact by allowing liquid to filter through the rotor by porous zones obtained by micro-drilling or by inserting porous material.

According to a particular embodiment of the engine according to the invention, the cylinder is also driven by a rotational movement, in the same direction as the pistons or in the opposite direction.

According to this embodiment, the output shaft can be clutched either on the cylinder or on a toothed wheel rotating at the average speed of the pistons.

This embodiment has the advantage of allowing, thanks to a suitable shape of the exhaust ports located on the cylinder, a propulsive effect (or “turbo”), induced by the residual pressure when they are opened.

It also offers the advantage of producing a supercharging effect, the cylinder turning causing the aspirated gases, which are thereby slightly compressed.

Finally, another advantage of this embodiment lies in the simplification that it makes possible to make the gearbox, the different speeds being obtained by locking the gear wheels and by the two possible interconnections of the gearbox. output shaft.

Other characteristics and advantages of the present invention will emerge from the following description of two of its embodiments illustrated by the appended drawing, it being understood that this description is in no way limiting with respect to the invention.

In the attached drawing
- Figure 1 shows a longitudinal sectional view, along section line XX 'of Figure 2, of a first embodiment of an engine according to the invention, in which the cylinder is fixed.

- Figure 2 shows a cross-sectional view of the same engine, along the section line YY 'of Figure 1.

- Figure 3 shows a cross-sectional view of the same engine, along the section line ZZ 'of Figure 1.

- Figure 4 shows a longitudinal sectional view, similar to that of Figure 1, of a second embodiment of an engine according to the invention, in which the cylinder is rotary.

If we first refer to Figure 1, it can be seen that the engine according to the invention which is represented therein comprises an engine part 1 proper, enclosed in a casing 10 and a transmission part 2, enclosed in a casing 20.

The engine part 1 comprises a fixed cylinder 3 housing pistons fixed alternately to one and the other of the half-rotors 4 and 5, at the rate of 4 pistons per half-rotor, i.e. 4 pistons 41 for the half-rotor 4 and 4 pistons 51 for the half-rotor 5. Two "castrated" wheels 45 and 55 are connected to each half-rotor 4 and 5, the "square" wheel 45 being engaged with 4 two-lobe pinions 46 each fixed to a shaft 47 , while the "square" wheel 55 is engaged with 4 gears with 2 lobes 56 each fixed to a shaft 57.

Gas pockets 48 arranged between the two half-shafts 4 and 5 allow an additional elastic coupling to be introduced into the engine.

The admission of gases into the cylinder is effected through conduits 11, and their discharge through openings 12 arranged on the cylinder, visible in FIG. 3.

The transmission part 2 comprises the shafts 47 and 57 each secured to a series of pinions: the shaft 57 to pinions 62, 63, 64, being toothed at its end 61 which engages with a toothed wheel 61 ', while the pinions 62, 63, 64 are engaged with toothed wheels 62 ', 63', 64 'capable of engaging with the output shaft 7, which is provided for this purpose with synchronizers 71, 72, 73.

Thus the toothed wheel 61 'associated with the ends 61 of the shafts 47 and 57 corresponds to the first speed of the engine, while the toothed wheels 62, 63, 64 correspond respectively to the second, third and fourth speeds, the wheel 65 corresponding to the running back.

If we then refer to Figure 2, we see in this figure the four shafts 47 and the four shafts 57 associated with a two-lobe pinion 46, 56, the "square" wheel 55 masking the square wheel 45 and the half. shaft 5 surrounding half-shaft 4.

If we now refer to Figure 3, we see in this figure the pistons 41 and 51 arranged around the two half-rotors 4 and 5 in the cylinder 3, with the gas inlets 11 and the gas outlets 12 and the two points d 'ignition 14 and 14' diametrically opposed.

It will be understood, in view of these figures, that the two ignition points 14, 14 'make it possible, with 4 pistons per half-rotor, to run the 4 times of the cycle over 1/2 turn, so that for one revolution rotor there are 16 ignitions. This results in significantly increased efficiency and power compared to known engines.

If we finally refer to Figure 4, this figure shows a second embodiment of the engine according to the invention, in which the cylinder itself is rotary, rotating around the same axis as the pistons.

In this case, the engine part 1 is similar to that of FIG. 1, but the transmission part is simplified.

Thus, the shafts 47, 57 carry pinions 31, 32, 33, respectively 31 ', 32', 33 'which are connected in pairs, the pinions 33, 33' by a toothed wheel 36, the pinions 32, 32 ' by a toothed wheel 35 and the pinions 31, 31 'by a toothed wheel 34, the latter secured, by means of a central rod, to a toothed wheel 34' allowing it to be connected by a clutch 8 to the shaft output 7, said toothed wheel 34 rotating the average speed of the pistons. The clutch 8 thus makes it possible to couple the output shaft 7 either to the wheel 34 or to the cylinder 30.

The toothed wheels 34, 35, 36 can rotate in free rotation, a central locking rod 9 movable in translation making it possible to block one or the other of them in order to engage one or the other of the engine speed.

Thus the neutral point is obtained by blocking the wheel 34 using the rod 9, the end of which is placed in position A, the output shaft 7 being either free or clutched on the toothed wheel 34 ', to which case only the cylinder 30 can rotate.

Reverse gear is obtained by locking the wheel 36 by the rod 9 in position C. The wheel 36 being of greater diameter than the wheel 34, and the output shaft 7 being clutched on the wheel 34 ', the latter rotates in reverse direction of cylinder 30.

The first forward speed is obtained by locking the wheel 35 by the rod 9 in position B, the cylinder 30 rotating around the wheel 35 in the direction of the pistons. The wheel 34 is clutched to the shaft 7 and the wheel 35 being of smaller diameter, the shaft 7 rotates in the direction of the cylinder, but more slowly.

The second speed is obtained by locking the wheel 36 by the rod 9 in position C, the shaft 7 being clutched on the cylinder 30.

Likewise, the third speed is obtained by returning the rod 9 to position A, the shaft 7 being clutched on the cylinder 30.

Finally, the fourth speed is obtained with the rod 9 in position B, the shaft 7 being clutched on the cylinder 30.

Of course, the present invention cannot be limited to the preceding description of two of its embodiments, which may undergo a certain number of modifications without however departing from the scope of the invention.

Claims (4)

1) Internal combustion engine with rotary pistons, of the type comprising, in a cylinder (3), two half-rotors (4, 5) supporting the pistons (41, 51) and animated by an oscillating movement superimposed on uniform rotation of the motor shaft, characterized in that it comprises 2, 3, 4 ... n simultaneous ignition points (14, 14 ') regularly distributed around the cylinder, each half-rotor (4, 5) comprising 4, 6 , 8 ... 2n pistons (41, 51) so as to make the four cycles of the cycle travel over 1/2, 1/3, 1/4 ... 1 / n revolution, so that for one revolution of the rotor there are 16, 36, 64 ... 4n2 ignitions. 2) Motor according to claim 1, characterized in that the movement of the half-rotors (4, 5) is achieved by implementing gears (45, 55) with variable radii associated with pinions (46, 56) at 1 , 2, ... n lobes. 3) Motor according to claim 2, characterized in that the variable spoke gears consist of "square" wheels (45, 55). 4) Engine according to claim 1, characterized in that the cylinder (3) is also driven by a rotational movement, in the same direction as the half-rotors (4, 5) or in the opposite direction.