EP0080070B1 - Internal-combustion engine - Google Patents

Abstract

A rotary engine comprises a circular rotor surrounded by an annular stator. The rotor is provided around its outer circumference with spaced combustion chambers and with recesses therebetween. Each recess serves as an expansion chamber for a jet of gas produced by combustion in an associated combustion chamber. Each recess is also provided, remote from the associated combustion chamber, with a cam. The stator at its inner circumference has retractible reaction members which are movable into the recesses to be acted on by the gas jet so as to create forces acting in opposite sense on the rotor and stator and thus cause the rotor to rotate. The reaction members have deflector surfaces arranged to deflect the gas jet in such a manner that the members are drawn into the recesses, the members being engaged by the cams during the rotor rotation and moved back into the stator.

Description

The invention relates to an internal combustion engine with a rotor having a circular cross section and an annular stator surrounding the rotor.

Numerous rotary piston engines in a wide variety of designs have become known, which have so far been unable to overcome their "teething troubles" and to prevail over conventional engines. The rotary piston engine known as the Wankel engine has been developed furthest in this field, but due to insurmountable material problems it has also not yet achieved a final breakthrough. Nevertheless, the basic idea behind all of these considerations of abandoning the "steam engine principle" and immediately converting the expansion forces of combustion gases into a rotary motion remains valid. This idea also led to the development of the turbine. However, the high speed of the turbine limits its application in many cases, since the high speed also limits its output. On the other hand, the power of the piston engine is practically limited, otherwise it will be too large in terms of space and weight.

Recently, a further problem has arisen in the attempt to switch from conventional piston engines to hydrogen as a fuel gas, which can be described as the problem of detonation. A hydrogen gas-air mixture ignites very easily by itself. In the compression phase of a piston engine, premature ignition can occur, which can result in considerable engine damage or at best lead to ineffectiveness. If you work with liquid hydrogen, this risk is smaller, but it is not eliminated, since part of the liquid-hydrogen-air mixture can transform into a gaseous-hydrogen-air mixture. The high operating temperature favors this process. Auxiliary problems that arise here are the refueling and supply line, for which special heat-resistant and cold-resistant materials and processes are required. The enormous amount of energy required to liquefy the hydrogen puts the economy of such an engine in question.

DE-C 283 368 describes an internal combustion engine with a rotor with a circular cross section and an annular stator (inner rotor) surrounding the rotor, a flap being mounted on the inside of the stator, which flap can be pushed back into the stator by a working cam on the rotor is, and in the circumferential surface of the rotor there are recesses in the form of circular sections as expansion spaces, at one end of which a combustion chamber is arranged and the other end of which runs out into a ramp; flaps can be pushed into the recesses of the rotor to absorb the forces of the expanding combustion gases and can be pushed back into the stator by means of a ramp. The flaps, however, have the disadvantage that their edges abutting the rotor are subject to high wear and tear, and thus all known sealing problems are present on the motor.

From DE-A 2 429 553 a rotary piston engine is known, with a rotor with a circular cross-section and an annular stator surrounding the rotor, a flap being pivotally mounted on the inside of the stator, which flap can be folded back into the stator by a working cam on the rotor is. The flap is pressed into its closed position by a leaf spring and sealed against the rotor by a sealing strip. At higher speeds, the spring can no longer perform its task and the sealing strip is subject to rapid wear. This motor, which operates on the principle of expansion, has the further known disadvantage that the rotor is also sealed off from the stator by a further sealing strip which is strongly subject to wear. In addition, the motor has a dead center, which is given by the fact that the outlet opening for the gas in the rotor and the outlet opening in the stator correspond to one another in a specific position. Finally, this engine also suffers from the fundamental disadvantage of all known rotary piston engines that there is practically no torque in the lower speed range.

The invention is therefore based on the object of providing an engine which avoids the disadvantages of known engines, which operates in particular as a rotary engine and which is at the same time able to process alternative fuels, in particular gaseous hydrogen, without problems and as environmentally friendly as possible.

To achieve this object, the invention is based on an internal combustion engine with an inner part which is circular in cross section and an annular outer part surrounding the inner part, at least one circular section-shaped recess being present as an expansion space in the peripheral surface of the inner part, at one end of which a combustion chamber is arranged and the latter the other end is delimited by a working cam which ends in a ramp towards the expansion space and at least one flap is pivotally mounted on the inside of the outer part, which flap can be folded into the recess of the inner part to absorb the forces of the expanding combustion gases and through the ramp into the Outside part can be folded back. The invention consists in that the flap towards the expansion space has the shape of a spoiler, against which the combustion gases flow in an effective flow-mechanical manner. This engine is characterized by the following properties: It can be operated with simple hydrogen gas, which is oxidized with the oxygen in the air. An early ignition cannot take place, since hydrogen and air are brought together in a combustion chamber just before the ignition. A compress There is no phase of development. Subsequent detonation of unburned gas residues does not have an adverse effect on the engine or its operation, but is converted into additional drive energy.

• Fig. 1 eine Ansicht des geöffneten Innenraumes eines Motors,
• Fig. 2 eine Ansicht des Motors mit teilweise geschlossenem Innenraum,
• Fig. 3 eine Ansicht des zusammengebauten Motors,
• Fig. 4a eine Vorderansicht, ein Querschnitt und eine rückwärtige Ansicht einer Brennkammer,
• Fig. 4b ein Motorausschnitt mit einer Brennkammer und einer Klappe,
• Fig. 4c ein Motorausschnitt mit der Klappe in zwei verschiedenen Stellungen,
• Fig. 5 eine Klappe in vergrössertem Massstab,
• Fig. 6a zwei Schnitte durch die innere Begrenzung und
• Fig. 6b die Klappe nach den Schnittlinien Vla-Vla, Vlb-Vlb von Fig. 4c,
• Fig. 7a einen Schnitt nach der Linie Vlla-Vlla von Fig. 7b und
• Fig. 7b eine Ansicht des Motors mit weggelassenem Ausenring aus Richtung des Pfeiles Vllb von Fig. 7a.

In the drawings, an embodiment of the invention is shown. Show it:

• 1 is a view of the open interior of an engine,
• 2 is a view of the engine with the interior partially closed,
• 3 is a view of the assembled engine,
• 4a is a front view, a cross section and a rear view of a combustion chamber,
• 4b is an engine section with a combustion chamber and a flap,
• 4c is a motor section with the flap in two different positions,
• 5 is a flap on an enlarged scale,
• Fig. 6a two sections through the inner boundary and
• 6b the flap according to the section lines Vla-Vla, Vlb-Vlb of Fig. 4c,
• Fig. 7a is a section along the line Vlla-Vlla of Fig. 7b and
• Fig. 7b is a view of the engine with the outer ring omitted from the direction of arrow Vllb of Fig. 7a.

1 shows the axial view of an engine 1 with the interior open, the direction of view forming a small angle with the engine axis 4. The view reveals the two main parts of the motor 1, namely the rotor 2 and the stator 3, from which it can be seen that the motor 1 is designed as an internal rotor in this exemplary embodiment. The rotor 2 has in its circumferential surface 21 circular cutouts 22 as expansion spaces for the combustion gases. A combustion chamber 23 is arranged at one end of the expansion space 22, while the other end ends in a ramp 24. On the other hand, flaps 32 are pivotally mounted on the inside 31 of the stator, which flaps can be folded into the recesses 22 of the rotor 2 to absorb the forces of the expanding combustion gases and can be folded back into the stator 3 by means of the ramp 24. As will be explained in more detail later, this is the convex version of the internal combustion engine 1 with respect to the combustion chambers 23. In the exemplary embodiment of the engine 1 shown in FIG. 1, the engine 1 has four drive units, each consisting of four expansion spaces 22 with eight flaps 32 and four combustion chambers 23. However, it goes without saying that this is only an example and that it is readily possible to provide 2, 3, 5, 7, 8 or even more drive units. The number of flaps is also arbitrary.

The combustion chambers 23 are fastened to the arm supports with arms, in the exemplary embodiment with four arms 431, 432, 433 and 434, in the example to the two arm supports 421, 422. At the outer end of the arms there are two inner rings 261, 262, of which only the inner ring 261 lying on the visible side is visible. The expansion space 22 extends between each two combustion chambers and is delimited towards the rotor axis 4 by an outer limiting part 34 and in the axial direction on each side by an outer ring 51, 52. In Fig. 2 the outer ring 51 is shown on one side. An identical ring 52 is located axially on the opposite motor side. The rotor 2 is fixed and supported in the stator 3 by two outer ring carriers 61, 62. In Fig. 3, an outer ring carrier 61 is shown, while the second outer ring carrier 62 is axially seen on the other engine side. The rotor axis 4 is mounted in a manner known per se with a ball bearing 63 in the outer ring carriers 61, 62.

The stator 3 consists of annular fins 35, of which the fins 351, 352, 353 are designated in FIG. 1, for example. Spacers 36 are located between the fins 35. The stator block consisting of fins 35 and spacers 36 is held together by connecting bolts 37 passing through the stator. In Fig. 1 one of the connecting bolts 37 is shown.

In a second embodiment of the stator 3, the stator 3 consists of segments in the form of circular sections, held together by fixings. These segments can preferably consist of suitable light metals or alloys customary in engine construction.

On its inside 31, the stator 3 has recesses 33 for receiving the flaps 32. These recesses 33 are preferably complementary to the shape of the flaps 32 or form-fitting with them. The flaps 32 have the shape of a spoiler towards the expansion space 22. The spoiler shape causes the flue gases flowing towards the flap 32 to pull the flap 32 into the expansion space 22, as shown by the arrow P3 in FIG. 4b.

4a shows a front view, a section and a rear view of the combustion chamber 23 on an enlarged scale. The combustion chamber 23 consists of the outlet nozzle 232, the combustion chamber 231, two inlet nozzles 233, 234 for the two reaction gases or fuel gases and an ignition probe 235. Hydrogen and air are preferably used as the combustion gases. Two fuel gases, which are brought together under certain pressure conditions in the combustion chamber 23, are ignited by the ignition probe 235, which projects into the combustion chamber 23. The amount of individual gases and their pressure can be precisely regulated and adjusted by compressors. The ignition probe 235 also makes it possible to precisely set the ignition, ie ignition temperature and ignition torque, corresponding to the respective gases. For the gases to be used, the usual stoichiometric proportions must be observed, as well as the effect on the material from which the combustion chamber 23 is made. The gas is not compressed in the combustion chamber 23. The problem of auto-ignition with certain gases, such as. B. hydrogen, therefore does not arise at all. In addition, early or late ignition for the function of engine 1 would be irrelevant, in contrast to the situation with a piston engine.

The mutual position of combustion chamber 23 and ramp 24 is shown in Fig. 4b and Fig. 4c. Because of the smaller scale of this illustration, the curvature of rotor 2 and stator 3 is not recognizable. The arrow P1 indicates the direction of rotation of the rotor 2. With the rotor 2 and the combustion chamber 23, the ramp 24 also moves in this direction of rotation. During this movement, the flap 32 runs with its front edge 321 onto the ramp 24. The flap 32 is pivotally mounted on a flap linkage 322, 323. In the flap linkage shown in FIGS. 4b, 4c, this consists of at least one straight lever 322 and two toggle levers 323. In FIGS. 4b, 4c, the two toggle levers 323 lie one behind the other on both sides of the flap 32, so that in the figures only one is visible. On the other hand, it is also possible for the flap linkage to consist of two straight and one toggle levers, in which case a straight lever lies on each side of the flap 32.

The pivoting movement of the flap 32 into the expansion space 22 is limited by a stop lug 324 molded onto the toggle lever 323 and abutting the flap 32 in the lowered position. This stop lug 324 limits the lowering movement of the flap 32 in such a way that the underside of the flap 32 is only a very small distance from the inner boundary 25 of the expansion space 22. This distance is only about 5/1000 mm.

In a further embodiment, the flap 32 can be pivotably supported by a flap linkage and a pivotable part of the outer boundary 34. It would also be possible to arrange the flap 32 in a rail without linkage, similar to an elevator, in or out of the expansion space 22.

When the rotor 2 rotates, the flaps 32 of the engine 1 are located in the expansion space 22 and absorb the forces of the expanding combustion gases. As a result, the rotor 2 performs a rotational movement with respect to the stator 3, with the result that, as shown in FIG. 4c, the front edge 321 of the flap 32 abuts the ramp 24 and initiates a folding back movement. In Fig. 4c, the flap 32 is shown in two successive times. The flap 32 is folded back into the stator by two sliding pins 325a, 325b located in the front edge 321 of the flap 32 and sliding on the ramp 24 (FIG. 5).

5, the flap 32 is shown in an enlarged view. The flap 32 is preferably cast from a light metal customary in engine construction. For example, two sliding pins 325a, 325b are located in the front edge 321. During the free movement shown in FIG. 6 a in the expansion space 22, the slide pins 325 a, b do not touch the inner boundary 25. Only when the flap 32 runs onto the ramp 24 do the sliding pins 325a, 325b come into contact with the inner boundary, as can be seen in FIG. 6b, and slide along the edge of the inner ring 261. Due to this very short-term contact of the pins 325a, b with the inner ring 261, 262, the sliding pins are only subjected to very little stress and therefore have a very long service life.

Since the flap 32 is mounted on the stator 3, the pins 325a, b can be readjusted or readjusted very easily in the event of excessive abrasion. In a second embodiment of the flaps 32, wheels which roll on the ramp 24 are mounted in the front edge 321. Rolling wheels can also be attached on the opposite edge 327, which, when the combustion chamber 23 is rotated past, convert the sliding friction of the flap 32 into rolling friction and thus protect the flap material. According to a third variant, a roller bearing is arranged in the ramp 24, on which the front edge 321 of the flap 32 can roll directly.

7a, 7b show the essential sealing elements of the motor 1. The sealing elements have to seal the expansion space 22 against the stator 3 and the flaps 32 against the rotor 2. 7a shows a section through the combustion chamber 23 and the expansion space 22 along the line VIIa-VIIa of FIG. 7b. Below the inner boundary 25 is the seal 611 and on both sides next to the front edge of the combustion chamber 23 there is a sealing strip 612a, 612b and seal the expansion space 22 with respect to the outer rings 51, 52. On the other hand, the flap 32 is also sealed by sealing strips 326a, 326b during its pivoting movement with respect to the outer rings 51, 52. With the engine, however, there is also the possibility of completely dispensing with the seals 611, 612a, 612b and 326a, b by a better fit of the inner boundary 25, combustion chamber 23, combustion chamber cover 236 and flap 32. Another possibility is to manufacture the inner limiting part 25 and / or the flap 32 from self-sealing material.

Furthermore, a motor is conceivable in which the rotor 2 is stationary and the stator 3 is rotating. One can speak here of a reversal of the rotor-stator property. Finally, it is also conceivable to design the motor 1 in such a way that the stator 3 and rotor 2 are designed as coaxial disks.

Claims (18)

1. Combustion engine (1) with an inner part (2) of circular cross-section and a circularly annular outer part (3) surrounding the inner part (2), wherein at least one recess (22) in the shape of a circular segment is present in the circumferential surface (21) of the inner part (2) as an expansion space, at the one end of which is arranged a combustion chamber (23) and the other end of which is bounded by an operating cam which runs out into a ramp (24) towards the expansion space, and wherein pivotably borne at the inside of the outer part (3) is at least one flap (32), which is tiltable into the recess (22) of the inner part (2) for reception of the forces of the expanding gases of combustion and tiltable back into the outer part (3) by the ramp (24), characterised thereby, that the flap (32) towards the expansion space (22) has the shape of a spoiler, against which the gases of combustion effectively flow in terms of flow mechanics.

2. Combustion engine according to claim 1, characterised thereby, that the inner part (2) of circular cross-section is constructed as rotor and the outer part (3) surrounding the inner part (2) is constructed as stator.

3. Combustion engine according to claim 1 or 2, characterised thereby, that the combustion chamber (23) displays a rotationally symmetrical shape with a combustion space (231) and an exit nozzle (232) and the longitudinal axis of the combustion chamber (23) is arranged tangentially at the circular inner part (2).

4. Combustion engine according to the claims 1 to 3, characterised thereby, that the fuel gases are conducted through the hollow rotor axle (4) to the combustion chambers (23).

5. Combustion engine according to the claims 1 to 4, characterised thereby, that the seals (611, 612) are arranged between the inner boundary part (25) and the combustion chambers (23) on the one hand and the outer rings (5.1, 52) on the other hand and seals (326a, 326b) are arranged between the flap (32) on the one hand and the outer rings (51, 52) on the other hand.

6. Combustion engine according to claim 5, characterised thereby, that the seals consists of bimetal compensated for expansion.

7. Combustion engine according to claim 5, characterised thereby, that the inner boundary part (25) and/or the flap (32) consist of self-sealing material.

8. Combustion engine according to the claims 1 to 7, characterised thereby, that the stator (3) or flap carrier consists of segments which are in the shape of circular segments and held together by fixings.

9. Combustion engine according to the claims 1 to 8, characterised thereby, that the stator or flap carrier (3) on its inner side (31) displays recesses (33), preferably shape-locking recesses, for the reception of the flaps (32).

10. Combustion engine according to the claims 1 to 9, characterised thereby, that each flap (32) is pivotably borne at a flap carrier (322, 323).

11. Combustion engine according to claim 9, characterised thereby, that the flap linkage (322, 323) consists of at least one straight lever (322) and two elbow levers (323) or two straight levers and one elbow lever.

12. Combustion engine according to claim 11, characterised thereby, that the pivotal movement of the flap (32) into the expansion space (22) is limited by an abutment lug (324), which is shaped on at the elbow lever (323) and abuts against the flap (32) in the lowered setting.

13. Combustion engine according to the claims 1 to 10, characterised thereby, that each flap (32) is pivotably borne by a flap linkage and a pivotably constructed part of the outer limitation (34).

14. Combustion engine according to the claims 1 to 9, characterised thereby, that the flap (32) is pushable into and out of the expansion space (22) at an equipment extending in radial direction.

15. Combustion engine according to the claims 1 to 9, characterised thereby, that the flaps (32) are borne at a pivot lever.

16. Combustion engine according to the claims 1 to 13, characterised thereby, that the return tilting movement of the flap (32) into the stator (3) takes place through two slide pins (325a, 325b) disposed in the front edge (321) of the flap (32) and sliding on the ramp (24).

17. Combustion engine according to the claims 1 to 13, characterised thereby, that the return tilting movement of the flap (32) into the stator (3) takes place through two little wheels borne in the front edge (321) of the flap (32) and rolling on the ramp (24).

18. Combustion engine according to the claims 1 to 13, characterised thereby, that a runner bearing, on which front edge (321) of the flap (32) rolls along directly, is arranged in the ramp (24).

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