Rotary Internal-combustion Engine

Abstract

A rotary internal combustion piston engine providing for relative operative positioning of the movable portions, such as rotary cogs and pistons to allow for multiple and varied utilization of the engine working volume. The pistons are divided into operative segments comprising suction-exhaust pistons and power-compression pistons having reduced clearance power loses and minimal or maximum pressure differentials as required by the relative pistons to allow for maximum efficiency.

Description

This invention relates to a rotary internal combustion piston engine with two or more rotors providing for multiple utilization of the working volume, the engine being adapted to be the prime mover, and particularly in cases where very small dimensions and a low weight are required.

In technical and patent literature there may be found descriptions of numerous rotary engines which in different aspects are similar to those hereinafter described. Concerned are engines each provided with a rotor having radial pistons generally coupled by means of a gear transmission with rotary sealing elements, the so-called rotary gates or combustion rotors, in which there are provide suitable chambers adapted to receive the pistons of the rotor. In all of these engines the rotor and the rotary gates have the shape of a circular cylinder. The rotor pistons are mounted on the outer side of the cylindrical surface of the rotor, while the chambers of the rotary gates are provided within the cylindrical surface of the gates. Both the rotor and the gates disposed thereabout are mounted in a conveniently shaped body and they are dimensioned to cooperate with one another and with the said body as tightly as possible.

The performance characteristics of these engines and the ranges of their applications are closely connected with the tasks fulfilled by the essential constructional elements of the given engine and they result from its essential constructional features. In particular, these characteristics depend upon the arrangement and shape of the inlet and outlet passages for the working medium, the shape of the rotor pistons and of the chambers in the rotary gates, on the number of the pistons and chambers and on the number of the rotary gates. Other constructional details such as the seals for the working volumes, the manner of supplying the fuel, the kind of ignition, the cooling system etc. are also of varying degrees of importance.

In the majority of known combustion engines of this kind all rotor pistons are all-purpose double-acting pistons. Each of the pistons sucks in with its rear side the working medium and simultaneously it compresses through its frontal side the medium sucked-in by the previously acting piston. In the successive working space between the rotary gates the rear side of the same piston is exposed to the action of the expanding gases, while the frontal side of that piston pushes out the combustion gases. This versatility of all pistons is indeed an advantage, but it also concurrently creates a number of disadvantages. For example: the pressure difference between the frontal and the back sides of each piston is at a maximum in all instances and results in considerable clearance losses. The individual working cycles of the engine always repeat in the same working spaces between the rotary gates, so as to cause very unequal heating of the body of the engine and of the rotary gates. This leads to considerable thermal deformations and to a reduction in the sealing of the working spaces, leading consequently to a lowering of the efficiency and shortening of the life of the engine. Every other gate is provided with a combustion chamber. Due to this fact, the sealing gates are insufficiently heated, whereas the gates and the combustion chambers become very hot. Still worse, there is no possibility of economically cooling these gates. The permissible heat loading limit of the gates considerably limits the specific power and specific weight of the engine. Besides, the mechanical loading of the rotary gates, of their bearings and gear wheels coupling them with the rotor shaft, is not uniform. These are all reasons in view of which the life of such an engine is relatively short.

The inlet and outlet passages for the working medium are, as a rule, arranged in the case of the engine and they are disposed either on its circumference or on its front surfaces. Consequently they are more or less overlapped by the rotor pistons or rotary gates, while frequently they are completely closed. This gives rise to various losses in the inlet and outlet passages and lowers the efficiency of the engine. Even in cases where these passages are only partially arranged in the rotor, they are improperly shaped. In connection therewith the hydraulic losses in these passages are accordingly comparatively high.

As far as concerns the shape of the rotor pistons and that of the chambers of the rotary gates, which are to some extent dependent upon the former, there are employed a lot of different combinations of rectilinear, circular, cycloidal, epicycloidal and hypocycloidal profiles. The shapes of these elements determines not only the facility of making them, but also influences, in different aspects, the magnitude of the entire working space of the engine, the character of the suction and pressing process, the repetition of the processes occuring in the individual working spaces, the quality of mutual sealing etc. In this respect, each known rotary engine reveals advantageous features while being simultaneously being subject to certain disadvantages.

The optimum number of rotor pistons, that of the rotary gates and of the chambers in the gates, is very different to determine in known rotary engines. There are a great many possible combinations, which is not only of formal but of practical significance. On the basis of the number of the elements depends their dimensions. To some extent these numbers determine the distribution and shapes of the inlet and outlet passages. They indirectly decide the main characteristics of the engine, among others, its specific power, rotational speed, repeatability of working cycles, uniformity of the torque, and the value of shearing forces. The selection of the best combination of the numbers of the elements, from the point of view of obtaining particularly favourable properties of the engine, in connection, of course, with the above-mentioned constructional features, is rather difficult. Therefore, it is not without good reason, that each of the known rotary engines of this type shows apart from advantages also a series of essential disadvantages.

The object of the invention is to eliminate the essential faults and inconveniences of rotary devices of this type, used as internal combustion engines. To achieve this object, the invention sets the task consisting, among others, in differentiating the equal role of the rotor pistons, elaborating an effective method of supplying the working medium, providing the most advantages shapes of rotor pistons and chambers in the rotary gates and in choosing the most convenient number of all these elements.

The invention encompasses a predetermined group of devices, especially rotary internal-combustion engines designed in compliance with a preset technical task. The tasks of the individual pistons have been differentiated therein, by providing the rotor -- hereinafter called piston rotor -- with two types of pistons, namely: suction-exhaust pistons and power-compression pistons. The outlets of the suction passages have been placed on the rear side in relation to the direction of the movement of the suction-exhaust pistons, while the outlets of the exhaust passages have been disposed in one or both front cover plates of the piston rotor, in proximity before each suction-exhaust piston.

The suction passages of the piston rotor unite in a common central inlet in the front central part of the engine, while the exhaust passages are connected with one, or if necessary, with two ring-shaped combustion gases collectors, one of which may be placed also in the front, but outer part of the engine, while the other maybe located in its central part. All the pistons have a nearly identical outer shape, which is a combination of e.g., an epicycloidal and circular line.

The number of the rotary gates, hereinafter called chamber rotors, is equal e.g., to the sum of all the pistons, or may be higher or lower by one than the sum of the pistons. The number of combustion chambers with which the chamber rotors are equipped, is advantageously an odd number. In the cross section of the chamber rotors, the combustion chambers have a profile which is a combination of e.g., an arc of a circle and two sections of a straight line. In the crank-case there may be located suitable passages for equalizing the pressure differences between the working spaces of the engine and its combustion chambers. There are also provided passages for leading off residuals of combustion gases from the combustion chambers, or for taking away the scavenging air.

In the cylindrical surfaces of the chamber rotors and of the piston rotor there are provided e.g., suitable labyrinth seal grooves. Of equal importance are also the remaining constructional elements which must be conveniently accommodated to the entirely new construction of the engine, such as: location of the sparking plugs and fuel injectors, positioning the rotors in bearings and other design of the rotational elements, rotational speed transmission gear of the piston rotor and of the driving shaft, method of eventually controlling the compression ratio, solution of blocking the toothed wheels used in synchronizing all of the rotors, removing of clearances between said toothed wheels, location of the ignition control device, etc.

The invention provides for exceptionally favourable performance characteristics of the novel engine. These advantages result from the optimal selection of all of the essential constructional features of the novel engine and also of such features that generally are considered to be of secondary importance in the art.

The functional division of the pistons into suction-exhaust pistons and power-compression pistons gives rise to some important advantageous consequences. The first of them is the elimination, to a great extent, of the problem of the clearance losses. The pressure difference between the frontal and rear surfaces of the suction-exhaust pistons is always minimal, generally never higher than several tenths of an atmosphere. In case of power-compression pistons the pressure difference may indeed be high, but for a very short time only. At that time in front of the piston there takes place the beginning of the working cycle, and behind the piston the beginning of the compression process. Already at any little movement of this piston, the pressure difference quickly drops to zero, then, changes its sign and increases to a value which appears when behind the piston there is finished the expansion of combustion gases, and in front of the piston the compression of air, which also only takes a very short time. In consequence of such a distribution of pressures during the movement of the power-compression piston, any leakages are immediately throttled and have the tendency to revert. Longer lasting pressure differences have been limited to locations where the seal does not involve greater difficulties, i.e., to the contact of the cylindrical part of the piston rotor with the cylindrical part of the chamber rotors.

The second consequence of the functional division of the pistons is the creation of perfect natural engine cooling conditions, decrease of the head load of the chamber rotors of the engine and equalization of the temperature distribution in its crankcase. The natural cooling of the engine and the equalization of the temperature distribution in its carnkcase each result from the fact that in each working space between the chamber rotors there take place successively all the following working cycles: exhaust, suction, compression, work.

The decrease of the heat loading on the chamber rotors is obtained due to the fact that the fuel combustion process takes place in the chambers of all chamber rotors, and not as in other rotary engines of this type -- in each other chamber rotor. Thereby the heat loading of said rotors is reduced to one-half without any change of the specific power of the engine -- or alternatively, this provides the possibility of obtaining double the specific power without any need for increasing the heat loading of the chamber rotors.

The third consequence of the functional division of the pistons is the improved internal heat regeneration resulting from the partial utilization of heat of the combustion gases. This is attained due to the fact that the portion of the power-compression piston exposed at its rear side to the continuous action of the high temperature of the combustion gases, is intensively heating with its frontal side the air which is being compressed in the adjacent working space. In case of two or more piston pairs there is, furthermore, provided a full symmetry of the forces by the pressure of the working medium, which act upon the crankcase and the rotor, whereas no radial forces act upon the bearing of the rotor. All these facts advantageously influence the efficiency of the engine, its specific power, and consequently also its dimensions weight, and also its life expectancy.

The above described method of designing the inlet and outlet passages provides additional favourable consequences. Above all there are now obtained features which were unobtainable in other combustion engines, viz. : a continuous air suction process and a continuous process of exhausting the combustion gases. The inlet passages as well as the outlet passages remain always open. The flow is of continuous character and is only slightly throttled when the suction-exhaust piston is traveling through the chambers in the individual chamber rotors. Thus, in the engine there have been eliminated to a great extent the losses entailed by opening and closing of the suction and exhaust valves, by the acceleration of the working medium at the inflow and outflow apertures, as well as any losses connected with the flow through contractions at a critical speed or a speed which is not much lower.

Furthermore, the inlet passages have been disposed in the piston rotor in a manner allowing the rotor to be effectively cooled from the inside thereof, and simultaneously to obtain the initial compression of the air before it reaches the working spaces, viz.:a slight supercharging of the engine. The central inlet is located in conformance with the direction of the main axis of the engine and then, when it is in the piston rotor, it separates into approximately radial directions, whereby the flow is the same as in a centrifugal compressor. The supercharging is the greater, the higher the rotations of the engine. Such a method of designing the inlet and outlet passages improves above all the efficiency of the engine and increases its specific power.

The shape, as above described, of the pistons has been designed according to the principle of improved co-operation with the chamber rotors, facility of production, possibility of arranging labyrinth seal grooves, and creation of sufficient space for location of the inlet passages and sparking plugs.

As far as combustion chambers are concerned, both the shape and the number of said chambers in each chamber rotor must be mentioned. The adopted shape of the combustion chambers, in effect, a combination e.g., of the semicircle and two sections of the straight line as measured through their cross-section, assures not only a proper co-operation with the pistons of the rotor but makes it also possible to obtain the highest precision in the positioning of the edges of the chambers and a very simple solution in the construction of the mechanism of the compression ratio control system. An odd number of the combustion chambers, particularly 3 in number, is of extreme importance in the proper performance of the engine. That number makes it possible to reduce and to equalize the temperature loading of the chamber rotors, it creates conditions for especially good scavenging of the combustion chambers, and it also assures provisions of the most convenient proportions of the chamber rotors in relation to the piston rotor.

The piston rotor is provided with an even number of pistons, the suction-exhaust pistons and the power-compression pistons being alternately placed. Therefore, combustion takes place in every other combustion chamber and occurs again in the same chamber once for every two turns of the chamber rotor. In consequence thereof, combustion takes place in a suitable sequence in 11 combustion chambers, thereby causing a uniform heating of the chamber rotors. From each chamber, in which the combustion process has just taken place, the residual combustion gases are expelled, and then, during the second turn of the chamber rotor, this chamber is filled with cold air. Consequently, cooling and scavenging are obtained. The foregoing factors have an advantageous effect particularly on the life expectancy of the engine and on the improvement of its other performances, among while others, they contribute to a more complete combustion and to a decrease of the impurity content of the combustion gases.

The number of the chamber rotors depends upon the ultimate purpose of the engine. On this number are dependent e.g., the frequency of the individual working cycles, the multiple of utilization of the geometrical working volume of the engine, its specific power, dimensions, weight etc. For instance, the multiple of utilization of the geometrical working capacity of the engine is, in the case of four chamber rotors, approximately twice as large as in the case of two said rotors. This means that also the specific engine power, at the same rotational speed, will be approximately twice as large. The working cycle frequency accruing to dependent upon one rotation of the piston rotor is in such a case, also twice as large. This also means obtaining of a more uniform torque, and consequently e.g., a smoother operation.

The cover plates affixed to the two frontal surfaces of the piston rotor although appearing to be unessential, are, however, of rather essential importance to the overall construction of the engine. Above all, they make it possible to exactly arrange the afore-said combustion gas outlet passages , and furthermore, they facilitate the sealing of the individual working spaces, while they simplify the axial setting of multi-chamber rotors.

On the frontal and rear sides of each chamber rotor there may be provided a passage for connecting the suitable working space and the cylindrical seat of that rotor. The passages on the frontal sides of the chamber rotors assure a correct sequence of the air compression processes in each working space of the engine. The passages on the rear sides of the rotors assure a correct sequence of the combustion gases expansion processes. This is possible due to the fact that through each of these passages there occurs the equilization of the pressures between the working space and the corresponding combustion chamber, and this both during the initial compression phase -- before connecting the given chamber units with the compression space -- and during the end compression phase -- when such a chamber is already disconnected from the expansion space. This determines above all the general efficiency of the engine, and also the specific rate of fuel comsumption.

The passages in the middle part of the cylindrical seats of the chamber rotors may be open or closed, as required. Residual combustion gases rejected by the centrifugal force may escape through these passages, and during the next operating turn of the chamber rotor -- the scavenging air may flow out. This provides for improved scavenging of the engine and more intensive cooling, which results in improving the cleanliness of the combustion gases.

The remaining improved constructional features of the engine are, perhaps, not as essential, but they basically result from constructional reasons or they are more self-evident and as such are described moe superficially or are completely omitted.

Glow plugs or sparking plugs are placed e.g., in power-compression pistons for the purpose of rendering possible the regulation of the ignition advance in any suitably large limits. The access to these plugs is easy -- at the disclosed constructional embodiment of the engine, and simultaneously -- the construction and the arrangement of the ignition device may be very simple.

The distribution of the fuel injectors in the crankcase of the engine, near the penetration edges of the cylindrical seats of the chamber rotors with the cylindrical seat of the piston rotor, is dictated by the possibility of obtaining a fuel injection sequence lasting sufficiently long during each air compression cycle in the working spaces of the engine. It is intended to avail oneself entirely of the advantage of a direct, timed fuel injection. In case of an even number of chambers, in each chamber rotor there may be applied continuous fuel injection into the central air inlet to the engine, or to a carburetor supply.

The method of blocking any toothed wheels on the pins of the chamber rotors is intended to create, above all, for conditions of unitary production of the engine or its prototypes, or for conditions in which the production takes place with a partial interchangeability of parts.

The hereinafter described method of reducing the rotational speed of the engine by applying a gear wheel with an inner indentation, engaging simultaneously all gear wheels of the chamber rotors, is especially convenient for tractive applications of the engine and for all other cases in which small dimensions and little weight are required. Transmission ratios between the rotational speed of the piston rotor and the transmission shaft of the engine of : 3; 2,5; 2; 1 and others are obtainable. The application of the solution makes it also possible to remove clearances in the transmission synchronizing the rotation of the chamber rotors and the piston rotor.

The method of embedding the bearing of the piston rotor and of the chamber rotors is been correlated as advantageously as possible with the overall construction of the novel engine. The outrigger support of the piston rotor in the rolling bearings is dictated by technological and assembling reasons, and also by the possibility of obtaining a long lasting and reliable operation of the engine. The same reasons recommend a bilateral support for to the chamber rotors e.g., in slide bearings separately mounted in ports of the crankcase of the engine.

Having in mind the hereinbefore mentioned reasons, the crankcase of the engine is preferably designed as a one-part-member which provides its great advantage. In the embodiments disclosed by way of example, it is technologically extremely simple and accommodated to large-scale production. The cylindrical seats of the chamber rotors have a constant diameter along the whole width of the crankcase and may be made out of one piece jointly with the cylindrical seat of the piston rotor. The cooling of the crankcase may be effected by air or by fluid, according to the purpose of the engine. The latter cooling method is more convenient to traction applications. When a high unit power of the engine is required, viz. if it is necessary to receive a great quantity of heat for a small size of the engine, a fluid cooling system is closed circulation with evaporation is provided.

Gap, labyrinth and opening seals of the working chambers of the engine are used for several reasons. It is intended to increase the highest rotational limit of the engine, and consequently its unit power , and above all to decrease considerably the sliding friction while distinctly improving the mechanical efficiency of the engine. Seals of such a type do not require intensive lubrication, whereby the oil consumption is considerably reduced. Burning of lubrication oil is also reduced and consequently, no intensive carbon deposit formation occurs whereby purer combustion gases are obtained.

The effectiveness of the seals of this type becomes sufficient on account of the hereinabove already partly mentioned properties of the novel engine, viz.: not too high and symmetrical heat loading of fundamental elements of the engine, simple rotational movement of its rotor at small considerable rotational speed, low and short lasting pressure differential on both sides of the piston, and relatively small or, in some cases, no mechanical load from gaseous forces and inertia.

In some applications it becomes advisable to use sliding seals. This mainly pertains to cases where the rotational speed of the piston rotor must be relatively low, and consequently also to engines in which the Diesel cycle is employed.

The device for infinitely variable adjustment of the compression ratio has been designed with the intention of making a research version of the engine or for cases where different types of fuel is required.

Generally taking, the rotary internal combustion engine in its construction is provided with e.g., a four-piston-rotor and four three-chamber-rotors and has, in comparison with other engines of this type, -- a series of advantages. Above all it is characterized by an exceptionally simple and very compact construction and small dimensions. Its unit power, at a rotational speed of 10,000 r.p.m., may be 400 - 800 B.H.P./l. A conveniently designed and properly made engine of this type will have a high overall efficiency rate of the order of 0.4 - 0.5 and a low fuel consumption -- within the limits of: 0.12 - 1.16 kg/BHP hour. The rotational speed range about: 3,000 - 20,000 r.p.m. -- without seals of the sliding type, and with sliding type seals: 500 - 8,000 r.p.m. Output range: 10 - 10,000 HP. The engine is characterized by a quiet and uniform run, and a high operating reliability. Moreover, the engine will have good driving properties, viz. such features as: easy starting and stopping, relatively advantageous traction performance, easy acceleration and deceleration. The engine is characterized by a large range of power and torque control due to the possibility of disengaging any of its chamber rotors. A feature of this engine lies also in the fact that it can be supplied with light fuel or natural gas, or it may easily be constructed for multifuel use. Finally, the engine is characterized not only by relatively low production costs -- due to its simple and technological construction, but above all by low operating costs. In the disclosed embodiment, a running-in period is unnecessary. The life of the engine is many times longer in comparison with that of other known rotary engines. Overhauls are practically unnecessary

The engine of the invention is shown by way of examples in the following descriptions in conjunction with the drawings in which the individual Figures represent:

FIG. 1 - a longitudinal section of the engine with a four-piston-rotor and four three-chamber rotors, the section being taken along the line B -- B in FIG. 2;

FIG. 2 - a cross-sectional view of the engine of FIG. 1, the section being taken along the line A -- A in FIG. 1;

FIG. 3 - a longitudinal section along the axis of symmetry of the engine shown without the transmission gear for decreasing the rotations, and provided with a device for infinitely variable adjustment of the compression ratio;

FIG. 4 - a cross-sectional view of a three-chamber -rotor of the engine of FIG. 3;

FIG. 5 - a cross-sectional view of the engine with a two-piston-rotor and one single-chamber rotor;

FIG. 6 - a cross-sectional view of the engine with a two-piston rotor and two single-chamber rotors;

FIG. 7 - a cross-sectional view of the engine with a two-piston rotor and three single-chamber rotors;

FIG. 8 - the cross-sectional view of the engine with a four-piston rotor and three three-chamber rotors;

FIG. 9 - a cross-sectional view of the engine with a four-piston rotor and four three-chamber rotors;

FIG. 10 - a cross-sectional view of the engine with a four-piston rotor and five three-chamber rotors;

FIG. 11 - a radial seal for the pistons and the frontal seal of the piston rotor;

FIG. 12 - showing seals for the cylindrical surfaces of the rotors; and

FIG. 13 - seals for the frontal surfaces of the chamber rotors and seals for the pistons along the edges of the combustion chambers.

The rotary internal combustion engine according to the invention in an embodiment provided e.g., with a four-piston rotor and four three-chamber rotors as shown in FIGS. 1 and 2 - is constructed as hereinafter described. In the central part of a crankcase 1 there is a four-piston rotor 2, and around it there are disposed four three-chamber rotors 3 which are kinematically coupled with the rotor 2 by means of a gear wheel 4 and four gear wheels 5. The internal surface of the crankcase 1 is formed by five interpenetrating, parallel extending circular cylinders of different size, the largest, central circular cylinder being the seat 6 of the four-piston rotor 2, while the remaining four circular cylinders are the seats 7 of the three-chamber rotors 3.

The four-chamber rotor 2 which on the cylindrical surface thereof is provided with two suction-exhaust pistons 8 and two power-compression pistons 9, and on the frontal surfaces with cover plates 10 and 11, is cantilever-like mounted in the bearings 12 and in the bearing 13 in the crankcase 1. The pistons 8 and 9 are mounted in a dovetail manner in the four-piston rotor 2 and are designed so that in a plane which is perpendicular to the axis of said rotor, the profile of their frontal and rear surfaces, in relation to the direction of movement of the pistons is epicycloidal, whereas the profile of the outer surface of the pistons which lies on the opposite side of the lock, is a circular one having conveniently shaped grooves forming the seal 14. In the rear surface of each suction-exhaust piston 8 there is the outlet for the suction passage 15. These passages lead to a common central inlet 16 in the four-piston rotor 2. At the front surface of each of the said pistons 8, and in the frontal cover plate 10 of the four-piston rotor 2 there is provided the combustion gases outlet passage 17 leading to the annular collector 18 in the crankcase 1.

The two power-compression pistons 9 are equipped with glow or spark plugs 19, the axes of which extend parallel to the axis of the four-piston rotor 2. In the frontal cover plates 10 and 11 of the four-piston rotor 2 there are provided labyrinth seals 20 and 21. At the front part thereof, this rotor is equipped with a labyrinth seal 22, whereas at its rear end, with a sliding seal 23. On the side of the central inlet 16 the four-piston rotor 2 is closed by means of a ring-shaped insert 24. The three-chamber rotors 3 are provided in their cylindrical surfaces with three identical combustion chambers 25. Each of these chambers has, in the plane perpendicular to the axes of the multi-chamber rotors 3, a profile which is a combination of e.g., a semicircle and two sections of a straight line, and which is conformed to the shape of the pistons 8 and 9 in such a manner that when cooperating with the pistons, the two edges of each combustion chamber 25 slide along corresponding surfaces, i.e. the front surface and rear surface of the pistons 8 and 9.

All of the three-chamber rotors 3 are supported on both ends through the intermediary of the pins 26 and 27 in slide bearings 28 and 29. These bearings are enabled to be set in a suitable axial position allowing the three-chamber rotors 3 to be tightly closed on the frontal surfaces.

Each three-chamber rotor 3 may be provided with a device for controlling the compression ratio as shown in the embodiment of the engine in FIGS. 3 and 4. This device comprises inserts 30 of lenticular cross-section, elements 31 integrating these inserts, and sleeves 32 mounted on the pins 26. These pins are provided with oblong cavities 33 constituting an extension of the combustion chambers 25. The inserts 30 are tightly fitted to the said cavities 33 and holes 34 in the elements 31, and also to the internal surfaces of the sleeves 32. The inserts 30 are shiftable in the axial direction of the chamber rotors 3 through the intermediary of the bearings 35.

In the cylindrical surfaces of the three-chamber rotors 3, there are provided, besides the combustion chambers 25 also the oblong grooves of the labyrinth seal 36. In the crankcase 1 between the three-chamber rotors 3 there are provided suitable passages 37 and 38 connecting the cylindrical seats 7 of the three-chamber rotors 3 to the cylindrical seat 6 of the four-piston rotor 2. These passages are designed for equalizing the pressures between the cooperative working spaces 39 and combustion chambers 25.

In the crankcase 1 there are also provided four passages 40 for carrying the residual combustion gases and the scavenging air out of the corresponding combustion chambers 25. In the circumferential part of the crankcase 1 there are also located four fuel injectors 41, and from the central inlet 16 in the front part of the said crankcase there extends the ignition control device 42. This device is equipped with a commutator 43 connected by means of a jack shaft 44 to the four-piston rotor 2, the casing 45 of the commutator together with carbon brushes adapted to be set in a convenient angular position.

The gears 5 of four three-chamber rotors 3 are rotatably mounted on pins 27 and are pressed down by nuts 47 against the frontal surfaces of the straps 48 which are mounted on the key 49. These gears are angularly locked in relation to the straps by means of set screws 50. The crackcase 1 of the engine, which is formed by a single piece, is cooled by a fluid and shaped so that the cylindrical seats 7 under the three-chamber chamber rotors 3 are made with a constant diameter, as port holes in this crankcase and in the ring-shaped insert 24 which closes the cylindrical seat 6 containing the four-piston rotor 2. The space 51 of the crankcase 1 including the gear 4 and four gears 5 is closed by means of a frontal cover 52 in which the bearings 13 and seal 53 are arranged. In this space there may also be the gear 55 with internal indentation, coupled simultaneously with all gears 5 of the three-chamber rotors 3 and mounted on the transmission shaft 56. The latter is rotationally mounted on the shaft 57 of the four-piston rotor 2 by means of bearings 58 and is sealed in relation to the shaft 56 with the aid of seal 59.

In the frontal cover 52 there are provided the outlets of the drives of such devices as: starter, injection device, oil pump, water pump, fan or possibly also the ignition device. The fittings of the engine are driven by a gear 60 made in conjunction with the transmission shaft of the engine and gears 61.

The construction of other embodiments of the rotary internal combustion engine, FIGS. 5 - 10, is similar to that described above. Differences in the construction relate only to the number of pistons 8 and 9 of the chamber rotor 2, to the number of chamber rotor 3 and combustion chambers 25 with which the rotors are equipped, to the ratio of the diameters of the chamber rotors 3 and of the piston rotor 2, to the size of the suction passages 15 exhaust passages 17, and to the number of fuel injectors 41, and to the number of glow or spark plugs 19 etc.

The construction of the engine with sliding leak seals, FIGS. 11 - 13, does not require any detail description. Radial seals for the pistons 8 and 9, or only for the pistons 9, are composed of one, two or more flat inserts 62 which are seated in grooves formed along the tops of the pistons. The length of the inserts 62 is greater than the width of the piston rotor 2.

The frontal seals of the piston rotor 2 are composed of sliding rings 63, located in grooves made about the circumference of the frontal cover plates 11 and 12 of the rotor. The seals of the cylindrical surfaces of the rotors are formed by flat packing pieces 64 which are seated in grooves formed along the generating lines of the cylindrical surface of the piston rotor 2. The length of the packing pieces 64 is greater than the width of the piston rotor 2, and the ends of the packing pieces are seated in openings made in the frontal cover plates 10 and 11 of the rotor 2.

The seals of the pistons 8 and 9, particularly those of pistons 9 with the edges or surfaces of chambers 25, referring to FIGS. 4 and 13 of the drawings, include yawing inserts 65 located within each combustion chamber 25. The yawing inserts 65 each include projections or lug portions, as shown in FIG. 13, adapted to extend into and be fastened with a plurality of flat cavities or recesses 68. The yawing inserts are designed in a manner whereby the centrifugal force generated upon rotation of chamber rotors 3 deflects their edges cooperating with the pistons 8 and 9 outwards from the pistons, while a suitably high pressure in the combustion chambers 25 causes the yawing inserts 65 to be pressed towards the pistons 8 and 9.

Similarly, the frontal seals of the chamber rotors 3 are formed by elastic circumferential radial seals 66 which have projections adapted to be positioned in a plurality of recesses or flat cavities 67 formed in the frontal srufaces of the chamber rotors 3, and seated on their pins 26 and 27.

In the chamber rotors 3, and possibly in the piston rotor 2 there may additionally be provided passages 69 which are designed for cooling of the rotors by means of oil supplied under suitable pressure.

The performance of the rotary internal combustion engine results from the description of the embodiments stated by way of example. In all embodiments, the turn of the piston rotor 2 brings about that all working spaces 39 of the engine from the rear side of the pistons 8 and 9 become larger, while the spaces from the front side of said pistons become smaller. Due to this fact, through the central inlet 16, air is sucked in which when flowing then through the suction passages 15 will be slightly compressed and forced into the working spaces situated on the rear side of the suction-exhaust pistons 8. At the same time, the front side of the pistons 8 pushes out the combustion gases which have earlier been expanded by the power-compression pistons 9. These combustion gases escape through the passages 17 in the frontal cover plate 10 of the piston rotor 2 into the annular collector 18 from which they pass through the passages 70 outwardly to the atmosphere.

The air sucked into the working spaces is then compressed by the power-compression pistons 9. Towards the end of the compression, before the pistons 9 will plunge into the corresponding combustion chambers 25 of the chamber rotors 3, the fuel is injected by the injectors 41. Then, when the pistons 9 are entirely plunged into the combustion chambers 25, ignition takes place due to the glow or spark plugs 19 seated in the pistons 9. The high pressure of the combustion gases acting on the rear side of each of the pistons 9 forces the piston rotor to turn, whereby the working spaces on the rear side of the pistons 9 are increased and the combustion gases expand. At the same time, the front side of these power-compression pistons 9 are compressing the air earlier sucked-in by the suction-exhaust pistons 8. All working cycles occur in the engine simultaneously and also in all working spaces 39. The action of the engine is thus extremely harmonized. In all working spaces 39 the suction-exhaust pistons 8 suck the air by their rear side, and simultaneously, they push out by their front side the earlier expanded combustion gases, while the power compression pistons 9 take over by their rear side the reaction of the combustion gases and simultaneously they are compressing by their front side the earlier sucked air. The suction, compression, expansion and exhaustion process occurs continuously and lasts for one-fourth of a turn of the piston rotor 2.

The working spaces located on both sides of each piston 8 and 9 are separated at every moment by the labyrinth seal 14 of the external side of the piston, which seal is sliding along the inner surface of the seat 6 of the piston rotor 2, or by one of the generating lines of the combustion chamber 25 of the chamber rotors 3, which generating line is sliding along the back or front surface of the pistons 8 and 9.

The engine acts as a four-stroke one. To two turns of a four-piston rotor, 16 full four-stroke cycles accrue, whereby the action of this engine can be compared -- as far as the working cycle frequency is concerned -- with the action of a 16-cylinder-four stroke engine. The pulsation of the torque is comparable with that of an eight-cylinder four-stroke engine. During the two turns of a four-piston rotor there occurs a quadruple utilization of the working volume of the engine, whereby it is comparable -- as far as the working volume is concerned -- with a four-stroke piston engine having a four times greater swept volume. The action of less essential elements of the engine results directly from the drawings and description of the construction.

The action of an engine having a two-piston rotor 2 and one single-chambered rotor 3, FIG. 5, is similar to the action of a one-cylinder four-stroke engine. The utilization frequency of the working volume during one turn of a two-piston rotor 2 amounts to one-half.

The action of an engine having a two-piston rotor 2 and two single-chambered rotors 3, FIG. 6, corresponds to the action of a two-cylinder four-stroke engine with cranks shifted every 180.degree.. Utilization frequency of the working volume: 1 pro one turn of a two-piston rotor 2.

The action of an engine having a two-piston rotor 2 and three single-chamber rotors 3, FIG. 7, corresponds to the action of a three-cylinder four-stroke engine with cranks shifted every 120.degree. with the difference that the suction and exhaust cycle is shifted by 60.degree. in relation to the work and compression cycle. Utilization frequency of the working volume: three-seconds pro one turn of a two-piston rotor 2.

The action of an engine having a four-piston rotor 2 and three three-chambered rotors 3, FIG. 8, is similar -- as far as the frequency of working cycles is concerned -- to the action of a 12-cylinder four stroke engine with cranks shifted every 60.degree.. Utilization frequency of the working volume: three-seconds - pro one turn of a four-piston rotor 2.

The action of an engine having a four-piston rotor 2 and four rotors 3, FIG. 9, is hereinbefore described: analogy to a sixteen cylinder four-stroke engine with cranks shifted every 90.degree.. Utilization frequency of the working volume: 2 - pro one turn of a four-piston rotor 2.

The action of an engine having a four-piston rotor 2 and five three-chambered rotors 3, FIG. 10, corresponds to the action of a 20-cylinder four-stroke engine with cranks shifted every 36.degree. with the difference that the suction and exhaust cycle is shifted by 18.degree. in relation to the working and compression cycle. Utilization frequency of the working volume: five-seconds - pro one turn of the four-piston rotor 2.

The action of an engine provided with sliding seals, FIGS. 11 -13, does not require a separate description.

The described embodiments, given by way of example, of the rotary internal combustion engine according to the invention do not comprise, of course, all the possible details and modifications of the solution, which might still develop the essence of the invention.

The rotary internal combustion engine according to the invention may e.g., act as a self-driven rotary internal combustion compressor. In such a case it is of advantage using to this purpose e.g., an engine provided with a four-piston rotor and four three-chambered rotors, two of which, facing each other, being chambered rotors of the rotary compressor, while the other two -- chambered rotors of a rotary internal combustion engine.

The rotary internal combustion engine according to the invention may also be used as a blower, compressor or pump, and also as a hydraulic, steam or gas engine. In such cases the piston rotor of the given device is equipped on the circumference solely with pistons provided with inlet and outlet passages. The action of such a device does not require a separate description. It is only to be mentioned that the direction of rotation of the piston rotor for the application of the device as a blower, compressor or pump, is reverse to that when the device is used as a hydraulic, steam or gas engine. The direction of flow of the working medium is for the above-mentioned applications also reverse.

Claims

What I claim is:

1. A rotary internal combustion engine comprising:

a housing having a central cylindrical seat seated in a principal axis of symmetry of said housing and at least one peripheral cylindrical seat located in parallel to said central seat, the spacing of said seats being determined so that their generating surfaces penetrate one another within the housing;

a piston rotor coaxially rotatably mounted in said central seat of the housing, two frontal cover plates fixed to end faces of said rotor and being provided on the circumference thereof with at least one pair of pistons, one of the pistons of said pair forming a suction-exhaust piston sucking in air with a rear face thereof and simultaneously exhausting expanded combustion gases with a front face thereof, the other of the pistons of said pair forming a power-compression piston exposed at a rear face thereof to the action of the expanding gases while a front face of said piston compresses the sucked-in air;

at least one chambered rotor rotatably mounted in said peripheral seats of the housing and being adapted for co-operation with said piston rotor, each said chambered rotor having on its circumference at least one combustion chamber adapted to receive said pistons of the piston rotor and dimensioned to provide a close dimensional tolerance during operative co-operation of said elements, so as to form forwardly and rearwardly of said pistons, and within said combustion chambers, working chambers of the engine;

a gear transmission synchronizing the rotary motion of said rotors and comprising a gear wheel of said piston rotor and gear wheels of said chambered rotors operatively, engaged therewith;

at least one inlet passage disposed in said piston rotor and extending from an air inlet through said rear faces of the suction-exhaust pistons, with said passages the air is sucked into all said working chambers being formed behind said rear faces of the suction-exhaust pistons;

at least one outlet passage disposed in at least one of said cover plates of the piston rotor and partially in said front faces of the suction-exhaust pistons, said passages providing for exhaustion of the combustion gases from all of said working chambers being formed before said front faces of the suction-exhaust pistons;

at least one annular collector located in said housing to which said outlet passages are connected, and at least one exhaust passage extending from said collector, whereby the combustion gases flow into said annular collector and then flow out of said collector toward the exterior of the engine;

at least one fuel injector mounted in said housing, said injector during of the compression cycles supplying fuel into said working chambers being formed before the front faces of the power-compression pistons; and

at least one ignition plug mounted in each said power-compression piston, said plugs ignite the air-fuel mixture at the right moment during of the immersion of each power-compression piston in said combustion chambers of the chambered rotors.

2. A rotary internal combustion engine according to claim 1, a central inlet for the air being located in the principal axis of symmetry of said housing and of said piston rotor, said inlet being connected with said inlet passages.

3. A rotary internal combustion engine according to claim 1, said suction-exhaust pistons and said power-compression pistons being approximately of the same outer shapes, the front and rear face of each said piston in its principal cross-section forming an epicycloid, and the lateral, circumferential surface of each said piston having a profile conforming to the central seat of said piston rotor.

4. A rotary internal combustion engine according to claim 1, the shape of each said combustion chamber of each chambered rotor in its principal cross-section being a combination of an arc of a circle and two sections of a straight line, each said chamber having two edges of which the distance is conformed to the thickness of said pistons so as to obtain the required close dimensional tolerance during operative co-operation of said elements.

5. A rotary internal combustion engine according to claim 1, the number of said combustion chambers of each of said chambered rotor being an odd number.

6. A rotary internal combustion engine according to claim 1, the number of said chambered rotors being equal to the sum of all said pistons of the piston rotor.

7. A rotary internal combustion engine according to claim 1, the number of said chamber rotors being lower by one than the sum of all said pistons of the piston rotor.

8. A rotary internal combustion engine according to claim 1, the number of said chambered rotors being higher by one than the sume of all said pistons of the piston rotor.

9. A rotary internal combustion engine according to claim 1, in said housing having passages extending from each said peripheral seat of the chambered rotor to said central seat of the piston rotor in the proximity of penetrating edges of said seats, so as to provide for the equalization of the pressures between the working chamber of the engine.

10. A rotary internal combustion engine according to claim 1, said housing having closeable passages connecting said peripheral seats of the chambered rotors to atmosphere, said passages being located in portions of the housing at the remotest distance from the principal axis of symmetry of the housing, said passages providing for escape of the remainder of combustion gases and scavenging air.

11. A rotary internal combustion engine according to claim 1, said ignition plugs being positioned within said power-compression pistons and extending parallel to the principal axis of the piston rotor.

12. A rotary internal combustion engine according to claim 1, said fuel injectors being mounted on the circumference of said housing proximate before each said chambered rotor in relation to the direction of rotation of said piston rotor.

13. A rotary internal combustion engine according to claim 1, comprising, in the front part of said housing in its principal axis of symmetry, an ignition control device having a commutator connected by a jack shaft to said piston rotor, said commutator having a casing with carbon brushes adapted to be set in predetermined angular positions.

14. A rotary internal combustion engine according to claim 1, each said gear wheel of the chambered rotor being mounted on a neck of said rotor so as to enable it to be set in a predetermined angular position, said gear wheel being pressed by a nut against a frontal surface of a stationary flanged sleeve, said sleeve being mounted by a key on said neck, and said gear wheel being angularly restrained in relation to said sleeve.

15. A rotary internal combustion engine according to claim 1, comprising a driving shaft rotatably mounted in the principal axis of symmetry of said housing and being kinematically coupled with said piston rotor by means of an internal gear and said gear wheels of the chambered rotors, said internal gear being swingably connected to said driving shaft and engaging simultaneously all said gear wheels of the piston rotors, so as to eliminate clearances in said gear transmission synchronizing the rotors, the rotational speed of said driving shaft of the engine being considerably lower than the rotational speed of said piston rotor.

16. A rotary internal combustion engine according to claim 1, said piston rotor being cantilever-mounted in rolling bearings and closed within said central seat on the side of said central inlet by a ring-shaped insert, said chambered rotors being supported on both sides through necks in removable sliding bearings set in predetermined axial positions, said piston rotor and said chambered rotors being closed on both sides at required axial clearances.

17. A rotary internal combustion engine according to claim 1, said housing being of unitary structure and adapted to be cooled with a cooling medium, each said peripheral seat of the chambered rotors having a constant diameter extending through said housing.

18. A rotary internal combustion engine according to claim 1, said two frontal cover plates of the piston rotors having in their outer faces circumferential grooves forming a labyrinth seal, and the cylindrical surfaces of all of said rotors having labyrinth seal grooves extending parallel to the axes of said rotors, the frontal surfaces of said chambered rotors having flat cavities forming multidirectional labyrinth seals.

19. A rotary internal combustion engine according to claim 1, each said chambered rotor having a compression ratio control device comprising: slidable inserts of lenticular cross-section of which the number is equal to the number of said combustion chambers, an element integrating said inserts, a sleeve fixed on a neck of said chambered rotor, oblong cavities in said neck forming an extension of said combustion chambers, a bearing for shifting said inserts by means of said element in the axial direction of said combustion chambers, said inserts being tightly fitted within said oblong cavities in said neck and the inner surface of said sleeve fixed on the neck.

20. A rotary internal combustion engine according to claim 1, said pistons of the piston rotor having radial sliding seals composed of at least one flat insert and at least one groove formed along the top of said pistons for receiving said inserts, the length of said inserts being greater than the width of the piston rotor, whereby the two ends of each of said inserts slide during the turn of the piston rotor along the inner circumferential surface of said central seat in the housing.

21. A rotary internal combustion engine according to claim 1, each of said two frontal cover plates of the piston rotor being provided with at least one circumferential groove having therein elastic slidable rings movable during the turn of the piston rotor along the inner frontal surfaces of the housing.

22. A rotary internal combustion engine according to claim 1, said piston rotor being provided with flat inserts seated in grooves formed along the generating lines of the cylindrical surface of said rotor, said inserts being pressed by centrifugal force into the cylindrical surfaces of said chambered rotors, the length of said inserts being greater than the width of the piston rotor, and the ends of said inserts being mounted in blind openings made in the inner faces of said two frontal cover plates of the piston rotor.

23. A rotary internal combustion engine according to claim 1, each of said chambered rotors being provided interiorly of its combustion chambers with yawing inserts which, under the influence of pressure of gases within said chambers, are pressed against the front and rear faces of said power-compression pistons of the piston rotor.

24. A rotary internal combustion engine according to claim 1, each said chambered rotor including elastic frontal seals extending into circumferential and radial grooves made in frontal surfaces of said rotors, said seals being mounted on necks of the chambered rotors.

25. A rotary internal combustion engine according to claim 1, said chambered rotors having inside passages adapted to facilitate cooling of said rotors by a cooling medium.

26. A rotary internal combustion engine according to claim 1, fuel burning occurring in only selected of said chambered rotors, so as to enable the engine to operate as a self-driving rotary internal combustion compressor.