GB2254373A

GB2254373A - Rotary cylinder i.c.engine,pump or compressor.

Info

Publication number: GB2254373A
Application number: GB9206575A
Authority: GB
Inventors: Ricardo Echarren-Uzabel
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-04-03
Filing date: 1992-03-26
Publication date: 1992-10-07
Also published as: FR2674903A1; IT1258258B; ITMI920805A1; DE4210712A1; JPH05106401A; ITMI920805A0; GB9206575D0

Description

2-254, D ROTARY MACHINE The present invention relates to a'rotary machine,

particularly of the type to be used as an internal combustion engine, compressor, vacuum pump or the like.

More particularly, the invention relates to a rotary machine specially suitable for the above mentioned uses and which, taking advantage of the known fluid compression and expansion effects inside variable volume chambers, is based on a novel operating principle which, when carried out with partial modifications of certain assembly accessories, allows its application to the above mentioned devices.

The operating principle on which the machine of the invention is based is that the variable volume chambers are formed, during rotation of the rotor, at radially inner regions of corresponding radial cylinders thereof, in which respective free pistons are slidably mounted, the strokes of the pistons being controlled by an outer hoop-like race, track, rim or felly, preferably of elliptical shape. Said chambers are connected by means of ports or channels to the central nucleus or core of said rotor in order to form inlet and outlet flows. Consequently, said pistons are free, i.e. they lack the conventional additional elements such as connecting rods, pins, etc., and they also do not require crankshafts and other mechanical means in order to connect them to the rotor shaft, since the rotor and its shaft are solidly linked together.

The basic functional features of the invention remain the same for any one of the earlier mentionod uses. Therefore, and in order to give a clear description of the invention, demonstrating at the same time the possibilities of the machine, it will be described on the basis of one of the more complex embodiments, i.e., as applied to an internal combustion engine. Obviously, this does not invalidate the possibility of using the invention in the earlier mentioned simpler applications, based on the same operating principle.

The results obtained by the novel constructional, constitutive and functional conception of the present invention have not been attained until now by any.of the known and patented rotary machines. When the invention is applied to internal combustion engines, a better powertoweight ratio is obtained, as well as higher thermodynamic yield and adaptability to various fuels. In addition, the way in which the gases are treated results in lower environmental pollution and also provides several advantages which will be apparent from the following description.

In one embodiment of this machine as applied to an internal combustion engine, the pistons reciprocate in succession, starting from a position of maximum proximity to the center or axis of the rotor (bottom-dead-centre).

The pistons slide radially outwardly and slidingly engage the track under the influence of centrifugal force during this induction stroke, thus creating an internal depression and drawing the air/fuel mixture successively into the associated cylinders through corr ' esponding ports from a stationary central tube concentric with the rotor. During the following compression stroke, as the rotor continues to rotate, the pistons are successively displaced radially inwardly by the track from a position of minimum proximity to the rotor axis (top-dead-centre).

After combustion has been initiated by ignition elements communicating with the variable volume combustion chambers at the radially inner ends of the cylinders, the radially outward expansion or power stroke is used to obtain the rotational movement of the rotor, due to the reaction of the piston against a relatively inclined region of the track which it slidably engages. During the following radially inward exhaust stroke, the central tube receives exhaust gases through exhaust ports from successive cylinders, the tube being internally partitioned to separate the exhaust gases from the inlet air/fuel mixture.

An optimum thermodynamic yield is obtained.because the fuel mixture flow is channelled through the engine center and enters the cylinders after a thermal exchange path that cools the nucleus or core and heats the inlet until a volumetric capacity loss is caused which is almost meaningless in an engine having such an advantageous power-to-weight ratio, especially when it takes place in front of a thermal yield, whose gain by inlet heating duplicates the cited loss (experiences at Shell Laboratories, England).

The induction through the rotor center allows centrifugation of the fuel mixture and a consequent reinforcement of the load, overcoming the effect known as the distribution "crossing" or the "ram-jet" effect, which cause the loss of unignited mixture.

Centrifugation attains a proper turbulence and gradually stratifies the charges, within the combustion chambers, wherein ignition ideally starts with a rich mixture next to the periphery, by means of two flame fronts propagating towards the poor mixture zone, obtaining effectively perfect combustion.

The frictional coefficient of the assembly is extremely low, which allows the dividing into zones of the lubricated parts.

Exhaus gases which are still burning when they reach the outlets of the exhaust conduits of the central tube, are incorporated into the cooling air current. Thus, the complete post-combustion of deleterious gases is assured due to the addition of this air, thus reducing the exhaust nitrogen gases almost to 60% since the gases are cooled immediately afterwards.

A preferred embodiment of the invention will now be described with reference to the attached drawings, in which:

Figure 1 is a schematic cross-section of a rotary machine to be used as an internal combustion engine, with its outer housing omitted; Figure 2 is a section along the line II-II in Figure 1, and including the outer housing; Figure 3 is a schematic perspective view of the rotor; Figure 4 is a perspective view of the central inlet/outlet tube, in accordance with one of the possible alternatives of the invention; and Figure 5 is composed of eight diagrams (I-VIII), similar to Figure 1, showing the positions in each eighth of a revolution of the rotor, in order to explain the operating cycle of the internal combustion engine.

In all figures the same reference numerals designate the same or equivalent parts..

As shown in Figures 1 and 2, the rotary machine embodying the invention includes a rotor 1 which is preferably generally cross-shaped, having four orthogonal and equal arms, as may be also seen from Figure 3, said rotor being integral with a drive or output shaft 2.

Rotor 1 has four cylindrical cavities or cylinders 3 radially located in opposed pairs, each being open at its radially outer end, and communicating at its radially inner end with the central portion of rotor 1 through a port 4.

Reciprocably mounted inside each cylindrica cavity 3 is a corresponding piston 5 provided with sealing or packing rings 6 of conventional type. Each of said pistons 5 has, at its radially outer end, a shoe, bearing or follower element 7 slidably contacting the inner surface of a preferably elliptical race, track or rim 8, which is rigidly attached to a housing 9 constituting the outer body of the machine. The rotor 1 is rotatably mounted in the housing 9 via appropriate bearings as shown in Figure 2.

Formed between each cylindrical cavity 3 and the inner face of its associated piston 5 is a variable-volume combustion chamber 3a, in which the conventional operating cycles or steps of an internal combustion engine are carried out, namely induction-compression-detonation/expansionexhaust.

Both side surfaces of the rotor 1 are provided with a plurality of fins 10 for dissipating heat. These fins also act as the blades of a centrifugal blower which, as the rotor rotates, produces an air stream by drawing air into the machine through openings in the end walls of the housing 9. The air is directed by internal baffles 12, flows around and thereby cools the rotor assembly, and the resultant hot air is discharged through one or more openings or slots 13 in the periphery of the housing 9, located generally in the rotational plane of the rotor. A collector or manifold may be provided externally of the housing 9 to direct the hot air stream towards any place desired.

Within the central, hollow cylindrical portion of the rotor is mounted a stationary tube 14 provided with openings 15 and 16 forming inlet and exhaust ports, respectively. The central tube is provided with an intermediate partition 17 as shown in Figure 4, having its end portions bent in opposite directions, so that the cavity within the tube 14 is divided into two inner, non-communicating chambers or ducts 18 and 19 which determine the inlet and exhaust paths, respectively. The central cylindrical portion of the rotor and the central tube thus coop(rate to form a rotary sleeve valve arrangement for sequentially charging and exhausting the combustion chambers 3a of the cylindrical cavities 3 via their associated ports 4 during rotation of the rotor. It is important to note that such inner sub-division of the tube 14, as well as the function provided thereby, may be replaced by other means separating the inlet and exhaust gas circuits. Therefore, the invention is not exclusively limited to the embodiment shown.

The combustion chamber 3a of each cylindrical cavity 3 is provided with one or more ignition elements, such as a spark-plug 20, as is known in the art of internal combustion engines.

Figure 5 shows, schematically, the different positions of one of the pistons as the rotor rotates through angular increments of 1/8 of a rotor revo.lution, forming the associated variable volume combustion chambers, which, in the example shown, accomplish the characteristic stages of a four-stroke cycle as hereinbelow described.

In diagram I, the piston 5 s at bottom-dead-center within the cylinder, i, e, most adjacent the rotor axis, and the port 4 of said cylinder is blocked and closed by the segment of the wall of the tube 14 separating the inlet and exhaust ports. The piston is urged and guided to this position within its cylinder by the track 8, because the shoe or bearing element 7 engages the track at one of the two points closest to the rotor axis, i.e. on the minor axis of the ellipse.

When the rotor rotates 1/8 of a revolution in the direction indicated by the arrow as shown in diagram II, the centrifugal force acting on the piston causes the piston to move radially outwardly from bottom-deadcenter within the cylinder, following the contour of the track 8, producing a depression or suction at port 4. In this angular position, the port 4 is not blocked anymore, but faces and communicates with the inlet port 15 of the central fixed tube 14, allowing the fuel/air mixture to enter the cylinder and continue to fill the variable volume chamber 3a until the maximum stroke of the piston is executed and the piston reaches the end of its induction stroke at top-dead-center as shown in diagram III, thus obtaining the maximum volume in chamber 3a, now completely filled by the fuel mixture. This is the induction cycle. Upon termination of this cycle, port 4 of the cylinder becomes closed by the wall of the tube 14.

Upon further rotation of the rotor, the track 8 drives piston 5 inwardly on its compression stroke to compress the fuel/air mixture, as shown in diagram IV, until reaching the minimum volume of the chamber corresponding to the type of fuel mixture used, as shown in diagram V. Ignition is then produced by the spark plug 20 and detonation consequently occurs,.which gives rise to the next expansion or power stroke and the resulting total combustion of the mixture. When detonation of the gas mixture takes place, the mixture expands, driving the piston 5 against the track or rim 8 as shown in diagram VI. Since the plane of the rim or track, where it is engaged by the shoe 7, is inclined relative to the piston axis, the rotor is turned or cammed in the direction of the arrow due to the effect of the reactional component exerted by shoe 7. This continues until the maximum extent of the outward stroke of the piston is reached which, as shown in diagram VII, coincides with the start of the overlap and communication between port 4 of the cylinder and exhaust port 16 of the central tube 14.

From this point, burnt gases are exhausted externally, expelled by the piston as the rotor executes the last quarter of its turn, from the position shown in diagram VII and though that shown in diagram VIII. During these periods, the port 4 of the cylinder faces and communicates with the port 16 of the central stationary tube 14, until piston 5 again reaches bottom-dead-center, as shown in diagram I.

It is to be noted that all the pistons of the rotor ef f ect the abovementioned cycle in a sequential and independent way.

Furthermore, the displacements or relationship between the various positions of the piston and the moment when overlap between the different ports starts at the beginning of the steps, as well as at the end thereof, are determined, along with the ignition advance or retard, by the theoretical and experimental development of the engine. These features are independent of the invention, since the basic operating concept is the same, irrespective of the timing or phase relationships between the components.

It is also important to note that the race,. rim or track 8 on which the shoes or heads of the pistons 5 rest may be made in such a way that it allows the maximum and minimum extents of the strokes of said pistons to be modified. Thus, the compression ratios may be changed, for example while the engine is running, and/or may be adjusted to suit different fuel grades without requiring additional Q modifications of the mechanical assembly. For this purpose, the race or track may be a strip of steel or other suitable flexible material.

Regarding the geommetrical shape or profile of the inner surface of the race or track 8, it is possible to introduce modifications with a view to obtaining a better thermodynamic yield, performance, efficiency or output of the assembly, although, in the exemplary embodiment, the race is elliptical in shape.

It is also to be noted that the exhaust of burnt gases may be carried out in different ways without affecting the basic characteristics of the invention. These gases may be exhausted through port 4 when it faces port 16 of the central tube 14, passing through the exhaust conduit 19 and out of the rotor 1 through passages 21. The passage 21 extend generally radially, and communicate with tubes 22 which extend towards the inner periphery of the ho.using 9 close to the opening or openings 13. Optionally, the ends of said tubes 22 may be tangential to the rotor in order to provide reaction forces, taking advantage of the amount of movement of the gases produced thereby.

Various modifications and/or improvements may be made without departing from the scope of the present invention as defined in the appended claims. For example the machine may incorporate dynamic balance elements, etc.

The fuel, as well as intake air, may be supplied to the cylinders via the ports 4 or equivalent. Alternatively, fuel may be directly or indirectly injected into the cylinders or combustion chambers 3a. Although described with reference to spark-ignition or petrol engines, it will be appreciated that the invention is also applicable to compression-ignition or diesel engines.

Claims

A rotary machine for use as an internal combustion engine, pump, compressor or the like, of the type comprising a rotor mounted within a housing and having a shaft projecting from the housing, wherein said rotor has a plurality of generally radial, cylindrical cavities in which corresponding free pistons are located, the strokes of which are limited by a non-circular, peripheral guide arrangement, secured to the housing, defining the intended end and intermediate positions for the pistons within their respective cylindrical cavities, each cylindrical cavity having, at its bottom a port for communication with inlet and outlet channels located at the central part of the rotor and fixed relative to said housing.
2. A machine as claimed in claim 2, wherein the inlet and outlet channels are provided inside a stationary tube fixed relative to the housing and extending concentrically into the rotor, said stationary tube having an internal partition that separates said channels.
3. A machine as claimed in claim 1 or 2, wherein said stationary tube has corresponding inlet and exhaust ports which successively face the ports in cylindrical cavities during rotation of the rotor.
4. A machine as claimed in claim 1, 2 or 3, wherein the outlet channel of the stationary tube communicates with one or more conduits or passages mounted on or provided in the rotor, which extend into associated, generally radially extending tubes secured thereto, located inside the housing.
5. A machine as claimed in claim 4, wherein the radially outer ends of the tubes are curved in a direction 1 tangential to the intended direction of rotation of said rotor.
6. A machine as claimed in any preceding claim, wherein the peripheral guide arrangement comprises a race, track or rim which is substantially elliptical in shape.
7. A machine as claimed in any preceding claim, wherein the rotor is provided with heat-dissipating fins or equivalent at least partially around each cylindrical cavity.
8. A machine as claimed in any preceding claim, wherein the housing has openings on both sides of the rotor defining inlet means for cooling air.
9. A machine as claimed in claim 8, including fixed plates or baffles within the housing for directing the cooling air.
10. A machine as claimed in any preceding claim, wherein the housing has at least one radial outlet opening for exhausting air from the housing and/or exhaust gases from the rotor.
11. A machine as claimed in any preceding claim, which comprises an internal combustion engine, wherein a variable-volume combustion chamber is defined between each piston and the radially inner end of its associated cylin drical cavity, and wherein, at leas ' t adjacent the radially inner end of each cylindrical cavity there is pro-vlided at least one ignition element such as a spark plug, and/or at least one injector or equivalent.
12. A machine as claimed in any preceding claim, wherein the shape of said guide arrangement is adjustable.
13. A machine as claimed in claim 12, wherein said guide arrangement comprises a hoop-like track made of a flexible material such as steel strip or the like.
14. A rotary machine, substantially as hereinbefore described with reference to the accompanying drawings.