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Title:
A ROTARY FOUR STROKE INTERNAL COMBUSTION ENGINE
Document Type and Number:
WIPO Patent Application WO/2016/092379
Kind Code:
A1
Abstract:
A rotary internal combustion engine in which the cylinder is divided into four segments by the vanes which are mounted on two shafts, two on each shaft opposing each other in such a way that when one shaft slides inside the other the vanes form a variable letter X which performs a scissors' like action to perform the four strokes.A cam attached to the same shaft as the vane which in turn is held stationary by a device performing a ratchet action which allows it to only go forward. In turn it hold back the vane from continuing to go forward whilst compression is taking place keeping it stationary until the exact compression ratio is reached. The cams co-ordinate the actions of the vanes ensuring that their successive and alternate actions are carried out as they should. The energy created inside the cylinder is led out to the fly-wheel via the two shafts and thence to the differential and finally to the flywheel.

Inventors:
PORTELLI JOSEPH (MT)
Application Number:
PCT/IB2015/050071
Publication Date:
June 16, 2016
Filing Date:
January 05, 2015
Export Citation:
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Assignee:
PORTELLI JOSEPH (MT)
International Classes:
F02B55/14; F01C1/063
Domestic Patent References:
WO1995034750A11995-12-21
WO2011050571A12011-05-05
WO2011035789A22011-03-31
Foreign References:
GB412006A1934-06-21
GB106386A1917-05-24
US4279577A1981-07-21
US20030138337A12003-07-24
US5727518A1998-03-17
US3909162A1975-09-30
EP0215194A11987-03-25
Other References:
None
Download PDF:
Claims:
Claims ( 6 in number)

i] The engine works without the use of a crankshaft/s and connecting rods attached to the piston in this case called a vane The result is a lighter, smaller engine with fewer parts than it would otherwise be. It is therefore more efficient and less trouble prone. ii] It employs a totally new device instead of con-rods and crankshaft to coordinate the movement and stroke sequence of the vanes. The device consists of two cam wheels with appropriate lobes, mounted on the two straight output shafts. The cams are controlled by a ratchet device.

iii] The cylinder is perfectly spherical to permit the use of semi circular vanes to provide maximum volume from a given area.

iv] The vanes are semi-circular lengthwise, V shaped and hollow for lightness, better heat dissipation and to make sealing easier.

v] A specially designed fly-wheel which incorporates a differential system of gears for space saving and reduced weight.

vi] Specially designed differential gear system to combine the alternate movement of the vanes to produce smooth continuous rotation with specially cut planetary gears to lock the system when the desired compression ratio is reached.

AMENDED CLAIMS

received by the International Bureau on 28 Octobre 2015 (28.10.2015)

1 I claim a New Type of Rotary Four Stroke Internal Combustion Engine which comprises a perfectly spherical chamber supporting in the middle two concentric shafts which exit two from one end which is the front and one from the back of the sphere, which shafts have the same outer diameter from a point midway along the axis of the chamber, on which four half-moon shaped vanes are fitted lengthwise two on each shaft diametrically opposite, each one half lying and free to move on the other shaft . The vanes and their shafts when fitted together can move alternately within the chamber so that if one pair is held and the other moves a figure X (scissors shape) is formed creating four spaces corresponding clock-wise from the top to the four strokes of the Otto engine that is 'expansion' 'exhaust' 'intake' and 'compression' with appropriately spaced ports provided on the chamber. The engine uses no valves and/or ancillary parts for any of the strokes. The vanes' movements are controlled by two cams each having two lobes on opposite sides, the leading one being twice as tall as the other, said cams being fixed one on each shaft just outside the chamber each with its own follower which is appropriately shaped to be able to both hold and release the cam (and vane) when it is being forced forward (during compression; see left side of X) or pushed backwards (during expansion; see right side of X) respectively. The followers which are above the cams are connected to each other on a single shaft which goes from front to back and so both move when one moves thus making it possible for one cam to lift its follower and be held by it by a ratchet action and release the held cam (and vane) on the other side which was being held by its shorter lobe, at practically the same time but the shorter lobe being released first whilst the follower is only half-way up. The two concentric shafts emerging from the front of the combustion chamber, the thinner slightly longer, each having a pair of vanes and one cam on it, have also a gear wheel (sun wheel) attached at their ends facing each other with two smaller gears (planetary gears) meshing with them so that a) when one sun gear moves the planetary gears trail behind at half the speed pulling with it the fly wheel to which the frame holding the said gears is attached , and b) when the sun gears move together the planetary gears stop moving along the sun wheels and move with them at the same rate. The fly wheel is free to move on the extreme end of the thinner shaft. The work of this differential arrangement is firstly to integrate the alternate movements of the vanes to produce smooth continuous rotation in a robust and reliable manner and secondly to make it impossible for the vanes to collide at any time by locking at the critical moment, stopping all individual movements whilst keeping the whole assembly i.e vanes, cams differential / fly wheel turning. Without this safeguard the engine and others similar to it will self destruct in a very short time. The combustion chamber and all above- mentioned parts are housed within the outer shell of the engine.

When the engine is turned over all vanes start moving until the leading vane's cam is held by its shorter lobe by its follower whilst the other cam and vanes go on moving until the vane immediately behind the held vane comes as close to it as the differential allows, the vanes now forming an X beneath the sparking mechanism. The differential is locked.

Just before ignition takes place the cam of top left vane (see X) is being held from moving backward by its taller lobe following a ratchet action from its follower, whilst the cam of the right vane (see x) which was held is freed by the same action when said follower is still only half way up. This causes a slight delay to ensure that the leading cam is fully free to move forward before ignition takes place. At this stage the sun gears change roles; it is now the turn of the gear which was being held to be free to move, the differential now being unlocked. Following ignition the moving vane expands the burning mixture behind it whilst pushing out the spent one in front, at the same time in-taking a fresh charge and compressing the previous one until the pressure built up exceeds that of expansion whereupon the 'held' vane is moved forward over a distance equal to that between the lobes of its cams, and stops when the short lobe comes against the same follower which was holding it from going backwards but the vanes continue to approach each other and squeezing the mixture further until just before colliding the differential 'locks' ( claim 7) and brings all movement of the cams and vanes and planetary gears to a stop relative to each other but still rotating driven by the momentum of the fly wheel until a new X is formed just beneath the sparking mechanism but with the position of the vanes now reversed. This last movement also reverses the order of which cam is held and which one is free as also that of the sun wheels making it possible for the planetary gears and fly-wheel to move; ignition may now take place.

The 'distance between the cams' lobes (line 51) is directly related to the angle formed by lines drawn from the centre of the shafts through the middle of the adjacent vanes when they are at the correct compression ratio which again is the angle formed by lines drawn from the centre of the shaft and the centres of the blank spaces on the sun wheels which hold the planetary gears when the differential is locked. 2 The engine claimed having an improved spherical engine chamber enabling the use of half moon shaped vanes on which circular rings rather than rectangular, can be fitted for better sealing.

3 The engine claimed having a box shaped outer housing or body which provides ample space around the spherical chamber within it where sufficient coolant can circulate to dissipate the heat generated by the four combustion strokes taking place in the same spot in every revolution. 4 The engine claimed having two specially shaped cams having four lobes each the leading ones resembling a quarter of a sign wave in shape and the others rectangular, two on opposite sides the leading lobe twice as high as the other, one cam to each set of vanes and on the same shaft, said cams being responsible for controlling the stop-go motions of the vanes, each cam doing the double job of releasing the leading vane to go forward following ignition, and holding it during compression. This action is essential whilst the engine is starting and during engine-braking.

S The engine claimed and one identical pair of improved cam followers so shaped as to be able to both 'hold' and release' the vanes, one for each cam, said followers being mounted on the ends of a common shaft which goes from the front of the chamber to the back; the two cams move together. Whilst a follower is lifted by the higher of the lobes of one cam it releases the cam on the other side which was held by its short lobe when said follower is still half-way up and very shortly after having reached the crest of the higher lobe of its own cam said follower springs back down and holds it from moving back. This slight delay ensures that the vanes are firmly in place before ignition takes place.

6 The engine claimed having four improved vanes which are half-moon or semi-circular in shape so as to fit the spherical shape of the engine chamber, said vanes are V shaped and have two grooves one on each edge wherein sealing rings can be fitted for optimum sealing, thus avoiding the more serious sealing problems encountered even by renowned innovative engines using rectangular vanes/pistons with sides vertical to the shaft's.

7 The improved vanes, rather than being flat and with poor compression ratios, are V shaped with convex sides to reduce the space between them whilst retaining the same base width so as to increase compression ratios and enhance ignition by forcing the gases upwards and closer to the sparking device; the vanes are hollow in the middle rather than solid to keep weight to a minimum whilst reducing inertial forces and heat build -up and retention. These vanes were specifically designed to enable high compression ratios and temperatures to be reached so as to meet European Emission Standards .

8 The engine claimed and an assembly comprising four bevel gears, two attached to the main shafts at their ends facing each other (sun gears) and two smaller gears (planetary) meshing with said gears at their periphery capable of rotating on shafts fixed to a frame attached to a fly-wheel which is mounted on the thinner of the two shafts but free of it, and said assembly acting like a differential/flywheel unit whose tasks are a) to combine the alternate stop -go motions of the vanes into seamless and continuous rotation in the most robust manner possible and b) to prevent collisions between the vanes. Without this safeguard most engines would suffer serious damage. These gears are capable of self- locking just before the moving vanes touch each other or collide at the end of the power/compression stroke and/or when the desired compression ratio is reached which action is accomplished when the planetary gears reach spaces on the sun wheels where a number of teeth are left uncut, and cannot proceed any further until a different sun gear takes over. Each sun wheel has four such spaces ninety degrees apart whose lengths determine how close the vanes can approach each other. This also enables the compression ratio to be accurately set. As the planetary gears always perform a quarter turn using a different sun wheel each time always on the same sector (translating into a half revolution of the vanes) the sun gears' lifetime can be doubled simply by moving the planetary gears to a fresh sector.

9 The engine claimed and all the individual parts considered holistically, which parts although sounding commonplace or 'deja-vu have been improved/ modified and or customised, some beyond recognition and some being made to do more than one task, add up to a novel and above all a credible rotary four stroke internal combustion engine which with its astonishingly few working parts which are easy and cheap to produce and a light compact and robust design, should make it attractive to industry and consumer alike not least because it could also meet European Emission and Pollution Standards.

Description:
A ROTARY FOUR STROKE INTERNAL COMBUSTION ENGINE

1 This machine was invented, designed and built with these specific aims: to surpass other types of internal combustion engines in efficiency power output and at the same time be smaller and simpler to build. These aims could not be achieved so long as a way was not found to eliminate the use of any form of crankshaft, connecting rods and valves and their ancillary parts in the engine. I consider the use of crankshafts to be to blame for internal combustion engines in current use to be relatively inefficient dirty heavy and bulky.

2 A way was found and a model of the engine was successfully built and although it runs on forced air, it proves beyond any doubt that the above objectives are not only feasible but results were better than expected.

DESCRIPTION OF THE INVENTION

3 The invention is a Rotary type of four stroke internal combustion engine; a list of the component parts is given at sheet 5. Below is a description of the parts and their functions. The main part is of course the outer shell housing the water jacket (if liquid cooled) surrounding the cylinder. The shape of the actual space (chamber) within which the pistons or vanes (hereinafter called vanes) move is a perfect sphere. (Diag 1)

Inside the cylinder it has two pairs of vanes mounted on two straight shafts one fitting partially inside the other. This is the assembly which converts the energy from the fuel into useful power via the vanes and the shafts. (Schem. Diag. 1 parts 10 to 13).

4 The moving parts ( the vanes and the shafts) inside the cylinder describe a perfect circle whilst carrying out the four strokes. These are 'intake', 'compression', 'combustion' and 'exhaust'; these are carried out successively as they rotate inside the cylinder. The engine does four power strokes per revolution.

'Intake' and 'exhaust are through ports in the cylinder. No valves or valve gear are employed.

5 The cylinder

The cylinder, viewed from the front is perfectly round and closed at both ends with outlets for the shaft (Diag. 2) centred on the horizontal axis. Viewed from the side, the cylinder looks like two half circles divided by a space which is taken up by the shaft (Diag. 1).

6 The shaft itself is made up of two separate pieces which fit together, one passing through the other to form a complete unit, and exit two from the front and only one from the rear of the cylinder. (Diags. l parts 10 &11). The former have splines at the ends where the gears forming part of a differential arrangement will go. A part on the shafts where they emerge from the chamber with a slot for a Woodruff key is reserved for the cam- wheels which are fitted just outside each end of the cylinder.

7 The Vanes (diag 2) Two vanes are attached to each shaft, one opposite the other such that each vane is half of its length on and attached to one shaft and the other half lying on the other shaft but not fixed. When viewed from the front the vanes form an X which can vary in shape to produce the 'strokes' (As shown in Diag 2, Section YY.

a) The shape of the vanes is semi -circular, their centre lying exactly on the vertical axis of the chamber viewed from the side; it is also the point where the shafts meet when fitted into each other. ( Diag 1 axis Y) ) The vanes are 'V shaped with a flat apex rounded to fit snugly on the shaft. The space inside the 'V is hollow all the way through; The top is partly bridged for strength and stiffness. This design was adopted a) for lightness b) to keep the centre of gravity and therefore centrifugal, inertial and lateral forces as close to the shaft axis as possible c) to assist cooling and d) to keep the holding bolts short.. Equally important however is that it permits the use of expanding semi-circular seals to obtain the best possible fit without the need of other parts. The flat parts where the free half of the vane slides on the other shaft will need flat seals aided by springs. The circular seals fit into grooves running along the edge of each side. c) From a machining and production aspect it offers fewer problems than say a toroidal shape, the same applies to the cylinder.

8 The shafts which exit from the front have gears (Diag. 1) affixed at their ends adjacent to and facing each other and meshing with two planetary gears (Diag. l parts 3 et. ) to form a differential arrangement. This is contained within a housing ( Diag.1 part 2 ) through which the two shafts pass but are not fixed to it. The planetary gears are mounted on opposite sides of the housing, facing each other meshing with the sun wheels. The differential locks when the compression ratio is reached, thus preventing the adjacent vanes from touching.

9 The housing (diag 1 part 2 ) is bolted on to the flywheel (diag 1 parti) to form one whole. The assembly is mounted on bearings on the longer (the inner one) and the outer shafts,; when one shaft rotates and the other remains stationary the 'sun' gear at its end, drives the planetary gear (Diagl.part.3) and this carries the complete housing and hence the fly wheel in a forward direction. The vane is held stationary by the cam till the exhaust port is exposed. The differential arrangement therefore combines the alternate power cycles of the vanes (and the shafts) to produce smooth unidirectional rotation assisted by the fly wheel / differential assembly.

10 The weight of the differential makes it possible to reduce the weight of the fly-wheel otherwise required. Their combined weight and momentum is sufficient to move the vanes and shafts during the final end of each cycle, when no power is being produced, to the point where the next one begins that is the ignition point. The vanes at this stage are close together having the fuel/air mixture compressed between them ready for ignition. Keeping one vane stationary during the expansion cycle ensures that as much energy as possible is extracted before the expanding gases are exhausted. This function is done by the cam-wheels (see para 12 ) This arrangement is very robust, simple and relatively light translating into more power. They take the place of the conventional crankshaft. The speed of the fly-wheel will obviously be half that of the vanes and shafts but the torque will be double. This offers two added advantages namely: a smaller, lighter final reduction gearbox and fewer parts. Shortly before the exhaust stroke, the planetary gears are designed to 'lock' the differential when the predetermined compression ratio is reached thus preventing the vanes from colliding or touching at any time. _The locking is achieved by specially designed planetary gears which have irregular teeth spacing. 11 Weighty and bulky synchronising gears, cranks, discs and relative counter weights are thus obviated and the function of co-ordinating the actions of the vanes (ie the four strokes) is done by the cam wheels (Diag.3 part 5) and their followers (Diag. 3 part 4) and the differential/flywheel (Diag. 1 parts 1&2). The energy, parts and space thus saved are considerable. Perhaps the greatest advantage from this arrangement is that the full expansionary forces from the explosions exert a linear, equal and opposite reaction on the 'driven' vane throughout the whole stroke which is not the case with some other methods employing cranks, elliptical gears and similar. The result is an enhanced linear output and a lesser overall weight.

12 The two cam wheels are securely mounted one on each shaft as they exit from the front and rear of the engine; they are perfectly round but have two pairs of two differently shaped lobes on opposite sides of the periphery. The distance between a pair, determine the beginning and end of each movement of the vanes as they are 'caught' and 'released' by two cam- followers (Diag.3 part 4 and diag.4 part 7 ) to perform each of the four strokes. These spring loaded followers, one to each cam are placed tangentially to the wheels with one end touching the wheel and the other fixed to a common shaft which goes through from the front to the back of the cylinder block. They are identical and move together. Their function is to catch and release the cams and hence the vanes at the proper time during the cycles. They do the function of the conventional crankshaft but with a big and important difference ( see para 10 ). In operation, the first lobe is caught by its follower in a 'ratchet' action and prevents the relative cam and vane from going backward following ignition, whilst the second, flat lobe, from going forward at time of compression. The flat lobe releases the vane to do the power stroke when the other cam is 'held' by the its follower from going backwards. This somewhat abrupt method of harnessing the power produced by the successive explosions is smoothed out firstly by the cushioning effect of compression and by employing a shock-absorbing device possibly inside the cam, like for example fitting a rubber core inside it or a torsion spring. Fine-tuning the timing of the ignition, precise positioning the exhaust port or a bit of everything will also help. The cam- wheels whose job as explained is essentially that of co-ordinating the movements of the vanes throughout the whole cycle can also be used to actuate the 'make-and break' device (mechanical or optical) of the spark/ ignition circuit. As explained, they are like the crankshaft in conventional engines, essential for the machine to complete all four strokes especially when starting from rest and to provide engine-braking but minus the drawbacks.

13 The engine as a whole is innovative in design; that is fairly evident from the unusual shape and nature of the component parts; but this in itself is not enough. The main feature to make it so is the absence of a crankshaft and its ancillary parts. Why does that make it so? The most obvious reason is that their functions could be said to have been replaced by a simple mechanism weighing only a very small fraction of their combined weight. Not so obvious is the considerable increase in the power output thanks to the way that the explosive power of the fuel is harnessed and transmitted without the losses which result from the use of crankshafts. These are inefficient by nature, weighty and not suitable for the job; they are responsible for the knocking and vibrations endured by the engines which have perforce to be very sturdily built and so require more space. They are totally unsuitable because they move slowest when the power applied to them is strongest (at top dead centre) and reach the 'optimum' position when the gases have cooled appreciably. This is explained by simple geometry and illustrated by a child playing with his hoop. To make it move forward he does not prod it with the stick from above knowing that if he did that the hoop will go nowhere except flat on the ground. He knows, that the most effective way is to push the hoop from behind. In my engine the vane is not pushed obliquely from above but sideways. The expanding gas. which exerts an equal and opposite pressure in all directions forces the containing vanes apart with the full force and whilst one is held stationary by the cam the other is pushed forward by the full explosive power of the gas which is at its peak potential energy. The whole of this energy applied to the vane at ninety degrees to its vertical axis, is totally converted into kinetic energy pushing the vane along its natural path and speed. This would not have been the case had it been connected to a crankshaft.

14 Power curves In the case of my engine, the torque will be at maximum at the beginning of the curve and declines naturally as the hot gas expands and losess heat;. In other words my engine starts each power stroke when the parts involved are at the best possible mechanical advantage and free to move;

The piston-con-rod crankshaft engine, on the other hand is at its worst possible position,, that is the top dead centre position. At this point the potential energy is at maximum but the piston is held or slowed down because it has to follow the crank.

The torque/ revolutions curve of crankshaft engines show that the torque starts at the bottom of the curve and increases with speed reaching the maximum half way along the curve and declines thereafter

The excellent torque of my engine especially at low revolutions coupled with its much lighter and smaller frame should make it ideally suited for most purposes.

15 From the above it is not hard to see why so relatively few parts were used in the

construction of this engine which albeit simple and small it could well prove to be more robust efficient and trouble free or even more so than its peers

Parts List

1 Flywheel

2 Differential Housing

3 Differential Bevel Gears

4 Cam Follower

5 Front Cam

6 Cam

7 Cam Follower

8 Cam Spring

9 Woodruff keyway

10 Hollow Drive shaft

11 Solid Drive shaft

12 Vanes

13 Rear Vanes

14 Compression Seal