RQTAKY ΩJTEFNAL CC-MBUSTICM KEVERSTB K CNE-aSTROKE ENGINE ϊhe present invention relates to an engine. Reciprocating internal cαribustion engines are susceptible to a nuπiber of problems. In particular, their reciprocation which in turn is converted into rotation causes wear and vibration problems. Their design necessitates the use of a crankshaft, and in slow-speed reciprocating piston engines developing high powers the use of crossheads, piston rods and connecting rods, which result in a bulky engine and may give rise to problems. They operate best on high quality expensive fuels and are inherently ill adapted to using a variety of fuels. Their geometrical design dictates a cycle of operation whereby, in the ta*o-strc_ke recip_x ^* cating piston engine, exhaust of the α_π_ustic ^* n gasses expanding in the working cylinder takes place v*ell before their crankshaft cαπpletes .one half revolution, i.e less than half the cycle duration, and by doing so the cc-ribustion gasses leave the cylinder before they have been given sufficient time to convert a large portion of their heat energy into useful πechanical work by sweeping as much volune as possible during the power stroke, thus resulting in a high percentage of exhaust gas losses and a relatively lew engine efficiency. In addition, they occupy a large amount of space especially in the vertical direction.

The engine of the invention is envisaged as an in rovement on such conventional engines and is designed as a reversible rotary one-stroke internal ccmbustion engine.

The engine comprises a stator which defines a cylindrical chamber, a drive shaft extending coaxially through said chamber, a rotor corrprising a cylindrical hub mounted coaxially on said drive shaft and a rotor arm extending radially from said hub. The engine also comprises two radia-lly movable wall meribers referred to as the reciprocating radial sealing walls each having a retracted position in which the radially inner face of the wall member lies flush with the inner periphery of the stator and an inserted position in which the said face of the wall mstiber is in contact with the peripheral surface of the hub, means for selecting one of the wall members to lie normally in the inserted position so as to divide said cylin- -drical stator charrber into a combustion cha_r ^* ber between such. wall meiiber and the rotor arm and an air compression chaπfaer. The engine is provided with means for introducing air and fuel into the ccπfcustiαn chamber whereby upon ignition of the fuel/air mixture the cαribusti-on gasses exert a force on the rotor arm to rotate the rotor in a p__edeter_rιined direction according to which wall member is selected, and timing means synchronised with the rotation of the rotor to retract the selected normally inserted wall manber for a period of time sufficient to allow the rotating rotor arm to move through the space occupied by said selected wall member when inserted and then to reinsert such wall member. With the above arrangement the engine of the invention has been designed with the aim of achieving the following basic features:

Its ge netry and one revolution cycle of operation is such that in theory the cαtbustion gasses expanding in the rotor space may be allowed to expand throughout 294 degrees of rotation, i.e in excess of 80% of the cycle duration thus, converting a very large portion of their heat energy into useful mechanical work by driving the rotor around its casing hence, resulting in a high engine efficiency. This follows from the fact that the longer the combustion gasses are allc-wed to expand in the working chamber of the engine swεep- -ing volume and thus converting their heat energy into useful mechanical work, the higher the engine efficiency.

Furthermore, the gas expansion occurs siirultaneously with the air cαηpression process within the same rotor space thus, the engine operates on the one-stroke principle. The engine is reversible thus, it can operate in either the clockwise or the an ^* -_i-clockwise direction of rotation, and the rotation may easily be reversed by means of suitable cαiponents fitted onto the engine.

These components are referred to as the reciprocating radial seali g walls and are fitted to the stator casing at predetermined positions as dictated by the engine cycle of operation. The engine has the capability of achieving high compression ratios and thus benefits the advantage of operating on a variety of fuels -and in particular fuels of low quality such as H.V.F and slurries e.g of coal.

The rotor -which carries the rotary piston rotates concentri- -

-cally with its driveshaft around the stator casing thus, avoiding the use of eccentric gears. The number of moving parts is relatively small resulting in easy maintenance and good reliability. Ωie engine occupies substantially less space than a oαnventional internal σoπfcustion __ecip-_o<-ating piston engine and is designed to operate mainly in the low to medium speed range finding its application in ships, power stations, oil fields and industry, operating as a main pcwer/propulsion unit or a generator prime mover however, it may be adapted to operate at higher .speeds thus also finding application in the car and aircraft industry.

Hence, in order to achieve the abσvementioned aims the engine is designed as a "Rotary .Internal cαrbustion reversible one-stroke engine ¹¹ having a stator casing with opposed spaced sidewalls and an i_nte__vεning, enclosing transverse cylindrical wall referred to as the peripheral part of the stator casing, defining together therein a cylindrical housing chamber, and a rotor mounted in the cylindrical housing chamber of the casing. The rotor is of a key hole cross-section shape and is coaxially mounted -upon a driveshaft which is rotatably supported on suitable bearings placed externally and on either side of the -opposed sidewalls of the stator casing and mounted on the engine sι_pporting structure,, the driveshaft extend- -ing coaxially through the cylindrical housing chamber of the stator casing.

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The driveshaft is also rotatably sealed by suitable gaskets which are situated coaxially around the cylindrical shaft opening of each of the aforementioned opposed sidewalls, and it extends through the cylindrical housing chamber of the stator from one sidewall through to the other, one end of the shaft carrying the engine flywheel while its other end is attached to the drive unit. The rotor may rotate in either the clockwise or the anti ^*** - ^* clockwise direction of rotation around the stator casing, and its axis coincides with that of its driveshaft which passes through the centre of the cylindrical chamber of the stator housing.

The rotor cαtpris-es a cylindrical hub mounted coaxially on said driveshaft and a rotor radial -arm extending from said bub outwards of the rotor centre towards the inner circumfe- ^* -rence of the stator casing, said radial arm referred to as the rotary piston. The lateral faces of the rotary piston may span a certain width, say over a 40 degree .angle, however this may be chosen accordingly to accomodate different design -and operational features of the engine. ^r J e radially outer end face of the rotary piston is recessed in order to accomodate any mσvanent of the inlet means which may otherwise hinder the rotation of the rotor, and- is at all times in contact with the peripheral cylindrical inner surface of the stator casing v±ach is equipped at the position as dictated by the engine cycle of operation with the following components:

Two identical reciprocating radial sealing walls, one operational during the clockwise .and the other during the anti-clockwise rotation of the rotor respectively. Both such radial sealing walls are positioned radially with their axes set at fourty degrees to each other forming a fourty degree vee. Each radial sealing wall is mounted in a cylinder and is spring or pressure biased outwards of the rotor centre at the retracted position where its radially inner face lies flush ^■ with the inner periphery of the stator casing. The top of each cylinder -which houses a radial sealing wall may be supplied with pressurized hydraulic fluid via a duct ^• which through a two way rotary -control valve cαimunicates with a hydraulic cylinder housing a piston v-hich. may be activated frcm its bottcm dead centre to its top dead centre position and vice-versa, by the engine camshaft at the exact position o<S the rotor .as dictated by the engine cycle of operation.

Hence, when the camshaft activates the said pistons to their top dead centre position, pressurized hydraulic fluid may enter the tcp of the cylinder which houses the -operational radial sealing wall and activate the sealing wall inwards towards the rotor centre against the action of its spring, to the inserted position where its ^' radially inner face is in contact with the peripheral surface of the rotor hub.

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The two way rotary control valves mentioned above control the admission of hydraulic fluid to the cylinders which house the radial sealing walls. When one of the above valves is set at its open position it allows cαηpressed hydr-aulic fluid to flow from the said hydraulic cylinder to the top of the cylin-

-der which houses the operational radial sealing wall and activate it. When the valve is set at its closed position it blocks the inlet of hydraulic fluid to the cylinder which houses the radial sealing wall and opens a return passage connected to the hydraulic fluid suπp hence, rendering the radial sealing wall inactive and retracted to the position where its radially inner face lies flush with the peripheral inner surface of the stator casing.

Hence, when the rotor is to rotate in the an-ϋ^clockwise direction, the rotary control valve corresponding to the cylinder -which houses the radial sealing wall which is opera- -tional during the anti-clockwise rotation of the rotor is set at its open position. Accordingly, the rotary control valve corresponding to the cylinder which houses the radial sealing wall which is operational during the clockwise rotation of the rotor is set at its closed position, and vice-versa in the case of the clockwise rotation of the rotor. Midway between the two radial sealing walls the peripheral wall member of the stator casing is equipped with a charge air inlet timing valve ^** zhich is disposed in the peripheral wall of the stator in the sector which lies between the planes of the two radial sealing walls and controls the t ming and duration of the admission of the cαtpressed charge air supply to the combustion chamber.

The charge air __nlet timing valve oαnπunicates with the air outlet of the air receiver Ey means of suitable piping, and opens at its iησuth. to the rotor space. This valve is hydrauli- -cally activated Ey the camshaft to open or close similarly to the radial sealing walls. Next to the charge air inlet tiiπing valve one or more fuel injectors are disposed in the peripheral ^" wall -meπfeer of the stator in the sector -which lies between the planes of the two r-adial sealing walls, which inject a given fuel charge in the cαπ&ustion chamber of the engine just before the time of ignition, depending on the ignition delay.

Dicjmetrically opposite the above mentioned sector an exhaust gas tώning valve is disposed in the peripheral wall of the stator casing for __e_L4_eying the rotor space from i±e combustion gasses at the end of the stroke, said valve -opening at its mouth to the __ot_j_r .space and Being hydraulically activated to open or close similarly to the above mentioned air t_iining valve and radial sealing walls.

If the engine is designed to rotate at high speeds, the above mentioned radial sealing walls, air inlet and exhaust gas timing valves -may be alternatively activated mechanically instead of hydraulically by overhead camshafts, or by a suitable -cairi rocker .arrangement which may be chain or gear driven by the engine driveshaft. ^" In addition to the above cαπponents, the peripheral wall member of the stator ^* casing is fitted with two air outlet ports, each set with its axis about

15 degrees distant from the axis of its closest/-adjacent radial sealing wall however, this distance is not restrictive.

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Each air outlet port, one operational during the clockwise and the other during the anti-clockwise rotation, opens at its mouth to the rotor space and σαttmunicates with the air inlet of the air receiver via suitable piping which is fitted with a rotary control valve which is set at its open or closed position according to the rotational direction of the rotor, and a one way non-return air outlet valve which permits air to flew only from the rotor space to the air receiver.

Between each such air outlet port and its closest radial sealing wall the peripheral wall member of the stator casing is fitted with an atmospheric air induction port which provides ccraiMnication between the rotor space and the atmosphere. This port is equipped with a one way non-return air inlet valve which permits air to flow only from the atmosphere into the rotor space at about the end of the scavenging process, and with a rotary control valve which is set at its open or closed position according to the rotational direction of the rotor. The atmospheric air induction ports open at their mouth to the rotor space while their end is fitted with an air filter. Hence, when one of the radial sealing walls is activated inwards towards the rotor centre at the inserted position where its radially inner face is in contact with the peripheral surface of the rotor hub, two chambers are defined between the activated radial sealing wall and the rotary piston.

The cαribustion chamber, which cαrprises a space with boundaries defined by i±e radial reaction face of the rotary piston, the part of the cylindrical surface of the rotor hub and the arc formed Ey the inner peripheral surface of the stator casing -which lie between the radial reaction face of the rotary piston and the forward radial face of the activated radial sealing wall, the forward radial face of i±e activated radial seal ng wall, and enclosed by the opposed sidewalls of the stator casing, and the .sir compression chamber ^" which cαrprises a space with boundaries defined by the radial leading face of the rotary piston, the r-adial back face of the activa- -ted radial sealing wall, the part of the cylindrical surface of the rotor hub and the arc formed by the inner peripheral surface of the stator casing -which lie between the leading radial face of the rotary piston and the radial Sack face of the a-ctivated radial sealing wall, and enclosed by the opposed sidewalls of the stator casing.

The engine is provided with means for intennittently supplying fuel and air under suitable pressure to the ccmbust- -ion chanber at the respective positions of the rotor as dictated by -the engine cycle of operation, the arranganent being such that on ignition of the injected fuel with the charge air in the cαπbustion chamber, cαnbustion will occur.

If the engine is designed to operate on a low compression ratio, the fuel/air mixture introduced in the ccmbustion chamber may be ignited by one or more spark plugs -which may be fitted to the peripheral wall member of the stator casing next to i±e fuel injectors, and may be fed .Intermittently with an electrical charge at the point in the cycle when i±e rotor reaches the firing position. The t ^* wo respective firing positions of i±e rotor for the clockwise and anti-clockwise rotation are as follows: For i±e anii-clockwise rotation ignition is timed to occur at the instant when the centre of the radially outer end face of the rotary piston coincides with i±e centre of the radially inner face of the radial sealing wall which is operational during the clockwise rotation of the rotor. For the clockwise rotation ignition is timed to occur at the instant when the centre of i±e radially outer end face of the rotary piston coincides with i±e centre of the radi-ally inner face of i±e ^* radial sealing wall which is operational during the anti- -clockwise rotation of i±e rotor. Since the two abσvementioned firing positions of i±e rotor are 40 degrees apart, in order to reverse the rotation from anti-clockwise to clockwise, the camshaft is rotated by 40 degr-ees in i±e clockwise direction, and vice-versa for i±e reversal frcm clockwise to anti-clockwise rotation. The reversing rotation of the camshaft is achieved by i±e inc_orpo-

-ration of a conventional reversing flap mechanism operating within the drive gear of the camshaft.

The engine of the invention may be provided with two or more identical rotors mounted on the same driveshaft for rotation in identical stator housings and having identical cycles of operation with any chosen phase difference between them. To help understanding of i±e invention, i±e abovedescri-

-bed engine will now be explained in detail fcy way of exarrple with reference to i±e accoπpanying drawings in which:

Figure 1 is a cross-section of i±e rotor of the engine a-ccording to the invention taken along i±e vertical plane -which passes through its centre.

Figures 2 to 4 are views similat to Figure 1 showing successive stages in the working cycle of the-engine for the clockwise rotation of the rotor.

Figures 5 to 8 are views similar to Figure 1 shewing successive stages in the working cycle of the engine for the anti-clockwise rotation of the rotor.

Figure 9 is a longitudinal section of the engine taken along the horrizontally inclined plane whic passes through i±e centre line of the activated radial sealing wall at the position of the rotor -where its rotary piston is dianetrically opposite i±e activated radial sealing wall.

Figure 10 is a schematic diaagram illustrating the hydraulic operation of i±e radial sealing walls.

Figure 11 is a table of the working cycle of the engine for both directions of rotation of i±e rotor.

Figure 12 is a cross-section of the rotor similar to Figure 1 but on a larger scale shewing details of the air induction ports and an alternative sealing arrangement, Figure 13 is an enlarged pictorial vl&t of p-art of the peripheral wall manber of i±e stator casing shc_wiι_g the arrangement of a radial sealing wall and i±e v-arious valves and ports located on either side of it.

Figure 14 is a cross-section of i±e air.receiver used vriien a scavenge air timing valve is added to i±e engine and is taken along the vertical plane which passes through i±e centre line of the air receiver, and

Figure 15 is a cross-section of i±e rotor taken along the vertical plane adjacent to a lateral face of the rotor.

Referring first to Figure 1, i±e engine cαπprises a rotor 2 mounted for rotation within the rotor space 43 of i±e housing and secured en i±e driveshaft 1. The rotor ααπprises a cylindri- -cal hub which extends to a rotary piston 3 having a radically outer end face 44 which is recessed in order to acccmodate any movaπent of the inlet means which would otherwise hinder i±e rotation of the rotor. The face 44 is also fitted with suitable seals 7 and is at all times in contact with the inner periphery 45 of the peripheral wall member 46 of i±e stator casing.

The peripheral wall 46 is fitted with two reciprocating radial sealing walls 4a and -4b.-which are mounted in cylinders 5a and 5b respectively, and are spring biased outwards of the rotor centre by the springs 6. The radially inner face of each radial sealing wall is also fitted with similar seals 7.

Each cylinder 5 may be supplied with pressurized hydraulic fluid via an inlet duct 9 which through a two way rotary control valve 8 may c uitunicate with a hydraulic cylinder containing the hydraulic fluid and housing a piston which may be activated fran its bottan dead centre to its top dead centre position, and vice-versa, Ey the engine camsh-aft. For the clockwise rotation, valve 8a corresponding to cylinder 5a is set and remains at its open position, -while valve 8b corresponding to cylinder 5b is set and ..emaing at its closed position, and vice-versa for the anti-clockwise rotation.

Hence, about ten degrees before i±e rotor reaches i±e firing position, when the top edge of the radial leading face 3a of the rotary piston ooincides with 350 degrees of i±e scale marked around the casing, -which is equivalent to

10 degrees before tcp dead centre in a reciprocating piston engine, the camshaft activates the pistons in the abσve- -i-entioned hydraulic cylinders, which correspond to the cylinders which house the radial sealing walls, to i±eir top dead centre position and pressurized hydraulic fluid flews frc the said hydraulic cylώnders to the valves 8a and 8b. Since during i±e clockwise __Oi ^* _ation valve 8b is set and remains at its closed position, the hydraulic fluid supplied to it returns to its sump via return line 9b.

Furthermore, since valve 8a is set and remains at its open position i±e hydraulic fluid supplied to it may enter cylinder 5a via inlet duct 9a and activate the radial sealing wall 4a inwards towards i±e rotor centre to i±e inserted position where its radially inner face is in contact with the periphe- -ral surface 2a of the rotor hub. Thus, with this arrangement two chambers are defined within i±e rotor space 43 between the rotary piston 3 and the activated radial sealing wall 4a, i±e cαribustion chaπber 47 and i±e air cαπpression chamber 48.

10 The two radial sealing walls 4a, 4b are disposed radially with i±eir axes set at 40 degrees to each other, and between them the peripheral wall 46 is fitted with a charge air inlet timing valve 12 and one or more fuel injectors 13 both dispo- -sed in the sector which lies bet ^* ween1±e planes of i±e two

^■ ^ radial sealing walls. Diametrically opposite the said sector the peripheral wall 46 is fitted with an exhaust gas timing valve 15. All the a__ ^* σvementioned valves open at i±eir mouth to the rotor space 43 and are hydraulically activated to their respective open or closed positions by i±e engine camshaft in 0 conjunction with the abovementioned hydraulic cylinder/piston

■arranganent. The wall 46 is also fitted with two air outlet ports 16a, 16b which are disposed opposite each other and ■each opening at its mouth to the rotor space 43 and cα iunica- -ting via a rotary control valve 17 and a one way non-return 5 air outlet valve 49 with i±e air inlet of i±e air receiver.

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Between each air outlet port 16 and its closest radi-al sealing wall the peripheral wall member 46 is equipped with -an atmospheric air induction port -which will be described later in detail. For the clockwise rotation of the rotor valve 17a is set and remains at its open position ojiiiiunicating port 16a with the air inlet of the air receiver, while valve 17b is set and remains at its closed position blocking -any outlet of gas frc port 16b, and vice-versa for the anti-clockwise rotation _. of the rotor. The same process is repeated for i±e rotary αontrol valve fitted to each atmospheric air induction port.

The fuel injector/s 13 are connected to the fuel supply line, and timing and duration of the fuel injection is oonve- -niently controlled by a suitable fuel t_imiιιg valve -not shown- which is activated by the camshaft, the fuel being supplied to the timing valve under suitable pressure by means of a fuel puπp and a fuel pressure regulating valve.

The cycle of operation of the engine will new be described for the clockwise rotation of the rotor, with reference to Figures 1 to 4. Inferring to Figure 1, when the rotor is at the firing position with i±e top edge of the leading radial f ce 3a of the rotary piston coinciding with zero degrees of the scale marked around the casing, which is equivalent to top dead centre in a reciprocating piston engine, the injected fuel in the σcsτbustion chamber 47 ignites as it mixes with i±e hot cαipressed air which has been previously supplied to the chamber 47 and ceπbustion takes place.

The injected fuel is syπbolized by the dotted lines in Figure 1. Once cx__τbustion occurs, i±e pressure of the cc bust- -ion gasses in chaπber 47 will rise sharply and will apply a net resultant force which acts vertically on the surface of the trailing reaction radial face 3c of i±e rotary piston thus, applying a direct torque on i±e rotor 2 and its drive- -shaft 1 -which will force the rotor to turn in a clockwise direction of rotation. As the oαtrbustion gasses expand against i±e rotary piston 3 the volume of the air compression chamber 48 decreases σonti-

-nously with the rotation of i±e rotor, and i±e rotary piston αα-presses i±e air in chamber 48, see Figure 2. The compressed air is delivered to the inlet of the air receiver via the operational air outlet port 16a. The f£ow of the σαrrpressed air is syπbolized by the arrcws in Figure 2. The cαipression process takes place over i±e whole stroke which lasts through- -out 290 degrees of rotation, and at the end of the stroke there is highly cαrpressed air trapped in chamber 48 between i±e radial leading face 3a of the rotary piston and the radial back face of the activated radial sealing wall 4a.

After 290 degrees of rotation, see Figure 3, the exhaust taming valve 15 is hydraulically activated open, and simulta- -neόusly the camshaft allows the piston in t&e hydraulic cylinder which compresses the fluid supplied to i±e cylinder 5a to move frcsn its top dead centre to its bottom dead centre position.

Hence, the hydraulic pressure in cylinder 5a falls and the operational radial sealing wall 4a is biased outwards of the rotor centre under the action of its spring 6 to the retracted position where its radially inner face lies flush with i±e inner periphery 45 of the peripheral wall member 46 of i±e stator casing. As the operational radial sealing wall 4a is activated to its fully retracted position, the compressed air previously trapped in the air compression chambefc between it and the radial leading face 3a of the rotary piston is released and sweeps the rotor space 43 to scavenge it from the exhaust gasses which leavesthe rotor space via the cpen exhaust gas tinting valve 15. Hence, after 290 degrees of rotation the exhaust and scavenging phases begin. The flow of the scavenge air is symbolized By the arrows shewn in Figure 3. The rotor continues to rotate under the mαnenttrn of the engine lywheel and the engine -t__jning-may be suitably adjusted to end the exhaust phase Ey activating valve 15 closed at any chosen point during the interval frcm i±e instant ^' the rotor has rotated throughout 310 up to 340 degrees of rotation however, in practice it is prefer-able to adjust the duration of the exhaust phase accordingly so that the exhaust gas timing valve 15 is activated closed about ten degrees before all of the scavenge air has left the rotor space.

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After i±e rotor has rotated throughout 350 degrees, see Figure 4, i±e piston in i±e hydraulic cylinder which corres- -ponds to the cylinder 5a -which houses the operational radial sealing wall 4a is activated by i±e camshaft back to its top dead centre position, and pressurized hydraulic fluid enters cylinder 5a and activates the radial sealing wall 4a inwards towards the rotor centre at the inserted position where its radially inner face is in contact with the peripheral surface 2a of i±e rotor hub. Simultaneously, the charge air inlet timing valve 12 is hydraulically activated open by the canshaft, and αcπpressed air leaves the outlet of the air receiver via duct 12a and through i±e valve 12 enters the σcmbustion chamber 47 along the arrows shown in Figure 4, to build up the pressure of i±e air in chamber 47 to that required for the fuel ignition. The engine timing may be adjusted so that i±e valve 12 is activated closed at any point during the interval frαn the instant the rotor has rotated throughout 355 up to 359 degrees, depending on the ignition delay, and simultaneously i±e fuel injection begins. When the rotor has performed one complete revolution after having rotated throughout 360 degrees, see Figure 1, ignition of the fuel/air mixture occurs in chamber 47, combustion takes place and the ^' above described 360 degree cycle of operation ^" is repeated. The fuel injection may be timed to last throughout about ten to twenty degrees of rotation.

In order to reverse the rotation, it is necessary to shift the engine cycle Ey 40 degrees, -which means that ignition will occur at 320 degrees engine angle instead of zero deg- -rees, see Figure 5. To achieve reversal of the rotation frαrt clockwise to anti- Lockwise, the camshaft is rotated through 40 degrees in i±e anti-clockwise direction by means of i±e aforementioned reversing flap mechanism.

In addition, the rotary control valve 17a will be activa- -ted and set from its open to its closed positipn, while valve 17b will be activated and set from its closed to its open position thiis, rendering poa?t 16b operational. The same will apply for the rotary control valves 8a and 8b, -whereby valve 8a will be activated and set fcαπ its open to its closed position while valve 8b will be activated and set frcm its closed to its open position. Hence, radial sealing wall 4b will become operational >tf_ile radial sealing wall 4a will be rendered inoperative at the retracted position where its radially inner face lies flush with the inner periphery 45 of the stator casing. The same process is also repeated for i±e rotary control valves of the two atmospheric air induction ports.

A suitable control mechanism may be fitted on the engine ^" so that every time the rotation is reversed, all the abσve- -described functions are performed simultaneously at the push of a button.

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The cycle of operation for the anti-clockwise rotation of i±e rotor is identical to ±e cycle for the clockwise rotation having a phase difference of 40 degrees, see Figures 5 to 8. Figure 11 is a table illustrating i±e engine cycle of operation for both the clockwise and anti-clockwise rotation of the rotor.

Figure 9 is a longitudinal section of i±e engine which has a driveshaft 1 mounted in bearings 27 which are supported in a composite engine fixed structure 11. At one of its ends the ■shaft 1 carries a flywheel 35 while its other end is attached to i±e drive unit -not shown. Intermediate i±e ends of shaft.1 i±e engine carries a gear 19 which via further gears 19 drives the camshaft 18, said camshaft πounted in bearings 27 which ■are supported in the αoπposite engine fixed structure 11. The camshaft carries six cams 77, said cams hydraulically activating the two radial -sealing walls, i±e exhaust and charge air inlet timing valves, and i±e fuel puπp plunger and fuel i ming valve. The valves and radial sealing walls are hydrauli- -cally activated by pistons 29 -which are mounted in cylinders 30 which contain the hydraulic fluid. Between i±e bearings 27 is secured on the -driveshaft 1 a rotor 2 mounted on i±e shaft 1 for rotation in its housing 10. The rotor housing 10 has -cooling passages 24 provided in its opposed sidewalls for cooling water circulation and also carries cylindrical gaskets 28 vdαich are fitted in the cylindrical shaft opening of each sidewall on which shaft 1 is supported. The peripheral part 46 of i±e casing is equipped .amongst other σcπponents with two reciproca- ting radial sealing walls 4 each mounted in a cylinder 5.

Hydraulic fluid may be supplied to each cylinder 5 via the inlet duct 9 and rotary control valve 8 from its corresponding h ^* ydraulic cylinder 30. Each radial sealing wall 4 may be provided with cooling passages 31 through which oil coolant may flow to cool it. The oil -cool-ant may enter each radial sealing wall from a telescopic pipe 32, circulates in passages 31 and leaves via i±e return telescopic pipe 33. The radi-ally inner face of each radial sealing wall and i±e radially outer end face of the rotary piston are each fitted with suitable seals 7 for peripheral gas sealing.

Lubrication of i±e rotor housing peripheral and lateral wall surfaces is achieved by means of a puπp in conjunction with a timing device, not sheen, which supply oil to the central oil feed bare 25 -which is drilled around i±e centre of shaft 1 an_a extends axially along part of its length ending at the mouth of a radial bore 26 -ehich extends up to i±e centre of i±e radially outer end face of the rotary piston.

Alternatively, if the peripheral lubrication is carried out externally by means of oil injectors disposed around i±e cylindriceal wall manber 46 in conjunction with an oil puπp, a timing device and an oil distributor, i±e pressurized oil ^■ which is supplied to i±e bore 25 may be used to force i±e seals 7 -which are fitted along i±e radially outer end face of i±e rotary piston to be always in firm contact with the peripheral cylindrical inner surface 45 of the stator casing, and also to cool the rotor.

With this alternative arrangement an oil injector is fed i_αter_τdttently with oil at i±e instant when the radially outer end face of the rotary piston is directly under i±e tip of i±e injector. Lubrication of the peripheral surface of the rotor hub and the lateral side faces of i±e rotor is achieved ty means of a puπp in conjunction with a timing device which supply oil to the telescopic pipe 34 which passes i±rough the activated radial sealing wall 4 and extends up to its radially inner face vhich is in contact with i±e peripheral surface of i±e rotor hub throu out a given part of the engine cycle of operation. The oil supplied for lubrication may be suitably adjusted to be recirculated or consumed within the engine. Lateral sealing of.the gasses is ensured by the incorpora- -tion of suitable seals fitted in grooves which are located along i±e lateral faces of i±e rotor and follow its profile, ^■ while peripheral gas sealing is ensured Ey the incorporation of suitable seals which are fitted along the radially inner face of each radial sealing wall as well as the radially outer end face of i±e rotary piston. These seals may be spring biased or forced by pressurized oil outwards of their supports to ensure theμ engage firmly their respective contact surfa-ces and thus, they provide the engine with adequate gasketing against escape of i±e cαribustion glasses in any direction rendering i±e latter gastight.

Figure 10 is a schanatic diagram illustrating the hydrauilic operation of the radical sealing walls. Hydraulic fluid is supplied to the cylinders 5a and 5b which house i±e radial sealing walls 4a and 4b respectively. The pressurized fluid is supplied to the cylinders 5a,5b by the pistons 29 which are mounted in hydraulic cylinders 30 -which contain the hydrau- -lic fluid, said pistons being activated to move from i±eir bottom dead centre to theit tcp dead centre position and vice- -versa, by cams 77a and 77b of i±e camshaft 18. Once the above pistons 29 are activated to their top dead -centre position, pressurized hydraulic fluid -reaches the rotary control valves 8a and 8b via the hydrauilic supply lines 9.

For the clockwise rotation the rotary control valve 8a is set at its open position henoe, hydraulic fluid may enter the cylinder 5a and activate the radial sealing wall 4a inwards towards the rotor centre against the action of its spring 6. The rotary control valve 8b is set at its closed position henoe, the hydraulic fluid supplied to it will leave via i±e return line 9b to return to its suπp 36, and vice-versa for i±e anti-clockwise rotation. The hydraulic fluid suπp 36 ccπtπumicates with the cylinders 30 via ducts each equipped, with a one way non-return hydraulic valve 50 which allows fluid to flow from i±e suπp 36 into the cylinders 30 only when i±e pistons 29 move from i±eir respective top dead centre to i±eir bottom dead σentre position.

Cams 77c and 77d activate the pistons 29 corresponding to i±e charge air inlet and exhaust -timing valve respectively, while cams 77e and 77f activate i±e fuel pump plunger and the fuel timing valve respectively. Figure 12 is an enlarged cross-section of the rotor taken along the vertical plane which passes through its centre, and shows details of the casing and the various σαtponents affixed i±erearound. Once i±e exhaust and scavenging end, before the pressure charging of i±e σ ribustion chaπber begins, the rotor space must be replenished with fresh atmospheric air. In order to achieve air induction, the rotor space uunuunicates with the ataosphere via one of the aic induction ports 66a or 66b, port 66a being .set operational during the clockwise rotation while port 66b is set operational during the anti- -clockwise rotation of the rotor. Each of the ports 66 is equipped with a rotary control valve 60, valve 60a set at its cpen position during i±e clockwise rotation, while valve 60b is set at its open position during the anti-clockwise rotation of i±e rotor. In addition to i±e s-aid rotary control valve each port 66 is also fitted with a one way non-return air inlet valve 49, which permits air to flow only from the atmosphere into the rotor space, and an air filter 61.

After i±e end of the exhaust and i±e scavenging process-es, w n i±e scavenge air pressure has dropped, atmospheric air may enter the rotor space 43 via i±e operational air induction port 66 and air induction takes place. The inlet/outlet directions of the atmospheric aiε are symbolized by the arrows shewn in Figure 12. In order to improve i±e .air induction process a suitable air puπp may be oonnected to i±e end of ports 66 so that during the air induction phase there is plenty of air induced under pressure in the rotor space 43. In order to siπplify maintenance and ensure good sealing, the peripheral -wall member 46 of i±e stator casing may be fitted with a cylindrical liner 80, and as the rotor rotates the radially outer end face of the rotary piston is always in contact with the inner peripheral surface 45 of the liner 80.

Peripheral sealing at i±e inner periphery of the atator is achieved by the incorporation of suitable seals 7 which are fitted in suitable grooves/supports disposed along the width of the radially outer end face of the rotary piston. The radially inner face of i±e r-adial sealing wall -4b which is operational during i±e anti-clockwise rotation of i±e rotor may be provided with similar seals 7.

Since i±e rotor in its actual operation will rotate in the forward'or clockwise direction of rotation throughout most of its running, a good alternative sealing systan should be provi- -ded between the peripheral βurface 2a of the rotor hub and i±e radially inner face of the operational radial sealing wall 4a which is in contact with i±e surface 2a i±roughout a given part of i±e engine cycle of operation du_ring i±e clockwise rotation, in order to gasket i±e combustion gasses in chamber 47 against escape from i±e point of contact between the radial sealing wall 4a and the peripheral surface of the rotor hub.

There are many types of sealing arrangements which could be applicable to this engine, and a proposed sealing system is the following: The rotor hub surface 2a is provided with a sliding seal -which is split in two parts 90a and 90b. Both such parts are secured in suitable grooves 64 -vΛiich are disposed around the surface 2a, and when the rotor is at i±e firing position, zero degrees of the scale marked around i±e casing, parts 90a and 90b are forced into firm contact under the action of springs 63, see Figure 12. When i±e combustion takes place, the pressure of the combuLstion gasses in chamber

47 will rise sharply and will force the rotor to rotate in i±e chosen clockwise direction as the gasses expand against the rotary piston 3. When i±e rotor begins to turn, seal 90a remains in firm contact with i±e radially inner face of the activated radial sealing wall 4a and slides along i±e surface

2a, while seal 90b follows the rotary piston.

In order to prevent seal 90b from sliding in the anti- -clockwise direction out of its position, a suitable stpper s is fitted in groove 64. Hence, as i±e rotor rotates seal 90b moves away from its counterpart-seal 90a until the rotor coro- -pletes 290 degrees of rotation, and at this point the opera-

-tional radial sealing wall 4a is foeced Ey its spring outwards of the rotor centre to its fully retracted position, -and as it lifts seal 90a is forced by spring 63 to slide in the clockwise direction along i±e surface 2a until it cones into firm contact with seal 90b, and this is shown by the dotted lines in Figure

12. With this arrangement, since sliding seal 90a is kept in firm contact with the radi-ally inner face of the activated radial sealing wall 4a throughout the whole stroke, good peripjheral sealing is ensured at the inner rotor periphery. In αrdeaf to ensure equally good lateral sealing, the lateral faces of the rotor may be fitted with suitable grooves -which follow its profile and house lateral strip or roller seals.- These seals may be .spring or pressure biased outwards of i±eir supports so that they engage firmly their respective contact surfaces.

Both of i±e abovementioned radial sealing walls extend laterally beyond the width of i±e peripheral wall member 46 of the stator casing, see Figure 13, and are firmly supported in .suitable radial guides 100 which are provided along part of the inner lateral surface of both opposed sidewalls. The inner surfaces of the guides 100 may be coated with suitable sealing material.

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With this arrangement, the operational radial sealing wall is always kept firm in position reciprocating radially in a perfect straight line along the guides 100. The direction of flow of air in and out of the rotor space is symbolized by the arrows shewn in Figure 13. The reciprocating radial seeing walls may be alternatively modified to reciprocate sideways instead of radially, from one sidewall through to i±e guide of its opposed sidewall. This suggested alternative arrangement could be beneficial in cases where i±e inner rotor,diameter is chosen to be appreciably smaller than its outer diameter, and i±e radial distance of reciprocation would by far exceed i±e suggested lateral distance of __ecip__ocatiαn. In order to iπprove the efficiency of the above described engine one or more turbochargers may be connected between the exhaust manifold and the air inlet of the air receiver.

In addition for :L_τproving i±e scavenging process, see Figure 15, a scavenge air inlet -timing valve 14 may be fitted to the peripheral wall member of i±e stator easing disposed in i±e sector which lies between the planes of i±e two radial sealing walls, said valve positioned radially opening at its mouth to i±e rotor space, and being hydraulically activated to open or close by the engine camshaft. With i±e addition of this valve, i±e air receiver 37 is divided in two portions, see Figure 14, the charging and the scavenging portion respectively, by a partition 38 which is fitted with a pressure sensitive valve

39 which allcws only such air as is in excess of i±e ch-arging requirement of i±e combustion chamber to pass from i±e charging to i±e scavenging portion.

Ccπpressed air is supplied to the air inlet 16 of the air receiver ^■ which cαtimunicates with the two -abovaπentioned air outlet ports 16a, 16b via ducts 16a , 16b respectively. The charging portion cαrmunicates with the charge air inlet timing valve 12 via duct 12a, while the scavenging portion σoπmunica-

-tes with the sceavenge air inlet timing valve 14 via duct 14a. Also as previously mentioned, i±e peripheral wall member 46 of i±e stator casing may be fitted with more than one fuel injectors for better distribution of the injected fuel charge in the -combustion chamber, or alternative fuel injection means may be used e.g carburetters. The afore mentioned described engine has the following advantages:

(i) The rotor rotates concentrically and the engine is reversi- -ble therefore, it dispenses with the crankshaft, crossheads, piston and connecting rods or a reversing gearbox -which are ccπmonly used in σoπventional two and/or four stroke recipro- -cating piston engines, and it also dispenses with eccentric gears ccmmonly used in "Wankel" type rotary engines. Further- -more, since the stator casing is of a uniform cylindrical shape i±e angle of contact between the seals fitted along the radially outer end face of i±e rotary piston and the inner peripheral surface of .the stator housing, as well as the angle of contact between the seals fitted along the radially inner face of i±e operational radial sealing wall and i±e peripheral surface of the rotor hub are constant throughout the rotation of the ^* rotor thus, restricting seal wear to a minimum.

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(ii) The engine operates on the one-stroke principle there¬ fore, its geometry and 360 degree cycle of operation allow i±e combustion gasses to expand against the rotary piston in i±e rotor space throughout up to 294 degrees of rotation, i.e in excess of 80% of the engine cycle of operation thus, in-Lπάzing the exhaust gas losses and hence resulting in an outstandingly high engine efficiency.

(iii) The number of engine moving parts is small and since there is no conversion of reciprocating into rotational motion i±e rotor can be easily balanced thus, resulting in easy maintenance, m_ϋij -m vibrations and good reliability. Further- -more, the engine occupies appreciably less space than a conventional ^* recipro<-ating piston engine developing the same power, especially in the vertical direction.

(iv) With the incorporation of a suitably designed charge air inlet timing valve the highly compressed charge air is inject- -ed under turbulence into i±e combustion chaπber hence, a good air injection system is achieved which in turn results in a high cαrbustion efficiency.

(v) The engine benefits the capability of achieving gas expan¬ sion and air cαtpression simultaneously within i±e same rotor space and is therefore distinguished as a one-stroke rotary internal combustion reversible en-fine. The engine is also capable of achieving high compression ratios thus benefiting the capability of operating on a variety of fuels and in par- -ticular on cheap fuels such as H.V.F and slurries e.g of coal.

(vi) With i±e incorporation of the air receiver in the engine design, the air pressure charging of i±e combustion chaπber is achieved under constant pressure, and this will contribute positively towards the engine efficiency.

(vii) Since the length/duration of the stroke of the above engine is more than double the rotational length of i±e power stroke of a conventional reciprocating piston and/or rotary engine capable of burning i±e same amount of fuel per second, it follows that i±e combustion gasses are kept muc± longer in the rotor space perforating useful work on the rotor and thus, since i±e stroke may be timed to least in excess of 80% of the engine cycle of operation, it follows that i±e efficiency of this engine will be outstandingly high and in addition, the combustion gasses will .exhaust at a significantly lower taπperature than the exhaust temperature of conventional reciprocating piston and/or rotary -engines thus, minimizing the wall knewn problems associated ^" with exhaust valve wear.

(viii) Two or more identical rotors may be mounted on i±e same driveshaft for rotation in identical housings and having identical cycles of operation with any chosen phase difference between them.