IES20020689A2 - Rotary engine - Google Patents

Abstract

A rotary engine comprises a mounting means (13,23), a rotor (13) supported on the mounting means and having a plurality of cylinders (3a), whose longitudinal axes are spaced radially outwardly from and substantially parallel to the axis of rotation of the rotor, each cylinder having a piston (26) formed for reciprocating motion therein, a revolvable device (8) connected to the pistons of the rotation about an axis which is co-axial with the axis of rotation of the rotor and in a plane which is at an oblique angle to the plane perpendicular to the axis of rotation of the rotor, the revolvable device being securely rotatably mounted in a housing (10) which is fixed relative to the rotor on the mounting means in a plane which is at the same oblique angle as the revolvable device so that in use firing of the cylinders in sequence in the opposite direction to the direction of rotation of the rotor causes rotation of the revolvable device and rotor. The engine of the present invention is capable of providing torque of in the region of three times greater than that generated by corresponding prior art reciprocating engines. <Figure 1>

Description

The present invention relatg§#4ef*Ei engine, in particular a rotary engine for use in propulsion.

At present, the most widely used internal combustion engines have cylinders with reciprocating pistons operating in Otto or Diesel cycles. The linear motion of a piston is converted in to rotational motion by the use of a crankshaft. The crank lever arm is necessarily short in order to keep the stroke length short so that the torque produced is low. As a consequence, the efficiency and/or performance of these engines is compromised.

The present invention seeks to overcome the above described disadvantage of prior art engines.

Accordingly, the present invention provides a rotary engine comprising a mounting means, a rotor supported on the mounting means having a plurality of cylinders, the cylinders having their longitudinal axes spaced radially outwardly from and substantially parallel to the axis of rotation of the rotor, each cylinder having a piston formed for reciprocating motion therein, a revolvable device connected to the pistons of the rotor for rotation about an axis which is co-axial with the axis of rotation of the rotor and in a plane which is at an oblique angle to the plane perpendicular to the axis of rotation of the rotor, the revolvable device being securely rotatably mounted in a housing which is fixed relative to the rotor on the mounting means in a plane which is at the same oblique angle as the revolvable device so that in use firing of the cylinders in sequence in the opposite direction to the direction of rotation of the rotor causes rotation of the revolvable device and rotor.

In a preferred arrangement, the revolvable device comprises a main body having a central bore extending therethrough.

Preferably, a power transmission means is mounted on the revolvable device.

OPEN TO PUBL’C INSPECTION UNDER SECTION 28 AND RULE 23 IE 0 2 06 8 9 Ideally, a power transmission means is mounted between the revolvable device and the rotor. Ideally, this comprises a bevel gear having a first gear wheel fixed co-axially about the bore of the revolvable device and a second co-operating gear wheel fixed on the rotor, the second gear wheel having an axis of rotation coaxial with the axis of rotation of the rotor.

In a preferred embodiment, a drive shaft is fixed on the second gear wheel for co-axial rotation therewith.

In a preferred arragement, the first gear wheel has a central bore and the drive shaft passes through the central bore of the gear wheel and the central bore of the revolvable device. Alternatively, the drive shaft is mountable on a side of the revolvable device facing away and distal from the rotor, the drive shaft being coaxial with the axis of rotation of the revolvable device.

Preferably, a starter motor is in operable communication with the engine to initiate rotation of the rotor.

Ideally, a connecting rod connects each piston to the revolvable device.

Preferably, a spherical bearing is mounted between the connecting rod and the piston.

Ideally, the connecting rod has an extension member depending from the end of the connecting rod which is connectable to the revolvable device, the extension member extending at an angle to the connecting rod and having a retaining means about its free end for securely housing a dynamic balancing weight.

Conveniently the revolvable device runs in an angular contact ball bearing which is connected to a separate rear housing. This rear housing contains a drive shaft bearing, which may have for example, face to face tapered roller bearings. £02068 9 The oblique angle is selected to be in the range of between ten and thirty five degree, preferably between fifteen and thirty degrees and most preferably between twenty and twenty five degrees.

One embodiment of an engine according to the invention will now be described by way of example only, with reference to the accompanying drawings. It is to be understood that the described embodiment contains eight cylinders as an example only, and alternative numbers of cylinders are also possible.

In the drawings: Figure 1 is a schematic drawing illustrating the various components of one embodiment of a rotary engine according to the invention; Figure 2a is a side section view of a rotor of the invention shown in Figure 1; Figure 2b is an end elevation view of the rotor of Figure 2a; Figure 3a is a plan view of a fuel distributor for the rotary engine shown in Figure 1; Figure 3b is a side section view of the fuel distributor of Figure 3a; Figure 4a is a side section view of a dynamic connecting rod shown in Figure 1; Figure 4b is a plan view of the dynamic connecting rod of Figure 4a; Figure 5 is a plan view of the D shaped pin shown in Figure 1; Figure 6 is a side section view of the dynamic balancing weight shown in Figure 1; Figure 7a is a side section view of the bevel gear shown in Figure 1; iEOZ Ob8 9 Figure 7b is an end elevation view of the driven gear of the bevel gear of Figure 7a; Figure 8a is an end elevation view of the revolvable device shown in Figure 1; Figure 8b is a side section view of the revolvable device of Figure 8a; Figure 8c is a side section view of a revolvable device cap socket; Figure 9a is a partial side section view of a first angular ball bearing housing shown in Figure 1; Figure 9b is a side section view of a second angular ball bearing housing shown in Figure 1; Figure 10a is a partial side section view of an outer ring; Figure 10b is an end elevation view of the outer ring of Figure 10a; Figure 11 is a side section view of the rear housing shown in Figure 1; Figure 1 la is an end elevation view of the rear housing of Figure 11; Figure 12a is a partial side section view of an oil pump flange; Figure 12b is an end elevation view of the oil pump flange of Figure 12a; and Figure 13 is a side section view of the outer exhaust ring shown in Figure 1.

Referring to the drawings and initially to Figure 1, there is shown a rotary engine indicated generally by the reference numeral 1 comprising an inlet shaft 2 which runs on twin front needle roller bearings 23. The inlet shaft 2 is hollow to allow entry of air and fuel and is connected to a rotor 3 by screws on a flange (not shown) of the inlet shaft 2. 1£ϋί ΰοβ ί Referring now to Figures 1, 2a and 2b, the rotor 3 comprises a number of cylinders 3a, for example eight cylinders 3 a in this embodiment. Each cylinder 3 a has an inlet port 3 c and an outlet port 3d. The inlet shaft 2 is attached to the rotor 3 so that air and fuel may enter through the inlet shaft 2 and pass through the inlet ports 3 c and into the cylinders 3 a. Cooling fins 3b on a front end of the rotor 3 generate a cooling air flow as the rotor 3 rotates. In the present embodiment, sixteen cooling fins 3b are provided, one in line with each cylinder 3a and one spaced between each pair of adjacent cylinders 3a. Any desired number of cooling fins 3b may be provided as required for different sized engines of the present invention. A rear end of the rotor is attached to a bevel gear indicated generally by the reference numeral 6.

As shown in Figures 1, 3a and 3b, a fuel distributor 4 has two injectors 4a, 4b and two nozzles 4c, 4d. The fuel distributor 4 is inserted into the inlet shaft 2 at a preferred position so that nozzles 4c, 4d are directed into the inlet port 3c of a cylinder 3a to ensure injection of fuel into the cylinder 3a. As the rotor 3 rotates, fuel is injected into the inlet port 3c of each cylinder 3a. The two injectors 4a, 4b are connected to the two nozzles 4c, 4d respectively and act as a safety feature in the event of one set of the injector and nozzle pairs becoming defective. The position of the fuel distributor 4 may be modified to ensure optimum injection conditions for successfully injecting fuel into each cylinder.

Referring still to Figure 1, a piston 26 operates in each cylinder 3a. Each piston 26, is attached to a dynamic connecting rod 5 by a spherical bearing 5d. A dynamic connecting rod 5 is shown in Figures 4a and 4b having a connecting section and an extension piece 5 a extending from one end of the connecting section of the dynamic connecting rod 5. The extension piece 5a retains a dynamic balance weight 5b (see Figure 1), the balance weight 5b being shown in Figure 6. The dynamic balance weight 5b comprises a bolt and nut which connect into a hole 5aa (see Figure 4a) at the end of the extension piece 5a. The extension piece 5a is offset at an angle to the connecting section of the dynamic connecting rod 5. During rotation of the rotor, the balance weight 5b serves to provide a counter balancing force to the centrifugal force on the piston 26 which ensures smooth running of the piston 26 during operation. The end of the connecting section of the dynamic IE 0 2 06 β 9 connecting rod 5 from which the extension piece 5a depends is connected to a revolvable device 8 by a D shaped pin 5 c, as shown in Figure 5, this end having a bore 5ab extending therethrough for receiving the pin 5c.

Referring now to Figures 1, 7a and 7b, a bevel gear 6 is shown having a driving gear wheel 6a and a driven gear wheel 6b, the driving gear wheel 6a being adapted to be attached to the revovable device 8 and the driven gear wheel 6b being adapted to be fixedly mounted onto the rotor 3. The driving gear 6a and driven gear 6b contact each other via spiral bevel teeth. The driven gear 6b is fixed on a drive shaft 7 which is journalled in the rotor 3 and rotates co-axially with the rotor 3. However, the driving gear 6a rotates in a plane which is at an oblique angle from the axis of rotation of the rotor 3, in this particular case the angle being 22°. The drive shaft 7 extends from its mounting in the rotor through the driven gear 6b, through the hollow interior of the driving gear 6a towards the rear of the engine where it is retained in a rear housing 13. The driving gear 6a is fixed to the revolvable device 8 at point A.

As shown in Figures 1, 8a and 8b, the revolvable device 8 is a disc shaped member with flattened edges. In the present embodiment there are eight flattened edges. The revolvable device 8 has a central bore which is threaded along the inner edge so that the revolvable device 8 may screw onto the driving gear 6a. As the driving gear 6a is connected co-axially with the revolvable device 8, it rotates at the same oblique angle, for example 22 degrees. The ends of the dynamic connecting rods 5 from which the extension pieces 5 a depend are attached to the revolvable device 8 by means of D shaped pins 5c (see Figure 5). The D shaped pins 5c slot into holes 5ab in said end of the dynamic connecting rods 5 and are retained by a pin and washer (not shown). These pins 5c further slot into openings 8b on the flattened edges of the revolvable device 8 and are held in place by revolvable device cap sockets 8a which fit over the D shaped pins 5c. Twenty six balls 8aa in each revolvable device cap socket 8a provide a bearing surface between the D shaped pins 5c and the revolvable device cap sockets 8a. Figure 8c shows a side section view of a revolvable device cap socket 8a.

IE 0 2 0 6 β 9 During rotation the revolvable device 8 runs in an angular contact ball bearing housing 10 and the revolvable device 8 rotating in this fixed plane causes the pistons 26 to stroke.

Figures 1 and 9a show the angular contact ball bearing housing 10 in which the revolvable device 8 runs. Figure 9b shows a second angular contact ball bearing housing 11 in which a rear lip 6aa (see Figure 7a) of the driving gear 6a runs. The angular contact ball bearing housings 10, 11 comprise thirty six balls 9, eighteen of which are contained in the forward end ball cages 10a and eighteen of which are contained in the rear end ball cages 11a respectively. The forward end ball cages 10a are curved to prevent rubbing against the revolvable device 8.

Figures 10a and 10b show an outer ring 12 which retains the angular contact ball bearing housings 10,11 (see Figures 9a and 9b). The angular contact ball bearing housings 10, 11 are retained by the outer ring 12 which is attached to a rear housing 13 (see Figure 11), for example the outer ring 12 may screw onto the rear housing 13.

Figures 1, 11 and 11a show the rear housing 13 which includes one part having a longitundinal axis co-axial with the axis of rotation of the rotor 3, inlet shaft 2 and drive shaft 7 at one end of the housing 13. The other end of the rear housing 13 also comprises a part having a longitudinal axis co-axial with the revolvable device 8 which is attached to the outer ring 12 (see Figures 10a, 10b). This part of the rear housing 13 is orientated at the same oblique angle as the rotatable device 8 from the axis of rotation of the rotor 3, in this case 22°. An oil pump flange 14 (see Figures 12a and 12b) is attached to the end of the rear housing 13 with a horizontal longitundinal axis. A face to face tapered roller bearing 13c (see Figure 1) is located in the rear housing 13 between a lip 13b and the oil pump flange 14. Shims may be used to provide clearance between the face to face tapered roller bearing 13c and the lip 13b and oil pump flange 14.

As shown in Figures 12a and 12b, the oil pump flange 14 is shaped to allow a nut on the drive shaft 7 of Figure 1 to run in it. The oil pump flange 14 bolts into the end of the rear housing 13 distal from the rotor 3. The nut on the drive shaft 7 provides axial retention for the rotor 3. Connected to the rear of the oil pump flange 14 is an oil pump 15 (see Figure £υ2υοβ 9 1). The oil pump 15 makes use of the drive shaft 7 as a power source, and is used to lubricate the components of the engine.

Referring again to Figure 1, a compressor 16 such as a centrifugal type compressor provides an air flow through a duct 17 which is attached to the inlet shaft 2. The compressor 16 may use the drive shaft 7 as a power source to provide a pressure of approximately 1.5 atmospheres in the present embodiment.

The components of the invention which have been described thus far are surrounded by an engine casing 25 which provides a mounting for the internal components.

Spark plugs 22 are provided at the front end of the rotor. One spark plug 22 is provided for each cylinder 3 a, contained in a threaded hole at the front end of the rotor. One threaded hole is provided for each cylinder 3a so that each spark plug 22 may activate a spark in each corresponding cylinder 3 a when required. The spark plugs 22 are activated by an ignition block 21 which is located on the engine casing 25, in line with a cylinder 3a directly above the central axis of the rotor 3. The ignition block 21 is fed by a coil 20 which is controlled by an Engine Control Unit or ECU 19.

Duct 17 provides an air flow into the inlet shaft 2 and has a throttle 24 for regulating the air flow close to the inlet shaft 2. The duct 17 also contains sensors used to measure properties of the air flow, for example air flow rate. The sensors send signals to the ECU 19. The ECU 19 also controls the throttle 24.

The engine casing 25 is provided with a plurality of openings (not shown) which allow exhaust gases to pass from the outlet ports 3d and through the openings in the engine casing 25 during operation of the engine 1. An outer exhaust ring 18 shown in Figure 13 is located around the engine casing 25, covering each of the engine casing openings. The outer exhaust ring 18 collects all the exhaust gases from each cylinder 3 a via the engine casing openings and also mixes the hot exhaust gases with the cooler air being circulated around the rotor 3 by cooling fins 3b during rotation of the rotor 3. The outer exhaust ring 18 is emptied through one exhaust outlet 18a. The outer exhaust ring 18 acts as a safety IE0 2 06 β 9 feature, by mixing the hot exhaust gases from the outlet ports 3d of the cylinders 3a with cool air to ensure the overall temperature at the exhaust outlet of the outer exhaust ring 18 is lower. A pneumatic wedge 27 is attached to the engine casing openings which serves to prevent loss of inlet gases through the outlet port 3d before combustion. Also, an exhaust gas control valve (not shown) is attached to the engine casing openings to balance the pressure between the inlet port 3c and the outlet port 3d.

A starter may be fitted to the drive shaft 7. In operation, a starter is activated on the drive shaft 7 to ensure rotation of the drive shaft 7, revolvable device 8 , drive gear 6, rotor 3, and inlet shaft 2. As the revolvable device 8 rotates at an oblique angle, the pistons 26 are caused to stroke in the cylinders 3 a as the pistons are attached to the revolvable device 8 by dynamic connecting rods 5.

A continuous air flow enters through the inlet shaft 2 via duct 17 and is directed into the inlet ports 3c of cylinders 3a. The reciprocating movement of the pistons 26 in the cylinders 3a serves to cover and uncover the inlet and outlet ports 3c, 3d so that inlet gases enter the cylinders 3a before ignition and the exhaust gases exit the cylinders 3a after ignition as required. A fuel distributor 4 is positioned with nozzles 4c, 4d directed towards the inlet port 3c of a cylinder 3 a at a preferred position. The timing of fuel injected into the inlet port 3c by the fuel distributor 4 is controlled by the ECU 19. The piston 26 in the cylinder 3a (see Figure 1) directly above the central axis of the rotor 3 is in top dead centre position. The spark plug 22 is energized by the ignition block 21 so that the air and fuel mixture ignites. This causes an increase in temperature and pressure of the gas which forces the piston 26 down the cylinder 3a. The linear energy on the piston 26 is converted to rotational energy by the revolvable device 8 and the ballbearing housing 10. As the rotor 3 rotates, the piston 26 in each cylinder 3a is acted upon by the ignition of inlet gases as described when each piston 26 is close to top dead centre position. As the revolvable device 8 is attached to the drive gear 6, the drive shaft 7 rotates at the same speed as the revolvable device 8, rotor 3, and inlet shaft 2 as it is also attached to the drive gear 6. The rotation of the drive shaft 7 may then be utilized to produce a useful work output.

IE 0 2 06 8 9 After the piston 26 has stroked, the exhaust gases are removed through the outlet port 3d by the continuous air flow in through the inlet port 3c.

A particular advantage of the rotary engine of the invention described herein is the use of a spherical bearing 5d to attach the piston 26 to the dynamic connecting rod 5. In one embodiment of the invention, the longitudinal axis of the dynamic connecting rod 5 extending between the revolvable device 8 and the piston 5 is not co-axial with the longitudinal axis of the cylinder 3a in which the piston 26 is housed. In order to produce greater torque, the radius of the revolvable device 8 is such that there may be a slight misalignment, for example 1°, between the longitudinal axis of the connecting rod 5 and the longitudinal axis of the cylinder 3 a so that the connecting rods 5 taper slightly from the revolvable device 8 to the piston 26. The use of the spherical bearing 5d ensures smooth running of the piston 26 and prevents irregular rattling movements of the piston 26 during its operation in the cylinder 3 a.

The positioning of the extension piece 5a at an angle from the connecting rod 5, for example 26.5°, along with the use of the dynamic balance weight 5b prevents the piston 26 exerting an excessive centrifugal force on the cylinder 3a wall. This prevents excessive wear on the cylinder 3a wall.

In the embodiment described herein containing eight cylinders 3 a, advantageously three cylinders 3 a are firing at any given moment during operation. Also, for one revolution of the rotor 3 each cylinder 3 a fires once, so there are eight fires per revolution.

The bevel gear 6 is designed such that there is a clearance between the teeth of the driving and driven gears 6a, 6b of 0.0508 millimetres when hot during operation and 0.1524 millimetres when cold as the bevel gear 6 is not rotating. This clearance allows oil to be directed between the teeth by the oil pump 15 and prevents gear backlash or wear due to too close a fit.

Furthermore the present invention is a pure rotary engine 1 so that the leverage is the distance between the centre of the revolvable device 8 and the point where the dynamic IE 0 2 06 8 9 connecting rods 5 attach to the revolvable device 8 via the D shaped pins 5c. In the present embodiment the leverage is 0.109 metres. This corresponds to the throw of a crankshaft in a reciprocating engine which is typically 0.033 metres to 0.038 metres. Therefore a torque in the region of three times that generated by known reciprocating engines is produced by the engine of the present invention. In the embodiment described herein, the size of the engine 1 of the present invention is 1760cc producing approximately 370 kilowatts and brake horse power of 400-500. A typical reciprocating engine of similar size may produce in the region of 85 kilowatts.

In the present embodiment of the invention with an engine 1 size of 1760cc and a break horse power of 400 to 500, an oblique angle of 22° between the revolvable device and a plane perpendicular to the axis of rotation of the rotor has been found to be ideal. However, the invention is by no means limited to this particular angle and the angle used in any given engine will be selectable to best suit the specification of that engine and the desired power and torque requirements. Any suitable angle within the range of 10° and 35° may be selected. For example, an angle of 10° may be suitable for a short stroke, high speed rotary engine, while an angle or 35° may be selected for a long stroke, slow running rotary engine.

Only one ignition block 21 is required. It is attached to the engine casing 25 in line with a cylinder 3 a directly above the central axis of the rotor 3. The ignition block 21 is positioned close to the spark plug 22 of each cylinder 3a as the rotor 3 rotates. As the rotor 3 rotates the spark plugs 22 pass the ignition block 21 so that the ignition block 21 energises the spark plugs 22 to cause ignition in each cylinder 3 a when the piston 26 is close to top dead centre position. The ignition block 21 may energise the spark plugs 22 to cause ignition in each cylinder 3 a when the piston 26 is in the top dead centre position. Alternatively it may be preferable for the ignition block 21 to energise the spark plugs 22 to cause ignition before or after top dead centre of the piston 26 as required. The timing of energising of the ignition block 21 is controlled by the ECU 19 so that it sparks periodically as each spark plug 22 is in position. ΙΕΟ 2 06 β 9 Similarly, only one fuel distributor 4 is required as the present invention is a rotary engine so that the fuel distributor remains stationary directing fuel into the inlet port 3 c of a cylinder 3a at a preferred position to ensure satisfactory ignition of the fuel and air mixture. The timing of the fuel distributor 4 is controlled by the ECU 19.

The ECU 19 continuously monitors and controls various components of the engine including fuel and ignition timing and sensors, fuel volume added, air flow rate, throttle 24 position, and revolutions per minute of the engine.

A dry sump at the bottom of the engine casing feeds oil back into an oil tank (not shown) which feeds the oil pump 15. The oil pump 15 feeds oil to many components of the engine 1 including the pistons 26, the dynamic connecting rods 5, the front needle roller bearing 23 in which the inlet shaft 2 runs, the angular ball bearing housings 10, 11 supporting the revolvable device 8 and the drive gear 6.

The angular ball bearing housing 10 which retains the revolvable device 8 takes the load of the pistons 5 ensuring that the linear motion of the pistons 5 is converted to rotational motion of the revolvable device 8.

The embodiment of the invention described herein runs on petrol. Adaptations may be made in order for the engine to run on other fuels, for example diesel, kerosene or alcohol.

The drive shaft 7 runs in a face to face tapered roller bearing 13c which is located in the rear housing 13. The face to face tapered roller bearing 13c comprises an outer fixed ring and an inner rotating ring separated by tapered rollers (not shown). It serves to counteract longitudinal and axial forces caused by the rotating drive shaft 7 and the firing pistons 5 respectively.

Compared to existing engines, the present invention has a superior power to weight ratio, fewer moving parts and enhanced smoothness of operation. The present invention has no fixed cylinder block, no cylinder head, no crankshaft and no flywheel. It has high piston leverage and makes use of high efficiency ball and roller bearings. Furthermore there is no IE 0 2 06 8 9 cooling liquid, no cooling liquid radiator or hoses, and no water pump utilized in the present invention.

Suitable materials for constructing the engine and components thereof will be apparent to the skilled person. The following materials are used in the particular embodiment described above in detail. Bearing steel is used for the inlet shaft, revolvable device and revolvable device caps. High carbon steel is used for the dynamic connecting rods, rear housing, outlet shaft. Tool steel is used for the rotor. High tensile steel bolts are used. Stainless steel is used for the outer exhaust ring. Aluminium is used for the rotor, oil pump housing, engine casing, fuel distributor, compressor, pistons. Chrome molybdenum steel balls are used in the angular ball bearings. Brass or bronze bearing cages are used in the angular ball bearings. Lead bronze spherical bearing are used in the dynamic connecting rod. The pistons are die cast from aluminium for smoothness. The dynamic connecting rods are machined from a solid piece of high carbon steel to ensure a high level of precision so that they are well balanced during rotation. Similarly, the revolvable device is machined from bearing steel.

It will be apparent that many alterations and variations may be made without departing from the scope of the invention. For example, other combinations of cylinders may be used other than eight. Accordingly the size and shape of the various components may be altered, for example the revolvable device may have a different number of flat edges than eight. Furthermore the engine could be enlarged or shrunk depending on the design requirements.

Typical applications of the rotary engine of the present invention include cars, light aircraft, tanks, boats, yachts, electricity generation etc.

It is to be understood that the invention is not limited to the specific details described * herein, which are given by way of example only, and that various modifications and alterations are possible without departing from the scope of the invention.

MACLACHLAN & DONALDSON

Claims (5)

CLAIMS:

1. A rotary engine comprising a mounting means, a rotor supported on the mounting means and having a plurality of cylinders, the cylinders having their longitudinal axes spaced radially outwardly from and substantially parallel to the axis of rotation of the rotor, each cylinder having a piston formed for reciprocating motion therein, a revolvable device connected to the pistons of the rotor for rotation about an axis which is co-axial with the axis of rotation of the rotor and in a plane which is at an oblique angle to the plane perpendicular to the axis of rotation of the rotor, the revolvable device being securely rotatably mounted in a housing which is fixed relative to the rotor on the mounting means in a plane which is at the same oblique angle as the revolvable device so that in use firing of the cylinders in sequence in the opposite direction to the direction of rotation of the rotor causes rotation of the revolvable device and rotor.

2. A rotary engine as claimed in claim 1, in which the revolvable device comprises a main body having a central bore extending therethrough and a power transmission means is mounted on the revolvable device.

3. A rotary engine as claimed in claim 2, in which a power transmission means is mounted between the revolvable device and the rotor and comprises a bevel gear having a first gear wheel fixed co-axially about the bore of the revolvable device and a second cooperating gear wheel fixed on the rotor, the second gear wheel having an axis of rotation coaxial with the axis of rotation of the rotor; optionally in which a drive shaft is fixed on the second gear wheel for co-axial rotation therewith, the first gear wheel having a central bore and the drive shaft passing through the central bore of the gear wheel and the central bore of the revolvable device or in which the drive shaft is mountable on a side of the revolvable device facing away and distal from the rotor, the drive shaft being coaxial with the axis of rotation of the revolvable device; optionally in which a starter motor is in operable communication with the engine to initiate rotation of the rotor; IE 0 2 0688 optionally in which a connecting rod connects each piston to the revolvable device; optionally in which a spherical bearing is mounted between the connecting rod and the piston; optionally in which the connecting rod has an extension member depending from the end of the connecting rod which is connectable to the revolvable device, the extension member extending at an angle to the connecting rod and having a retaining means about its tree end for securely housing a dynamic balancing weight; optionally in which the revolvable device runs in an angular contact ball bearing which is connected to a separate rear housing; and optionally in which the rear housing contains a drive shaft bearing having face to face tapered roller bearings.

4. A rotary engine as claimed in any preceding claim, in which the oblique angle is selected to be in the range of between ten and thirty five degree, preferably between fifteen and thirty degrees and most preferably between twenty and twenty five degrees.

5. A rotary engine substantially as herein described with reference to and/or as shown in the accompanying drawings.