GB2218467A

GB2218467A - Rotary combustion engine

Info

Publication number: GB2218467A
Application number: GB8616889A
Authority: GB
Inventors: Moehasyim Soetrisno Hadi Bin
Original assignee: Individual
Current assignee: Individual
Priority date: 1986-07-11
Filing date: 1986-07-11
Publication date: 1989-11-15
Also published as: GB8616889D0

Abstract

The engine comprises a compressor 1 supplying compressed air or air/fuel mixture to a combustion chamber 12 which in turn supplies an expander 2. The expander is of the rotary positive displacement type as shown and the compressor may be of that type also. However, in alternative embodiments the compressor is of the reciprocating piston type (Fig 4, not shown) and may supply two expanders (Fig. 5, not shown). <IMAGE>

Description

A SOURCE OF POR The present invention relates to a source of power and more particularly to an internal combustion engine.

Internal combustion engines comprising a piston reciprocating within a cylinder have been linoa,5n for a long time. In the spark-ignition engine a mixture of fuel and air is compressed and then ignited by a spark and the expansion of the combustion products causes the piston to perform work. In the compression-ignition engine the mixture of fuel and air is also compressed but to a greater extent and ignition is caused by the compression itself. In both these engines compression and expansion occur in the same cylinder.

According to the present invention there is provided a source of poser comprising a compression chamber, means to compress a fluid within the compression chamber, a world chamber separate from the compression chamber to receive products of combustion of the compressed fluid and a combustible fluid and a rotor rotatable within the work chamber by expansion of the products of combustion of the combustible medium and compressed fluid.

The means to compress the fluid may comprise a rotor rotatable within the compression chamber.

The source of power may comprise a combustion chamber for combustion of the combustible medium and compressed fluid.

The source of pilfer may comprises valve means between the combustion chamber and the compression chamber to control the flow of compressed fluid to the combustion clamber.

The source of po'.r may comprise valve means between the combustion chamber and the work chamber to control the flow of the combustion products to the lçor'i chamber.

The source of poser may comprise a camshaft means connected to the rotor in the work chamber and arranged to operate the valve means between the combustion chamber and the compression chamber and the valve means between the combustion chamber and the work chamber in dependence on the rotational position of the rotor in the lrork chamber.

Tile source of polçer may comprise valve means to control the introduction of fluid to the compression chamber.

The camshaft means may be arranged to operate the valve means for controlling the introduction of fluid to the compression chamber.

The source of power may be a spark-ignition source of power wherein the production of the spark may be actuated in dependence on the rotational position of the camshaft means.

The source of power may be a compression ignition source of power wherein introduction of the combustible medium may be actuated in dependence of the rotational position of the camshaft means.

The rotor in the work chamber may comprise a lobe wllich sweeps the inner wall of the work chamber1 diaphragm means extending within the work chamber and engaging the rotor, the diaphragm means being retractable by the lobe of the rotor as the lobe passes the diaphragm means and returned to extend within the work chamber after the lobe has passed the diaphragm means.

The diaphragm means may communicate with a piston via hydraulic fluid, the piston being displaceable in one direction on retraction of the diaphragm means and in the opposite direction by pressure from the expansion of the products of combustion to urge the diaphragm means to return to extend within the work chamber.

The hydraulic fluid may communicate via a one way valve with a reservoir of hydraulic fluid, the valve permitting hydraulic fluid to flow from the reservoir when the piston is displaced in the said opposite direction.

The rotor in the compression chamber may comprise a lobe which sweeps the inner wall of the compression chamber, and wherein diaphragm means may extend within the compression chamber and engages the rotor, the diaphragm means being retractable by the lobe of the rotor as the lobe passes the diaphragm means and returned to extend within the compression chamber after the lobe has passed the diaphragm means The compression chamber may comprise a piston reciprocably displaceable within the cylinder.

The work chamber may comprise outlet valve means selectively communicable with exhaust and with the compression chamber.

The compression chamber may be cornunicable with the work chamber via a combustion chamber.

The combustion chamber may comprise first inlet valve means for uncompressed fluid and second inlet valve means for compressed fluid received from the compression chamber.

The source of power may comprise a further work chamber, each lfork chamber comprising outlet valve means selectively communicable with exhaust and with the compression clamber.

The compression chamber may be communicable with each work chamber via a respective combustion chamber.

Each combustion chamber may comprise first inlet valve means for uncompressed fluid and second inlet valve means for compressed fluid received from the compression chamber.

The compression chamber may comprise outlet valve means for compressed fluid.

The rotor in the working chamber and the rotor in the further working chamber may be mounted on a common shaft to rotate in unison.

The source of power may comprise camshaft means to operate the first inlet valve means to the combustion chamber for the uncompressed fluid, the second inlet valve means to the combustion chamber for the compressed fluid and the outlet valve means from the compression chamber for the compressed fluid.

The camshaft means may be arranged to rotate at a quarter of the speed of the rotors.

The source of pilfer may comprise a Geneva Mechanism to provide the rotation of the camshaft means.

Each work chamber may comprise respective diaphragm means actuated by hydraulic fluid from a corimon source.

The source of poser may comprise means to lock the diaphragm means of the or each work chamber against the or each rotor when the or each lobe is not in contact with the or each rotor.

The locking means may comprise hydraulic fluid to urge a piston against the rotor and spinning valve means arranged to rotate at the same speed as the or each rotor and to release the flow of hydraulic fluid when the or each lobe engages the or each diaphragm means.

The present invention twill now be described by way of example and with reference to the accompanying drawings in which: Figures 1 to 3 show an embodiment of a source of power according to the present invention in which the rotors in the work and compression chambers are in different positions, Figures 4A to D show a modification of the source of porter shown in Figures 1 to 3 in which compression is accomplished by means of a recipro catin & compressor.

Figures 5A to D show a modification of the source of power shown in Figures 4A to D, in w icl, compressed fluid is fed to two work chambers, Figure 6 shows a sectional view of the source of power shown in Figures 5A to 5D in which the compressor is an integral part of the source of power and the pistons of both work chambers are rotatable on a common shaft, Figure 7 shows a modification of the diaphragm means shown in Figures 1 to 3 for use in the source of power shoal in Figures 5A to D, in which the diaphragm means can be locked against the surface of the rotor in the work chambers, and Figure 8 shows part of an hydraulic circuit for use in operating the diaphragm means shorn in Figure 7.

Referring to Figures i to 3 there is shorn a source of power in the form of an internal combustion engine comprising a compression chamber 1 and a work chamber 2. Within each chamber is respective rotor 3, 4 which are rotatable clockwise at the same speed. Each rotor 3, 4 comprises a lobe 5, 6 which sweeps the lfall of the respective chamber 1, 2 as the rotor 3, 4 rotates.

Air/fuel mixture is sucked through intake 7 by the result of the vacuum caused by the rotation of the rotor 3 and induction of this air is controlled by an intake valve 8. The intake process occurs during the first rotation of the rotor 3 in the compression chamber 1 and this intake mixture will be compressed during the next rotation of the rotor 3. In Figure 1 the intake mixture is shoin by means of dots and the compressed mixture from the previous rotation of the rotor 5 is shol.m by dashes 10. The compressed mixture is fed through a passage 11 to a combustion chamber 12 where it is ignitied by means of a spark plug 13.The products of combustion expand as a result of this ignition and pass through the passage 14 to the work chamber 2. The products of combustion are shown by means of dot-dashesl4a.The expansion of the products of combustion causes the rotor 4 in the work chamber to rotate. lv'hen the lobe 6 of the rotor 4 has passed the exhaust outlet 15 the exhuast gases shorn by lrary line 16 are able to flows from the work chamber 2.Located within the passage 11 is a charge valve 17 regulating the time at which the compressed mixture is permitted to pass into the combustion chamber and a chec' valve 18 for controlling the flow of mixture from the com- pression chamber 1. Located within the passage 14 between the combustion chamber 12 and the work chamber 2 is a throat valve 19 for regulating the time at which the products of combustion are able to pass into the work chamber 2.During the period in llich the intake valve 8 is open and mirtare is being drain into the compression chamber 1 the charge valve 17 is open to allow previously compressed mixture to pass to the combustion chamber 12 but the throat valve 19 is closed. This can be seen in Figure 1. At the instant the face 20 of the lobe 6 in the work chamber 2 reaches the exhaust outlet 15 the check valve 17 opens and the throat valve 19 closes as s'.lown in Figure 1.In practice tie check valve 17 opens slightly earlier tha- the throat valve 19 closes in order that any combustion gas remaining in the combustion chamber 12 can be expelled out of the work chamber 2 by incoming compressed mixture. As the rotor 4 in the work chamber 2 continues to rotate the back 21 of the lobe 6 engages diaphragm means 22 causing the diaphragm to retract into the housing 23.

The diaphragm comprises two elements 23 and 24 each provided with a collar 25, 26. The collar 26 engaging the upper surface of the element 23 and the collar 25 slides against the wall of the space 23. The extent to which the elements can depend into the work chamber 2 is limited by these collars 25, 26. In order to maintain engagement dth the rotor 4 when the diaphragm is not in contact with the lobe light springs 27 are provided and in order to reduce the frictional engagement between the diaphragm 22 and the rotor 3 each element 23, 24 of the diaphragm 22 is provided with a shoe or slipper 28, 29.

The diaphragm elements 23, 24 are stacked together in the space 23. The collar 25 of the diaphragm element 23 provides suspension of the diaphragm on the wall of the guide housing. By this arrangement, no spring pressure is forced to the surface of the rotor 4 when the diaphragm engages the rotor 3. The function of the diaphragm 22 is to provide a partition and seal in the bore of the work chamber 2. A passage 30 extends from the passage 13 between the throat valve 19 and the work chamber 2 and opens into a cylinder 31 within which is located a piston 32. The piston 32 is biased towards the lower end of the chamber by means of a coil spring 33. A passage 34 communicates between the upper end of the cyliner 31 and the diaphragm 22.

The passage 34 contains oil fed from a reservoir 35 via a line 36 containing a one-way valve 37 which allows the oil to flow fron the reservoir to the cylinder 32 but not in the reverse direction. The line 36 also extends from the reservoir 35 to a lower region of the cylinder 31 at a position just above the top of the piston 32.

The purpose of this push device is to push the diaphragm 22 quickly do.,mlrards at the instant of ignition in the combustion chamber 12. As mentioned above the diaphragm 22 is urged agt the surface of the rotor 2 by means of coil springs.

Hol.ever, the stronger the springs 27 the greater the friction between the shoes 28, 2q and the surface of the rotor 4. If this frictional force is reduced by making the springs 27 too Ifeak there is a possibility that the diaphragm 22 will not return sufficiently quickly once the lobe 6 has passed the diaphragm 22. The push device is actuated by gas pressure at the instant of combustion and this gas pressure pushes the piston 32 upltrardly in the cylinder 31. This causes the oil in the cylinder and the passage 34 to push the diaphragm dowm sufficiently quickly at a speed proportional to the pressure of the combustion gas.The gas pressure is trapped in front of the throat valve instead of the combustion chamber 12 so that the pressure inside the combustion chamber 12 during compression process does not affect the piston 32. The line 36 communicates with the cylinder 31 at a point above the maximum height to which the cylinder 32 can reach.If the cylinder 32 returned dol fards as the combustion pressure in the cylinder is decreased oil fro the reservoir 35 enters the cylinder 32 through the non-return valve 37 thereby preventing formation of a vacuum in the cylinder 31 enabling the piston 32 to move freely dolmlfards. The arrangement of the oil supply system as described above may be varied, for example by use of a low pressure oil pump.

A diaphragm 40 also extends into the compression chamber, which diaphragm 40 comprises three elements 41, 42 and 43 urged into the work chamber 1 by means of three springs 44, 45 and 46. The element 41 has a collar 47 which engages the element 42, the element 42 has a collar 48 which engages the element 43 and the element 43 has a collar 49 which engages the inner wall of a housing 50. As the face 51 of the rotor 2 passes, the element 41 returns first followed by the element 42 and then the element 43. The return of the element 41 causes a vacuum to develop under elements 42 and 43 as the rotor 2 rotates.Consequently the spring force and the atmospheric pressure inside the housing 50 pushes down the elements 42 and 43 quickly.

The travel of the rotor face 51 from top dead centre to the intake 7 gives sufficient time to the diaphragm 40 to close completely.

The engine operates as follows: Referring to Figure 1, air-fuel mixture 10 is being compressed by the back 52 of the lobe 5 of rotor 3 of compression chamber 1 whilst further mixture 9 is being drat= in from the intake 7.

Combustion gases 14a from the previous ignition expanding in the work chamber 2 and the exhaust process of the gas 16 is beginning. The charge valve 17 is open and the throat valve 19 is closed.

Referring to Figure 2, the compression process of the mixture 10 has been completed and the charge valve 17 closes and the throat valve 19 opens.

In the meantime the lobe 6 of the rotor 4 has just passed the diaphragm 22. The spark plug 13 ignites and combustion in the combustion chamber 12 tales place. Combustion pressure pushes the piston 32 upwards which causes the oil in passage 34 and its telescopic pipe which engages the diaphragm 22 to push the diaphragm 22 dolçn immediately.

Referring to Figure 3, the rotor 4 of the work chamber 2 is pushed round by the expanding gases 14a acting on the face 20 of its lobe 6 whilst the back 21 of the lobe sweeps the exhaust gases 16 of the previous combustion process through exhaust outlet 15. As the combustion pressure decreases the piston 32 gradually returns to the base of the cylinder 31. This tends to produce a vacuum.

in the cylinder above the piston but the nonreturn valve 33 prevents this tendency enabling the piston 32 to move freely dolSmlsards. As the rotor 4 continues to rotate the diaphragm element 49 closes and a vacuum under elements 47 and 48 develops which hastens the return of elements 47 and 48. The travel of the face 51 of the lobe 5 of rotor 3 from top dead centre to the intake 7 is to give the diaphragm time to completely close.

Although the above described engine draws in an air-fuel mixture which is ignited by a spark plug, the engine can be adapted for use as a compression ignition engine and a fuel injector 53 can be used.

In order to operate the throat valve 19, the charge valve 17, the intake valve 8 and either the spark plug 13 in the case of a spare ignition engine or the fuel injector in the case of a compression ignition engine, a camshaft 54 is driven by the shaft of the rotor 4 at the same speed.

Figures 4A to D show a modification of the engine shorn in Figures 1 to 3, in which the compression chamber 1 and its rotor 3 are replaced by a reciprocating compressor 100. In Figure 2 it can be seen that compression has been completed far before the face 51 of the rotor 3 reaches top dead centre and in this case there will be no difference if the rotor 4 in the work chamber were to provide compression. In the embodiment shorn in Figures 4A to D the complete compression stage is delayed. This is accomplished by accummulating the intake air-fuel mixture after being partially compressed by the rotor 4 in the work chamber 2 in the culinder 101 of reciprocating compressor 100.The compression effected in the work chamber 2 is hereinafter referred to as the first stage compression and the compression effected in the reciprocating compressor 100 as the second stage compression.

Ref erring to drawing I of Figure 4A there is shorn the beginning of the first cycle which is an intake process in which an intake valve 103 and a throat valve 10S are both open. The combustion chamber 104 is located between the two valves.

As the rotor i rotates it sucks in air-fuel mixture.

widen the rotor reaches the exhaust outlet 105 as shorn in drawing II of Figure 4A a valve 106 changes over to provide communication between the ork chamber 1 and the cylinder 101 of the reciprocating compressor 100 via a line 107 provided with a non-return valve 108 to prevent mixture passing back to the chamber 1. At this time as shown in drawing II of Figure 4A the throat valve 104 is closed.

Drawing I of Fibure 4B shows the start of the second cycle which is the second intake process.

The mixture of the first intake process is beginning to be compressed by the rotor 4 into the cylinder 101 through line 107 causing the piston 109 to move towards the left. As the face 20 of the rotor 4 reaches bottom dead centre, the reciprocating compressor 100 begins a compression stroke by the piston 109 moving to the right.

17hen the face 20 of the rotor 4 reaches the exhaust outlet 105 as shown in drawing II of Figure 4B the intake valve 103 closes and the outlet valve 106 of the reciprocating compressor 100 changes over and the valve 110 to the combustion chamber 111 opens to allow the mixture to pass to the combustion chamber 111 via a line 112. At this stage the second intake mixture is in the chamber 1.

Drawing I of Figure 4C shows the beginning of the third cycle. The second stage compression has been completed and the first ignition and compress ion process begins. The throat valve 104 is open.

This is followed by the first expansion process and torque is developed in the shaft of the rotor 4. The air-fuel mixture of the second intake process is compressed into the cylinder 101 of the reciprocating compressor 100, as the piston 109 moves to the left while the rotor 4 rotates to provide the second first stage compression. As the rotor 4 reaches the exhaust outlet 105 (drawing II of Figure 4C) the valve 106 changes over to its exhaust position to allow the expanded gas to exhaust to atmosphere. The piston 109 of the reciprocating compressor 100 is nor moving to the right compressing the mixture of the second intake.The intake valve 103 and the throat valve 104 are both closed.

Drawing I of. Figure 4D shots the beginning of the fourth cycle in which the second stage compress ion process has been completed and the rotor 4 has passed top dead centre. The intake valve 103 and the throat valve 104 are open. The second ignition and combustion process now take place followed by expansion and torque is again developed in the shaft of the rotor 4. As the rotor 4 rotates the exhaust gases front the first combustion process are swept out of the exhaust outlet 105 by the back 21 of the rotor 4.When the lobe 6 of the rotor 4 reaches the exhaust outlet 105 the intake valve 103 is open and the outlet valve 113 of the reciprocating compressor 100 changes over to prevent compressed mixture leaving the reciprocating compressor. Exhaust gases from the second combustion will be sept out through the exhaust outlet 105 during the next intake process which is that shorn in drawing I of Figure 4A.

In summary for every four revolutions of the rotor 4 of the eingine shown in Figures 4A to D two consecutive intake processes followed by two consecutive combustion processes occur. In the engine shorn in Figures 1 to 3, compression and combustion processes follow one another.

In the embodiment shol.-n in Figures 4A to D, after completion of the second compression process in the fourth cycle and then repeated to the first cycle by the first intake process, the reciprocating compressor 100 is not functioning. The outward movement of the piston 109 creates a vacuum winch is a resistance to the movement of the shaft in spite of the fact that the rotor 4 is twice in a "powerless" position.To overcome this an embodiment as shown in Figures 5A to D and 6 can be used which comprises two working rotor units A And B arranged to operate with a single reciprocating compressor.

Drawing II of Figure 5D shows the beginning of the second combustion process after the final second compression process. At this time the reciprocating compressor 200 is not needed by the unit A. However, at this moment the back 201 of the lobe 202 of the rotor 203 of the chamber 204 of unit B commences the first stage of the first compression process and the front 205 of lobe 202 corliflences the second intake process. The outward movement of the piston 206 of the reciprocating compressor 200 sucks the mixture of the first intake process from the chamber 204 of unit 13.Referring to the drawing I of Figure 5A, the first cycle starts again and the back 207 of the lboe 20t3 of the rotor 209 of the chamber 210 of unit A sweeps out the exhaust gases from the second combustion process of the fourth cycle sholo in Figure 5D, while the face 211 of the lobe 203 commences a freely first intake process. At this moment in unit B the face 205 of the lobe 202 begins the first co-.lbustion process whilst its back 201 commences the second first stage compression process and the air-fuel mixture is charged into the reciprocating compressor 200. During the net two rotations or cycles unit 13 will not need the reciprocating compressor 200 but unit A will. The process continues through the second and third cycles as shorn in Figures 5B and 5C until it is completed again in fourth cycle.

The intake valve 214 of each unit is open continuously from the begining of the first intake process until the end of the second intake process.

During the first and second combustion processes the intake valve 214 is closed. The outlet change-over valve 215 operates in either an exhaust position where exhaust gases can be exhausted to atmosphere or in a charging position where compressed mixture can be charged to the reciprocating compressor 200.

The outlet valve 216 of the reciprocating compressor 200 operates to allow mixture to be admitted to either chamber 210 of unit A or chamber 204 of unit 13.

Referring ot Fiure 6, the two units A and B are built inline, on the same shaft, the angular positions of both rotors 203 and 209 being the same.

Figure 6 shows only the rotor unit A. Each of the units is equipped with diaphragms 220 similar to those shol.m in Figures 1 to 3 complete with push device 221. They are also equipped with a throat valve 222 and a charge valve 223.

A camshaft (not sholtm) functions in a similar manner to that sllolm in Figures 1 to 3. The crankshaft 224 of the reciprocating compressor 200 is driven by the main shaft and revolves at the same speed as the shaft of the rotors 203, 209.

The cranjcshaft 224 drives the reciprocating compressor 200 which operates as the two rotors 203, 209 and has a displacement smaller than that of each rotor unit. A change over camshaft revolves intermittently at one quarter of the rotor speed and this intermittent motion is achieved by coupling the changeover camshaft directly or indirectly to the rotor shaft by means of a Geneva Mechanism 225. One rotation of the driver shaft 225 of the Geneva mechanism 225 causes the change over camshaft to rotate by 900 . The function of this change over camshaft is to actuate the intake valve 227, the rotor outlet valve 215 and the reciprocating compressor outlet valve 228.

The diaphragm push device 230 is similar to that sho.m in Figures 1 to 3. In addition, to pushing dol-m the diaphragm of thc rotor which is subject to an intake process, oil pressure is taken from the other rotor which is under a combustion process. Referring to Figure S this is accomplished by providing a change over valve 231 in thc hydraulic circuit for the push device of each unit. The change over valve 231 is actuated by the change over camshaft.

A check valve 232 located just behind the rotor outlet valve 215 automatically controls the flout; of the intake air-fuel mixture from the chamber 204, 210 to the reciprocating compressor 200 and prevents flow in the reverse direction.

In the case of a spark ignition engine an additional switch should be provided to the primary circuit. During the intake processes this switch must be "off", and "ons' at the instant the intake valve is shut.

In the case of a compression-ignition engine a by-pass valve should be provided at the discharge side of the pump, or any point in the line before the fuel injector. During the intake processes the by-pass valve should be open.

Tlie surface underneath the diaphragm 220 which makes sliding contact with the rotor surface may be subject to leakage. Should this leakague exist the gas pressure would tend to push the diaphragm. 220 up and this situation could be dangerous. The piston 232 of the push device is capable of holding the diaphragm 220 in place during the expansion process only if the area of the piston 232 is larder than the underneath of the diaphrag:ti 222. To install a piston 232 of such a large size is very difficult is not imposs- ible.To overcome this problem, a locrdn device as sho-Tn in Figure 7 may be provided. The lockins device is combined with the push device 230 to make one unit. A piston 240 slides on the outer side of a telescopic pipe 241 and within a cylinder 242. The hydraulic fluid 243 in the cylinder 242 pushes dorm the piston 240 which transmits the downward force on to the diaphragm.

The fluid 243 in the cylinder 242 communicates with a spinning valve 244. The spinning valve 244 comprises a rotor 245 spinning inside a cyliner 246 and is driven by and at the same speed as the camshaft. The valve rotor 245 has a groove 247 on its outer circumference and the rotor has an axial bore 248. The groove 247 and the bore are connected by a transverse bore 249. Oil is allowed to flow through the groove 247, the transverse bore 249 and the axial bore 248 and then discharge to a reservoir.If the spinning valve 244 is open (as shol,Sn in drawing A of the spinning valve) oil 243 in the cylinder 242 of the locking device communicates with the reservoir. In this position the piston 240 is free to move upl.ard.

If the spinning valve 244 is shut (as sho:m in drawing B of the spinning valve), oil 243 in the cylinder 242 is blocked, and the piston is locked.

In Figure 8 the engine is subject to a combustion process and oil pushes the piston 240 together with the diaphragm220 do':nward. Oil pressure hich is tapped from the einsine's lubricating oil pump, is then admitted into the cylinder 22 through a non return valve 250. At the same tine the spinning valve 244 is shut. The piston 240 is now locked until the spinning valve 244 completes its rotation and returns to the open position.

The spinning valve 244 starts to open at the instant the back of the work rotor is about to lift the diaphragm up and as the face of the work rotor reaches top dead centre the spinning valve has returned to its shut position. The piston 240 is locked and the diaphragm 220 is held in place.

Claims

CLAIDIS.

A source of power comprising a compression clamber, means to compress a fluid within the compression chamber, a work chamber separate from the compression chamber to receive products of combustion of the compressed fluid and a combustible fluid and a rotor rotatable within the work chamber by expansion of the products of combustion of the combustible medium and compressed fluid.

2. A source of potter as claimed in claim 1, wherein the means to compress the fluid comprises a rotor rotatable within the compression chamber.

3. A source of power as claimed in claim 1 or 2, comprising a combustion chamber for combustion of the combustible medium and compressed fluid.

4. A source of power as claimed in claim 3, comprising valve means between the combustion chamber and the compression chamber to control the flow of compressed fluid to the combustion chamber.

5. A source of power as claimed in claim 3 or claim 4, comprising valve means between the combustion chamber and the work chamber to control the flow of the combustion products to the work chamber.

6. A source of power as claimed in claim 5 comprising camshaft means connected to the rotor in the work chamber and arranged to operate the valve means between the combustion chamber and the compression chamber and the valve means between the combustion chamber and the work chamber in dependence on the rotational position of the rotor in the work chamber.

7. A source of power as claimed in any one of the preceding claims, comprising valve means to control the introduction of fluid to the compression chamber.

8. A source of power as claimed in claim 7 when dependent on claim 6, wherein the camshaft means is arranged to operate the valve means for controlling the introduction of fluid to the compression clamber.

9. A source of power as claimed in claim 8, being a spark-inition source of poser wherein the production of the spark is actuated in dependence on the rotational position of the camshaft means.

10. A source of power as claimed in claim 8, being a compression ignition source of power wherein introduction of the combustible medium is actuated in dependence on the rotational position of the camshaft means.

11. A source of power as claimed in any one of the preceding claims, wherein the rotor in the work chamber comprises a lobe which sweeps the inner wall of the work chamber, and wherein diaphragm means extends within the work chamber and engages the rotor, the diaphragm means being retractable by the lobe of the rotor as the lobe passes the diaphragm means and returned to extend within the work chamber after the lobe has passed the diaphragm means.

12. A source of power as claimed in claim 11, wherein the diaphragm means comrlunicates with a piston via hydraulic fluid, which piston is displaceable in one direction on retraction of the diaphragm means and in the opposite direction by pressure fro the expansion of the products of combustion to urge the diaphragm means to return to extend within the work chamber.

13. A source of power as claimed in claim 12, lsslerein the hydraulic fluid communicates via a one way valve with a reservoir of hydraulic fluid, the valve permitting hydraulic fluid to flol from the reservoir when the piston is displaced in the said opposite direction.

A A source of power as claimed in any one of claims 1 to 10, wherein the rotor in the compression chamber comprises a lobe which sweeps the inner wall of the compression chamber, and wherein diaphragm means extending within the compression chamber and engages the rotor, the diaphragm means being retractable by the lobe of the rotor as the lobe passes the diaphragm means and returned to extend within the compression chamber after the lobe has passed the diaphragm means.

15. A source of power as claimed in any one of claims 11 to 14, lçllerein the diaphragm means is resiliently biased towards the work chamber.

16. A source of power as claimed in any one of claims 11 to 15, wherein the diaphragm means comprises a plurality of elements disposed side-byside and so connected that movement of one causes movement of the or an adjacent element.

17. A source of power as claimed in any one of claims 11 to 16, wherein the diaphragm means comprises shoe means which resiliently contact the work rotor.

18. A source of power as claimed in any one of the preceding claims1 wherein the compression chamber comprises a piston reciprocably displaceable within the cylinder.

19. A source of power as claimed in claim 18, wherein the work chamber comprises outlet valve means selectively communicable with exhaust and with the compression chamber.

20. A source of power as claimed in claim 19, wherein the compression chamber is communicable with the work chamber via a combustion chamber.

21. A source of power as claimed in claim 20, wherein the combustion chamber comprises first inlet valve means for uncompressed fluid and second inlet valve means for compressed fluid received from the compression chamber.

22. A source of power as claimed in claim 18, comprising a further work chamber, each work chamber comprising outlet valve means selectively coninunicable with exhaust and with the compression chamber.

23. A source of power as claimed in claim 22, wherein the compression chamber is communicable with each world chamber via a respective combustion chamber.

24. A source of power as claimed in claim 23, wherein each combustion chamber comprises first inlet valve means for uncompressed fluid and second inlet valve means for compressed fluid received fro the compression chamber.

25. A source of poser as claimed in claim 24, therein the compression chamber comprises outlet valve means for compressed fluid.

26. A source of poser as claimed in any one of claims 22 to 25 wherein the rotor in the wonking chamber and the rotor in the further working chamber are mounted on a common shaft to rotate in unison.

27. A source of power as claimed in claim 26, comprising camshaft means to operate the first inlet valve means to the combustion chamber for the uncompressed fluid, the second inlet valve means to the combustion chamber for the compressed fluid and the outlet valve means from the compression chamber for the compressed fluid.

28. A source of power as claimed in claim 27 wherein the camshaft means is arranged to rotate at a quarter of the speed of the rotors.

29. A source of power as claimed in claim 28, comprising a Geneva Mechanism to provide the rotation of the camshaft means.

30. A source of power as claimed in any one of claims 18 to 29, wherein each work chamber comprises respective diaphragm means actuated by hydraulic fluid from a coru.lon source.

31. A source of power as claimed in any one of claims 11 to 30, comprising means to lock the dia32. A source of power as claimed in claim 31, wherein the locking means comprises hydraulic fluid to urge a piston against the rotor and spinning valve means arranged to rotate at the same speed as the or each rotor and to release the flow of the hydraulic fluid when the or each lobe engages the or each diaphragm means.

33. A source of porter substantially as hereinbefore described with reference to Figures 1 to 3, or Figures 4A to 4D, or Figures 5A to 5D and Figure 6, or Figure 7.