GB2101686A - Rotary internal-combustion engine - Google Patents

Abstract

The engine has a pair of eccentric cylindrical rotor 14a,b revolving in a cylindrical bore 11 and fixed between journals 13 of an output shaft 12, the circumferential surfaces of the rotors co-operating with spring-loaded vanes, or "seals", 16,17 lodged in bores 18. Fuel-air mixture inducted through a port 21 is compressed by the rotor 14a and ignited by a spark plug 25 while in a transfer passage 22. The expanding combustion products rotate the rotor 14b. A modified form of the engine shown in Fig. 1 is described, Fig. 3 (not shown). Alternatively, the seals and transfer passage may be in the rotors and shaft, Fig. 2 (not shown). As another alternative the rotors may be disposed side-by-side, Figs. 4-7 (not shown). <IMAGE>

Description

SPECIFICATION Improved rotary internal combustion engine This invention relates to a rotary internal combustion engine having at least one pair of relatively rotatable members mounted one within the other to provide variable volume working chambers. The outer member may be a stationary or rotary member and the inner member a rotary or stationary member respectively, or both the inner and outer members may rotate so long as the configuration of each and the relative angular displacement of one member with respect to the other is such as to form said variable volume working chambers.The outer member may be a stationary member and the inner member may be the rotary member; alternatively the outer member may be the rotary member and the inner member the stationary member; or both the outer and inner members may be rotary members with one ofthe members rotating at a greater angular velocity than the other.

An object of the invention is to provide a new and improved rotary internal combustion engine.

According to the present invention, I provide a rotary internal combustion engine having a first pair of relatively rotatable members comprising a first inner member and a first outer member, the inner member being mounted within the outer member to provide both an intake chamber and a compression chamber during relative rotation and a second pair of relatively rotatable members comprising a second inner member and a second outer member, the inner member being mounted within the outer member to provide both an ignition/expansion chamber and an exhaust chamber, during relative rotation the first and second outer members each having an inner cylindrical wall, a part of which is in continuous sealing contact with a part of said first and second inner members respectively, the inner members each being substantially circular in section and eccentrically mounted within said outer members whereby relative rotation between the inner and outer members provides said chambers, transfer means to transfer compressed gas from said compression chamber to said ignition/expansion chamber, means to create a fuel-air mixture within said compression chamber or in said ignition chamber and/or said transfer means prior to ignition, ignition means to cause said mixture to ignite in said ignition/expansion chamber and/or said transfer means only, and exhaust means to exhaust ignited mixture from said exhaust chamber.

The inner members may each be provided at axially spaced positions relative to an axis of relative rotation common to the first and second pairs of outer members.

The first pair of relatively rotatable members may rotate about a first axis and the second pair of relatively rotatable members may rotate about a second axis, said first axis being spaced transversely relative to the second axis.

A radially slidable sealing means may be provided at a location between an intake port of the intake chamber and a transfer port of the compression chamber in the case of said one pair of members, and between a transfer port of the ignition/expansion chamber and an exhaust port of the exhaust chamber in the case of said second pair of members.

A non-return valve may be provided in the transfer means to prevent passage of gas from said second pair of members to said first pair of members.

Preferably the non-return valve is adapted to open to permit passage of gas from said compression chamber to said ignition/expansion chamber when the pressure of gas acting on the valve exceeds a predetermined value.

Alternatively, the sealing means may comprise a slide valve to control passage of gas through the transfer means.

The rotatable member of the second pair of relative rotatable members may rotate in an opposite direction to the rotatable member of the first pair.

The first and/or second outer member may be stationary and the first and/or second inner member may be connected to a drive means.

The sealing means may be radially slidably mounted in the first and/or second outer member.

The transfer means, mixture creating means, ignition means and exhaust means may be provided in said first and/or second outer member.

Alternatively, the first and/or second inner member may be stationary and the first and/or second outer member may be connected to drive means.

The sealing means may be radially slidably mounted in said first and/or second inner member.

The transfer means, mixture creating means, ignition means and exhaust means may be provided in said first and/or second inner member.

The radially slidable sealing means may comprise an element pivotally connected to the member not containing the transfer means and slidable relative to the member containing the transfer means and the inner and outer members being mounted for eccentric and oscillatory relative movement.

In the case where the first and/or second outer member contains the transfer means, the first and/or second inner member being mounted so that its central axis follows an eccentric path and the first and/or second inner member oscillates about its pivotal connection to the sealing element which is radially slidably mounted relative to the first and/or second outer member.

Four embodiments of the invention will now be described in more detail by way of example with reference to the accompanying drawings wherein: FIGURE lisa diagrammatic perspective view partly exploded, of a rotary internal combustion engine embodying the invention; FIGURE 2 is a diagrammatic transverse crosssectional view through a second embodiment of the invention; FIGURE 3 is a view similar to that of Figure 1 of a third embodiment ofthe invention; FIGURE 4 is a diagrammatic cross-sectional view through a fourth embodiment of the invention; FIGURES 5, 6 and 7 are views similar to that of Figure 4 but showing alternative phases of operation.

Referring to Figure 1, there is Sr rvn a rotary internal combustion engine comprising a stationary housing 10 in which is formed a cylindrica < ~ore 11 in which is rotatably mounted a drive shaft 12 having three cylindrical bearing portions 13 which are in bearing engagement with the wall ofthe bore 11.

Between the bearing portions 13 are cylindrical eccentric portions 14a, 14b. The eccentric portions 14a,14b are adapted, in the regions indicated at 15, to be in contact with the wall of the bore 11 and thus together with sliding seals 16 and 17 form with the bore 11 a plurality of variable volume working chambers.

The seals 16 and 17 comprise generally cylindrical members slidably mounted in radial cylindrical bores 18 and formed, at their lower ends, with a generally prism-shaped part 19 which terminates in a sealing edge 20 in engagement with the eccentrics 14a, 14b. Coil compression springs (not shown) are provided to bias the seals 16 and 17 into engagement with the eccentrics 14a, 14b.

The eccentric 14a forms the inner member of the first pair of relatively rotatable inner and outer members, the outer member being provided by the part of the bore 11 associated with the eccentric 1 4a.

Likewise the eccentric 14b forms the inner member of a second pair of inner and outer members, the outer member of which is afforded by the associated part of the bore 11.

The eccentric 14a and the bore 11 provide an intake chamber through which fuel/air mixture is fed through an inlet port 21 from a carburettor (not shown). The eccentric 14a also provides a compression-transfer chamber from which a trans fer passage 22 extends with a spring loaded non transfer ball valve 23 and which communicates with a spark plug duct 24 in which a spark plug 25 is received and hence with a compression-ignition chamber afforded by the eccentric 14b which also provides an exhaust chamber from which an exhaust port 26 extends.

The transfer passage 22 is formed by drilling intersecting passages, as shown in Figure 1, the external ends of which are closed by suitable closure means (not shown).

In use, with drive shaft 12 rotating in the direction of the arrow A in Figure 1, mixture is drawn through the inlet port 21 into the intake chamber as a result of the volume of said chamber increasing as the eccentric 14a rotates. The mixture is thus transferred into the compression chamber and is compressed and enters the transfer passage 22, passes the nonreturn valve 23, when the pressure acting on the valve 23 exceeds a predetermined value, and enters the ignition/expansion chamber associated with the eccentric 14b still under pressure, the eccentric 14b being positioned so as to maintain the volume of the ignition/expansion chamber at or about a minimum at the time of transfer.The spark plug 25 then ignites the mixture and the resultant explosion drives the eccentric 14b and causes expulsion of previously exploded gas and subsequent transfer of the just exploded gas to the exhaust chamber and hence to exhaust through the port 26.

Although in this example mixture has been described as being provided by a carburettor, if desired, air only could be introduced through the port 21 and fuel injected directly in the ignition chamber.

Also, although in the above described example the housing 10 has been described as being stationary, the housing and the shaft 12 and eccentrics 14a and 14b could rotate relative to each other and to a fixed supporting structure.

In a second embodiment of the invention shown in Figure 2, in which parts corresponding to those shown in Figure 1 are indicated by similar reference numerals, with the addition of a prime sign, the eccentrics 14a' and 14b' are stationary whilst the housing 10' rotates and is connected to a driving means (not shown). The carburettor, inlet passage, transfer passage 22', spark plug 25', non-return valve 23', exhaust port 26' and seals 16' and 17' are all provided in appropriate passageways in the eccentrics 14a' and 14b' and drive shaft 12'.

Referring now to Figure 3, a third embodiment is illustrated which is basically similar to that shown in Figure 1 and hence parts corresponding to those shown in Figure 1 are indicated by similar reference numerals with the addition of a double prime sign.

The only difference between the embodiment shown in Figure 3 compared with that of Figure 1 is in the nature of the transfer passage and ball valve.

The transfer passage 22" extends from a position 30 in the wall of the bore 18" in which the seal 16" is received. The seal 16" has a cut-away portion 31 which, when aligned with the region 30 of the transfer passage, provides communication between the interior of the working chamber and the transfer passage 22", whilst when the seal 16" is moved further radially inwardly, its cylindrical wall 32 is aligned with portion 30 and thus provides a slide valve to close the transfer passage 22".

A similar arrangement is provided at the other end of the transfer passage 22", the seal 17" likewise being provided with a cut-away portion (not shown) corresponding to the portion 31 and again acting as a slide valve.

The above described arrangement avoids the need to provide a spring-loaded ball valve.

Referring now to Figures 4 to 7, there is illustrated a further alternative embodiment of the invention.

This embodiment comprises a first pair of relatively rotatable inner and outer members 40,41 respectively and a second pair of inner and outer relatively rotatable members 42 and 43 respectively. The outer members 41 and 43 are formed as cylindrical chambers arranged side by side in a common cylinder block indicated generally at 44. The inner members 40 and 42 are both cylindrical and rotatably mounted on an eccentric on a drive shaft, the two drive shafts being geared together so as to rotate in opposite directions.

Seal members 45a, 456 are slidably mounted in bores 46 formed in the cylinder block 44 and have bearing means indicated at 47 to pivotally connect the seals 45,46 to the inner members 40,42 respectively.

Induction passage 48 is provided for the first pair of members 40,41 whilst an exhaust passage 49 and a spark plug 50 are provided for the second pair of members 42,43.

A transfer passage 51 extends between the bores 46 for the seals 45a, 45k and the seals 45a, 45b each have a cut-away portion 52 which, when aligned with the transfer passage 51, permits flow of gas from the working chamber defined between the members 40,41 to the working chamber defined between the members 42, 43.

Turning now to consider operation of the engine shown in Figures 4 to 7. The members 40 and 42 are geared together so as to be at a phase angle of 900 to each other. In Figure 4 the engine is shown at the beginning of an induction phase. As the engine operates, the inner member 40 moves to the position shown in Figure 5 by rotation about the bearing 47 as shown by the arrow and as a result of translational movement due to its mounting upon the eccentric on the drive shaft, referred to herein before.

Thus mixture is drawn through the induction passage 48 into the region 53, at the same time, mixture previously inducted and now in the chamber 54, is compressed.

Further, as shown in Figure 4, when the member 40 is at the beginning of its induction stroke, combustion has just taken place in the working chamber 55 behind the second inner member 42 and thus the member 42 is driven from the position shown in Figure 4 to that shown in Figure 5, at the same time exhausting previously combusted mixture from the chamber 56 th rough the exhaust port 49.

Upon continued rotation of the engine to the position shown in Figure 6, the member 40 continues to induct mixture into the chamber 53 and to compress previously inducted mixture in the chamber 54 whilst the other inner member 42 completes exhaust of the gases from the chamber 56 and starts to create a new chamber 56 for the gases shown combusted in Figure 4 in the chamber 55.

Referring now to Figure 7, the member 40 starts to swing back in the direction of the arrow shown in Figure 7 whilst the seals 45a and 45b open the transfer passage 51 and the compressed mixture is transferred from the chamber 54 to a newly formed working chamber 55 formed behind the member 42, the member 42 swinging in the direction of the arrow during this stage, and rotation continues until the position shown in Figure 4 is reached and the sequence of operations described hereinbefore repeated.

Because in the above embodiment the seals 45a and 45b are connected by the bearings 47 to their associated inner members 40,42 there is no need to provide springs acting on the seals 45a, 45k thereby aleviating sealing problems due to accelerations between the seals 45a and 45b and the surface ofthe members 40,42.

It is to he noted that because the combustion chamber 55 is wedge-shaped, it is of the desired shape for good combustion and to achieve good exhaust emission characteristics.

The induction passage 48 may be made large so as to achieve good induction of mixture into the chamber 53.

It is also to be noted that since the inner members 40,42 engage the wall of the outer members 41,43 over a relatively large arc, sealing problems in this region are avoided.

It is preferred for the inner members 41,42 to be 90" out of phase so as to permit the transfer passage 51 to be made as short as possible. However, if desired, other phase angles may be provided with corresponding alteration of the location of the transfer port and seals etc.

Because in the above described engines all the relatively rotating parts are of circular configuration, manufacture of the parts is more simple and economic compared with epitrochoidal type rotary engines. In addition, the acceleration forces on the sealing elements are relatively small and hence sealing is achieved without the need for sophisticated sealing materials.

By providing the ball valve or the slide valves in the transfer passage, combustion of the mixture upstream of the valve is prevented. In addition, when the ball valve is provided, by providing means to adjust the spring pressure acting upon the valve, the compression ratio of the engine may be adjusted as desired.

If desired, the need for the ball or slide valves may be eliminated by arranging the eccentrics 14a, 14b at a phase angle of, for example between 90-180".

If a ball or slide valve is provided then the phase angle between the eccentrics may be any desired angle between 180 and a very small angle, possibly even 0". If the engine is to run at high speed and the phase angle is preferably 90 .

Openings such as that indicated at 26 in Figure 1 are provided in the bearing portions to balance the rotating assembly.

The capacity of the engine may be varied by adjusting the diameter and/or length of the eccentrics and/or the diameter and/or length of the associated housing part.

If desired, instead of being a petrol engine as described, or other spark-ignition engine, the engine may be a diesel engine and the engine may have a compression ratio of up to 15-20:1.

In the embodiments of Figures 2 to 3, the seals 16 and 17 may be pivotally connected to their associated inner member 14a, 14k and rotate and oscillate as described in connection with Figures 4 to 7. Conversely, the embodiment described with reference to Figures 4 to 7 may be modified by arranging that the seals 45a, 45k are shaped and are in sliding sealing engagement with their associated inner members 40,42, similar to the seals 16, 17 of Figure 1.

Claims (20)

1. A rotary internal combustion engine having a first pair of relatively rotatable members comprising a first inner member and a first outer member, the inner member being mounted within the outer member to provide both an intake chamber and a compression chamber during relative rotation and a second pair of relatively rotatable members comprising a second inner member and a second outer member, the inner member being mounted within the outer member to provide both an ignition/expansion chamber and an exhaust chamber, during relative rotation the first and second outer members each having an inner cylindrical wall, a part of which is in continuous seang ng contact with a part of said first and second inner members resr.ec- tively, the inner members each being substantially circular in section and eccentrically mounted within said outer members whereby relative rotation bet ween the inner and outer members provides said chambers, transfer means to transfer compressed gas from said compression chamber to said ignition/expansion chamber, means to create a fuel-air mixture within said compression chamber or in said ignition chamber and/or said transfer means prior to ignition, ignition means to cause said mixture to ignite in said ignition/expansion and/or said transfer means only, and exhaust means to exhaust ignited mixture from said exhaust chamber.

2. An engine according to Claim 1 wherein the inner members are each provided in axially spaced positions relative to an axis of relative rotation common to the first and second pairs of members.

3. An engine according to Claim 1 wherein the first pair of relatively rotatable members rotate about a first axis and the second pair of relatively rotatable members rotate about a second axis, said first axis being spaced transversely relative to the second axis.

4. An engine according to any one of the preced ing claims wherein radially slidable sealing means is provided at a location between an intake port of the intake chamber and a transfer port of the compres sion chamber in the case of said one pair of mem bers and between a transfer port of the igni tion/expansion chamber and an exhaust port of the exhaust chamber in the case of said second pair of members.

5. An engine according to Claim 4 wherein a non-return valve is provided in the transfer means to prevent passage of gas from said second pair of members to said first pair of members.

6. An engine according to Claim 5 wherein the non-return valve is adapted to open to permit passage of gas from said compression chamber to said ignition/expansion chamber when the pressure of gas acting on the valve exceeds a predetermined value.

7. An engine according to any one of Claims 1 to 4 wherein the sealing means comprises a slide valve to control passage of gas through the transfer means.

8. An engine according to any one of the preceding claims wherein the rotatable member of the second pair of relative rotatable members rotates in an opposite direction to the rotatable member of the first pair.

9. An engine according to any one of the preceding claims wherein the first and/or second outer member is stationary and the first and/or second inner member is connected to a drive means.

10. An engine according to Claim 9 wherein the sealing means are radially slidably mounted in the first and/or second outer member.

11. An engine according to Claim 9 or Claim 10 wherein the transfer means, mixture creating means, ignition means and exhaust means are provided in said first and/or second outer member.

12. An engine according to any one of Claims 1 to 8 wherein .he first and/or second inner member is stationary and the first and/or second outer member is connected to drive means.

13. An engine according to Claim 12 wherein the sealing means is radially slidably mounted in said first and/or second inner member.

14. An engine according to Claim 12 of Claim 13 wherein the transfer means, mixture creating means, ignition means and exhaust means are provided in said first and/or second inner member.

15. An engine according to any one of Claims 4 to 14 when dependant upon Claim 4 wherein the radially slidable sealing means comprises an element pivotally connected to the member not containing the transfer means and slidable relative to the member containing the transfer means and the inner and outer members being mounted for eccentric and oscillatory relative movement.

16. An engine according to Claim 15 wherein the first and/or second inner member contains the transfer means, the first and/or second inner member being mounted so that its central axis follows an eccentric path and the first and/or second inner member oscillates about its pivotal connection to the sealing element which is radially slidably mounted in the first and/or second outer member.

17. An engine substantially as hereinbefore described with reference to and as shown in Figure 1 ofthe accompanying drawings.

18. An engine substantially as hereinbefore described with reference to and as shown in Figure 2 of the accompanying drawings.

19. An engine substantially as hereinbefore described with reference to and as shown in Figure 3 of the accompanying drawings.

20. An engine substantially as hereinbefore described with reference to and as shown in Figures 4 to 7 of the accompanying drawings.