GB2109856A

GB2109856A - Internal combustion engine rotary valves

Info

Publication number: GB2109856A
Application number: GB08134374A
Authority: GB
Inventors: Richard Furneaux Kinnersly
Original assignee: Individual
Current assignee: Individual
Priority date: 1981-11-14
Filing date: 1981-11-14
Publication date: 1983-06-08

Abstract

Cooling of a cylindrical valve rotor 26 with porting for charge inlet to and exhaust from a cylinder port 34 is provided by concentric passages 10 and 12 between which liquid flows via rotor passages A, B, and C. Sealing between the rotor and its sealing 32 is provided by sealing members 40a, 40b, in a groove 38 surrounding the port 34 or a cylindrical member (92), Figures 12 and 13 (not shown), urged into engagement with the rotor. The sealing members may take various forms, Figures 4 to 11 (not shown). <IMAGE>

Description

SPECIFICATION Improvements relating to internal combustion engines This invention is concerned with improvements relating to internal combustion engines, in particular of the kind (hereinafter referred to as being of the kind specified) wherein the exhaust gases from, and preferably also the admission of fuel to, the engine cylinder, is controlled by a valve member mounted for rotation about a longitudinal axis (hereinafter referred to for convenience as the rotor) having one or more ports which, during rotation of the rotor, are periodically aligned and in communication with an opening into the engine cylinder.

Such rotors are, during use, subjected to the high temperature of the exhaust gases, and it is desirable to provide cooling means to reduce the overall temperature of, and to minimise temperature differentials throughout the rotor.

Heretofore the provision of rotors for internal combustion engines of the kind specified with cooling means has proved difficult to accomplish with reliability and economy.

According to a first aspect of this invention, there is provided a rotor for an internal combustion engine of the kind specified, said rotor comprising a generally cylindrical body, with at least one port in the circumferential surface of the body, in which rotor one or more flow passages are provided, each such flow passage comprising a first section lying on or adjacent to the longitudinal axis of the rotor, a second section lying radially outwardly of the first section, and a third section extending between the first and second sections and which is in thermal conductive contact with the body of the rotor.

In use, a coolant fluid will be caused to flow through the flow passage and at least by virtue of the thermal conductive contact between the third section and the body, will cool the body.

The second section of the passage may be utilised as an inlet section, along which coolant fluid is pumped to the third section and thence to the first section, which latter section is utilised as an outlet section.

Preferably however, the first section of the passage is utilized as an inlet section, along which coolant fluid flows to the third section and thence to the second section, which latter section is thus utilised as the outlet section, and by virtue of the radially outer disposition of the second section, a self-propelling to some extent at least of cooling fluid along the first, second and third sections may be achieved, permitting the separate pumping energy required to obtain such flow to be at least reduced.

Preferably some at least of such passages share a common first section, which is afforded by an axial duct, with the third sections of the passages extending from the axial duct.

Preferably some at least of such passages share a common second section, which is conveniently also afforded by an axial duct, advantageously a duct of annular cross-section which extends around the duct affording the first sections.

Thus, inlet sections and outlet sections for the coolant fluid are disposed coaxially (that is one within the other) on one side of the valve member.

Preferably the flow passages comprise one or more flow passages, the third sections of each of which bounds the port or one of the ports of the valve member around three sides thereof.

Preferably the flow passages comprise one or more flow passages which are in thermal conductive contact with the circumferential surface of the body.

Preferably the flow passages comprise one or more flow passages which are in thermal conductive contact with a radially extending face of the rotor.

The third sections at least of the flow passages may be provided in the casting of the rotor, or may be provided by driiling axially, circumferentially and/or radically. Preferably such third sections are afforded by conduits, such as copper tubes, formed to a desired shape and secured in the rotor body during the casting thereof.

Another problem encountered in internal combustion engines of the kind specified is the provision of sealing means which is operative between the rotor and the part of the engine defining the opening into the cylinder, particularly during the ignition and explosion phase of the engine.

Thus according to a second aspect of the invention, there is provided an internal combustion engine of the kind specified comprising a member affording a cavity within which the rotor extends, an opening extending from the cavity to the engine cylinder, wherein there is provided a continuous channel bounding the opening within which channel a sealing member is located, means being provided which is operative in the operation of the engine to urge the sealing member against the rotor.

The member defining the cavity may be the member in which the or part of the engine cylinder is provided, or may be a member secured to the top of that member.

Preferably the sealing member is urged by said means into a position in which it is marginally proud of the surface of the cavity, which would generally correspond to the circumferential surface of the rotor. Preferably the sealing member comprises or is afforded by thin strip material, whereby a relatively small surface area is presented to the rotor.

Preferably the construction and arrangement is such that the pressure which is produced in the engine cylinder is effective to increase the pressure of the sealing member on the rotor and this may constitute said means in its entirety or in part.

The sealing member may be afforded by one or more portions of strip material terminating at junctions at which a small gap is afforded between adjacent end faces of the portions, and preferably additional means is provided to prevent leakage through such small gap. Such additional means may comprise the use of two such sealing members in said channel, so arranged that the small gaps of the two sealing members are not in register.

Alternatively, or in addition, such additional means may be afforded by additional elements which extend across such gap.

According to another aspect of this invention there is provided an internal combustion engine of the kind specified wherein the circumferential surface of the rotor bears against a sealing member extending around the opening into the engine cylinder, and wherein the construction and arrangement is such that pressure in the engine cylinder is operative to move the sealing member into sealing engagement with the circumferential surface of the rotor.

An arrangement of the kind set out in the last preceding paragraph is particularly useful wherein the rotor is journalled on bearings which are fixed in relation to the engine cylinder, and in which the sealing member is capable of limited movement between the cylinder and the rotor.

The invention set out in the last preceding paragraph but one may be applied to a construction in which the sealing member is afforded by, or comprises strip material located in a channel extending around the opening into the engine cylinder, or to a construction in which the sealing member provides an extensive sealing surface against which the circumferential surface of the rotor acts. In such a latter construction preferably the sealing member is mounted for limited movement on that body member of the engine which defines the engine cylinder, and means is provided to effect sealing between the sealing member and that body member.

In such circumstances, such means may be afforded by a relatively simple expedient, such as a resilient member, e.g. an O-ring.

Preferably as viewed in the direction of traverse thereof by the rotor, the sealing surface on the rotor upstream of the opening into the engine cylinder is of greater surface area than that downstream of said opening. In this manner, the wear which takes place of the sealing member, as is caused by the thrust between the sealing member and the rotor, is more evenly balanced, and produces more uniform wear of the sealing member.

Preferably, the sealing member, or at least the bearing surface thereof, is of closed-cell porous construction, e.g. a porous metal.

The above and other of the various aspects of this invention will become more clear from the following detailed description, which is to be read with reference to the accompanying drawings of embodiments which have been selected for the purpose of illustrating the invention by way of example.

In the accompanying drawings: Figure 1 is a perspective view illustrating schematically a rotor which is the first embodiment of this invention; Figure 2 is a side elevation, part being shown in section illustrating a practical application of the invention shown in Figure 1; Figure 3 is a schematic sectional view of part of an internal combustion engine which is the second embodiment of this invention; Figure 4 is a plan view of the embodiment shown in Figure 3; Figure 5 is a sectional view taken on the line V-V of Figure 4; Figure 6 is a sectional view taken on the line VI--VI of Figure 4; Figure 7 is a view corresponding to Figure 3, showing a modified form of the invention; Figure 8 is a view which corresponds to Figure 7 in the same manner that Figure 6 corresponds to Figure 3;; Figure 9 is a view, similar to Figure 3 showing a third embodiment of the invention; Figure 10 is a plan view of the embodiment shown in Figure 9; Figure 11 is a perspective view of the sealing member shown in Figures 9 and 10; Figure 12 is a schematic sectional view showing a fourth embodiment of the invention; and Figure 13 is a perspective view of a sealing member of the fourth embodiment.

The various embodiments hereinafter described are all internal combustion engines of the kind specified, comprising a cylinder and a piston reciprocably mounted in the cylinder.

Mounted over an opening into an upper part of the cylinder is a rotary valve member (commonly referred to as a rotor) which is provided with inlet and exhaust ports which are sequentially brought into communication with the cylinder, to allow respectively a combustible fluid consisting of a mixture of fuel and air, to enter the cylinder and burned gases to be ducted from the cylinder.

The rotor illustrated in Figures 1 and 2 is for such type of internal combustion engine, and is provided with cooling means to reduce the temperature attained by the rotor in the operation of the engine, and to reduce thermal stresses throughout the rotor.

The rotor is mounted in bearings 5, and comprises a generally cylindrical body 6, through a circumferential surface 7 of which a port 8 extends, this being the port through which in the rotation of the rotor exhaust gases are ducted from the engine cylinder. At least one other port will be provided in the circumferential surface of the body 6 through which fuel is ducted into the cylinder, and there may be a further exhaust port and a further inlet port.

The rotor is provided with cooling means shown schematically in Figure 1 in the form of a plurality of cooling circuits A, B, C. All the circuits comprise a common inlet section afforded by an axial inlet duct 10, and a common outlet section, afforded by an annular outlet duct 12 extending around the inlet duct 10. Each circuit also comprises an intermediate section extending between the inlet and outlet sections, the path taken by the intermediate section being dependent upon the type of circuit.

Thus, the type A circuit comprises an intermediate section which is in thermal conductive contact with the circumferential surface 7 of the body, whilst the type B circuit comprises an intermediate section which extends adjacent to the surface 7 around at least two, and preferably at least three, sides of the port 8, whilst the type C circuit comprises an intermediate section comprising radial portions in thermal conductive contact with a radially extending face of the body 6 and a circumferential portion adjacent to the circumferential surface 7 and in thermal conductive contact therewith.

It will be appreciated that other types of circuit may be designed if convenient, and one or more type of circuit described above may be combined.

In the use of the engine of which the rotor illustrated in Figure 1 forms part, coolant fluid is pumped into the inlet duct 10 and flows into the intermediate sections of the various circuits from which it is returned through the outlet duct 12 From the outlet duct 12 the coolant fluid may be ducted to a radiator to be cooled prior to being returned through the inlet duct 10.

In view of the outlet duct 12 being located at a position radially outwardly of the inlet duct 10, cooling fluid in said outlet duct will have a potential energy which is lower than cooling fluid in the inlet duct. In this manner, to some extent at least the flow of coolant fluid from the inlet duct through the intermediate sections to the outlet duct is self-impelling.

The cooling fluid may be water, which may be cooled by the conventional engine radiator, albeit it may be desirable to maintain separation of the cooling circuit for the rotor and the cooling circuit for the remainder of the engine. Alternatively a pressurised coolant circuit may be utilised for the rotor, or a high boiling point liquid may be utilised, if extremely high rotor temperatures are encountered.

In the second embodiment of this invention, a rotor 26 for an internal combustion engine of the kind specified is mounted for rotation on bearings 28, and extends into a semi-cylindrical cavity 30 provided in the cylinder head 36, the curvature of the surface 32 of the cavity being generally similar to that of the circumferential surface of the rotor, an opening 34 extending from the cavity into the engine cylinder 35. Provided in the surface 32 around the opening 34 is a continuous channel 38, said channel being continuous curved (that is following a smooth line with no corners, comprising opposed parallel sections and semicircular sections extending therebetween as is shown in Figure 4), and within the channel 38 there is located at least one, preferably two, sealing members 40.

Each sealing member 40 comprises a strip of metal which is inserted into the channel 38 and which conforms to the peripheral shape of the channel, the length of the strip being such that, when the sealing member is in the channel, a small gap 42 is provided at the junction of the end portions of the strip, an arcuate insert 44 being utilised to prevent the escape of gases in an axial direction through this gap (see Figure 6).

It will be appreciated that where two such sealing members are used, the strip providing the outer sealing member 40a will be slightly longer than that providing the inner sealing member 40b.

Most conveniently the junction of each strip is generally on the centreline CL of the opening 34 (see Figure 4) as is shown. However other arrangements may be used, provided that the two junctions and hence the two gaps 42 do not overlap.

The channel 38 may be of uniform depth, with the height of the strip generally equal to the height of the channel, as is shown in Figures 5 and 6. Alternatively, the base of the channel may be planar, the channel thus being of minimum depth on the centerline CL of Figure 4, and increasing in depth to either side in accordance with the curvature of the surface 32. In such circumstances, the sealing members will be of corresponding varying height, so that when fully inserted into the channel an upper margin is provided which extends generally flush with the surface 32.

Preferably resilient means is provided in the channel to urge the sealing member or members away from the base of the channel. Such resilient means may be afforded by a thin shim or "wavy" spring inserted into the channel prior to the sealing members and which is operative to urge the sealing members into positions in which the upper surfaces thereof are marginally proud of the surface 32 of the cavity 30, as is shown in Figure 5. In this manner the rotor, with the bearings 28 in fixed axial relationship with the cavity, is contacted by engagement surfaces of the sealing members.

Alternatively or in addition, the means to urge the sealing members away from the base of the channel may be afforded by, or may comprise a ducting system, whereby pressure pertaining in the cylinder 35 acts upon the undersides of the sealing member or members to urge them into contact with the rotor during the period in the combustion cycle when sealing engagement therebetween is most necessary. Thus, as is shown in Figure 4, preferably there is provided in the inner surface 39 of the channel 38 a number of ducts 48 spaced around the inner periphery of the channel, through which ducts gases may pass between the channel and the innermost sealing member, to act on the undersides of both sealing members to urge them into positions in which the contact surfaces are proud of the surface 32, to bear against the rotor 28 (see Figure 5).

In the embodiment illustrated in Figures 3 to 6, the sealing members are each parallel-sided, extending generally parallel to the longitudinal axis of the cylinder 35, the contact surfaces of the sealing members lying on a cylindrical surface.

However in a modified form of this embodiment, illustrated in Figures 7 and 8, the sides of the channel 38' provided in the surface 32' around the opening 34' are inclined at an angle to the longitudinal axis of the cylinder. The sealing members 40a' and 40b' are correspondingly canted, with the contact surfaces of the sealing members appropriately offset, the direction of such inclination being such that the sealing members lean towards the direction of travel of the rotor surface. In this manner better sealing and drag characteristics are provided on the leading side of the opening, and better wear characteristics of the sealing members are provided on the trailing side of the opening.

In this modification of the second embodiment, location of the insert 44' is modified in the manner shown in Figure 8.

In the third embodiment of this invention, illustrated in Figures 9 to 1 a similar sealing system is used, but whereas in the second embodiment the channel extending around the opening 34 is continuous curved, in the third embodiment the channel 48 is rectangular in plan view, being provided by a pair of parallel grooves 50 extending on opposite sides of the opening 46 into the cylinder in one direction, and a pair of parallel grooves 52 extending between the grooves 50 also on opposite sides of the opening 46 in the transverse direction. Located in the channel 48 are two similar sealing members 54, (see Figure 11), each comprising two L-shaped parts 56 and 58, each of which parts comprising two perpendicular limbs 60 and 62, which limbs are brazed or welded together as a gas-tight fit.

The limbs 60 of at least the outer sealing member are each provided with a spring plunger 61 which, when the sealing member is inserted into the channel 48, press against the opposing limbs 62 of the other part.

When each sealing member is inserted into the channel, there will be small gaps 65 between each pair of adjacent limbs 60 and 62 of the two parts. However, the two sealing members (which will of course be of slightly different size) are positioned in the channel in different orientations, so that none of the gaps 65 are in alignment.

Thus, with the two sealing members located within the channel, one within the other, the limbs 62 of the outermost sealing member 54a are pressed against the outer sides of the grooves 50 and the limbs 62 of the innermost sealing member 54b are pressed against the limbs 62 of the outermost sealing member.

Outer, contact surfaces of the various limbs of the two sealing members are provided with partcylindrical surfaces 59, so that the sealing members may bear and seal against the rotor of the engine.

The grooves 52 each open into a larger arcuate groove 68, which is deeper than the groove 50 and 52, and in which grooves 68 arcuate bearing members 70 are provided, said bearing members being flush with the surface of the rotor bore and being held in position by the rotor cover (not shown). The bearing members 70 serve to close the otherwise open ends of the grooves 50, to reduce leakage of gas between the sealing members through the gaps 65, and permit the grooves 50 and 52 to be provided with square corners by a milling operation. In Figure 9, the bearing member has been removed from the groove 68, for clarity.

As with the second embodiment, the sealing members of the third embodiment are urged into a position in which they are marginally proud of the housing by a thin shim or "wavy" spring 76 (see Figure 9) into contact with the rotor surface.

In the engine which is the fourth embodiment of this invention, shown in Figure 12, the cavity 80 provided in the cylinder head, and which provides a cylindrical opening 82 extending into the cylinder 84, is circular in plan view, comprising (in vertical cross-section) generally parallel side faces 86, inwardly convergent sloping side faces 88, and parallel side faces 90 which define the opening 82. Mounted as a tight sliding fit within the cavity 80 (including the opening 82) is a sealing member afforded by a block 92 (see Figure 13) having side faces 94, 96 and 98 complementary to the side faces 86, 88 and 90 of the cavity 80, respectively, said sealing block 92 defining a generally part-cylindrical cavity 100 from which an opening 102 extends into the engine cylinder and in which the rotor 104 extends, part-cylindrical bearing faces being provided on the rotor seats.

Extending into the bearing face on one side of the opening is a cavity 110, which will not hereinafter be described, and for an explanation as to the purpose of which reference should be made to the specification of our co-pending application No. 8123624.

Part of the sealing block 92 defines the top of the engine cylinder, and is thus subjected to pressures occurring within the engine cylinder. As has been said, the block 92 is a tight sliding fit within the cavity 80 and the sealing block 92 thus moves, under the action of the pressure within the engine cylinder, against the rotor, ensuring a sealing contact between the rotor and the bearing faces thereof.

A resilient gasket 114 is provided in the cylinder head which extends around the opening 82, to prevent leakage of gases between the cavity 80 and the sealing block.

If desired, a preload may be provided between the sealing block and the rotor housing, to urge the sealing block against the rotor under static conditions, and which may be afforded by a thin shim or "wavy" spring. Such upward pressure on the sealing block is preferably low, for example in the order of 51bs, per square inch. However, under dynamic conditions, the sealing block is urged against the rotor by the pressure within the engine cylinder acting on the sealing block.

Preferably the area of a portion 106 of the bearing face which is upstream of the opening 102, is greater than the area of a portion 108 of the bearing face which is downstream of the opening 102. The greater area of contact between the rotor and the bearing face on the leading side, as compared with the trailing side, is believed to produce a more uniform wearing of the contact surfaces of the sealing block.

Preferably the sealing block comprises porous material, preferably of a closed-cell porous structure, over part thereof sufficient to provide at least the bearing surfaces 106, 108 thereof. Such a construction enables small reservoirs of oil to be contained in the exposed cells, assisting in the retention of a thin film of oil operative between the peripheral surface of the rotor and the bearing faces.

Claims (Filed on 25 Oct 1982) 1. A rotor for an internal combustion engine of the kind comprising a cylinder and a piston movable in said cylinder, the rotor providing means which is operative to deliver a combustible fluid to the cylinder wherein the combustible fluid is ignited, and/or to exhaust gases from said cylinder, the rotor comprising a generally cylindrical body with at least one port in the circumferential surface of the body, in which rotor one or more flow passages are provided, each such flow passage comprising first section lying on or adjacent to the longitudinal axis of the rotor, a second section lying radially outwardly of the first section, and a third section extending between the first and second sections which is in thermal conductive contact with the body of the rotor, through which flow passage, in use, coolant fluid may be caused to flow.

2. A rotor according to Claim 1 wherein the second section of the passage is utilised as an inlet section, along which coolant fluid is pumped to the third section and thence to the first section, which latter section is utilised as an outlet section.

3. A rotor according to Claim 1 wherein the first section of the passage is utilised as an inlet section, along which coolant fluid flows to the third section and thence to the second section, said latter section thus constituting an outlet section.

4. A rotor according to any one of the preceding claims wherein some at least of such passages share a common first section, which is afforded by an axial duct with the third sections of the passages extending from the axial duct, and a common second section, which is afforded by an axial duct of annular cross-section which extends around the duct affording the first sections.

5. A rotor according to any one of the preceding claims wherein the flow passages comprise one or more flow passages, the third sections of each of which bounds the port or one of the ports of the valve member around three sides thereof.

6. A rotor according to any one of the preceding claims wherein the flow passages comprise one or more flow passages which are in thermal conductive contact with the circumferential surface of the body.

7. A rotor according to any one of the preceding claims wherein the flow passages comprise one or more flow passages which are in thermal conductive contact with a radially extending face of the rotor.

8. A rotor according to any one of Claims 1 to 7 wherein the third sections at least of the flow passages are provided in the casting of the rotor.

9. A rotor according to any one of Claims 1 to 7 wherein the third sections at least of the flow passages are provided by drilling axially, circumferentially and/or radially.

10. A rotor according to any one of Claims 1 to 7 wherein the third sections at least of the flow passages are afforded by conduits, such as copper tubes, formed to a desired shape and secured to the rotor body during the casting thereof.

11. An internal combustion engine comprising a rotary valve member provided with cooling means in accordance with any one of the preceding claims.

12. An internal combustion engine comprising a cylinder, a piston movable in said cylinder, a cylindrical chamber within which is mounted a rotary valve member which provides means which is operative to deliver a combustible fluid to the cylinder wherein the combustible fluid is ignited, and/or to exhaust gases from said cylinder, an opening extending from the chamber into the engine cylinder, wherein there is provided a continuous channel bounding the opening, within which channel a sealing member is located, means being provided which is operative in the operation of the engine to urge the sealing member against the rotor.

13. An internal combustion engine according to Claim 12 wherein the sealing member is urged by said means into a position in which it is marginally proud of the surface of the cavity.

14. An internal combustion engine according to one of Claims 12 and 13 wherein the sealing member comprises or is afforded by thin strip material, whereby a relatively small surface area is presented to the rotor.

1 5. An internal combustion engine according to any one of Claims 12 to 14 wherein the pressure which is produced in the engine cylinder is effective to increase the pressure of the sealing member on the rotor and this constitutes said means wholly or in part.

1 6. An internal combustion engine according to any one of Claims 12 to 1 5 wherein the sealing member is afforded by one or more portions of strip material terminating at junctions at which a small gap is afforded between adjacent end faces of the portions.

1 7. An internal combustion engine according to Claim 1 6 wherein additional means is provided to reduce leakage through such small gap.

1 8. An internal combustion engine according to Claim 1 7 wherein such additional means comprises the use of two such sealing members in said channel, so arranged that the small gaps of the two sealing members are not in register.

1 9. An internal combustion engine according

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. the bearing face which is downstream of the opening 102. The greater area of contact between the rotor and the bearing face on the leading side, as compared with the trailing side, is believed to produce a more uniform wearing of the contact surfaces of the sealing block. Preferably the sealing block comprises porous material, preferably of a closed-cell porous structure, over part thereof sufficient to provide at least the bearing surfaces 106, 108 thereof. Such a construction enables small reservoirs of oil to be contained in the exposed cells, assisting in the retention of a thin film of oil operative between the peripheral surface of the rotor and the bearing faces. Claims (Filed on 25 Oct 1982)

1. A rotor for an internal combustion engine of the kind comprising a cylinder and a piston movable in said cylinder, the rotor providing means which is operative to deliver a combustible fluid to the cylinder wherein the combustible fluid is ignited, and/or to exhaust gases from said cylinder, the rotor comprising a generally cylindrical body with at least one port in the circumferential surface of the body, in which rotor one or more flow passages are provided, each such flow passage comprising first section lying on or adjacent to the longitudinal axis of the rotor, a second section lying radially outwardly of the first section, and a third section extending between the first and second sections which is in thermal conductive contact with the body of the rotor, through which flow passage, in use, coolant fluid may be caused to flow.

1 9. An internal combustion engine according

to one of Claims 17 and 18 wherein such additional means is afforded by additional elements which extend across such gap.

20. An internal combustion engine comprising a cylinder, a piston movable in said cylinder, a cylindrical chamber within which is mounted a rotary valve member which provides means which is operative to deliver a combustible fluid to the cylinder wherein the combustible fluid is ignited, and/or to exhaust gases from the cylinder, an opening extending from the chamber into the engine cylinder, wherein a circumferential surface of the rotor bears against a sealing member extending around the opening, the construction and arrangement being such that pressure in the engine cylinder is operative to move the sealing member into sealing engagement with the circumferential surface of the rotor.

21. An internal combustion engine according to Claim 20 wherein the sealing member is afforded by, or comprises, strip material located in a channel extending around the opening into the engine cylinder.

22. An internal combustion engine according to Claim 20 wherein the sealing member provides an extensive sealing surface against which the circumferential surface of the rotor acts.

23. An internal combustion engine according to Claim 22 wherein the sealing member is mounted for limited movement on the body member of the engine which defines the engine cylinder, and means is provided to effect sealing between the sealing member and that body member.

24. An internal combustion engine according to one of Claims 22 and 23 wherein that part of the sealing surface of the sealing member which, viewed in the direction of traverse by the rotary valve member, is upstream of the opening in the engine cylinder, is of greater surface area than that part of the sealing surface which is downstream of said opening.

25. An internal combustion engine according to any one of Claims 22, 23 and 24 wherein the sealing member, or at least the bearing surface thereof, is of closed-cell porous construction.

26. A rotor for an internal combustion engine constructed and arranged substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

27. An internal combustion engine constructed and arranged substantially as hereinbefore described with reference (a) to Figures 3 to 8; (b) to Figures 9 to 11;or(c)toFigure 12 and 13 of the accompanying drawings.

28. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.