GB2033012A - Semi-rotary internal combustion engines - Google Patents

Abstract

The engine has cylinders (2) containing co-axial shafts (3) with pistons in the form of flanges (4) that span the cylinders. Fixed elements (13) divide the cylinders into chambers (14, 15, 16, 17), and a valve member (8) is rotatable to effect opening and closing of ports (9, 10) to each chamber. A sparking plug (18) or fuel injector is positioned adjacent each fixed element. A transmission mechanism translates oscillation of the shafts into continuous rotation of a drive shaft. As a modification the cylinders (2) are mounted in line and served by a common shaft, in which case conventional valves are provided and operated by a cam shaft. <IMAGE>

Description

SPECIFICATION Improvements relating to internal combustion engines This invention relates to internal combustion engines.

It is not concerned with conventional engines having pistons reciprocating in separate cylinders, nor with Wankel engines with a rotary piston, but it proposes what is thought to be an entirely new concept.

According to the present invention there is provided an internal combustion engine with a number of cylinders, each containing a coaxial shaft with flanges that span the respective cylinder, fixed elements dividing the respective cylinder, on one side of the flanges, into two chambers, a valve operating member effective to open and close valve ports to such chamber, a sparking plug or fuel injector for each chamber with its electrodes or nozzle adjacent the associated fixed element, timing means for sequential operation of the sparking plugs or fuel injectors, and a transmission coupled to the shafts that will translate reciprocating rotation of the shafts, which occurs during operation, into continuous rotation of a drive shaft, the operation being a four stroke cycle.

In one preferred embodiment, the valve operating member is directly interconnected with inlet and outlet manifolds and has separate openings associated with the manifolds which will interconnect with the valve ports of the chambers in sequence, as the valve member rotates. As an alternative the valve operating member may comprise a rotatable member carrying a pair of cam surfaces which will act upon conventional valves for connecting the chambers to inlet and outlet manifolds. In this latter instance, the cam surfaces may advantageously be carried by a conventional cam shaft. Also, with this arrangement pairs of cylinders may ideally be mounted in line and have a common shaft carrying said flanges.

Where the valve operating member rotates to open and close the valve ports it may serve two adjacent cylinders so that, for each complete cycle, it serves each of the four chambers in turn for the respective functions of induction, compression, power stroke, and exhaust.

The engine can be run as a petrol or diesel engine, provided suitable compression ratios are designed into it.

Generally the reciprocal rotative movement of the shafts will be through 90 , and this lends itself to a transmission in which crank arms angled out from the ends of the shafts engage opposite sides of a gearwheel. As the shafts move back and forth so the free ends of the crank arms describe successive 180 arcs to drive that wheel with continuous rotative movement in one direction.

For a better understanding of the invention one preferred constructional form will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-section of an internal combustion engine of this invention, and Figure 2 is a section on line Il-Il of Fig. 1.

The engine has a cylinder block 1 made in three parts and defining two generally cylindrical parallel chambers 2aand 2b. The block provides the usual cooling water jacket. Each chamber contains a co-axial shaft 3a, 3b which have respective integral flanges 4a, 4b substantially diametrically opposed and supported on one side by strongbacks 5a, 5b.

The flanges have slots Sa, 6bto contain vanes 7a, 7bwhich have the function of piston rings to bear against the cylinder lining. Each shaft is rotatable between the positions shown in Fig. 2 and positions after rotation anti-clockwise through 90 from the positions shown in Fig. 2.

A rotary valve 8 is disposed between the chambers 2a, 2b and co-operates with both of them. It comprises a hollow shaft whose cross-section at an intermediate portion is of generally horse-shoe configuration with the "shoe" itself being hollow and having at one outer side a number of ports 9 of the same circumferential extent as the distance between the free ends of the "shoe.', The latter provide a number of ports 10 to the centre of the valve, which lead to exhaust 11 at one end, while the horse-shoe shaped chamber is itself connected to a carburettor (not shown) at the other end. As the valve rotates, in synchronism with the movement of the shafts 3a, 3b the ports 9 and 10 successively pass openings 12a, 12b(Fig. 2) into the chambers 2a and 2b.Between the openings 12aand 12b the outer face of the valve 8 rotates in a cylindrical passage formed by the block 1, which intermittently closes the ports 9 and 10. Parts 1 3 a and 1 3 b of the block which provide walls of this valve passage opposite each chamber 2a, 2b also co-operate closely with respective shafts 3a, 3bto provide generally cylindrical, segmental combustion chambers 14, 15, 16 and 17. Sparking plugs 1 8 are fitted into the casing and their electrodes are adjacent the combustion chamber openings 1 2 a, 1 2 b. The firing sequence, synchronised with the valve and shaft movements, is achieved by known means.

The rocking motion of the shafts is translated into complete and continuous rotary movement by the crank and gear arrangement shown in Fig. 1. The shafts 3a, 3bextend beyond the cylinder block, in the same direction and to the same extent, and are equipped at the projecting ends with crank arms 1 9a, 19bwhich can pivot about parallel axes 20a, 20b perpendicular to the axes of the shafts.

The ends of the cranks mate with angled recesses 21 a, 21 bin opposite sides of, and at diametrically opposed points of, an externally toothed gearwheel 22 which runs by means of ball bearings 23 in an outer annular track 24. The gear teeth are split to be in two sets 25a, 25b one on each axial side of this track.

They engage with toothed collars 26a, 26b fixed to a main drive-shaft 27 which extends transversely to the rocking shafts 3a, 3band parallel to the axis of the gear wheel 22. The valve 8, which is continuously rotated, is driven from this shaft.

The cycle of the engine is as follows, referring principally to Fig. 2, and starting from the position shown there. A stroke has just been completed, and a fuel-air mixture has been compressed in chamber 1 6. The associated sparking plug fires, exploding the fuel-air mixture, and the shaft 3b is rotated anticlockwise, taking with it the other shaft 3a, which is coupled through the crank/gear system described. The valve 8, continuing to rotate clockwise, opens the reducing chamber 1 7 to exhaust via port 10, and opens the expanding chamber 14 to the inlet port 9, fuel-air mixture thus being drawn into that chamber. Chamber 15, also reducing and having previously received a fuel-air mixture, compresses that mixture during this stroke.

The stroke is for 90 motion of the shafts, and when it is completed the valve 8 will also have rotated through 90 and its ports 9 and 10 will be closed. The sparking plug 1 8 associated with chamber 1 5 fires next driving the shaft 3a clockwise,the other shaft 3b following. These cycles repeat and the shafts rock to and fro.

Referring back to Fig. 1, the motion of the shafts 3a, 36 also swings the crank arms 19a, i9bthrough an arc of 90 , and as viewed in the- direction of those shafts they move in opposite directions. However, they are angled at 45 to the axis of the gearwheel 22, they can rotate about their own axes in the recesses 21 a, 21 b and they can pivot about axes 20a, 20b. This makes the crank arms capable of describing, for one complete stroke, a 180 arc. Fig. 1 shows them at midstroke.At the extremes, inertia, aided by a flywheel (not shown) on the main drive shaft, will maintain the gearwheel rotating in the same direction and the cranks will each describe the opposite 180 arc to the one for the previous stroke, and continue to drive the gear wheel.

Various lubricant passages and other details of possible construction are shown in the drawings, but will not be described in detail.

It will be appreciated that this engine, although embodying the standard four stroke cycle, has a much simpler valve arrangement than engines employing reciprocating pistons, each requiring separate inlet and outlet valves. Here, just one valve suffices and services all inlet and outlet ports. Although not completely rotative like the Wankel engine there are considerable advantages in construction, with substantially ali surfaces being cylindrical or plane, and there are unlikely to be the same sealing problems.

Although described as a petrol engine, it can be modified to work on the diesel principle.

The engine described could be modified to a form having four cylindrical chambers and rocking shafts, but still with a single common valve member. This would require diametrically opposed inlet ports and a corresponding diametrically opposed pair of outlet ports.

Furthermore, the valve member could comprise a rotatable member (instead of the valve 8) carrying a pair of cam surfaces which would act upon conventional valves for connecting the various chambers 14, 1 5, 16, 1 7 to inlet and outlet manifolds.

As a further alternative the engine could carry a conventional valve arrangement operated by the usual cam shaft. With such an arrangement it is possible to align the shafts 3 of two cylinders so as to create a single common shaft. As this shaft reciprocates it will create compression and expansion of the various chambers within the cylinders in the same manner as for the embodiment illustrated in Figs. 1 and 2 of the drawings. For this prupose the flanges in one cylinder would be set at an angle of about 45 to the flanges disposed within the other cylinder. As before the shaft 3 will be connected by a crank and gear arrangement to a drive shaft in the manner illustrated in Fig. 1 of the drawings.

Claims (8)

1. An internal combustion engine with a number of cylinders, each containing a coaxial shaft with flanges that span the respective cylinder, fixed elements dividing the respective cylinder, on one side of the flanges, into two chambers, a valve operating member effective to open and close valve ports to each chamber, a sparking plug or fuel injector for each chamber with its electrodes or nozzle adjacent the associated fixed element, timing means for sequential operation of the sparking plugs or fuel injectors, and a transmission coupled to the shafts that will translate reciprocating rotation of the shafts, which occurs during operation, into continuous rotation of a drive shaft, the operation being a four stroke cycle.

2. An internal combustion engine according to claim 1, wherein the valve operating member is rotatable and directly interconnected with inlet and outlet manifolds and has separate openings associated with the manifolds which will interconnect with the valve ports of the chambers in sequence, as the valve member rotates.

3. An internal combustion engine according to claim 1, wherein the valve operating member comprises a rotatable member carrying a pair of cam surfaces which will act upon conventional valves for connecting the chambers to inlet and outlet manifolds.

4. An internal combustion engine according to claim 3, wherein the cam surfaces are carried by a conventional cam shaft.

5. tn internal combustion engine according to claim 4, wherein pairs of cylinders are mounted in line and have a common shaft carrying said flanges.

6. An internal combustion engine according to any one of claims 1 to 3, incorporating two cylinders and wherein the common valve operating member rotates once for a complete cycle, serving each of the four chambers in turn for the respective functions of induction, compression, power stroke, and exhaust.

7. An internal combustion engine according to any one of claims 1 to 6, wherein crank arms angled out from the ends of the shafts engage opposite sides of a gear wheel carried by said drive shaft.

8. An internal combustion engine substantially as herein described with reference to the accompanying drawings.