WO1997033073A1

WO1997033073A1 - Continuously rotating engine

Info

Publication number: WO1997033073A1
Application number: PCT/GB1997/000621
Authority: WO
Inventors: Edward Seal
Original assignee: Edward Seal
Priority date: 1996-03-07
Filing date: 1997-03-06
Publication date: 1997-09-12
Also published as: AU2100897A; GB9604818D0; IL126092A0; EP0890017A1; AU734332B2; JP2000506245A; CA2248719A1

Abstract

The present invention concerns engine comprising: a piston casing (3) mounted for rotation about a casing axis; at least a pair of opposing weights or pistons (4, 4') disposed within the casing, each weight being mounted for rotation about an axis parallel to the casing axis; a coupling means (6, 7, 6') providing a mechanical link between opposing weights whereby a movement by one linked weight in one direction about its rotation axis produces a movement of the other linked weight in an opposite direction about its axis of rotation; and means capable of applying, in alternation, a displacement between the casing and one weight of a pair in said one direction and a displacement between the casing and the other weight of a pair in said opposite direction.

Description

CONTINUOUSLYROTATINGENGINE

The present invention relates to engines, and in particular to a rotary inertia-recoil free-piston engine.

Engines, in particular of the internal combustion variety, are well known and generally work to either a two or a four stroke principle.

In this regard, the term 'stroke' refers to different operational stages of the engine, namely in a four stroke engine, an induction stroke, a compression stroke, a power stroke and an exhaust stroke.

A common principle of such engines is that the reciprocating action of a piston within a cylinder is converted via a connecting rod and a crank shaft arrangement into rotational movement of the crank shaft. In conventional engines, a number of cylinders are generally provided, each of which is fixed in position relative to the engine block, the power of the engine being taken as rotational movement of the crank shaft.

In a four stroke engine, the power is developed only during one stroke. Thus a single cylinder four stroke engine has a low degree of uniformity whereby rotation of the crank shaft is subject to considerable accelerations and decelerations during a cycle. For more smooth and uniformed running, multi-cylinder engines are provided, in which the operation of the various cylinders is staggered so that the various cylinders do not develop the power stroke simultaneously but successively. By increasing the number of cylinders, the smoothness and uniformity of the engine is increased, but also disadvantageously there is an increase in the engine size and weight and its complexity, involving complicated crank shaft and connecting rod arrangements. A further problem arises in that by increasing the number of cylinders, achieving and maintaining accurate timing of the engine is made more difficult.

In two stroke engines, a complicated arrangement of fans or vacuum chamber arrangements is necessary so that the four operations of induction, compression, power and exhaust are incorporated into two strokes of the piston and cylinder. The provision of fans and/or vacuum arrangements adds to costs and often such engines require high maintenance by virtue of the sealing criteria required for correct operation thereof.

There is also known a rotary piston engine (Wankel) wherein a piston having a generally triangular shape with convex sides rotates within a cylinder housing having a generally oval shape and which is slightly constricted in its middle. The edges of the rotating piston open and close ports in the cylinder walls so that the piston itself controls the breathing of the engine without the aid of valves. The three enclosed spaces formed between the piston and the cylinder walls successively increase and decrease in size as the piston rotates. These variations in the spaces are used for drawing in the fuel and air mixture, for compressing the mixture, for combustion and discharging the burned gases. Rotary piston engines suffer however from sealing problems between the three spaces as the rotating piston rotates.

It is an object of the present invention to provide an engine arrangement which seeks to alleviate the disadvantages of the prior art engines.

According to a first aspect of the present invention there is provided an engine comprising:- a rotatably mounted piston casing; at least a pair of weights mounted for oscillatory movement within a casing; wherein a coupling means is provided between the weights to alternately urge in use each of weights in a first direction about the axis of rotation of the casing in response to a combustion force that drives the non-urged one of the pair of weights in a second direction that is opposite to the first direction, the piston casing itself being urged in the first direction. With such an arrangement a powerful and compact engine can be provided.

Preferably, the weights are coupled by way of respective lever arrangements connected by a connecting rod, whereby the movement of each weight corresponds to a linear movement of the connecting rod. In this way, undesirable forces that would oppose the rotation of the engine can be effectively dissipated.

In preferred embodiments, the respective lever arrangements each comprise a rotatably mounted transmission arm having an engagement portion arranged to slidably engage its associated weight and a lever portion that extends from its respective rotation point from a side opposite to the engagement portion, the respective lever portions of the transmission arms being coupled by way of the connecting rod.

Depending on the position of the respective weights, the transmission arms are urged to move by one of the weights or move one of the weights. By virtue of their connection, a rotational movement of one transmission arm causes an opposite rotational movement of the other transmission arm.

Preferably, the transmission arms are arranged to rotatively reciprocate in association with movement of the weights.

In preferred embodiments, an output shaft is coupled to the piston casing. According to a second aspect of the present invention there is provided an engine comprising:- at least two cylinder/piston combinations extending substantially circumferentially relative to an axis of the engine; the pistons being coupled together such that they alternately urge each other to respective points of combustion in their respective cylinders, wherein in use the engine is driven by providing a reaction force between alternate piston and cylinder combinations.

According to a third aspect of the present invention there is provided a engine comprising:- a piston casing mounted for rotation about a casing axis; at least a pair of opposing weights disposed within the casing, each weight being mounted for rotation about an axis parallel to the casing axis; a coupling means providing a mechanical link between opposing weights whereby a movement by one linked weight in one direction about its rotation axis produces a movement of the other linked weight in an opposite direction about its axis of rotation; and means capable of applying, in alternation, a displacement between the casing and one weight of a pair in said one direction and a displacement between the casing and the other weight of a pair in said opposite direction.

Preferably, the casing has a first pivot point means and a second pivot point means and wherein said mechanical link is connected to pivot about said first and second pivot point

Examples of the present invention will now be described by way of example and with reference to the accompanying drawings in which:- Figure 1 shows a cross-sectional view through an engine of a first embodiment of the present invention at a first position;

Figure 2 shows a cross-sectional view through the engine of Figure 1 at a second position;

Figure 3 shows in perspective a second embodiment of the present invention;

Figure 4 shows an exploded view of the embodiment of Figure 3; and

Figures 5A to 5C show operational views of the embodiment of Figures 3 and 4.

Figure 1 hence shows in cross-sectional view the internal parts of an engine 1 of a first embodiment of the present invention. The engine includes a rotatably mounted piston casing 3. The generally cylindrical piston casing houses a pair of weights in the form of pistons 4, 4' which are arranged to reciprocate circu ferentially. The pistons 4, 4' are rotatably mounted about centre E via piston arm members 5, 5' .

Transmission or rocker arms 6, 6* are rotatably mounted about centres I, the centres being fixed in relation to the piston casing. Each of the arms 6, 6' comprises an engagement portion arranged to slidingly engage a suitable surface on the piston arm members 5, 5'. Centres I are generally diametrically opposed about the centre E.

The transmission arms 6, 6' are connected by way of a connecting rod 7, which is rotatably mounted at its ends to a portion of each transmission arm that extends from its respective centre I on the other side of the engagement portion. In other words, the transmission arms are arranged to act generally as levers transferring the rotational movement of the piston arm members into a linear movement of the connecting rod. The centres I act in this respect as fulcrum points.

Rotation of, for example, transmission arm 6 about its centre results in rotation in the opposite direction of transmission arm 6' , with consequential forces being applied by and to the respective piston arms members 5, 5' . Each piston therefore moves in a predetermined manner within the piston casing in relation to the other piston.

The operation of the engine is as follows. In Figure 1, piston 4 at point A is about to undergo combustion. As the gases within the piston cylinder are ignited, the piston head is forced in an anti-clockwise direction shown by arrow P. The cylinder casing at point A is at the same time urged in a clockwise direction, this clockwise movement being the general movement derivable from the engine. The weight of each piston relative to the cylinder casing is formulated appropriately to ensure a correct operation of the engine. I-: general terms, the pistons are comparatively heavy and tαe cylinder casing is relatively light.

Piston 4 is thus caused to move anti-clockwise within the piston cylinder towards the point B. At the same time, by way of piston arm member 5, and transmission arm 6, the connecting rod 7 is provided with a linear movement which in turn causes a rotational movement of transmission arm 6*. The rotational movement of arm 6' results in the piston arm member 5• and thus piston 4' being urged to rotate about centre E in a clockwise direction from position D to position F.

At point D, the piston 4' is at the end of its combustion stroke. The clockwise movement imparted to piston 4' will move it to its combustion point F. Thus, the power stroke of piston 4 causes piston 4' to move to its combustion point, in so doing going through its induction and compression strokes.

Referring to Figure 2, once the piston 4' has reached the combustion point F, it is ready to undergo combustion, whereby it will be accelerated relative to the cylinder casing back towards point D. At the same time piston 4 will, by way of the transmission arms and piston arm members, be urged from point B back towards its combustion point A.

By way of this arrangement the piston casing gains an overall clockwise rotation, which can be taken from the engine via central shaft 10 fixed relative to the piston casing. The engine (the piston casing) is thus driven in a clockwise direction as a consequence of the inertia transfer of energy from each 'heavy' piston to its respective 'light' cylinder. Negative forces that tend to oppose rotation of the engine can be dissipated in a linear, outward direction through centres I.

Figures 3 to 5 concern a second embodiment of the present invention. The major difference between the embodiment of Figures 1 and 2 and that of Figures 3 to 5 is that the latter embodiment has two axially aligned piston sets 14, 14' received in respective piston casings 13.

As shown particularly in Figure 4, each piston set comprises a pair of diametrically opposed piston heads 19 and 20. The "top" piston heads are provided on a drive plate 21 which is fixed relative to output shaft 22.

The coupling means between the piston sets includes transmission arms 16, 16^», shaft members 17 and 17' and connecting member 23.

Bearing members 24 ensure low friction rotation of the output shaft 22. Operation of the engine is very similar to that of the embodiment of Figures 1 and 2. The difference is that rather than a single piston undergoing combustion at any one time, in this embodiment pairs of piston heads from the same set undergo combustion together.

For example, referring to Figure 5A, top piston heads 19 are about to undergo combustion. On combustion, piston set 14 is hence driven in an anticlockwise direction as shown by arrow P. The top casing at points A is at the same time urged in a clockwise direction, this clockwise movement being the general movement derivable from the engine via shaft 22. Again, the piston set is comparatively heavy and the piston casing is relatively light.

Piston set 14 is thus caused to move anti-clockwise within the piston casing so that the piston heads 19 move towards the points B. At the same time, by way of transmission arm 16 and shaft member 17, the connecting rod 23 is provided with a linear movement which in turn causes a rotational movement of shaft 17' and transmission arm 16'. The rotational movement of arm 16' results in piston set 14 ' being urged to rotate about centre E in a clockwise direction so that the piston heads 20 move to their combustion points.

Once piston heads 20 of piston set 14' have reached their combustion points, they are ready to undergo combustion, whereupon they will be accelerated anticlockwise relative to piston casing 13. At the same time piston set 14 will be urged clockwise from points B back towards combustion points A..

By way of this arrangement the piston casing 13 gains an overall clockwise rotation. The engine is thus driven in a clockwise direction as a consequence of the inertia transfer of energy from each 'heavy' piston to the respective 'light' cylinder. Negative forces that tend to oppose rotation of the engine can be dissipated in a linear, outward direction through centres I as shown by arrows N in Figures 5A to 5C.

The use of diametrically opposed piston sets enhances the balance and hence reliability of the engine.

The engine works therefore through the principle of firing relatively heavy solid construction pistons in a combustion process. This construction allows free heavy pistons to be the only combustion driven parts from one combustion cycle to the next. Unlike conventional internal combustion engines, there is no process of bringing the pistons to a halt through mechanical means as such in preparation for combustion.

During each combustion cycle, the non-combusted piston set is effectively catching up within the piston casing to the combustion point of its respective piston cylinder.

As the pistons are relatively heavy, they can be made of stronger and stiffer materials. Such stronger pistons will enable the use of greater pressures so as to increase the relative volumetric potential of the engine. The pistons will also be more resilient against piston twist or slap.

For added work efficiency, the engine components optimally have aerodynamically formed lead edges so as to reduce drag.

By virtue of its arrangement, the engine is free running. The cylinder is arranged to rotate freely and for operation the engine does not require a fixed point from which to create drive. This greatly simplifies the engine and reduces the likelihood of failure due to wear.

The engine may be supplied with fuel/air and have exhaust products removed by any suitable method. However, for example, the fuel/air mixture may be provided and exhaust products may be removed by way of transfer ports provided in the cylinder casing.

The engine components may be made from any suitable materials, such as metals, metal alloys, ceramics, plastics etc. Conventional cooling systems may be incorporated into the engine as desired.

It will be understood that the embodiment illustrated shows an application of the invention in one form only for the purposes of illustration. In practice, the invention may be applied to many different configurations. The detailed embodiments being straight forward for those skilled in the art to implement.

For example, rather than a pair of piston cylinder combinations, any suitable number may be used as required.

Whilst the coupling means is shown as a lever arrangement, other arrangement may of course be used, for example gears and/or chain drive means.

The engine need not be limited to the field of internal combustion engines. For example, it could also be configured as a compressed air/bounce chamber flywheel engine.

Claims

Claims :

l. An engine comprising:- a rotatably mounted piston casing; at least a pair of weights mounted for oscillatory movement within a casing; wherein a coupling means is provided between the weights to alternately urge in use each of weights in a first direction about the axis of rotation of the casing in response to a combustion force that drives the non-urged one of the pair of weights in a second direction that is opposite to the first direction, the piston casing itself being urged in the first direction. With such an arrangement a powerful and compact engine can be provided.

2. An engine according to claim 1, wherein the weights are coupled by way of respective lever arrangements connected by a connecting rod, whereby the movement of each weight corresponds to a linear movement of the connecting rod.

3. An engine according to claim 1 or 2, wherein the respective lever arrangements each comprise a rotatably mounted transmission arm having an engagement portion arranged to slidably engage its associated weight and a lever portion that extends from its respective rotation point from a side opposite to the engagement portion, the respective lever portions of the transmission arms being coupled by way of the connecting rod.

4. An engine according to any preceding claim, wherein the tr.nsmission arms are arranged to rotatively reciprocate in association with movement of the weights.

5. An engine according to any preceding claim, wherein an output shaft is coupled to the piston casing.

6. An engine comprising:- at least two cylinder/piston combinations extending substantially circumferentially relative to an axis of the engine; the pistons being coupled together such that they alternately urge each other to respective points of combustion in their respective cylinders, wherein in use the engine is driven by providing a reaction force between alternate piston and cylinder combinations.

7. An engine comprising:- a piston casing mounted for rotation about a casing axis; at least a pair of opposing weights disposed within the casing, each weight being mounted for rotation about an axis parallel to the casing axis; a coupling means providing a mechanical link between opposing weights whereby a movement by one linked weight in one direction about its rotation axis produces a movement of the other linked weight in an opposite direction about its axis of rotation; and means capable of applying, in alternation, a displacement between the casing and one weight of a pair in said one direction and a displacement between the casing and the other weight of a pair in said opposite direction.

8. An engine according to claim 7, wherein the casing has a first pivot point means and a second pivot point means and wherein said mechanical link is connected to pivot about said first and second pivot point means.

9. An engine substantially as hereinbefore described with reference to the accompanying drawings.