COMBUSTION ENGINE

The present invention relates to a combustion engine according to the preamble of claim 1.

There is a great need to provide an improved combustion engine which is usable in, for example, passenger cars. It is a great advantage if such an engine is of great flexibility as regards possible kinds of fuel and low fuel consumption. Improvements in environmental factors and in operating economy factors are desirable. In this context it is desirable to provide, for example, variable compression and driving cycle optimised combustion processes, etc. The possibility of temporary parking of one or more cylinders during engine operation is also desirable.

An object of the present invention is to provide a combustion engine which is extremely advantageous from the economic and environmental points of view. This object is achieved by the combustion engine having the characteristics indicated in the claims.

The following may inter alia be mentioned among the many advantages of the invention.

The engine is of simple construction and high efficiency. In addition, variable compression, parking of any desired number of cylinders, working cycle variations etc. are possible. The engine's performance and mode of operation are readily adaptable to using different types of fuel. Combustion optimisation rendering the engine particularly environmentally friendly is also possible. The engine is very economical on fuel and has both technical and economic advantages.

Examples of embodiments of the invention are described below in more detail with reference to the attached drawings, in which Fig. 1 depicts schematically a partly sectioned sideview of a cylinder of the engine according to the invention, Fig. 2 depicts schematically a partly sectioned longitudinal view of two cylinders of the engine, Figs. 3-5 illustrates schematically a sideview of the engine's motion pattern resulting from different piston rod settings (phase

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displacements), Fig. 6 illustrates schematically a sideview of the engine's motion pattern resulting from a further link system configuration, Fig. 7 illustrates schematically a sideview of a common position change of the centres of rotation of the planet wheels, Fig. 8 illustrates schematically a sideview of an embodiment for change of eccentricity of the piston rod bearing points on the planet wheels, and Fig. 9 illustrates schematically a longitudinal view of an embodiment for planet wheel manoeuvring in relation to piston disconnection (cylinder parking) and/or phase angle changes.

The combustion engine depicted schematically in Fig. 1 comprises a bed, mounting or frame (not depicted) intended to support necessary components. The engine 1 comprises at least one piston 11 and at least one cylinder 12. The engine 1 further comprises an engine shaft/driveshaft 13 supported for rotation relative to the engine's frame/mounting/bed in a conventional manner. The engine shaft 13 comprises at least one external ring gear 14 intended to mesh with the respective external ring gears 19 of two gearwheels/planet wheels 15,16, which gearwheels 15, 16 are supported for rotation relative to the engine bed via bearings 17 and 18 respectively. The wheel 15 supports eccentrically a first piston rod 21 which is pivotable at a bearing point 101. The wheel 16 supports eccentrically a second piston rod 22 which is pivotable at a bearing point 102. A middle rod (pair rod) 23 is pivotable at its one end relative to the piston 11 via a bearing point 103.

The middle rod 23 is connected at its other end for pivoting relative to the free/other ends of the piston rods 21 and 22 at a bearing point 104. The piston rods 21 and 22 and the middle rod 23 thus form a movable and variable link configuration or link system 30 which may be regarded as being substantially Y- shaped with varying orientation. Each piston 11 in a multi-cylinder engine is provided with a link system 30 and a planet wheel pair 15,16.

The engine 1 may in one embodiment also comprise an outer ring 25 provided with an internal ring gear 26 which meshes with the teeth of the planet wheels 15 and 16. The outer ring 25 rotates when the engine 1 is in operation, and outer bearings or other guide means or guide rollers 27 are disposed as necessary relative to the engine bed/frame. The outer ring 25 may be adapted to communicating with the engine's generator and starting motor, in which case the

outer ring may also form part of these latter means. In a simple embodiment of the engine the outer ring may be omitted. In a multi-cylinder engine there may be a plurality of outer rings.

Fig. 2 illustrates schematically how a multi-cylinder engine may be constructed. Its main components have the same reference notations as in Fig. 1. The engine's valve system 40 may for example be constructed according to any desired available technical solution with or without camshaft. Variable valve opening times etc. may of course be applied. The engine's ignition system 41, if any, may of course be constructed according to any desired prior art. The engine's fuel supply system may of course be varied within the scope of available technology. In general, the various auxiliary systems of the engine 1, e.g. the lubricating system etc., may of course be varied within the scope of the state of the art.

The engine 1 can of course be designed in many different cylinder configurations, e.g. in-line, V, boxer or star formations, etc.

The mode of operation of the engine according to the invention is explained below in more detail with reference to Figs. 3-5.

Fig. 3 depicts schematically how the piston movement takes place in an engine 1 according to the invention in a first operating state. The piston rods 21,22 in the example depicted are attached to the planet wheels 15,16 at the same phase position, i.e. the phase angle (phase displacement angle) α = 0. The directions of rotation of the engine shaft 13, the planet wheels 15,16 and the outer ring 25 are indicated by arrows in the drawing. The bearing point 104 has a motion pattern according to the broken line 110, while at the same time the bearing point 103 of the cylinder-guided piston 11 has a vertical/rectilinear motion illustrated by the broken time line 111 on which the current position is represented by the point 112. The stroke length of the piston 11 corresponds to the height change (two-way amplitude) of the curve 111. The graphs 110 and 111 correspond to a single revolution of the planet wheels 15,16.

Fig. 4 illustrates schematically how the piston movement takes place in an engine 1 according to the invention in a second operating state. The piston rods

21,22 in the example depicted are attached to the planet wheels 15,16 at different phase positions, resulting in a phase angle α of about 60°, whereby the planet wheel 15 is "trailing". As in Fig. 3, the directions of movement are marked by arrows. The bearing point 104 has a motion pattern according to the broken line 120, while at the same time the bearing point 103 of the cylinder-guided piston 11 has a vertical/rectilinear motion illustrated by the broken time line 121 on which the current position is represented by the point 122. The stroke length of the piston 11 corresponds to the height change (two-way amplitude) of the curve 121. The graphs 120 and 121 correspond to a single revolution of the planet wheels 15,16.

Fig. 5 illustrates schematically how the piston movement takes place in an engine 1 according to the invention in a third operating state. The piston rods 21,22 in the example depicted are attached to the planet wheels 15,16 at different phase positions, resulting in a phase angle α of about 30°, whereby the planet wheel 16 is "trailing". As in Fig. 3, the directions of movement are marked by arrows. The bearing point 104 has a motion pattern according to the broken line 130, while at the same time the bearing point 103 of the cylinder- guided piston 11 has a vertical/rectilinear motion illustrated by the broken time line 131 on which the current position is represented by the point 132. The stroke length of the piston 11 corresponds to the height change (two-way amplitude) of the curve 131. The graphs 130 and 131 correspond to a single revolution of the planet wheels 15,16.

In the examples depicted in Figs. 3-5, each of the piston rods in the pairs 21,22 has the same length dimension.

Fig. 6 depicts an embodiment in which the piston rods 21',22' have different length dimensions. The planet wheels 15,16 in this example are situated asymmetrically relative to the centreline C of the piston 11. The bearing point 104 has a motion pattern according to the broken line 140, while at the same time the bearing point 103 of the cylinder-guided piston 11 has a vertical/rectilinear motion illustrated by the broken time line 141. The stroke length of the piston 11 corresponds to the height change (two-way amplitude) of the curve 141. The graphs 140 and 141 correspond to a single revolution of the planet wheels 15,16.

Figs. 3-6 exemplify various operating states or variations of an engine 1 according to the invention, but it should be noted that a great variety of different operating states can be achieved by variation of, for example, the phase angle α and/or by other geometric variations. According to an embodiment of the invention, the engine is so adapted that the phase angle α can be varied during engine operation, thereby making it possible inter alia for the engine to be run with variable compression. This in its turn entails inter alia the possibility of fuel saving, good operating economy and potential for adaptation to different types of fuels with further advantages. The phase angle control can of course be automated, e.g. by fitting sensors which indicate need for adjustment, etc. It should therefore be realized that the engine 1 according to the invention can provide optimum piston movements for different types of fuels and running conditions. The engine is thus extremely suitable for use in, for example, passenger cars etc.

Fig. 7 shows how the rotation/rotational centre 17,18 of the planet wheels

15,16 can be set/moved as desired. This is achieved by means of a rotary ring 330 which is supported by the engine frame and which itself supports the rotatably supported planet wheels 15,16, whereby the rotary ring 330 is turned to a desired rotational position relative to the piston centreline C and is fixed in that position until the need for a change of setting arises, etc. Fig. 7 illustrates a common position change for the centres of rotation 17,18 of the planet wheels 15,16. If it is desired to effect individual changes of position of the centres of rotation 17,18 of the planet wheels 15,16, this can be achieved by, for example, dividing the rotary ring 330 into two separately rotatable segments each supporting its respective planet wheel.

Fig. 8 illustrates a radial change of the bearing point 101 of a planet wheel 15 whereby the eccentricity of the bearing point 101 can be set as desired. The eccentricity resetting may for example be effected hydraulically or mechanically. Similar reasoning does of course also apply to the planet wheel 16 and the bearing point 102.

The engine 1 in one embodiment further affords the possibility of temporary disconnection of the piston rods 21,22 from accompanying the rotary

movement of the planet wheels 15,16. This makes it possible for a desired number of cylinders in a multi-cylinder engine to be temporarily parked by putting a desired number of pistons into a temporary stationary state, e.g. when economical running at reduced engine power is desired.

Fig. 9 illustrates one of many conceivable embodiments which effect disconnecting and/or changing the rotational position (changing the phase angle) of the planet wheels 15,16. The planet wheel 15 is divided into two portions 15a, 15b which in a normal operating state are caused to rotate together by a number of driving means 35, e.g. gear teeth. The inner portion 15b comprises the external ring gear 19, and the outer portion 15a supports the bearing point 101 for the piston rod 21. An actuator 200 supported by the engine frame is adapted to executing, when necessary, an axial movement of the outer portion 15a so that the engagement of the driving means 35 ceases, after which the actuator 200 is adapted to executing, when necessary, a rotary movement of the outer portion 15a in order to achieve a desired phase angle change, after which the actuator 200 effects an axial return movement so that the driving means 35 reverts to an engaged state. Normally, each of the planet wheels 15,16 in a planet wheel pair is configured as above and provided with an actuator 200. Both piston parking (cylinder parking) and phase angle resetting are thus possible even when the engine is in an operating state.

It is of course possible to provide selective actuators in, for example, a multi-cylinder engine. It is also possible to arrange common actuators for a plurality of planet wheels or a plurality of cylinders etc.

Consequently a selective cylinder parking is possible when the engine is in an operating state. There is also a possibility of effecting desired phase angle changes when the engine is in an operating state, with the consequent possibility of variable compression and, for example, efficiency optimisation based on driving style.

In a simple basic variant, the engine according to the invention comprises the following characteristic basic components: engine shaft/driveshaft and a desired number of planet wheels, piston rods and middle rods.

A simple variant may comprise a planet wheel pair with stationary arranged bearing points for the piston rods or a resettable piston rod bearing point on only one planet wheel of a pair of planet wheels.

In one variant of the engine according to the invention, the outer ring 25 may serve as the engine's driveshaft, making it possible to omit the driveshaft 13.

In an exclusive variant, the engine according to the invention comprises in addition one or more outer rings and one or more actuators 200 or the like.

Any desired intermediate variants are of course possible.

The construction of the engine according to the invention is thus readily adaptable to all the needs which arise as regards both small engines, e.g. lawnmower engines, and large engines, e.g. engines for large vehicles.

Appropriate sensor arrangements and control means make desirable operational optimisation possible with respect to, for example, fuel type, fuel economy, performance requirements, environmental requirements etc.

The flexibility of the engine according to the invention makes it possible for many future alternative fuels to be used. The engine thus has very good potential for coping with future fuel ranges and environmental requirements.

The engine's fuel injection or fuel supply, exhaust system, lubrication system and other auxiliary systems/components are not described in further detail but may of course be varied within the scope of the state of the art in relation to the engine according to the invention.

It should be noted that the gear drive described above by way of example between, for example, the driveshaft and the planet wheels may be replaced by chain drive or some other alternative drive.

It should therefore be noted that many component variations are possible within the scope of the concept of the invention.

It should be noted that the motion pattern of, for example, the bearing points 101,102 may of course be varied beyond what is described above by way

of examples.

It should be mentioned that in a certain setting state of the link system 30 the piston may be caused to be stationary.

The fact that the outer ring 25 and the shaft 13 can, if so desired, serve as alternative driveshafts provides the possibility, when needed, of a simple gear arrangement.

The engine according to the invention is readily adaptable to two-stroke operation, four-stroke operation and other working cycle variants which, for example, comprise blowdown strokes/ventilation strokes for cylinder cooling etc. The engine is thus adaptable to any desired working cycle variants.

It should further be mentioned that the engine 1 affords, for example, the possibility of driving-zone-related engine resetting and driving-zone-related fuel selection and a multiplicity of other environment adaptation measures.

Many variations are thus possible within the scope of the invention concept described above.

The invention is therefore not limited to what is here depicted and described, since changes and modifications are possible within the scope of the attached claims.