GB2454533A

GB2454533A - Internal combustion engine with oscillating cylinder(s)

Info

Publication number: GB2454533A
Application number: GB0722181A
Authority: GB
Inventors: Adrian Meynell Vale
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-11-12
Filing date: 2007-11-12
Publication date: 2009-05-13
Also published as: GB0722181D0

Abstract

An internal combustion engine comprises a cylinder block 10 containing a piston 12 operatively connected to the pin 15 of a crank 16 for effecting reciprocating movement of the piston 12 within a cylinder 11 formed in the block 10 as the crank 16 rotates. The piston 12 is rigidly connected to the crank pin bearing 14 and the cylinder 11 is mounted, eg by pivot pin 18, for oscillating pivotal movement about an axis parallel with the axis of rotation of the crank 16. In use, the thrust exerted on the piston 12 during the power stroke is directed straight towards the crank pin 15 with no loss in efficiency and there is a considerable saving in reciprocating weight compared with a conventional engine. The piston 12 may be connected to the crank pin 15 by a rod integrally cast with the piston. A multi-cylinder engine may have a number of discrete cylinder blocks pivoted about a common axis.

Description

Internal Combustion Engine This invention relates to internal combustion engines of the reciprocating-piston type and particularly but not exclusively provides an internal combustion engine which has components of less reciprocating weight and, in use, generates less friction than conventional engines and thus uses less fuel.

In a conventional internal combustion engine of the type described, whether operating on the four-stroke or two-stroke principle, the piston is connected to the crank shaft by a connecting rod which at the small end is connected to the piston by a gudgeon pin and at the other end is connected to the crankshaft by a big end bearing. The piston reciprocates, in use, in the cylinder along an axis which intersects the axis of rotation of the crankshaft, irrespective of the rotary position of the big end bearing as determined by the position of the piston within the cylinder. Thus, except at the top-dead-centre and bottom-dead-centre positions, the big end bearing is always displaced laterally of the axis of rotation of the crankshaft and, on the power stroke, there is an energy loss in the thrust exerted on the piston to the extent that the connecting rod is angularly displaced from the longitudinal axis of the cylinder. Furthermore, this results in a side thrust as between the piston and the cylinder wall which produces friction, generates heat and wastes fuel.

It is an object of the present invention to provide an internal combustion engine which is so arranged that the above disadvantages are reduced.

In one aspect, the invention provides an internal combustion engine comprising a cylinder block containing a piston operatively connected to the pin of a crank for effecting reciprocating movement of the piston within a cylinder formed in the block as the crank rotates, in which the piston is rigidly connected to the crank pin bearing and the cylinder is mounted for oscillating pivotal movement about an axis parallel with the axis of rotation of the crank.

In operation of an internal combustion engine according to the invention, the thrust exerted on the piston during the power stroke is, by virtue of the rigid connection of the piston to the crank pin bearing and the oscillating mounting of the cylinder, always directed straight towards the crank pin with no loss in efficiency, thus applying optimum rotational force to the crank pin especially when at the 3 o'clock position and substantially eliminating friction arising from a component of lateral thrust between the piston and cylinder.

In a combustion engine where the cylinder is disposed above the crankshaft, which is conventional in many applications, the pivot axis of the cylinder is preferably disposed above the piston at the upper end of its throw, for example within or above the cylinder head.

The connection means between the piston and the crank pin bearing may be integrally cast with the piston itself or may constitute a separate connecting rod but, in either case, there is no requirement for a gudgeon pin, nor for the bosses required internally of the piston to accommodate the gudgeon pin, nor for a little end bearing. There is therefore a considerable saving in reciprocating weight compared with a conventional engine and which, again, results in a reduction in fuel consumption through a reduction in reciprocating weight. Additionally, the connecting rod, if present as such, can extend towards the crank pin substantially from the lower end or skirt of the piston, this again resulting in a saving in reciprocating weight compared with a conventional arrangement.

The crank is preferably rotatably mounted in a main bearing carried by the cylinder block and a crank case is formed at the lower end of the cylinder block including an oil sump attached to the bottom thereof. The main crank bearing should be spatially fixed in relation to the pivot axis of the cylinder, for example by use of suitable tie bars or by virtue of the mounting arrangement of the cylinder and crank within the cylinder block.

An internal combustion engine according to the invention may be of the single-cylinder or multi-cylinder type; in the case of a multi-cylinder engine, the respective cylinder blocks are preferably pivoted about a common axis. If the engines are water-cooled, each cylinder block preferably is equipped with a respective cooling water jacket with provision for ingress and egress of cooling water in a recirculation system through a radiator, as currently known.

Embodiments of the invention will be described by way of example with reference to Figures 1-4 of the accompanying drawings, which illustrate schematically the operation of an internal combustion engine according to the invention at the various stages of rotation of the crank and the consequential positions of the piston within the cylinder.

Referring firstly to Figure 1, the engine consists of a cylinder block/crank case 10 in which is carried a cylinder 11. The cylinder carries a piston 12 arranged for sliding reciprocating motion within the cylinder in the usual manner, with provision of oil seal rings (not shown) around the periphery thereof and in contact with the cylinder walls. The lower end of the piston is formed with a connecting rod 13 the lower end of which is joumalled via a bearing 14 to the pin 15 of a crank 16. The upper end of the cylinder is joumalled through a bearing 17 to a pivot pin 18 which, in the case of a multi-cylinder engine, may be constituted by a rod, axially aligned in parallel with the axis of rotation of the crankshaft and equipped with spaced-apart bearing surfaces for the respective bearings 17. As shown in Figure 1, the piston 12 is at the top-dead-centre position and a spark 19 is created at a sparking plug (not shown). The pin 18 isjoumalled in the upper part of the cylinder block, which at its lower end forms a crank case, and the crank 16 is also journalled via a main bearing carried in the cylinder block/crank case 10.

With reference now to Figure 2, the piston has moved downwardly in the cylinder, under the force of the expanding gases created by combustion of the fuellair mixture drawn or injected into the upper part of the cylinder by conventional valve means (not shown) and the crank has rotated 90° in a clockwise direction, as shown by the arrow, to the 3 o'clock position. Because the connecting rod 13 is fast with the piston, the cylinder has pivoted to accommodate movement of the crank pin through the first quadrant within the cylinder block/crank case and, at the position shown, there is the optimum force being exerted on the crank pin as the piston moves directly towards the pin.

As shown in Figure 3, the crank pin is at the bottom-dead-centre position and, in Figure 4, the crank pin is at the next quadrant position and the piston is rising within the cylinder on the exhaust stroke, exhaust valves and manifolding not being shown.

It can be seen that, during the power stroke as illustrated in Figure 2, there is no lateral or sideways thrust or friction-generating effect as between the piston and the cylinder and, more significantly, there is a considerable saving in reciprocating weight. As a result, the engine operates with improved efficiency compared with a conventional combustion engine of the type described.

Although the invention has been particularly described by way of example with reference to a spark-ignition petrol engine, it would be equally appropriate for a compression-ignition diesel engine.

Claims

Claims 1. An internal combustion engine comprising a cylinder block containing a piston operatively connected to the pin of a crank for effecting reciprocating movement of the piston within a cylinder formed in the block as the crank rotates, in which the piston is rigidly connected to the crank pin bearing and the cylinder is mounted for oscillating pivotal movement about an axis parallel with the axis of rotation of the crank.
2. An internal combustion engine according to claim 1, in which the cylinder is disposed above the crankshaft, the pivot axis of the cylinder being disposed above the piston at the upper end of its throw.
3. An internal combustion engine according to claim 1 or claim 2, in which the connection means between the piston and the crank pin bearing is integrally cast with the piston itself.
4. An internal combustion engine according to claim I or claim 2, in which the connection means between the piston and the crank pin bearing extends towards the crank pin substantially from the lower end or skirt of the piston.
5. An internal combustion engine according to any preceding claim, in which the crank is rotatably mounted in a main bearing carried by the cylinder block, a crank case being formed at the lower end of the cylinder block including an oil sump attached to the bottom thereof.
6. An internal combustion engine according to claim 5, in which the main crank bearing is spatially fixed in relation to the pivot axis of the cylinder.
7. An internal combustion engine according to any preceding claim, of the multi-cylinder type including a plurality of discrete cylinder blocks.
8. An internal combustion engine according to claim 7, in which the respective cylinder blocks are pivoted about a common axis.