WO1987000243A1

WO1987000243A1 - Multi-cylinder two-cycle wobble plate engine

Info

Publication number: WO1987000243A1
Application number: PCT/AU1985/000142
Authority: WO
Inventors: Peter Robert Rolliston
Original assignee: Peter Robert Rolliston
Priority date: 1985-06-28
Filing date: 1985-06-28
Publication date: 1987-01-15
Also published as: EP0227649A1

Abstract

A multi-cylinder two-cycle engine has cylinders (17) disposed about and parallel to a power output shaft (13). Each cylinder (17) contains a pair of double-ended pistons which reciprocate towards and away from each other, piston motion being transferred to the power output shaft (13) through a pair of wobble plates (12). The inner ends (2) of the pistons control inlet ports (6) and exhaust ports (7) in a common combustion space (1). The outer ends (3) of the pistons act as pumping pistons in compression spaces (4) formed at the outer ends of the cylinders (17). Charging air is drawn into compression spaces (4) through inlet valves (11), compressed and transferred to the combustion space (1) via transfer ducts (5) and inlet ports (6). The air is further compressed in the combustion space by inward movement of the pistons, fuel injection and ignition then following. As the pistons are forced apart under the influence of combustion gas pressure, exhaust ports (7) and inlet ports (16) are exposed. Exhaust gases are purged by some part of the fresh incoming charge for further combustion in the exhaust chamber (9) and catalytic reactor (10).

Description

MULTI-CYLINDER TWO-CYCLE WOBBLE PLATE ENGINE

The basic design of the Parallel Internal Combustion Engine utilizes a central power shaft with a swash plate fitted. Connected to this swash plate, by swiveling - sliding bearings, is a double piston unit which reciprocates parallel to the power shaft. One end of the piston unit is called a charge piston as the downward stroke of this piston force charges the combustion chamber of which the opposite end of the piston unit is the working piston of that combustion chamber.

Many variants utilizing this basic design are possible by combining piston unit quantities, swash plate quantities, single or combined combustion chambers, cooling systems, polution control systems, fuels or steam pressures either as engines or as compressors.

The Parallel Internal Combustion Engine described is of a six piston, two stroke asperated, wet oil sump design using low octane, non-leaded fuel and fuel injection into a two piston unit combustion chamber. It is water cooled and has a secondary burn chamber and catolitic convertor.

The piston units consist of a double ended piston (2 - 3) which is attached to a swash plate (12) by a swiveling and sliding bearing located between the pistons. The piston at one end is a working piston (2) and at the other end a larger diameter, charging piston (3). This piston unit reciprocates along its centreline and parallel to the centreline of the power shaft (13). "DESCRIPTION" (2)

The central components of the Parallel Internal Combustion Engine are the swash plates (12) and the power shaft (13). Located on equal radis from the power shaft's (13) centreline, are the piston cylinders (17) centrelines. The centreline of the upper piston cylinder is perpendicular to the. centreline of the power shaft (13). The centrelines of ^~ the lower two piston cylinders (17) are at 120° either side of that perpendicular line. The centrelines of the power shaft (13) and piston cylinders (17) run parallel to one another.

Fitted into the piston cylinders (17) are the piston units. Two piston units share a common piston cylinder with the working pistons (2) facing inward forming a combustion chamber (1) between them. The piston units are attached to the swash plates (12) by the swivel-slide bearings and due to the opposite angling of the swash plates (12) recipricate in.unison. Both working pistons (2) reach top dead centre simultaneously and simultaneously to the charging pistons (3) reaching bottom dead centre.

The outer ends of the piston cylinders are blanked off so as to form compression chambers (4). Fitted into these blanks are one way inlet valves (11) and outlet transphere ducts (5). The transphere ducts (5) run down the side of the piston cylinders (17) and terminate at the combustion chamber Inlet port (6).

The combustion chamber exhaust port (7) is connected directly to the secondary combustion chamber (9) and fitted into the exhaust outlet is a catolitic convertor

(10). Fuel is injected into the compression chamber by the injector (15) and the mixture is ignited by a spark plug (14) (removed for clarity). Lubrication is achieved by a wet oil sump (16) and pump. The engine is cooled by liquid circulation. " CLAIMS"

"ADVANTAGES OF THE PARALLEL INTERNAL COMBUSTION ENGINE"

The Parallel Internal Combustion Engine has several advantages over conventional engine types. These are:-

1 Low Exhaust Edmi-ssions

2 Good Fuel Economy

3- Higher Horse Power Yield

4 Higher Torque Yield

5 Low Vibration

6 Low Number of Moving Parts

7 Low Manuf cturing Costs

8 Free Reving

9 Lightness

10 Compactiness

11 Opens New Avenues for Engine Developments

12 Uses Known Technoligy

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Claims

"CLAIMS"

1 ) LOW EXHAUST EDMISSIONS POINT A

The basic design of the Parallel Internal Combustion Engine incorporates a two stroke asperated system and a wet sump lubrication system. This results in only clean oxygenated gasses and fuel entering the combustion chambers and so none of the polutants associated with conventional two stroke engines are produced.

POINT B

The two stroke engine does not require the use of leaded fuels therefore the polutants associated with those fuels are eliminated.

POINT C

The production of polutants in conventional four stroke engines due to hot burn regions is greatly .lessened in conventional two stroke engines. In the Parallel Internal Combustion Engine the gasses are caused to swirl during compression and ignition causing hot burn areas to disipate with the resulting drop in polutant production.

POINT D

The Parallel Internal Combustion Engine incorporates an independent combustion chamber charge piston. By this system an excess o„f oxygenated gasses is forced into the combustion chamber during the combustion chamber's intake stroke. The burnt, burning and unburnt gasses are purged from the combustion chamber by this rush of pressurized oxygenated gasses and pass through the

open exhaust ports and into the secondary burn chamber.

A quantity of oxygenated gasses also flow into the secondary burn chamber where they support the continuatio of mixture combustion in that chamber. " C LAIMS"

POINT E-

High temperatures are obtained in the secondary burn chamber and this results in the oxidization of the majority of the exhaust gasses.

POINT F

Fuel may be injected on every compression stroke, every second or third compression stroke. When fuel is injected on every second or third compression stroke oxygenated gasses are allowed to pass through the combustion chamber into the secondary burn chamber, There they further support and mixture combustion and oxidization in that chamber and so further reducing polutant emissions.

POINT G

A catolitic converter is fitted close to the rear of the secondary burn chamber. As the exhaust gasses pass through this into the exhaust outlet, the bulk of the remaining poluting gasses are converted to harmless gasses. The back pressures created by the catolitic converter and secondary combustion chamber are over come by the forced charging of the combustion chamber by the charging piston system.

2 ) FUEL ECONOMY

POINT A

Fuel may be injected on every compression stroke, every second or third compression stroke or a combination of these systems, depending on engine power demand. A combination system would result in a smaller capacity engine which is capable of various levels of horse power and torque yields. Fuel is burnt economicly to only produce horse power on demand.

POINT B

The low number of moving parts in the Parallel Internal Combustion Engine produce a correspondently low level of internal friction resistance resulting in less fuel- used to over come that resistance.

POINT C .

The swash plate power shaft system has a mechanical advantage over the crankshaft system. This results in more horse power available for each litre of fuel burnt.

POINT D

The weight of the Parallel Internal Combustion Engine is less than that of a conventional engine. The fuel burnt to produce horse power to overcome this weight resistance is therefore corrospondently less. " CLAIMS"

3 ) HORSE POWER YIELD

POINT A

When the pistons are at top dead centre more than double the volume of explosive gasses are contained with in combustion chamber of the Parallel Internal Combustion Engine than in the combustion chamber of a conventional engine with its piston at top dead centre. Due to the forced asperation of the Parallel Internal Combustion Engine the compression pressures are equal to those in a conventional engine. When ignited the explosion pressures obtained are greater than in a conventional engine. This is due to the expansion of this greater volume of gasses within the correspondently equal swept volumes of the combined combustion chamber of the Parallel Internal Combustion Engine to that of two combustion chambers of a conventional engine. This results in higher piston thrust and horse power yield.

POINT B

During the combustion chamber intake cycle oxygenated gasses are forced into the combustion chamber and over come the exhaust back pressures. The resulting pressurizing of the combustion chamber has the effect of super charging the engine.

POINT C

Due to the forced asperation and its designed over coming of exhaust back pressures there is no power loss due to those back pressures. " CLAIMS"

POINT D

When fuel is injected on every compression stroke, ignition occures on every downward stroke. In a conventional four stroke engine ignition occures on every second downward stroke, so applying only one half of the number of power strokes per thousand revolutions.

POINT E

The mechanical advantage of the swash plate over the crankshaft makes more horse power available for equal piston thrust.

POINT F

The low number of moving parts within the Parallel Internal Combustion Engine have a correspondents low internal friction level. This results in less piston thrust being used to over come the internal friction and more piston thrust being available to produce usable horse power.

4. ) TORQUE YIELD

POINT A

The design of the described Parallel Internal Combustion Engine has, when ignition occures on every stroke, six pistons applying forces to the swash plates on every revolution. The piston units work as pairs and apply force to seperate, through unitized, swash plates. These piston pairs are at 120° spacing around the power shaft centreline and so even constant forces are applied to ^'the power shaft, resulting in a high and even torque yield. "CLAIMS"

TORQUE YIELD CONT'D

PART B

As detailed in Point A of horse power yield, higher explosion pressures are obtained in the Parallel Internal Combustion Engine combustion chamber resulting in greater piston thrust. This thrust is stronger and more even than that of a conventional engine resulting in higher torque yields.

5 ) LOW VIBRATION

The recipricating parts of the Parallel Internal Combustion Engine move in parallel with the centreline of the^" ower shaft. For any movement within the Parallel Internal Combustion Engine there is a counter movement by a identical component and so cancelling out any vibration produced.

6 ) LOW NUMBER OF MOVING PARTS ^'

In the six piston Parallel Internal Combustion Engine described there are only seven moving parts of which one part rotates and six parts recipricate.

7 ) LOW MANUFACTURING COSTS

Due to the small number of parts and the simplicity of design of the Parallel Internal Combustion Engine, manufacture is simple and straight forward. There are no specialized manufacturing methods or proceedures to be developed for production of the basic Parallel Internal Combustion Engine- " CLAIMS"

8 ) FREE REVING

The simplicity of design and natural balance of the Parallel Internal Combustion Engine combined with the asperation and fuel systems makes a compact free spining engine capable of a very high number of revolutions.

9 ) LIGHTNESS

The internal forces are taken up directly by the swash plates and so the need for large cast engine blocks and engine heads are eliminated.

10) COMPACTNESS

All cylinders and components are in parallel with the power shaft centreline and so have a low compact three diamentional profile.

11 ) OPENS NEW AVENUES FOR ENGINE DEVELOPMENT

The Parallel Internal Combustion Engine design makes possible development and improvements in engine designs, horse power and torque yields, production control, fuel economy etc that are not possible with conventional designs.

12) USES KNOWN TECHNOLOGY

The design of the Parallel Internal Combustion Engine uses known technology and so no special development is required before manufacture may commence.