1 DESCRIPTION OF THE DISCLOSURE TITLE OF INVENTION: "Improvements in Engine Technology to Improve Efficiency and Fuel Economy and Reduce Emissions" TECHNICAL FIELD [001] The invention relates to internal-combustion engines, and in particular to the sealing of gases in the combustion chamber, as per International Patent Classifications F02F 05/00; F02F 11/00; and F16J 09/00, and is intended to reduce friction and wear, fuel consumption, and harmful (HC, CO and NOx) exhaust emissions. BACKGROUND ART [002] Engines have previously used piston rings (in piston engines) and mechanical seals (in oscillating and rotary engines) in the belief that the optimum performance of the engines could only be achieved by (virtually) completely sealing the gases in the combustion chamber(s), by means of strong mechanical seals; certainly, this belief had sound merit in the past. [003] These engines generate a lot of friction and subsequent wear - of the mating surfaces, and oil is required to continually lubricate these surfaces in an attempt to reduce the magnitude of 2 these problems, but unfortunately the friction losses are still high, thus reducing the efficiency of the engines, while requiring a powerful starter motor to start them. [004] These engines will have trouble meeting the ever-decreasing limits for harmful exhaust emissions in the future, as they have inherent disadvantages. SUMMARY OF INVENTION This invention: [005] Provides improvements in internal-combustion engine technology; [006] Is intended primarily for engines where the pistons or rotors (or such) can be positively located by bearings or bushes, such that the pistons or rotors do not touch each other, or touch their mating cylinders or housings; [007] Is primarily intended for Scotch-Yoke piston, and twin-wedge oscillating and rotary, engines; [008] Completely or partially eliminates the need for conventional mechanical piston and rotor rings or seals; [009] Completely or partially eliminates the need for conventional lubrication between the seals or rings and their mating surfaces; 3 [010] Significantly reduces friction between, and subsequent wear of, these elements; [011] Uses a plurality of grooves into which air is admitted, creating high-speed eddies within the grooves to provide a gas-sealing effect, in lieu of mechanical piston/rotor rings or seals. [012] NOTE: It is recognised that the air sealing will not provide a 100% seal against blow-by gases, but it is also recognised that the advantages of the technology out-weights this disadvantage. TECHNICAL PROBLEMS: [013] The technical problems with engines that use piston rings or mechanical seals, or such, include: [014] Friction between the rings/seals and their mating surfaces; [015] Wear of the rings/seals and their mating surfaces; [016] The need to continually lubricate the rings/seals and their mating surfaces; [017] The cost of the rings/seals, and their installation; [018] The need to recondition or replace the rings/seals and their mating surfaces as the wear exceeds a satisfactory amount; 4 [019] The need to have a powerful starter-motor and battery to start the engine, because of the large amount of friction in the engine; [020] The loss of mechanical efficiency of the engine, because of the large amount of friction in the engine; [021] The entrapment of fuel in the "lands" around the periphery of the pistons, or rotors, with a subsequent increase in harmful emissions; [022] The tendency for the periphery of the pistons, or rotors, to over-heat, with subsequent detonation and/or mechanical damage. SOLUTION TO PROBLEMS: This invention provides the following solutions: [023] Low friction; no lubrication required; no wear; ultra-long life; [024] High efficiencies - mechanical, volumetric & thermal; [025] Improved fuel economy; ultra-low exhaust emissions; [026] Increased power output; flat torque curve; smooth operation; 5 [027] Variable compression ratio and efficient engine braking; [028] Lighter and more compact engines; [029] Provides a "cushion" or air around the periphery of the combustion chambers, to help prevent fuel entrapment, detonation, and damage to the engine components. ADVANTAGEOUS EFFECTS OF INVENTION: [030] This invention provides the following advantageous effects: [031] Reduces the emissions of harmful exhaust gases - CO, HC and NOx; [032] Provides a stratified-charge air-fuel mixture for combustion; [033] Provides an "after-burn" of exhaust gases; [034] Lowers the possibility of engine seizure; [035] Lowers the possibility of over-heating of internal engine components; [036] Requires a less-powerful starter motor (which may be an air-powered motor); 6 [037] Continually cleans internal engine components including spark-plugs and fuel injectors; [038] Inherently super-charges the induction air; [039] Permits a smaller coolant system; [040] Provides quieter and smoother engine operation; [041] Reduces the cost of engines. [042] Reduces the cost of engine maintenance. BRIEF DESCRIPTION OF DRAWINGS [043] Fig.1 shows the principle of the invention, where 1 is the cylinder or housing of an internal combustion engine, 2 is the piston or rotor, 3 is the plurality of grooves in all surfaces of the piston or rotor that are in close proximity to the cylinder or housing where sealing of gases is required, and 4 is the direction that the piston or rotor moves during the compression stroke of the engine. [044] Fig.2 shows an enlarged view of a groove 3, showing the prime dimensions responsible for the sealing effectiveness of the invention, with 4 being the angle of the grooves, 5 being the radius (which may be zero) of the inner end of the groove, 6 being the clearance between the piston and the mating 7 cylinder bore, or between the rotor and the mating surface of the housing, and 7 being the depth of the groove. [045] Fig.3 shows a typical arrangement of the groove pattern for an oscillating or rotary engine using one or two twin-wedge rotors and a housing. [046] Fig.4 shows a typical arrangement of the groove pattern for a piston in a Scotch-Yoke or horizontally-opposed engine. BEST MODE FOR CARRYING OUT THE INVENTION [047] The grooves are machined in the piston(s) or rotor(s), and in the appropriate mating surface(s) of the housing(s) for some embodiments of oscillating or rotary engines, in order to obtain the necessary precision. DESCRIPTION OF EMBODIMENTS [048] Fig.1 shows the principle of the invention, where 1 is the cylinder or housing of an internal combustion engine, 2 is the piston or rotor, 3 is the plurality of grooves in all surfaces of the piston or rotor that are in close proximity to the cylinder or housing where sealing of gases is required, and 4 is the direction that the piston or rotor moves during the compression stroke of the engine.
8 [049] While the invention may be used to advantage in other engine designs and configurations, it is intended to be used in engines where the pistons or rotors do not "flop around" inside, and do not contact the surface of, their mating component, but rather where the pistons or rotors are positively located, by bearings or bushes, so that while always in very close proximity to the mating component, they do not contact them. [050] When the moving element 2 - piston or rotor - moves along its mating stationary element 1 cylinder or housing - it tends to compress the gas ahead of it. Due to the differential-pressure, gas will tend to pass through the very narrow passage designated by 6 in Fig.2 - into the region of lower pressure. [051] This escaping (blow-by) gas travels at a very high speed, due to the extremely small cross sectional area of the passage. As the gas passes the grooves, exceptionally high-speed "eddies" are formed, such that they provide an effective degree of sealing against further gas passing by. [052] Tests have confirmed that the sealing effectiveness is significantly affected by the number of grooves 3 - as shown in Figs. 1, 2, 3 & 4 - and by their dimensions, angle 4, radius, clearance 6, & depth 7 - as shown in Fig. 2.
9 [053] The clearance 6 is critical, and is designed to be as small as possible, but large enough to ensure that the moving and stationary elements do not touch during any operating mode of the engine. In this regard, the selection of the material, along with the heat-treatment and surface-finish - for both of these elements - is vitally important. [054] In addition, the degree of cooling - or the operating temperature - of these two elements, in regards to thermal expansion/contraction, is important, so that the clearance between them remains within the design limits for all engine and atmospheric conditions. Selective-cooling, via different fin sections, and/or coolant air/liquid flow rates, may be incorporated. [055] One embodiment of the invention provides for pressurised air (from an external source, not shown) to be to the moving element, on its non-combustion surfaces, to provide additional cooling, if required. This additional air may also be admitted to the grooves, via a one-way valve, if desired. [056] Generally, the maximum possible number of grooves are provided on the surfaces to be sealed. However, the grooves are of the optimum profile(s), as per dimensions 4, 5, & 7, and may become smaller and more-closely spaced as their location from the combustion surface increases.
10 [057] Some grooves, furthest away from the combustion surface, may be reverse-angled, so as to provide a sealing effect in the opposite direction, in an effort to prevent lubricating oil (from shaft and mechanism bearings/bushes) from entering the combustion chamber. [058] In some embodiments, a lightly-loaded, self lubricated, ceramic (or such) seal(s) may be added, so as to further increase the sealing effectiveness. [059] In some embodiments, a number of deformable metal rings or seals may be positioned in a number of the grooves, such that they normally are retracted so that they do not contact the surface of the stationary element, but at very low engine speeds, such as when the engine is being started, they extend outwards so as to increase the sealing effect. [060] It is acknowledged that the invention will not provide 100% sealing of the gases, but this loss of some of the pressure in the combustion chamber is compensated for by having a design compression-ratio higher than would normally be used, and/or by using a super-charger or turbo-charger to increase the pressure of the induction air. [061] While there have been described and illustrated embodiments of the invention, it will be obvious that variations in the details of the embodiments specifically described and illustrated 11 may be made without departing from the true spirit and scope of the invention as defined in the appended Claims. EXAMPLE: [062] The invention can be used to replace either fully or partially - the piston rings and mechanical seals in certain types of piston, oscillating twin-wedge, and (true) rotary twin-wedge engines. INDUSTRIAL APPLICABILITY: [063] The invention is applicable to internal combustion engines (except turbine engines) as used for automotive, aircraft, agricultural and industrial purposes. [064] The invention is applicable to engines where the piston(s) or rotor(s) are positively located so that they do not contact the mating surface(s) of the cylinder(s) or housing(s). [065] The invention is applicable to these engines, whether running on petrol, kerosene, diesel, hydrogen, propane, butane, methane or ethane - or any combination of these fuels - especially in situations where low harmful exhaust emissions are required.