DE4110945A1 - Contactless double piston of reduced size - is formed from part with bowl-shaped pistons with very thin bases and which taper into thin shafts - Google Patents

Abstract

The two piston surfaces (1) are dished. Each piston bottom is connected to thin round rod. The two rods (2) are connected to a ring (3) which accommodates a slide or roller bearing. The bases of the pistons are spherically formed as rotation bowls with a very reduced wall thickness, which is determined by the heat period stability of the material used as againsta the gas pressure in the combustion chamber. The rotation bowls are finished on the combustion chamber side with a sharp edge, and on their periphery is a narrow ring with the same rotary axis as themselves. Each thin round rod can slide is embedded in longitudinally movable bearings, and accordingly the double piston is also able to execute a longitudinal movement in the cylinder, without any contact occurrring between the hot piston and the hot cylinder. USE - Reduced size contactless double piston. Is used in IC engines.

Description

The present invention is concerned with an integral part Double piston with low mass for a contactless movement in cylinders of internal combustion engines in 4 and 2-stroke systems just like with reciprocating compressors. The intention is one To achieve low mass to reduce the oscillating mass forces at high speeds, also a very thin piston crown train for good heat dissipation from the thermally stressed Piston plate, furthermore to form an integral double piston Avoiding screw connections on the piston head or connecting rods and to avoid piston pins, deflection and noise and the poor lubricity of piston pins, furthermore the avoidance of uneven thermal expansion of the piston and the avoidance the tilting movement of previous reciprocating pistons, avoiding the use of Connecting rods and piston rings and cylinder lubrication or gasoline-oil mixtures in 2-stroke engines. Furthermore, lower displacement resistances aimed at the air flow of fresh air flushing with 2-stroke Engines.

The contactless, gas dynamic sealing piston was patented on the Strach 11 58 753 patent in Germany and 9 82 470 in England from 1960 or 1963. Over the built afterwards 4-cylinder engine has been widely reported.

Based on the knowledge that the cross crank used engine is too high a vibrating mass, became a new one Gearbox developed, which has been registered for a patent and is available under the published specification Strach DE 35 38 532, 1985.

This engine forms the basis for the formation of a double piston with the intentions as described above, in particular in that the crank pin forming the stroke is on an exactly straight line Path moves and thus a double piston also straight and can move in a cylinder without contact and that Guide parts are not in the hot combustion chamber.

According to the invention, the double piston is made from a heat and scale-resistant steel alloy as a forged turned part. The piston crown is shaped according to the ideal spherical combustion chamber shape and the shell thickness is minimized according to the membrane theory to avoid bending stresses to achieve the thinnest wall because it is stationary Heat transport according to Fourier's law is a temperature difference  on the two faces of the shell gives the inversely proportional the thickness is.

The gas force is centrally applied via very thin round shafts Plain or roller bearings guided or supported, which is constant the linear movement of the crank pin rotates in the center executes.

The hollow design of the piston ensures a sharp cutting edge on the outer edge the counterflow of the gas dynamic seal and a narrow outer edge forms the sealing ring surface for the vortex flow.

The outer spherical shape of the piston requires z. B. with 2-stroke Engines versus a crankcase blower or one Using a piston underside a much smaller one Flow resistance for the purge air flow.

The drawing shows such a whole part according to the invention Double piston with low mass as an application in a 4-cylinder Oilless 2-stroke engine with fresh air purging and exhaust gas control by means of a rotary valve.

Instead of the membrane valve, the fresh air supply can also be via the rotary valve take place through the same exhaust slot, which would reduce thermal stress.

The rotating double crank couples the oscillating masses of the two double pistons such that each has the greatest kinetic energy of a double piston occurs at half stroke and thus in the greatest power requirement for the reverse acceleration of the other double piston.

With these changing power flows, the rotating shaft of the Double crank reaction forces periodically on the rotating flywheel out.

The irregularity of the respective rotation of this flywheel thus decreases proportionally with the reduction in mass of the oscillating double pistons. The bearing pressure is also reduced.

Instead of the double pistons, single pistons can also be used on both sides can be attached, a combination of Internal combustion engine and compressor, each in pairs one-sided or mutual.

Claims (4)

1. Double pistons for internal combustion engines or compressors with low mass, characterized in that two piston-like surfaces in a symmetrical design merge in one piece into a thin round shaft and form a ring in the middle for receiving a sliding or rolling bearing. 2. Double piston with low mass according to claim 1, characterized characterized in that the bottom of the piston in a spherical Is designed as a rotating bowl with a very small shell thickness, which is determined by the warm creep strength of the material used against gas pressure in the combustion chamber. 33. Double piston with low mass according to claim 1 and 2 thereby characterized in that the rotating bowl on the combustion chamber side ends in a sharp edge on the outside and a narrow one on the circumference Ring carries with the same axis of rotation as the rotating bowl. 4. double piston with low mass according to claim 1, that the thin shafts are embedded in longitudinally movable bearings and thus the double pistons also move longitudinally can run in the cylinders without touching hot piston and hot cylinder takes place.