US 6,279,519 B1Granted

Air and water cooled opposed cylinder aircraft engine

OwnerWilliam S. Nagel, Phillip L. Reidinventors

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Abstract

An internal combustion piston engine with horizontally opposed cylinders. Each opposed pair of cylinders fires simultaneously, providing symmetric cranking force on the crankshaft 13. Each cylinder 1 is a simple solid of rotation with air-cooling fins 10. The cylinder heads 5 are modular. Each module covers two adjacent cylinders, and has liquid cooling channels. All cylinders are identical, and all cylinder heads are identical. The cylinders are held inward against the crankcase by the cylinder heads. Each cylinder head is held inward against the cylinders by two tension bolts 42 that span to the opposite cylinder head. One tension bolt crosses above the crankcase, and one below it. In a preferred 12-cylinder engine embodiment, each opposed pair of cylinders is separated from the other opposed pairs in spark timing by a sequence of 105 and 135 degrees that reduces torsional harmonic resonance in the crankshaft, eliminating harmonic balancers.

Claims17

Dependent claims

An internal combustion engine comprising;

a crankcase having front and back ends, top, bottom, left and right sides;
a crankshaft having a longitudinal axis, the crankshaft mounted in the crankcase between the front and back ends of the crankcase;
a row of left cylinders mounted on the left side of the crankcase along a line parallel to the longitudinal axis of the crankcase;
a row of right cylinders mounted on the right side of the crankcase along a line parallel to the longitudinal axis of the crankcase;
each left cylinder having one generally opposed right cylinder;
each cylinder having an inner end against the crankcase, an outer end, and an axis;
each cylinder being substantially a simple solid of rotation with air cooling fins;
a row of left cylinder heads, each head covering the outer ends of two adjacent left cylinders;
a row of right cylinder heads, each head covering the outer ends of two adjacent right cylinders;
each of the left cylinder head generally opposed to one of the right cylinder heads;
each cylinder head connected to the generally opposed cylinder head by at least one tension bolt spanning between them above the crankcase, and at least one tension bolt spanning between them below the crankcase;
each cylinder head having at least one liquid cooling channel;
the cooling channel of adjacent cylinder heads in each row of cylinder heads inter-connected by tubes;
a piston slidably mounted in each cylinder;
the crankshaft having a crank for each piston;
each piston connected to the respective crank by a connecting rod;
an ignition system providing at least one electrical spark in each cylinder at specific repeating timing intervals;
each cylinder having simultaneous spark timing with the generally opposed cylinder.

15 more elements

An internal combustion engine comprising:

a crankcase having first and second ends, first and second sides, a top, and a bottom;
a crankshaft mounted through the crankcase between the first and second ends;
a plurality of engine modules mounted on the crankcase, each module comprising:
two adjacent pairs of cylinders, each pair of cylinders comprising first and second cylinders mounted on generally opposite sides of the crankcase;
each cylinder being a separate part that is substantially a simple solid of rotation, having first and second ends and an outer surface with air cooling fins, the first end of the cylinder contacting the crankcase;
first and second cylinder heads, each cylinder head covering the second ends of two adjacent cylinders of a given module on one side of the crankcase, each cylinder head having at least one internal coolant passage, at least one intake valve per cylinder, and at least one exhaust valve per cylinder, each cylinder head for two cylinders being a separate part;
a tension bolt spanning between the first and second cylinder heads above the crankcase, and a tension bolt spanning between the first and second cylinder heads below the crankcase, the tension bolts holding the two cylinder heads inward against the cylinders, and holding the cylinders inward against the crankcase, thus bracketing and retaining the 4 cylinders of one module against the crankcase;
each cylinder having an internal bore with a piston slidably mounted therein;
the crankshaft having a crank for each piston, the cranks for the first and second cylinders of each of the generally opposed pair of cylinders being diametrically opposed on the crankshaft, or 180 degrees apart in crank rotation;
each piston connected to the respective crank by a pivoting connecting rod;
and the engine is assembled from two or more of said modules in sequence along the crankcase.

8 more elements

An internal combustion engine comprising:

a crankcase having first and second ends, first and second sides, a top and bottom;
a crankshaft mounted through the crankcase between the first and second ends;
a plurality of pairs of generally opposed cylinders mounted on the crankcase, each generally opposed pair of the cylinders comprising a first cylinder mounted on the first side of the crankcase, and a second cylinder mounted generally opposite the first cylinder on the second side of the crankcase;
each cylinder being a separate part that is substantially a simple solid of rotation, having first and second ends and an outer surface with air cooling fins, the first end of the cylinder contacting the crankcase;
a first cylinder head for each two adjacent cylinders on the first side of the crankcase, a second cylinder head for each two adjacent cylinders on the second side of the crankcase, each cylinder head covering the second ends of the respective two adjacent cylinders on one side of the crankcase, each cylinder head having at least one internal coolant passage, at least one intake valve per cylinder, and at least one exhaust valve per cylinder;
at least one tension bolt spanning between the first and second cylinder heads above the crankcase, and at least one tension bolt spanning between first and second cylinder heads below the crankcase, the tension bolts holding the two cylinder heads inward against the cylinders, and holding the cylinders inward against the crankcase, thus bracketing and retaining the cylinders against the crankcase;
each cylinder having an internal bore with a piston slidably mounted therein, each generally opposed pair of cylinders having a generally opposed pair of pistons therein;
the crankshaft having a crank for each piston, the cranks for the first and second cylinders of each of the generally opposed pair of cylinders being diametrically opposed on the crankshaft, or 180 degrees apart in crank rotation;
each piston connected to the respective crank by a pivoting connecting rod;
a first camshaft mounted through the crankcase above and parallel to the crankshaft;
and
a second camshaft mounted through the crankcase below and parallel to the crankshaft.

9 more elements

Dependencies are inferred from the claim text.