Internal combustion engine

A method of using a split crankshaft to operate an internal combustion engine, comprising the steps of:

• providing rotational motion to a split crankshaft that includes:
• a cross-head connected to a piston;
• two connecting rods each having a first end pivotally connected to the cross-head, and a second end distal from the first end, wherein the two connecting rods are disposed on opposite sides of the cross-head;
• a first crank pivotally connected to the second end of a first of the two connecting rods;
• a second crank pivotally connected to the second end of a second of the two connecting rods;
• a first split crankshaft section connected to the first crank at a connection point;
• a second split crankshaft section connected to the second crank;
• a plurality of crank keyholes formed in the first crank at the connection point;
• a plurality of crankshaft keyholes formed in the first split crankshaft section at the connection point, said crankshaft keyholes each having a center axis that is offset from a center axis of said crankshaft at the connection point;
• and
• a plurality of pins/keys disposed in and extending between the plurality of crank keyholes and the plurality of crankshaft keyholes, said pins/keys having a size, shape and material,
• wherein said first crank is comprised of a single integral part and said second crank is comprised of a single integral part,
• wherein the number of the pins/keys, the size of the pins/keys, the shape of the pins/keys and the material of the pins/keys are configured to cause the pins/keys to shear when the crankshaft is subjected to detrimental levels of acceleration, deceleration, non-circular motion, or over-limit torque,
• wherein the pins/keys are configured to cause the crank and the crankshaft to disengage and prevent transmission of unacceptable forces to other components in the engine when the crankshaft is subjected to detrimental levels of acceleration, deceleration, non-circular motion, or over-limit torque.

An internal combustion engine comprising:

• a piston;
• a cross-head connected to the piston;
• two connecting rods each having a first end pivotally connected to the cross-head, and a second end distal from the first end, wherein the two connecting rods are disposed on opposite sides of the cross-head;
• a first crank pivotally connected to the second end of a first of the two connecting rods;
• a second crank pivotally connected to the second end of a second of the two connecting rods;
• a first split crankshaft section connected to the first crank at a connection point;
• a second split crankshaft section connected to the second crank;
• a plurality of crank keyholes formed in the first crank at the connection point;
• a plurality of crankshaft keyholes formed in the first split crankshaft section at the connection point, said crankshaft keyholes each having a center axis that is offset from a center axis of said crankshaft at the connection point;
• and
• a plurality of pins/keys disposed in and extending between the plurality of crank keyholes and the plurality of crankshaft keyholes, said pins/keys having a size, shape and material,
• wherein said first crank is comprised of a single integral part and said second crank is comprised of a single integral part,
• wherein the number of the pins/keys, the size of the pins/keys, the shape of the pins/keys and the material of the pins/keys are configured to cause the pins/keys to shear when the crankshaft is subjected to detrimental levels of acceleration, deceleration, non-circular motion, or over-limit torque,
• wherein the pins/keys are configured to cause the crank and the crankshaft to disengage and prevent transmission of unacceptable forces to other components in the engine when the crankshaft is subjected to detrimental levels of acceleration, deceleration, non-circular motion, or over-limit torque.