A piston arrangement includes a piston movable within a cylinder in reciprocating motion along a piston axis, a rack movable with the piston, a sector gear configured to engage and disengage the rack and rotatable around a sector gear axis, a track adapted to rotate relative to the cylinder around a track axis of rotation, the piston being coupled to the track. The sector gear and the track are coupled in rotation. The track may have a shape such that the movement of the piston coupled to the track is substantially non simple harmonic. Also, an internal combustion engine comprising the piston arrangement.

A piston arrangement includes a piston movable within a cylinder in reciprocating motion along a piston axis, a rack movable with the piston, a sector gear configured to engage and disengage the rack and rotatable around a sector gear axis, a track adapted to rotate relative to the cylinder around a track axis of rotation, the piston being coupled to the track. The sector gear and the track are coupled in rotation. The track may have a shape such that the movement of the piston coupled to the track is substantially non simple harmonic. Also, an internal combustion engine comprising the piston arrangement.

A crank mechanism for the use in an in-line boxer engine has at least two diametrically opposed cylinders, that has a crankshaft and the respective pistons as well as connecting rods for each cylinder of the in-line boxer engine, with the connecting rods cooperatively connecting the pistons with the crankshaft. Each of the connecting rods encompasses a respective piston connecting portion, at one end having bushings accepting a gudgeon pin. At the other end, the central connecting rod has a one-piece crankshaft bearing portion for the crankpin whereas the forked connecting rod has a crankshaft bearing portion with two spaced limbs resultant in bifurcated crankshaft bearing portions for the crankpin. The crankshaft possesses a cylindrical central middle crankpin, that is eccentric towards the crankshaft, onto which a cylindrical outer crank pin is immediately attached at each side without crank webs.

A crank mechanism for the use in an in-line boxer engine has at least two diametrically opposed cylinders, that has a crankshaft and the respective pistons as well as connecting rods for each cylinder of the in-line boxer engine, with the connecting rods cooperatively connecting the pistons with the crankshaft. Each of the connecting rods encompasses a respective piston connecting portion, at one end having bushings accepting a gudgeon pin. At the other end, the central connecting rod has a one-piece crankshaft bearing portion for the crankpin whereas the forked connecting rod has a crankshaft bearing portion with two spaced limbs resultant in bifurcated crankshaft bearing portions for the crankpin. The crankshaft possesses a cylindrical central middle crankpin, that is eccentric towards the crankshaft, onto which a cylindrical outer crank pin is immediately attached at each side without crank webs.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder, configured to draw a fluid into the second cylinder via a fluid inlet, and expel the fluid via a fluid outlet. A pressure accumulator may receive the fluid from the second cylinder and provide a reservoir of pressurized fluid. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.

An internal combustion engine may include a first piston reciprocatingly disposed in a first cylinder, a combustion chamber fluidly coupled with the first cylinder, and an ignition source at least partially disposed within the combustion chamber. An intake valve may provide selective fluid communication between an intake system and the combustion chamber, an exhaust valve may provide selective fluid communication between an exhaust system and the combustion chamber. A second piston may be reciprocatingly disposed within a second cylinder, configured to draw a fluid into the second cylinder via a fluid inlet, and expel the fluid via a fluid outlet. A pressure accumulator may receive the fluid from the second cylinder and provide a reservoir of pressurized fluid. A crankshaft may be coupled with the first piston and the second piston for rotational motion associated with reciprocating movement of the first piston and the second piston.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.

A piston engine is provided; the piston engine has a cylinder, a main piston and an auxiliary piston; a combustion chamber is formed between the main piston and the auxiliary piston within the cylinder; the main piston has an crankpin offset L0, the auxiliary piston and the main piston move in different frequencies, an extended constant V≈Vc of the combustion chamber is formed from θ to >10° CA; when at a=θ=arc sin[L0/(L+R)] the main piston is at its top dead center; at a=arc sin(L0/R) the side force on the main piston is 0; when peak pressure of combustion is located at PPmax by choosing ignition timing, the most effective torque can be obtained; the torque is controlled by the amount of fuel injected; engine knocking can be prevented by retarded ignition at a>θ.

A connecting rod assembly has a connecting rod with a large end and a small end, a piston wrist pin, and fasteners to connect the connecting rod to the piston wrist pin and optionally one or more shims in between the connecting rod and piston wrist pin. A notch on the wrist pin allows for the seating of a flat surface on the small end of the connecting rod in the connecting rod assembly. Side walls on both the notch and the small end of the connecting rod limit twist. The connecting rod assembly allows for the adjustment of piston location in a cylinder while limiting connecting rod twist.

An engine balancing system includes an engine body. At least two slider-crank mechanisms are provided inside the engine body. One of the slider-crank mechanisms is arranged opposite to the other slider-crank mechanism. A slider in one of the slider-crank mechanisms is moved at a speed and acceleration similar to a speed and acceleration of a slider in the other slider-crank mechanism. The slider-crank mechanism includes a connecting rod and a crankshaft with a crank. One end of one of the slider-crank mechanisms and one end of the other slider-crank mechanism are connected to the same crankshaft through the crank. The balancing system can effectively eliminate first-order, second-order and higher-order vibrations generated during engine operation, thus reducing the probability of equipment damage.