An internal combustion engine may include an engine block, a cylinder defining at least one combustion chamber, and a piston in the cylinder. The piston may travel in a first stroke from one end to an opposite end of the cylinder, and may be sized relative to the cylinder to enable an expansion stroke portion of the first stroke while the piston travels under gas expansion pressure, and a momentum stroke portion of the first stroke for the remainder of the first stroke following the expansion stroke portion. A passageway may be formed in the piston rod to communicate gas flow between a first combustion chamber and an area external to the cylinder when the piston is in a first position, and to communicate gas flow between a second combustion chamber and an area external to the cylinder when the piston is in a second position.

An internal combustion engine may include an engine block, a cylinder defining at least one combustion chamber, and a piston in the cylinder. The piston may travel in a first stroke from one end to an opposite end of the cylinder, and may be sized relative to the cylinder to enable an expansion stroke portion of the first stroke while the piston travels under gas expansion pressure, and a momentum stroke portion of the first stroke for the remainder of the first stroke following the expansion stroke portion. A passageway may be formed in the piston rod to communicate gas flow between a first combustion chamber and an area external to the cylinder when the piston is in a first position, and to communicate gas flow between a second combustion chamber and an area external to the cylinder when the piston is in a second position.

Proposed is a hydraulic cylinder rod in which a rod eye is robustly coupled to a hybrid round rod for weight reduction. To this end, the hydraulic cylinder rod is configured with a hybrid round rod including a metal tube and a composite material round rod provided for weight reduction inside the metal tube, wherein a side of the metal tube is formed to be relatively longer than the length of the composite material round rod to thereby provide a space defined by a length difference therebetween; and a rod eye is coupled to the space.

Proposed is a hydraulic cylinder rod in which a rod eye is robustly coupled to a hybrid round rod for weight reduction. To this end, the hydraulic cylinder rod is configured with a hybrid round rod including a metal tube and a composite material round rod provided for weight reduction inside the metal tube, wherein a side of the metal tube is formed to be relatively longer than the length of the composite material round rod to thereby provide a space defined by a length difference therebetween; and a rod eye is coupled to the space.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

A clamping device with a housing, with a piston with piston rod running in the housing, and with a monitoring unit arranged at least partially in the housing, wherein the monitoring unit includes at least two sensor units. The sensor units are spaced apart from one another along a longitudinal axis of the piston rod, and are arranged at a distance from the piston rod. The piston and the piston rod, and a metallic signal transmitter arranged on the piston or on the piston rod, are movable in a positively driven manner between a first end position and a second end position. The first sensor unit is arranged at the first end position of the signal transmitter, and the second sensor unit is arranged at the second end position of the signal transmitter. Each sensor unit has a first and second sensor and includes an induction coil and an oscillator.

A clamping device with a housing, with a piston with piston rod running in the housing, and with a monitoring unit arranged at least partially in the housing, wherein the monitoring unit includes at least two sensor units. The sensor units are spaced apart from one another along a longitudinal axis of the piston rod, and are arranged at a distance from the piston rod. The piston and the piston rod, and a metallic signal transmitter arranged on the piston or on the piston rod, are movable in a positively driven manner between a first end position and a second end position. The first sensor unit is arranged at the first end position of the signal transmitter, and the second sensor unit is arranged at the second end position of the signal transmitter. Each sensor unit has a first and second sensor and includes an induction coil and an oscillator.

A piston includes a piston cap, a piston rod body, and a piston head, with the piston cap being removable from the piston rod body. The piston cap includes a cap body and a connecting portion extending from the cap body and away from the piston rod body. The connecting portion includes a neck and a cap head with the cap head connected to an end of the neck disposed opposite the piston rod body. The cap head is wider than the neck. A mounting portion of the piston rod body extends into a receiving portion of the cap body to connect the piston rod body to the piston cap.

A piston includes a piston cap, a piston rod body, and a piston head, with the piston cap being removable from the piston rod body. The piston cap includes a cap body and a connecting portion extending from the cap body and away from the piston rod body. The connecting portion includes a neck and a cap head with the cap head connected to an end of the neck disposed opposite the piston rod body. The cap head is wider than the neck. A mounting portion of the piston rod body extends into a receiving portion of the cap body to connect the piston rod body to the piston cap.