Abstract: Provided is an engine that includes a first member, a second member, a first hydraulic pressure chamber formed between facing parts of the first and second members, and a hydraulic pressure adjustment mechanism. The hydraulic pressure adjustment mechanism has a plunger pump having a pump cylinder and a plunger and configured to supply hydraulic oil in the pump cylinder to the first hydraulic pressure chamber by pushing the plunger into the pump cylinder. The plunger pump moves in a stroke direction along with a piston and a power transmission section, and the plunger is pushed into the pump cylinder by receiving a reaction force opposite to reciprocating forces of the piston and the power transmission section.

Abstract: Provided is a crosshead engine that includes: a cylinder; a piston; a piston rod; a crosshead; a connecting rod; a crankshaft; and a variable mechanism varies positions of top and bottom dead centers of the piston by changing a relative position between the piston rod and the crosshead in a stroke direction of the piston. The variable mechanism includes: a hydraulic pressure chamber which is provided in the crosshead and into which an end of the piston rod is inserted; and a hydraulic pressure adjustment mechanism which supplies hydraulic oil to the hydraulic pressure chamber or discharges the hydraulic oil from the hydraulic pressure chamber and which adjusts an entering position at which the end of the piston rod is inserted into the hydraulic pressure chamber in the stroke direction.

Abstract: Provided is a crosshead engine that includes: a cylinder; a piston; a piston rod; a crosshead; a connecting rod; a crankshaft; and a variable mechanism varies positions of top and bottom dead centers of the piston by changing a relative position between the piston rod and the crosshead in a stroke direction of the piston. The variable mechanism includes: a hydraulic pressure chamber which is provided in the crosshead and into which an end of the piston rod is inserted; and a hydraulic pressure adjustment mechanism which supplies hydraulic oil to the hydraulic pressure chamber or discharges the hydraulic oil from the hydraulic pressure chamber and which adjusts an entering position at which the end of the piston rod is inserted into the hydraulic pressure chamber in the stroke direction.

Abstract: Provided is an engine that includes a first member, a second member, a first hydraulic pressure chamber formed between facing parts of the first and second members, and a hydraulic pressure adjustment mechanism. The hydraulic pressure adjustment mechanism has a plunger pump having a pump cylinder and a plunger and configured to supply hydraulic oil in the pump cylinder to the first hydraulic pressure chamber by pushing the plunger into the pump cylinder. The plunger pump moves in a stroke direction along with a piston and a power transmission section, and the plunger is pushed into the pump cylinder by receiving a reaction force opposite to reciprocating forces of the piston and the power transmission section.