Patent ID: 7367305

Claim:
An internal combustion engine comprising as main moving parts a piston and a connecting rod connected to the piston, wherein: the piston has a crown part, a cup-shaped support part provided on a rear side of the crown part and opening downward for forming a spherical joint, and multiple radial ribs extending from the cup-shaped support part to a circumferential wall formed cylindrically at an outer edge of the crown part, the connecting rod has a spherical small end part for forming the spherical joint together with the cup-shaped support part, and the connecting rod is held place by a single nut member that presses a pair of holder halves against the spherical small end part, the nut member having an inner diameter larger than a diameter of the spherical small end part, and the cup-shaped support part is a cylindrical cup having a configuration concentric with respect to the spherical joint and has a single threaded portion concentric to the spherical joint, the nut member has a threaded portion threadedly engaged with the threaded portion of the cup-shaped support part of the piston.