A modular internal combustion engine (10) comprising a cam crank (74) having a piston stroke guide pattern (76) to control the stroke motion profile of the piston (70), which can be expanded by replacing the crank shaft (22) with a longer crank shaft (22), and installing a supplemental engine block (18) with a supplemental cam crank assembly (75).

A modular internal combustion engine (10) comprising a cam crank assembly (75) having a cam crank (74), an intake cam (90) and an exhaust cam (92), the cam crank (74) having a piston stroke guide pattern (76) to control the stroke motion profile of the piston (70), which can be expanded by replacing the crank shaft (22) with a longer crank shaft (22), and installing a supplemental engine block (18) with a supplemental cam crank assembly (75).

A bearing device includes a piston arranged in a cylinder of a rotor, and a half bearing mounted on the piston to support a roller. The piston includes a recessed holding surface, and holding side surfaces on both axial sides thereof. Each holding side surface includes a ridge portion having an arc-shaped or elliptic-arc-shaped profile protruding toward a radially inner side of the piston. The half bearing includes a partially cylindrical portion, and protruding portions at a circumferential center thereof. Each protruding portion has a protruding portion end face which includes a central recessed surface, and two support recessed surfaces located on both circumferential sides thereof, that have an arc shape or an elliptic arc shape to correspond to the profile of the ridge portion, so that only the two support recessed surfaces are in contact with the ridge portion.

A modular internal combustion engine (10) comprising a cam crank assembly (75) having a cam crank (74), an intake cam (90) and an exhaust cam (92), the cam crank (74) having a piston stroke guide pattern (76) to control the stroke motion profile of the piston (70), which can be expanded by replacing the crank shaft (22) with a longer crank shaft (22), and installing a supplemental engine block (18) with a supplemental cam crank assembly (75).

A modular internal combustion engine (10) comprising a cam crank (74) having a piston stroke guide pattern (76) to control the stroke motion profile of the piston (70), which can be expanded by replacing the crank shaft (22) with a longer crank shaft (22), and installing a supplemental engine block (18) with a supplemental cam crank assembly (75).

A bearing device includes a piston arranged in a cylinder of a rotor, and a half bearing mounted on the piston to support a roller. The piston includes a recessed holding surface, and holding side surfaces on both axial sides thereof. Each holding side surface includes a ridge portion having an arc-shaped or elliptic-arc-shaped profile protruding toward a radially inner side of the piston. The half bearing includes a partially cylindrical portion, and protruding portions at a circumferential center thereof. Each protruding portion has a protruding portion end face which includes a central recessed surface, and two support recessed surfaces located on both circumferential sides thereof, that have an arc shape or an elliptic arc shape to correspond to the profile of the ridge portion, so that only the two support recessed surfaces are in contact with the ridge portion.

A rotary cam radial engine formed of two primary components engaged at a mid section to allow for an easy repair to the vehicle. The device features a body having radially oriented apertures; and a plurality of pistons in a respective reciprocating engagement, within each respective said cylinder. The pistons are driven by low pressure fluids and/or a vacuum and the engine being formed of two main components can be taken apart without tools for maintenance and reconfiguration.