A compression ring for an engine piston includes an upper and lower face, and an inner face positioned between the upper and lower faces along an inner diameter of the ring. An outer face is positioned between the upper and lower faces along an outer diameter of the ring and is formed by a continuous curve along the axial direction of the ring. The continuous curve has first and second convex surfaces connected by a concave surface with each convex surface defined by first and second radii, respectively. A method of forming a piston compression ring includes machining an outer face of the ring to form a continuous curve along an axial direction of the ring, where the continuous curve has a first convex section and a second convex section connected by an intermediate section.

A piston assembly and method of construction thereof for an internal combustion engine are provided. The assembly includes a piston head having an upper combustion wall with an undercrown surface and a ring belt region. The piston head has a floor with an upper surface and a bottom surface. The floor is spaced beneath the upper combustion wall in radial alignment with the ring belt region. A substantially enclosed, annular cooling gallery is bounded by the undercrown surface and the floor. A pair of pin bores depends directly from the floor of the cooling gallery. The assembly further includes a pin having ends configured for oscillating receipt in the pin bores. A pin bearing surface extends within the pin bores and between the pin bores in the lower surface of the floor. The assembly includes a connecting rod with an end fixed to the pin for conjoint oscillation therewith.

A piston assembly and method of construction thereof for an internal combustion engine are provided. The assembly includes a piston head having an upper combustion wall with an undercrown surface and a ring belt region. The piston head has a floor with an upper surface and a bottom surface. The floor is spaced beneath the upper combustion wall in radial alignment with the ring belt region. A substantially enclosed, annular cooling gallery is bounded by the undercrown surface and the floor. A pair of pin bores depends directly from the floor of the cooling gallery. The assembly further includes a pin having ends configured for oscillating receipt in the pin bores. A pin bearing surface extends within the pin bores and between the pin bores in the lower surface of the floor. The assembly includes a connecting rod with an end fixed to the pin for conjoint oscillation therewith.

An auxiliary device for installing piston rings is described, which includes a mounting base, a transmission device, a connecting rod and a bracing structure. The mounting base includes a platform, an opening hole and an accommodating space. The transmission device is disposed in the accommodating space and includes a guide screw rod, a sliding base and a motor. The sliding base is slidably screwed on the guide screw rod. The motor can drive the guide screw rod to move the sliding base. The connecting rod is disposed on the sliding base. An external diameter of the piston ring while being put around the connecting rod is greater than an inner diameter of the opening hole. The bracing structure is disposed on the connecting rod. An external diameter of the bracing structure is getting greater from one end connected to the connecting rod. The bracing structure can accommodate the piston.

The present disclosure provides a sealing ring assembly having ring segments configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The sing segments are configured to move radially outward and wear during operation of the piston via the cylinder device. The ring segments include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces between ring segments. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the ring segments stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.

The present disclosure provides a sealing ring assembly having ring segments configured to seal a high-pressure region from a lower pressure region of a piston and cylinder device. The sing segments are configured to move radially outward and wear during operation of the piston via the cylinder device. The ring segments include, for example, wedge-shaped features that engage with corresponding wedge recesses in the interfaces between ring segments. The sealing ring assembly may include a high-pressure boundary and a low-pressure boundary. As the sealing ring wears, the ring segments stay engaged with the interfaces, so that ring gaps do not form on the low pressure boundary.