A geared turbofan engine that has a planetary gearbox which couples a fan shaft and a turbine shaft to each other. The planetary gearbox includes a sun gear that is driven by the turbine shaft. The turbine shaft and the sun gear form a spline shaft connection that is lubricated with oil. Sealing means are provided, sealing off the oil in the toothing area of the spline shaft connection. The sealing means have an elastic sealing ring that has a variable diameter and is springing outwards, and that is arranged inside a groove extending in the circumferential direction of the turbine shaft, wherein the sealing ring abuts at an inner circumferential surface of the sun gear with its radially outer circumferential surface. In further aspects, the invention relates to a method for mounting a planetary gearbox on a turbine shaft and to a spline arrangement.

Rotary steerable drilling systems are subjected to harsh environments including high temperature and pressure. A metallic seal ring prevents or limits erosive wear by limiting the velocity of the fluid that traversers from the high pressure side of the metallic seal ring to the low pressure side of the metallic seal ring to a value that can be sustained by the material of the metallic seal ring. A metallic seal ring is capable of withstand the wear and tear of drilling mud or other fluids used for downhole drilling operations. A metallic seal ring includes a mating configuration that creates a seal as the metallic seal ring is contracted when or a tension is applied when disposed or positioned in the piston bore. The metallic seal ring maintains an adequate seal to protect the components of a pad assembly over the life or specified duration of a downhole drilling operation.

A body of a seal ring is in an annular shape and includes an abutment joint at a location in the circumferential direction. The opposite ends of the body forming the abutment joint include an overlapping part where one end and the other end of the body overlap each other. The overlapping part includes a step cut joint that forms an overlap in the radial direction and a lap joint that forms an overlap in the plate thickness direction. Facing faces that face each other in the plate thickness direction in the lap joint are planes extending from an inner peripheral circular arc of the seal ring up to an outer peripheral circular arc of the seal ring.

A body of a seal ring is in an annular shape and includes an abutment joint at a location in the circumferential direction. The opposite ends of the body forming the abutment joint include an overlapping part where one end and the other end of the body overlap each other. The overlapping part includes a step cut joint that forms an overlap in the radial direction and a lap joint that forms an overlap in the plate thickness direction. Facing faces that face each other in the plate thickness direction in the lap joint are planes extending from an inner peripheral circular arc of the seal ring up to an outer peripheral circular arc of the seal ring.

A combined piston structure for a compressor includes a first piston ring, a second piston ring, an expandable ring, a guide ring, and a piston. A side of the first piston ring has a slit defined as a first cut. An upper end of an outer surface of the first piston ring is provided with an annular protruding portion. A side of the second piston ring has a slit defined as a second cut. A side of the expandable ring has a slit defined as a third cut. The guide ring is annular and made of a self-lubricating material having a low friction coefficient. A side of the guide ring has a V-shaped opening. An upper end of an outer surface of the piston is provided with an annular first groove. An annular second groove is disposed below the first groove.

Provided is a piston ring for an internal combustion engine that enables size reduction of a chamfered edge without leading to the chipping, and sufficient size reduction of a flow passage of a blow-by gas in a piston ring gap, thus effectively restraining the blow-by gas from passing through the piston ring gap. A piston ring 1 with a piston ring gap 2 used for an internal combustion engine includes a chamfered edge 3 continuous to at least one of piston ring end faces at the piston ring gap 2 and an outer peripheral surface 1a of the piston ring 1. The chamfered edge 3 has a curved shape.

Provided is a piston ring for an internal combustion engine that enables size reduction of a chamfered edge without leading to the chipping, and sufficient size reduction of a flow passage of a blow-by gas in a piston ring gap, thus effectively restraining the blow-by gas from passing through the piston ring gap. A piston ring 1 with a piston ring gap 2 used for an internal combustion engine includes a chamfered edge 3 continuous to at least one of piston ring end faces at the piston ring gap 2 and an outer peripheral surface 1a of the piston ring 1. The chamfered edge 3 has a curved shape.

The present disclosure relates generally to seal rings useful in rotating systems such as automobile transmissions, torque converters and automatic clutches. In one embodiment, the disclosure provides a seal ring in which the first end includes a platform in a radially inward portion of each lateral region thereof, and a vertically-extending blade in a radially outward portion of its central region; and the second end of the seal ring has two vertically extending fingers in a radially outward portion of each lateral region thereof, and a platform in a radially inward portion of its central region. When the ends are engaged, a portion of the extension of the blade is disposed radially directly over the central platform, a portion of each finger is disposed radially directly over a lateral platform, and the blade of the central region of the first end is disposed between the fingers.

The present disclosure relates generally to seal rings useful in rotating systems such as automobile transmissions, torque converters and automatic clutches. In one embodiment, the disclosure provides a seal ring in which the first end includes a platform in a radially inward portion of each lateral region thereof, and a vertically-extending blade in a radially outward portion of its central region; and the second end of the seal ring has two vertically extending fingers in a radially outward portion of each lateral region thereof, and a platform in a radially inward portion of its central region. When the ends are engaged, a portion of the extension of the blade is disposed radially directly over the central platform, a portion of each finger is disposed radially directly over a lateral platform, and the blade of the central region of the first end is disposed between the fingers.

An oil scraper piston ring which includes a running face region formed by at least two running face lands, an inner circumferential surface, and upper and lower flank surfaces extending between the running face region and the inner circumferential surface, also includes a joint and oil passage openings extending radially between the running face lands from the outside to the inside, optionally operatively connected to a spring element, wherein the joint is formed by at least two spaced slotted regions having a predefinable shape and dimensions, which are not directly connected to one another, so that each slotted region formed by a slot extends, proceeding from the associated flank surface, at least into one oil passage opening provided between at least two running face lands.