A power cylinder system for a reciprocating engine includes a piston configured to move within a cylinder of the reciprocating engine. The system also includes a groove extending circumferentially about the piston and configured to support a ring. An axially-facing surface of the groove has circumferential undulations at ambient temperatures that are configured to compensate for distortions to the groove caused by operation of the reciprocating engine.

A power cylinder system for a reciprocating engine includes a piston configured to move within a cylinder of the reciprocating engine. The system also includes a groove extending circumferentially about the piston and configured to support a ring. An axially-facing surface of the groove has circumferential undulations at ambient temperatures that are configured to compensate for distortions to the groove caused by operation of the reciprocating engine.

The hydraulic piston with a depressurized groove is capable of translating in a cylinder and includes a fixed skirt, an axial compression face which forms with the cylinder a fluid chamber, and an axial working face which cooperates with a transmission; the piston also includes a seal, a depressurized radial groove emerging onto the surface of the fixed skirt, an axial decompression duct fitted inside the skirt which emerges in the vicinity of the axial working face, and a radial decompression duct which depressurizes the radial groove in communication with the axial decompression conduit.

A fluid actuator includes housing defining a cylinder bore and first and second fluid passages. A circumferential detent groove extends into the housing from the cylinder bore. The cylinder bore receives a piston having a top face and a skirt in sliding engagement. A circumferential detent ring groove extends radially inwardly into the skirt. The detent ring groove has a first portion of a first depth and a second portion of a second, greater depth. An o-ring is at least partially received in the second portion. A wear ring is at least partially received in the first portion and overlies the o-ring. The o-ring biases the wear ring outwardly of the detent ring so that the wear ring may be selectively engaged with the detent groove.

An internal combustion may include a cylinder having a first combustion chamber at one end and a second combustion chamber at an opposing end, first and second cylinder heads located at an end of the first and second combustion chambers, respectively, and a double-faced piston slidably mounted therein. The piston may be configured to move in a first stroke that includes an expansion stroke portion and a non-expansion stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. A recess in the piston rod portions may be configured to communicate gases between a combustion chamber and locations outside the cylinder. There may also be a chamber surrounding the first or second piston rod portion, the chamber configured to be supplied with gas and the chamber being isolated from the first combustion chamber and the second combustion chamber.

An integrally formed piston has a crown portion having an upper crown surface and an undercrown surface. A ring belt extends from the undercrown surface at a periphery thereof. The ring belt includes an uppermost ring land and at least one oil galley contoured to extend around at least two surfaces of the uppermost ring land. The oil galley has an opening at the undercrown surface for receiving a cooling fluid therein for cooling the uppermost ring land. A skirt extends from the undercrown surface and the ring belt and has a plurality of stiffening features arranged in a truss formation. At least one of the plurality of stiffening features has an I-beam cross-section and another of the plurality of stiffening features has a negative draft angle.

The invention relates to a die casting ring (1) internally fitted with radial teeth (11) to be engaged into matching seats (22) provided on a piston (2). This piston-ring assembly prevents mutual rotation or axial translation, in addition to ensuring an optimal seal against infiltration of liquid metal during the die casting process. When the ring has a cutout (10), it can be mounted accurately onto the piston because the teeth (11) allow the cutout to be positioned anywhere relative to the piston.

The invention relates to a piston (1), comprising a ring carrier (2) and a glass piston (3) for observing processes in a combustion chamber (B) of an internal combustion engine, wherein the glass piston (3) is placed upon the ring carrier (2) and is securely connected thereto in the region of an inner casing surface (8) of the ring carrier (2). In order to avoid overly high heat strain in the glass piston (3), the glass piston (3) is connected to the ring carrier (2) via at least one form-fit connection (20), and preferably via a force-fit connection (30).

A barrier package aerosol container includes a can, valve, and piston disposed in the interior volume of the can. The piston is movable toward a top end of the can to facilitate dispensing of flowable material in the can. Opposing surfaces of the piston and the can and the valve define an interstitial space of the interior volume in which the flowable product is receivable. The piston is contacts at least one of the interior surface of the can at its top end and the valve, to define a piston interface when the piston is at the top end of the can during use. At least one of the piston, the can, and the valve defines one or more flow passages at the piston interface to allow flowable material in the interstitial space to flow through the piston interface toward the valve inlet during use.

A piston may be provided which includes a first piston body portion having an end wall extending radially about a central axis along which the piston reciprocates. The piston may also include a second piston body portion having an end wall extending radially about a central axis along which the piston reciprocates. The first piston body portion and the second piston body portion are axially opposed. The piston may further include a first piston rod bore disposed in the first piston body portion extending along the central axis and a second piston rod bore disposed in the second piston body portion extending along the central axis. The piston may also include a circumferential opening disposed between the mating of the first piston body portion with the second piston body portion.