A cylinder apparatus for a brake may include: a piston configured to reciprocate in a cylinder body; a rod coaxially coupled to the piston; a stopper disposed in the cylinder body with the rod penetrated and inserted into the stopper; and an elastic member disposed between the piston and the stopper and configured to elastically support the piston in a direction away from the stopper. The piston and the rod may be integrally formed by injection molding.

A hydraulic fluid cylinder is equipped with a cylinder tube, a piston unit, and a piston rod. The piston unit has a piston body comprising a plurality of members and provided with a gasket-mounting groove. The piston body has a first piston member and a second piston member which are layered in the axial direction. The gasket-mounting groove is formed from a combination of at least two members. A thin section exhibiting depth in the axial direction is provided in the first piston member and/or the second piston member.

A gap seal device includes a housing with a fluid-filled guiding chamber and a multi-part piston that is translationally and/or rotationally moveable in the guiding chamber. The piston separates a high-pressure region from a low-pressure region of the guiding chamber. The piston forms an annular gap having a nominal gap width with an inner wall delimiting the guiding chamber. The piston has a stepped rod, a sleeve, which is slipped over a stepped-down region of the rod and which has a blind hole, and a coupling. The stepped-down region of the rod or in a tube portion of the sleeve includes a stiffness change. A gap width of the annular gap that is reduced compared with the nominal gap width can be set in a region radial to the stiffness change by stress-caused expansion of an outside diameter of the tube portion of the sleeve in accordance with the set stressing force.

A piston is provided for an internal combustion engine. The piston may include a cylindrical first piston portion having a first diameter, a cylindrical second piston portion of the first diameter, and a cylindrical third piston portion of a second diameter less than the first diameter located between the first piston portion and the second piston portion. The first piston portion may be configured such that prior to assembly, the first piston portion is separate from the second piston portion. The piston may also include a continuous, gapless piston ring circumscribing the third piston portion, where the piston ring may be configured such that when heated the piston ring deforms in an axial direction of the piston.

The piston and connecting rod assembly includes a connecting rod having opposed upper and lower ends, the upper end being pivotally secured to the piston by a conventional piston pin. The lower end of the connecting rod has a passage formed therein for receiving a conventional crankpin. However, an additional sleeve is provided for the piston. The sleeve has at least one sidewall, a closed upper end and an open lower end. The sleeve is releasably secured to the piston by any suitable type of releasable attachment or engagement. An upper surface of the closed upper end of the sleeve may have a plurality of apertures or recesses formed therein, allowing a tool with corresponding pins to engage the sleeve for removal thereof from the piston.

The piston and connecting rod assembly includes a connecting rod having opposed upper and lower ends, the upper end being pivotally secured to the piston by a conventional piston pin. The lower end of the connecting rod has a passage formed therein for receiving a conventional crankpin. However, an additional sleeve is provided for the piston. The sleeve has at least one sidewall, a closed upper end and an open lower end. The sleeve is releasably secured to the piston by any suitable type of releasable attachment or engagement. An upper surface of the closed upper end of the sleeve may have a plurality of apertures or recesses formed therein, allowing a tool with corresponding pins to engage the sleeve for removal thereof from the piston.

Pistons and clutch assemblies including the pistons are disclosed. A clutch assembly may include at least one rotatable clutch plate, a reaction plate arranged to rotate with and apply a force to the at least one rotatable clutch plate, and a spring configured to urge the reaction plate away from the at least one rotatable clutch plate. A piston may be provided including a first segment formed as a plate and defining an internal space between the first segment and a housing and a second bulk segment that occupies at least a portion (e.g., 50% by volume) of the internal space. At least one bearing rolling element may be arranged between the reaction plate and the piston to permit relative rotational motion therebetween. The second bulk segment may be formed of plastic or a plastic composite and may reduce the amount of hydraulic fluid present in the internal space.

A reciprocating rod pump apparatus includes a pump barrel having an inner bore and a plunger disposed within the pump barrel. The plunger includes a plurality of plunger segments. The reciprocating rod pump apparatus further includes an articulating connector disposed between and connecting plunger segments. The articulating connector is adapted to allow for deflection between plunger segments.

A method for producing a piston may include forming a piston blank in a first forming tool such that the piston blank surrounds a ring carrier configured to receive a piston ring via positive engagement after producing the ring carrier by a sintering process. The piston blank, at least in a circumferential region disposed at a piston head, may be composed of a light metal alloy suitable for forging. The method may also include removing the piston blank from the first forming tool and placing the piston blank in a second forming tool, and inserting a holding-down tool into the second forming tool to hold the ring carrier down. The method may further include pressing a final forming punch into the second forming tool to deform the piston blank and form a piston.

The present disclosure provides a sealing ring assembly with one or more piston-integrated gap cover features, configured to seal a high-pressure region from a relatively lower pressure region of a piston and cylinder device. The sealing ring assembly may include two rings which each may include one or more ring segments. The one or more gap-cover features, which may be in the form of protrusions in the piston ring groove, may engage with corresponding flat sections of the ring segments. As the sealing ring wears, the gap-cover features may stay engaged with the ring segments, thereby maintaining a seal.