A plunger member 3 used for a belt type continuously variable transmission is configured by cold press molding a blank material 32 according to deep-drawing molding, and closed forging, compression molding or a combined molding thereof, where during the cold press molding, a thickness of a bent corner portion 3f, which at least makes a sleeve portion 3c and a step-like formed portion (spring seating portion) 3d continuous to each other, is configured to be increased by 30% or more relative to a thickness of the blank material 32, and then a hardened surface layer 3B is configured to be formed on both of the entire front and back sides of the plunger member by performing a soft nitriding treatment.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing unitary hollow pistons from a single solid rod as a starting material.

The present disclosure provides an open-faced piston with a circumferential groove into which a piston ring assembly is arranged. Openings at the bottom of the circumferential groove and between a front land of the open-faced piston and the piston face are provided. The openings are arranged to allow for a combustion reaction to propagate through the volume defined between the bottom of the piston ring assembly and the piston face such that at least a portion of an air and fuel mixture located in that volume is reacted.

A piston (10) for an internal combustion engine has discrete, cylindrical support surfaces (18, 24) for supporting a piston pin, wherein, between at least two support surfaces (18, 24), there is provided a recess (26) which has a radial depth of at least 10% of half of the distance between two opposite support surfaces.

Disclosed are hollow pistons made from a single piece of starting material and methods of manufacturing hollow pistons from the single piece of starting material.

The invention relates to a piston for a brake caliper, which can be actuated in combined fashion, of a disk brake, which piston 1 is produced by shaping processes from a metallic material, in particular from a planar metal sheet, and which piston 1 is formed as a pot which is open on one side and which has a longitudinal axis, a wall and a piston crown, and which piston has a twist prevention facility for a drive nut. The invention is based on the problem of providing a robust piston construction which is better capable of tolerating erroneous repair work. To solve the problem, it is proposed that the twist prevention facility has, between the piston and drive nut, at least one reinforcement for protecting against plastic deformation of at least one driver.

The present disclosure provides an open-faced piston with a circumferential groove into which a piston ring assembly is arranged. Openings at the bottom of the circumferential groove and between a front land of the open-faced piston and the piston face are provided. The openings are arranged to allow for a combustion reaction to propagate through the volume defined between the bottom of the piston ring assembly and the piston face such that at least a portion of an air and fuel mixture located in that volume is reacted.

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.

Steel plungers for hydraulic fracturing pumps having enhanced surface hardness properties, preferably made of alloyed steel and a method for manufacturing said plungers, comprising an ion nitriding process.

The present invention provides piston production device and piston production method capable of surely holding friction-resistant ring regardless of presence or absence of decrease in accuracy of outside diameter of holding pin. Device has lower mold provided thereinside with cavity for forming piston and having opening, upper mold provided movably to open/close opening of cavity, and three holding pins rotatably supported by holding holes of upper mold and having top end portions protruding from lower surface of upper mold. Top end portions have flat holding surfaces formed by cutting tip end sides of top end portions in half from tip end edges along axial direction and stepped surfaces formed from upper ends of holding surfaces toward radial direction. By rotating holding pins in synchronization with each other in the same direction, friction-resistant ring is held by three points of holding surfaces.