A piston for an internal combustion engine and method of construction thereof are provided. The piston includes an upper crown formed at least in part by a first metal material and a thermally insulating insert. The upper crown has an upper wall forming an upper combustion surface and a ring belt region. The upper combustion surface is formed at least in part by the thermally insulating insert. The thermally insulating insert has a base surface with pores extending upwardly therein. The first metal material is infused and solidified in the pores, with the first metal material forming a first bonding surface. The piston further includes a body portion formed from a second metal material. The body portion provides pin bosses having coaxially aligned pin bores and diametrically opposite skirt portions. The body portion has a second bonding surface bonded to the first bonding surface of the first metal material.

A method is provided for designing and producing fiber-reinforced polymer (FRP) pistons. Pistons made with FRP have a lower mass than prior art metal pistons conferring advantageous engine efficiency and stability. FRP pistons also increase the thermal efficiency of engines by having a lower thermal conductivity, with tighter piston-to-bore clearance, and/increased air-fuel ratio than pistons of metal. The technical parameters of the piston are identified, and a piston body blank is produced. The blank is then machined, a bearing surface for the pin bore is created, the piston blank is optionally coated, is optionally subjected to Heavy Metal Ion Implantation (HMII) treatment and is subjected to sodium silicate impregnation to produce the final pistons.

The present invention relates to a method for producing a piston (1) for an internal combustion engine from a piston upper part (2) and a piston lower part (3).

The method has the following method steps: producing a piston upper part (2) having a piston top (6), at least parts of a ring section (12) and at least part (7) of a cooling channel (8), by forging or casting for example, producing the piston lower part (3) and closing the part (7) of the cooling channel (8) which is arranged in the piston upper part (2) by means of an additive method, finish-machining the piston (1), including the production of at least one annular groove (4) in the ring support (5) for receiving a piston ring.

In this way, it is possible to provide a piston (1) that has a greater strength in its piston upper part (2), which is subjected to high thermal and mechanical loads, than in its piston lower part (3), which is subjected to lower thermal and mechanical loads, and that permits greater freedom of manufacture in respect of the shape of the piston lower part (3).

A piston for an internal combustion engine includes a piston head and a piston skirt, wherein the piston head has a piston base, a circumferential ring part and, in the region of the ring part, a circumferential closed cooling channel or sealed cavity. An inner side of the piston has two lower surfaces which transform continuously in the region of the piston central axis (M) to form an arched surface. The piston skirt has piston hubs provided with hub bores which are interconnected by means of running surfaces which have inner surfaces facing the inside of the piston. Starting from the free ends of the piston skirt, inside the piston on the pressure side (DS) and/or counter pressure side (GDS), an inner surface of a running surface continuously transforms into a guiding surface for a coolant which transforms continuously on the side thereof into a lower surface.

In one aspect, a circlip includes a circlip body defining (i) a first end surface, (ii) a second end surface spaced circumferentially from the first end surface so as to define a gap between the first and second end surfaces, and (iii) an outer curved surface defining an outer perimeter of the circlip body. The outer curved surface extends from the first end surface to the second end surface. Further, the circlip includes at least one row of teeth defined at the outer curved surface, and extending from at least one of the first and second end surfaces circumferentially along a direction away from the gap. When installed in a circlip groove, the teeth engage the circlip groove to limit rotation of the circlip within the groove.

Provided is an engine, including: a cylinder including a cylinder liner; a piston provided inside the cylinder liner; a piston ring provided on the piston; a contact detector configured to detect a contact between a step formed in an inner peripheral surface of the cylinder liner and the piston ring; and a compression ratio controller configured to control a top dead center position of the piston so that the piston ring at the top dead center position is located on a combustion chamber side with respect to the step when the contact is detected.

The system comprises an opposed piston engine. The pistons (1) consist of a top piston half (1a), a spring (1b) and a bottom piston half (1c). The cylinders (3) have inlet channels (8) for compressed air as well as outlet channels (10). fuel injector (12), steam injector (13) and ignition clement (14). A bipartite crankshaft (15) is fitted with exit shafts (19a, 19b) connected with impellers (22) via clutches (20a, 20b). Rotor rims (26) around the impellers contain magnetic dipoles (28), whereas stator rims (27) have induction coils (29). One method concerns using of resilience of a spring situated between two halves of the piston, furthermore piston halves are cooled by a spurt of compressed air. Another method concerns transferring some part of energy of the impeller to the system of collecting and transferring energy attached to it, from which energy is taken in case of an insufficient torque on the impeller shaft.

Methods and systems are provided for a piston. In one example, system may comprise a piston comprising a chamber in which a piston bowl may actuated independent of an oscillation of the piston. The chamber may receive a hydraulic fluid in order to adjust a position of the piston bowl within the chamber, thereby adjusting a compression ratio of a combustion chamber in which the piston may oscillate.

Certain exemplary embodiments can provide a piston comprising a piston head, a connecting rod coupled to the piston head, a stabilizer bar, a retaining ring, and a stabilizer bar collar. The stabilizer bar collar defines one or more apertures. The one or more apertures are constructed to receive the stabilizer bar. The piston is constructed to reduce energy losses in an engine comprising the piston.

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 within the cylinder. The piston may be configured to move in the cylinder in a work stroke from one end to another. The work stroke may include an expansion stroke portion and a non-expansion stroke portion. The non-expansion stroke portion may include a momentum stroke portion, and a compression stroke portion. The engine may further include first and second piston rod portions extending from opposite faces of the piston. Passageways in the piston rod portions may be configured to communicate gases between a combustion chamber and other locations.