Abstract: A steel piston with a piston upper part (12) with combustion chamber recess (11) and ring wall (5), and with a piston lower part (13) with piston body or piston skirt and with connecting rod bearing (8) for internal combustion engines with cylinder crankcases made of lightweight metal alloys, with at least the piston lower part consisting of a steel alloy which has a coefficient of thermal expansion in the range from 13 to 20×10?6 1/K.

Abstract: A piston device for internal combustion engines includes a first compression ring and a second compression ring in an outer circumference of a piston, wherein the second compression ring includes a notch extending from the inner circumference to the outer circumference on a lower surface of at least one of a pair of ends of the ring, and a gap between the ring ends at the notch on the second compression ring is larger than a gap between the ring ends of the first compression ring, and a gap between the ring ends at the section other than the notch on the second compression ring is the same or smaller than the gap between the ring ends of the first compression ring, and the second compression ring contains an outer circumferential surface comprised of a tapered surface decreasing the ring radial thickness towards the upper side, and an axial parallel surface formed below the tapered surface.

Abstract: The present invention utilizes rolling elements, such as balls or rollers acting as bearings carried in openings in the skirt or equivalent portion of a piston, to engage the cylinder walls and replace the sliding bearings of the skirt with the roller elements in the skirt. The rolling elements then absorb all or some of the thrust loads conventionally absorbed by the skirt walls sliding along surfaces of an associated cylinder and thereby reduce the friction forces developed by the reciprocating action of the piston skirt.

Abstract: The invention relates to a method for producing a cooled ring carrier (1) for an aluminium piston pertaining to an internal combustion engine and produced according to a casting method, comprising a cooling channel (6) which is embodied on the rear (3) of the ring carrier as a downwardly open turned groove (4) According to the invention, salt granules are pressed into the turned groove (4) at a pressure of between 100 and 300 N/mm2, in such a way that a salt core (5) is formed in the turned groove (4) The composite consisting of the ring carrier and the salt core is then immersed in an alfin bath.

Abstract: A cast piston having a metal insert that includes a cooling gallery and defines a piston ring groove. The piston insert includes an annular base having an annular cavity formed therein and an annular ring which extends radially outward from the base. A cast piston is fabricated by positioning the piston insert in a piston mold and casting a piston. After the piston is cast, the piston groove ring is machined in a portion of the annular ring and at least one channel is formed between the annular cavity and a bottom portion of the piston. In use, a cooling fluid is directed through the at least one channel and into the annular cavity.

Abstract: A guide ring for a piston comprises a split ring member having end edges which can be spread apart to slip the guide over the piston head and into a circumferential groove on an outer surface of a skirt portion of the piston head with the portions of the guide ring located in the pin bore area, including the end edges, being flattened. The guide ring is axially elongated and overlaps the piston pin bores. The guide ring is formed of low friction polyimide material which is firm yet flexible, compressible, and returns to its preformed configuration when the end edges are released.

Abstract: A piston assembly (10) for use in an engine. The piston assembly (10) includes a piston body (12) with a liner (24) covering the interior surface (22) thereof. The liner (24) imbues added strength and dimensional stability during casting, machining, engine assembly, and in service. At the same time, piston weight for a given volume is reduced without sacrificing strength. The invention also includes a method for manufacturing the piston assembly (10).

Abstract: A piston having a head with ring grooves, a skirt having hub bores, and a pin, with the following dimensions:L/D=0.45-0.8H/D=0.25-0.5A/D=0.3-0.5T/D=0.45-0.8whereL=maxium length of the pistonD=maximum diameter of the pistonH=compression heightA=maximum skirt height below the bottom ring groove in a peripheral area having the approximate same skirt height of at least 45 degrees on the major thrust face of the piston with approximately symmetrical division of this area on both sides of a plane extending perpendicular to the pin axis and passing through the longitudinal axis of the piston,T=diametrically opposite distance between the hub bore ends located radially on the outside.The skirt bulges along the axis of the piston and has an oval cross-section. An axis of the hub bores is offset slightly towards the major thrust face. The piston includes a horizontal slit, which separates the head from the skirt. In a polar plane perpendicular to the piston axis the skirt has a greater ovality on the minor thrust face.

Abstract: A piston 2 for an internal combustion engine includes side wall portions 12 connecting skirt portions 10 to pin boss portions 6 so as to support the skirt portions 10 in a direction perpendicular to an axis 8 of the pin boss portions. The skirt supporting stiffness of each side wall portion 12 is gradually changed in an axial direction of the piston 2 so as to have a maximum stiffness at a lower end portion of the side wall portions b 12 and to decrease in the direction upwardly away from the lower end portion of the side wall portion 12. Due to this structure, the skirt portion 10 is unlikely to be deformed at its lower end portion so that a clearance between the skirt portion 10 and a cylinder bore surface 20 is maintained small. Further, the skirt portion 10 has a soft structure at the shoulder of the skirt portion 10 so that a shock at the shoulder will be decreased to prevent breakage of an oil membrane from happening at the upper portion of the skirt portion 10.

Abstract: A piston comprises a crown part, a piston under part, a first shoulder at a thrust side formed between the crown part and the piston under part, a second shoulder at an anti-thrust side formed between the crown part and the piston under part, a first in-low part at the thrust side formed in the piston under part, and a second in-low part at the anti-thrust side formed in the piston under part, wherein a thickness of the first shoulder is formed thinner than a thickness of the second shoulder, and a height of the first in-low part is formed smaller than a height of the second in-low part.

Abstract: The technical problem is to reduce the operating noise of such a piston. It is solved by means of a piston having the following dimensions: a) A=(0.45-0.65) D; b) H=(0.25-0.4) D; c) A=(0.3-0.4) D; d) A greater than or equal to B; e) T=(0.45-0.8) D; f) the piston ribs between the annular grooves (2, 3, 4) and the rod region with a very narrow operating clearance have, in the case of a hot operating piston, approximately the same clearance in relation to the cylinder operating path. An additional improvement consists in inserting an annular jacket in the piston head in the radial region behind the annular grooves, said jacket consisting of a material having a thermal expension factor less than that of the basic piston material. In a hot operating internal combustion engine, the piston has, in the region of the ribs, a clearance which, in the direction pressure/counter-pressure reaches approximately only 3-5 times the clearance in the very narrow clearance region of the piston rod.

Abstract: A piston-cylinder combination for internal combustion engines made from a varying bonded combination of two or more alloys having dissimilar coefficients of thermal expansion. By regulating the volumetric percentages of the alloys vis-a-vis their location within the piston and cylinder wall, the degree of thermal expansion experienced during operation may be controlled. The concept is especially useful for low heat rejection engines.

Abstract: A cruciform internal combustion reciprocating engine characterized by two right angularly related pairs of axially spaced cylinders with related piston units including pairs of axially aligned, axially spaced pistons, each piston is engaged in one of the cylinders. The pistons of each unit are rigidly connected by an elongate yoke. A crank shaft has an eccentric crank pin at right angle to the axes of and positioned between the cylinders of the pairs of cylinders. A double isosceles sliding block linkage motion-translating mechanism drivingly couples the crank pin and the yokes and includes a twin eccentric disc driver rotatably carried by the crank pin with the discs thereof rotatably engaged with the yokes. The pistons of the piston units include elongate annular bearing sleeves in rotary bearing engagement about the pistons and in linear sliding and rotary bearing engagement with the bores of related cylinders.

Abstract: An aluminium or aluminium alloy cast piston has a piston ring carrier of a ferrous material encast therein. The carrier has sides which converge towards their radially inner ends. As a result of this, and as a result of a lesser coefficient of thermal expansion of the ferrous material of the carrier as compared with the aluminium or aluminium alloy of the piston body, solidification of the piston material causes elastic outward expansion of the carrier which is sufficient to prevent any clearance occurring between the two parts, even at operating temperatures. Thus the carrier is not, and need not, be locked to the piston body against radial movement.

Abstract: A piston carries on its skirt surface a number of separate strips of a plastics material, such as a polyetheretherketone alloy, so that the strips are hydrodynamically lubricated and transmit lateral thrust from the piston to an associated cylinder or liner. The strips are just proud of the skirt surface and may be contained in recesses formed in the skirt surface.

Abstract: A light metal alloy cast piston including a thermal strut (32, 48, 52) arranged in a shoulder portion of the piston skirt. The thermal strut is composed of an annular fiber-reinforced metal portion in which high-tensile-strength reinforcing fibers are integrally molded. The reinforcing fibers include first fibers (34), such as carbon fibers, having a coefficient of linear expansion substantially smaller than that of the matrix metal alloy, and second fibers (36), such as silicon carbide fibers and alumina fibers, having a flexural or bending strength larger than that of the first fibers. The first fibers primarily serve to restrain thermal expansion of the piston skirt and the second fibers, having a larger bending strength, act to protect the first fibers from excessive bending forces. In a preferred embodiment, the first fibers are located in the inner region of the thermal strut and the second fibers are arranged in the outer region.

Abstract: A piston mainly composed of an aluminium alloy for use in a cylinder of aluminium alloy. The piston is provided with one or more inserts of ferritic steel. The insert or inserts extend across opposed thrust faces of the piston and form part of the running surface of the piston skirt.