Abstract: A liquid cooled piston of an internal combustion engine includes a piston lower part and piston upper part which has a combustion chamber recess. These piston components are supported via joining lands which are spaced apart radially and together form a dividing plane, and are joined together with a material-to-material fit. In order to receive piston rings, the piston upper part has a ring area and includes an annular cooling channel which extends into the piston lower part and is connected to an inner cooling space via connecting channels. The cooling channel is adjoined by recesses which are oriented in the direction of a piston head, are configured as a blind hole and widen conically starting from the cooling channel as far as a recess bottom. The recess bottom can be of a pronounced undulating enlarged surface or a finely undulating configuration.

Abstract: A piston including a crown and a skirt extending generally axially away from the crown. The skirt includes a pair of opposed skirt panel portions and a band spaced away from the crown and extending generally around a perimeter of the piston. The piston further includes a pair of strut assemblies, each strut assembly including a pair of struts which converge in a radially outward direction. Each strut terminates at or adjacent to one of the panel portions.

Abstract: A two-part piston for an internal combustion engine has an upper part that has a pin having an outside thread on the underside of its piston crown, and has a lower part that has a crown part, onto which an expansion sleeve that can stretch elastically in the axial direction is formed, radially on the inside. A pin is introduced into the sleeve in order to screw the upper part to the lower part. The expansion sleeve is stretched in the axial direction. In order to improve its strength, the material of the expansion sleeve has a higher stretching limit as compared with the rest of the piston material. The increase in the stretching limit is achieved by permanent stretching of the expansion sleeve in the axial direction, by approximately 1% of its length.

Abstract: An upper part (1) of an assembled piston is disclosed, comprising a radially directed inner contact surface (2) arranged on the underside of an annular rib (15) and a radially directed outer contact surface (3) arranged on the underside of an annular wall (25), the outer (3) and the inner contact surface (2) each having a grooved profile in the form of concentric grooves with an average depth between Rz 10 and Rz 30. The wear on the contacting surfaces of the upper piece and the lower piece of the assembled piston is thus reduced.

Abstract: A piston, especially a cooling channel piston of an internal combustion engine, has an upper part and a lower part which can be produced separately from each other and subsequently be assembled. The upper part has at least three radially peripheral joining webs and the lower part likewise at least three radially peripheral joining webs. During assembly, the webs are put together and connect the upper part firmly to the lower part.

Abstract: The invention relates to a split piston for an internal combustion engine, comprising an upper piece, connected to a lower piece, by means of a screw connection. The screw connection comprises a tubular connector piece, mounted on the underside of the piston upper piece with an external thread, a spacer sleeve with an external and an internal thread and a support rib formed on the lower piece of the piston with an internal thread. The upper piece can thus be screwed to the lower piece, by means of the connector piece, the spacer sleeve and the support rib. The spacer sleeve acts as a compressing body and the connector piece as an extending body, to generate the mechanism tension necessary for fixing the screw connection.

Abstract: The invention relates to an aluminum piston for a combustion engine having a ring element, which is made of NiResist, is placed in the radially outer edge area of the piston head, and which, together with the base body, forms an annular cooling channel. The ring element is fastened to the base body of the piston via a screwed connection.

Abstract: A monobloc piston assembly has at least two parts fixedly joined together forming a piston body having an oil cooling gallery. The oil cooling gallery is defined by an upper wall, a lower wall, and a pair of radially spaced inner and outer annular walls. A skirt is formed as one piece and of the same material with at least one of the two parts and depends generally along a longitudinal axis from the lower wall. A pair of pin bosses are spaced laterally from the longitudinal axis and depend generally from the lower wall. At least one elongated opening extends generally between the pin bosses with the opening preferably spanning a substantial portion of the distance between the pin bosses. Oil flows into and out of an oil cooling gallery through the opening.

Abstract: A monobloc piston assembly has at least two parts fixedly joined together forming a piston body having an oil cooling gallery. The oil cooling gallery is defined by an upper wall, a lower wall, and a pair of radially spaced inner and outer annular walls. A skirt is formed as one piece and of the same material with at least one of the two parts and depends generally along a longitudinal axis from the lower wall. A pair of pin bosses are spaced laterally from the longitudinal axis and depend generally from the lower wall. At least one elongated opening extends generally between the pin bosses with the opening preferably spanning a substantial portion of the distance between the pin bosses. Oil flows into and out of an oil cooling gallery through the opening.

Abstract: This invention relates to a two piece piston with a variable compression height, wherein a piston top part can be adjusted with respect to a piston bottom part along the longitudinal axis of the piston preferably by hydraulic devices and can be caused to perform a progressive rotating movement. This rotating movement is achieved by means of two thread sections of opposed pitch which, depending on the moving direction of the piston top part, alternately engage in corresponding counterthread sections on the piston bottom part. These threads and counterthreaded sections are multiple coarse pitch threads and are located on one side only as flanks disposed in the moving direction of the piston top part so that when the moving direction of the piston top part is reversed, a moving-apart of the engaged thread sections and counterthread sections occurs and the thread sections with an opposed pitch engage correspondingly on the flanks on the corresponding counterthread sections.

Abstract: A piston for an internal combustion engine is described, the piston having a lower crown portion and an upper crown portion, the upper crown portion including a combustion bowl and a piston ring-groove belt of generally annular form depending from the outer periphery of the crown surface, the lower crown portion comprising a generally circular plate member having an upstanding ring on the upper surface thereof, the upper crown portion and the lower crown portion being joined together by retention means between the combustion bowl and the upstanding ring, and between co-operating spigot and socket means formed on the base of the combustion bowl and on the plate member, to prevent withdrawal by axial forces, and there being an oil cooling gallery defined between the upper crown portion and the lower crown portion.

Abstract: A piston has a piston head made of ceramics, and includes a ceramic piston head having a male rounded thread portion at the outer periphery thereof, a metal piston body having a depression in the top portion for receiving the piston head, and a female rounded thread at the inner periphery of the depression for mating with the male thread portion. A rotation restraint member is provided between the male thread portion and the female thread portion for restraining the piston head from turning with respect to the piston body. The ratio of the height of the thread to the pitch preferably is from 1/4 to 1/2.