A piston for an internal combustion engine includes a skirt and a crown coupled to the skirt. The crown is produced in isolation from the skirt using an additive manufacturing process. The piston includes a first air gap between the crown and the skirt. According to an example embodiment, the crown includes a plurality of sections produced in isolation from the skirt. The crown may include a second air gap disposed between two of the plurality of sections.

A piston for an internal combustion engine includes a skirt and a crown coupled to the skirt. The crown is produced in isolation from the skirt using an additive manufacturing process. The piston includes a first air gap between the crown and the skirt. According to an example embodiment, the crown includes a plurality of sections produced in isolation from the skirt. The crown may include a second air gap disposed between two of the plurality of sections.

A heavy duty piston for an internal combustion engine comprises a thermally conductive composition filling 10 to 90 vol. % of a sealed cooling gallery. The thermally conductive composition includes bismuth and/or tin. For example, the thermally conductive composition can be a single-phase binary mixture of bismuth and tin. The thermally conductive composition has improved thermal properties, for example a melting point around 139° C., a thermal conductivity around 22 W/m.Math.K, and a thermal diffusivity around 1.43E-5 m.sup.2/s. The thermally conductive composition is not reactive and does not include toxic or cost-prohibitive metals. During high temperature operation, as the piston reciprocates in the cylinder bore, the thermally conductive composition flows throughout the cooling gallery to dissipate heat away from the upper crown and thus improve efficiency of the engine.

A heavy duty piston for an internal combustion engine comprises a thermally conductive composition filling 10 to 90 vol. % of a sealed cooling gallery. The thermally conductive composition includes bismuth and/or tin. For example, the thermally conductive composition can be a single-phase binary mixture of bismuth and tin. The thermally conductive composition has improved thermal properties, for example a melting point around 139° C., a thermal conductivity around 22 W/m.Math.K, and a thermal diffusivity around 1.43E-5 m.sup.2/s. The thermally conductive composition is not reactive and does not include toxic or cost-prohibitive metals. During high temperature operation, as the piston reciprocates in the cylinder bore, the thermally conductive composition flows throughout the cooling gallery to dissipate heat away from the upper crown and thus improve efficiency of the engine.

A galleryless piston for an internal combustion engine is provided. The piston has a monolithic piston body including an upper wall forming an upper combustion surface with first and second portions. The first portion extends annularly along an outer periphery of the upper wall and the second portion includes a combustion bowl. The first portion can also include valve pockets formed therein to reduce weight. The upper wall has an undercrown surface directly opposite the second portion of the upper combustion surface. To enhance cooling, a center portion of the undercrown surface is concave, such that oil is channeled during reciprocation of the piston from one side to the opposite side of the piston. The concave center portion is axially offset from the surrounding area of the undercrown surface.

A galleryless piston for an internal combustion engine is provided. The piston has a monolithic piston body including an upper wall forming an upper combustion surface with first and second portions. The first portion extends annularly along an outer periphery of the upper wall and the second portion includes a combustion bowl. The first portion can also include valve pockets formed therein to reduce weight. The upper wall has an undercrown surface directly opposite the second portion of the upper combustion surface. To enhance cooling, a center portion of the undercrown surface is concave, such that oil is channeled during reciprocation of the piston from one side to the opposite side of the piston. The concave center portion is axially offset from the surrounding area of the undercrown surface.

This piston for internal combustion engines, which is capable of achieving high heat shielding properties and high durability, comprises: a base that is formed from aluminum or an aluminum alloy; a composite material part which is formed in a first region of the surface of the base, and which is formed from a composite material that is reinforced with inorganic fibers or whiskers; and an alumite coating film that is formed on the composite material part and a second region of the surface of the base, said second region being different from the first region.

This piston for internal combustion engines, which is capable of achieving high heat shielding properties and high durability, comprises: a base that is formed from aluminum or an aluminum alloy; a composite material part which is formed in a first region of the surface of the base, and which is formed from a composite material that is reinforced with inorganic fibers or whiskers; and an alumite coating film that is formed on the composite material part and a second region of the surface of the base, said second region being different from the first region.

The present application relates to a method for producing at least one component for a hydraulic displacement unit, wherein the method is characterized by the steps: prefabrication of a blank component for the at least one component, wherein at least one defined surface region of the blank component is fabricated intentionally with oversize, surface-hardening of the blank component, and final forming of the component from the hardened blank component by removal of the excessive material at the at least one defined surface region fabricated with oversize.

A steel piston with a bushing applied to pin bore surfaces by laser cladding or laser additive manufacturing is provided. The bushing is formed of metal, such as bronze, and metallurgically bonded to the steel of the piston. Thus, the bushing cannot fail by rotating relative to pin bore surfaces. The bushing has a porosity ranging from 0.05% to 5%, based on the total volume of the bushing, and a thickness ranging from 0.07 mm to 6 mm. Since the metal is applied directly to the steel by laser cladding or laser additive manufacturing, the overall size of the piston is reduced, compared to typical pistons with a separate steel backed bushing, and the possibility of bushing rotation is avoided. The bushing also provides scuffing resistance and increased unit load capacity of the pin bore.