The present invention provides a power device generating greater propelling force and finds that traditional power devices do not include all propelling forces based on the fundamental core propelling force source problem. External pressure is guided to the traditional power devices since the inner speed is higher the outer speed, power consumption for overcoming fluid resistance is high, and mutual contradiction results are obtained. The unique difference between the present invention and general common sense lies in opposite fluid pressure directions; inner fluid channels and outer fluid channels with higher flow speeds are formed to generate pressure differences which guides the fluid pressure to the outside and serve as propelling force, thus the present invention creatively finds three propelling force sources, two lifting force or propelling force sources of helicopters or airplanes driven by propellers and two propelling force sources for sufficient burning of fuel in combustion chambers of engines.

The present disclosure relates to a piston for a reciprocating-piston internal combustion engine, comprising a piston head and a piston barrel, wherein the piston head has an encircling ring belt with at least one ring groove for a piston ring and has, in the region of the ring belt, an encircling cooling duct. The cooling duct extends from the ring belt as far as a wall of the piston barrel in order to increase an oil film temperature of the oil film in the cylinder liner between the piston barrel and cylinder and to thereby reduce the piston barrel friction.

Piston has crown portion 2 having crown surface 2a defining combustion chamber, thrust-side and anti-thrust-side skirt portions 3a, 3b formed integrally with crown portion and sliding on cylinder wall surface, a pair of apron portions 4a, 4a joined to skirt portions in circumferential direction, recessed portion 6 formed on back surface that is opposite side to crown surface and extending between skirt portions along substantially longitudinal direction, and a plurality of protrusions 7 formed integrally with bottom surface of recessed portion and extending along arrangement direction of skirt portions. At least one end edge in longitudinal direction of protrusion is integrally connected to inner side surface, facing one end edge of protrusion, of recessed portion. Adequate transcription performance to molding surface can therefore be ensured while removing remains of air on bottom side of recessed portion of mold for molding protrusions on crown portion back surface during casting.

A steel piston (10) for an internal combustion engine comprises a ring zone (12), a shaft (14), openings (16) between the ring zone (12) and shaft (14) which extend from the piston outer side to the piston inner side, and, between two openings (16), a rib (18) which is substantially central with respect to a length of a piston pin to be received, wherein, when viewed in the circumferential direction, the rib (16) has a decreasing thickness from the middle thereof, as measured in the radial direction. In a method for producing a steel piston for an internal combustion engine comprising a ring zone and a shaft, openings are formed between the ring groove region and the shaft which extend from the piston outer side to the piston inner side, and at least one rib is formed between the openings which is substantially central with respect to a length of a piston pin to be received, wherein, when viewed in the circumferential direction, the rib (16) has a decreasing thickness from the middle thereof, as measured in the radial direction.

Methods and systems are provided for a surface structure for a piston. In one example, the surface structure is located on at least a portion of the piston.

A galleryless piston having a reduced temperature during operation in an engine is provided. The piston includes an upper wall with an exposed undercrown surface. A ring belt and pin bosses depend from the upper wall, and a pair of skirt panels depend from the ring belt and are coupled to the pin bosses by struts. The piston includes an inner undercrown region and outer pockets extending along the undercrown surface. The inner undercrown region is surrounded by the skirt panels, the struts, and the pin bosses. Each outer pocket is surrounded by one of the pin bosses, a portion of the ring belt, and the struts adjacent the one pin boss. A plurality of holes extend through the pin bosses and/or the struts from the inner undercrown region to one of the outer pockets to convey cooling oil from the inner undercrown region to the outer pockets.

Provided is a high pressure piston crown capable of withstanding a higher pressure than the existing piston crown by changing an internal structure of the piston crown reciprocating in a cylinder while being coupled with an upper portion of a piston skirt. The high pressure piston crown includes: a rib part 100 including a plurality of main ribs 110 that are radially disposed, have one side connected to a central portion C of the high pressure piston crown, and have a cross sectional area wider toward an outside of the high pressure piston crown; an oil gallery 200 formed by the rib part 100 and making cooling oil introduced from the piston skirt flow therein; and a lower plate 300 formed under the central portion C and connected to the rib part 100 to have an inside thereof connected to the oil gallery 200.

A casting mold for casting a piston for an internal combustion engine may include a mold body having a surface texture in a region corresponding to a subsequent internal surface of a piston skirt. The surface texture may be defined by a plurality of grooves. The plurality of grooves may have the following dimension: a depth of 0.2 mm<t<0.5 mm, a width of 0.02 mm<b<0.05 mm, and at least two groove walls which are inclined outwardly at 0<<10.

A piston for a two stroke engine which operates with advanced scavenging has a piston base and a piston skirt. The center axis of the piston skirt forms a longitudinal center axis of the piston. The piston has two piston pin eyes, in which piston pin receptacles are configured. The center axis of the piston pin receptacles forms a transverse axis of the piston. The piston has at least one piston pocket. At least one piston pin eye is connected via at least one connecting rib to the piston skirt. Here, the connecting rib runs on that side of the piston pocket which faces away from the piston base.

A galleryless piston having a reduced weight and a reduced operating temperature is provided. The piston includes an undercrown surface exposed from an underside of the piston, a ring belt, pin bosses each presenting a pin bore, and skirt panels depending from the ring belt and coupled to the pin bosses by strut. The piston further includes an inner undercrown region extending along the undercrown surface and surrounded by the skirt panels, the struts, and the pin bosses. The piston also includes outer pockets each extending along the undercrown surface and each surrounded by a portion of the ring belt, one of the pin bosses, and the struts coupling the one pin boss to the skirt panels. Cutouts are located in the pin bosses above the pin bores to increase the area of the undercrown surface and thus allow cooling oil to remove more heat from the undercrown surface.