Linear generators with a piston having a valve are described herein. The linear generator includes a combustion module and at least one linear motor. The linear motor includes at least one piston having: a piston head with an opening therein; a piston skirt opposed to the piston head; a piston side wall extending between the piston head and the piston skirt, the piston side wall having at least one port therein. The piston also includes a valve mechanism movable relative to each of the piston head, the piston seat and the piston side wall. The valve mechanism includes a valve stem extending through the piston skirt and the interior piston volume into a mover shaft of the motor, and a valve head coupled to the valve stem and configured to cover the opening of the piston head.

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, and 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 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.

Linear generators with a piston having a valve are described herein. The linear generator includes a combustion module and at least one linear motor. The linear motor includes at least one piston having: a piston head with an opening therein; a piston skirt opposed to the piston head; a piston side wall extending between the piston head and the piston skirt, the piston side wall having at least one port therein. The piston also includes a valve mechanism movable relative to each of the piston head, the piston seat and the piston side wall. The valve mechanism includes a valve stem extending through the piston skirt and the interior piston volume into a mover shaft of the motor, and a valve head coupled to the valve stem and configured to cover the opening of the piston head.

A one-piece cast piston (10) for an internal combustion engine includes a cooling channel (12) and at least one rib (18) on the inner side of the piston opposite the recess base of a combustion bowl (14).

A piston of an internal combustion engine may include a piston shaft and a piston head. The piston head may be provided with a closed cooling channel with a cooling medium arranged therein. The piston shaft may have a spherically round cross-sectional shape, wherein a deviation from the roundness with respect to a piston diameter may be less than 0.5 per thousand.

Piston (1) of an internal combustion engine, which piston is designed in structured construction, comprising two oppositely arranged load-bearing skirt wall portions (2), wherein a connecting wall (3) respectively extends, starting from a pin boss (4), in the direction of the side edge of the load-bearing skirt wall portions (2), characterized in that in an interior of the piston (1) is (are) disposed at least one rib (5, 6, 7), preferably three ribs (5, 6, 7), and the material of the regions around the at least one rib (5, 6, 7) is reduced.

A two-stroke engine piston (1) is disclosed comprising a piston top (3), a mantle surface (5), a stratified scavenging channel (7) in the mantle surface (5), and a weight reduction space (9) arranged between the piston top (3) and the stratified scavenging channel (7). The weight reduction space (9) has a largest first axial extent (a1) at the mantle surface (5) and a second axial extent (a2) radially inside the mantle surface (5), and wherein the second axial extent (a2) is greater than the largest first axial extent (a1). The present disclosure further relates to an engine (30), a hand-held tool (40), and a method of manufacturing an engine piston (1).

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.

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.