An internal combustion engine has a cylinder block and a cylinder head fixed to each other with a plurality of bolts, and a piston fitted in a cylinder bore of the cylinder block so as to be able to reciprocate. A portion of the cylinder bore having a minimum diameter in a travel range of a skirt across which the skirt travels as the piston reciprocates is located within a range facing the skirt when the piston is at a bottom dead center. A clearance between the skirt and the minimum-diameter portion has a minimum value of a clearance between the skirt and a wall surface of the cylinder bore.

An internal combustion engine including a block movement mechanism comprising a single control shaft extending in parallel with the crankshaft and supported by one of a crankcase and cylinder block and having a main shaft part and eccentric parts with an axial center at a position offset by a predetermined amount from the axial center of the main shaft part, coupling members with one end parts attached to the eccentric parts and the other end parts attached to the other of the crankcase and cylinder block and connecting the control shaft and the other of the crankcase and cylinder block, and an actuator making the control shaft rotate in both directions within a predetermined range of rotation so as to make the axial center of the eccentric parts swing about the axial center of the main shaft part in the direction of relative movement of the cylinder block.

An internal combustion engine including a block movement mechanism comprising a single control shaft extending in parallel with the crankshaft and supported by one of a crankcase and cylinder block and having a main shaft part and eccentric parts with an axial center at a position offset by a predetermined amount from the axial center of the main shaft part, coupling members with one end parts attached to the eccentric parts and the other end parts attached to the other of the crankcase and cylinder block and connecting the control shaft and the other of the crankcase and cylinder block, and an actuator making the control shaft rotate in both directions within a predetermined range of rotation so as to make the axial center of the eccentric parts swing about the axial center of the main shaft part in the direction of relative movement of the cylinder block.

The invention relates to a cast iron material with lamellar graphite formation. It further relates to a motor vehicle part made of the cast iron material. In order to create a ferritic cast iron material having a higher thermal conductivity, it is proposed according to the invention that, in addition to Fe, the cast iron material contains 3.9 to 4.2 wt. % C, 0.3 to 0.9 wt. % Si and 2.0 to 7 wt. % Al. It has been demonstrated within the scope of the invention that not only the thermal conductivity but also the wear resistance and corrosion resistance of the material are increased in comparison to known cast iron materials.

A piston assembly for an internal combustion engine includes a cylinder bore and a piston having a plurality of ring grooves, and a ring positioned within a ring groove. The ring includes a cross-section having a lower surface and an outer radial surface that form a scraping corner, an inner radial surface, and an upper surface. The upper surface and the lower surface are generally parallel with one another, and both upper and lower surfaces form a positive first angle with respect to a radial axis, and the outer radial surface forms a second positive angle with respect to a central axis. A constant twist occurs in the ring about a rotational center of the cross-section, the constant twist occurring at each cross-sectional location of the ring about the circumference of the ring and between adjacent free ends of the ring.

A piston assembly for an internal combustion engine includes a cylinder bore and a piston having a plurality of ring grooves, and a ring positioned within a ring groove. The ring includes a cross-section having a lower surface and an outer radial surface that form a scraping corner, an inner radial surface, and an upper surface. The upper surface and the lower surface are generally parallel with one another, and both upper and lower surfaces form a positive first angle with respect to a radial axis, and the outer radial surface forms a second positive angle with respect to a central axis. A constant twist occurs in the ring about a rotational center of the cross-section, the constant twist occurring at each cross-sectional location of the ring about the circumference of the ring and between adjacent free ends of the ring.

An internal combustion engine, includes a cylinder; a piston supported in the cylinder for linear displacement, wherein the piston is operatively connected with a crankshaft of the internal combustion engine via a piston rod; a linear motor including a stator and a rotor, wherein the stator has an independently operable stator element assigned to the cylinder and partially surrounding the piston in circumferential direction with respect to a longitudinal center axis of the cylinder, wherein the rotor is assigned to or forms a part of the piston, and wherein the linear motor being operable for exerting on the piston a compensation force directed in radial direction.

An internal combustion engine, includes a cylinder; a piston supported in the cylinder for linear displacement, wherein the piston is operatively connected with a crankshaft of the internal combustion engine via a piston rod; a linear motor including a stator and a rotor, wherein the stator has an independently operable stator element assigned to the cylinder and partially surrounding the piston in circumferential direction with respect to a longitudinal center axis of the cylinder, wherein the rotor is assigned to or forms a part of the piston, and wherein the linear motor being operable for exerting on the piston a compensation force directed in radial direction.

An internal combustion engine is provided. Facing pistons eliminate a cylinder head, thereby reducing heat losses through a cylinder head. Facing pistons also halve the stroke that would be required for one piston to provide the same compression ratio, and the engine can thus be run at higher revolutions per minute and produce more power. An internal sleeve valve is provided for space and other considerations. A combustion chamber size-varying mechanism allows for adjustment of the minimum size of an internal volume to increase efficiency at partial-power operation. Variable intake valve operation is used to control engine power.

The following description pertains to flexure structures, apparatuses comprising flexure structures, systems comprising flexure structures, methods of using flexure structures, methods of using apparatuses comprising flexure structures, and methods of using systems comprising flexure structures. The following description also pertains to methods, systems, and apparatuses for linear to rotary motion converters.