A piston member for a high-pressure pump for pumping fluid in a sample separation apparatus, wherein the piston member comprises a piston configured for being mountable to reciprocate in a piston chamber for displacing fluid, and a sealing for sealing between the piston member and the piston chamber when the piston member is mounted in the piston chamber to reciprocate, wherein the sealing is mounted on the piston so as to reciprocate together with the piston.

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.

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 rod assembly for a fluid pressure cylinder includes a rod member and a packing that is mounted on an outer circumferential part of the rod member and slides along a slide hole. Assembly is simple because a conventional hard piston is not used. The assembly can be carried out simply by hand without the use of a dedicated tool. Thus, the rod assembly simplifies assembly work.

A rolling cylinder displacement compressor including a minimum pressure bypass port as an opening of a minimum pressure bypass valve flow path, which is connected to a compression chamber formed in the compression portion in a lowest pressure state, of the bypass valve flow path is arranged such that a compression chamber faces an opening of the discharge flow path or the minimum pressure bypass port. The minimum pressure bypass port may be configured such that a minimum pressure port center as the center of the minimum pressure bypass port is arranged in a rotation advanced-side region with respect to an advanced radius line as a line connecting a cylinder advanced corner point of the compression chamber at the start of a compression stroke and the rotation center of the rolling cylinder.

A projecting-shape portion projecting toward a first sliding surface in a section along a sliding direction of a second sliding surface is provided on the second sliding surface which slides relative to the first sliding surface, and an apical portion, which is a most projecting part, and a bottom edge portion, which is at a position that is most spaced apart from the first sliding surface, are provided on the projecting-shape portion, and when a gap between the first sliding surface and the second sliding surface at the apical portion is assumed to be a minimum gap h1 and a gap at the bottom edge portion is assumed to be a maximum gap h2, h1 is set to be within a range of 0.5 m to 40 m and h2/h1 is set to be within a range of 1.5 to 5.0.

A piston for an internal combustion engine includes: a pair of groove portions which are positioned on the back surface side of the crown portion, and which extend along outer wall surfaces of the apron portions, each of the skirt portions having a width in the circumferential direction of the piston, the width being gradually decreased toward a piston axially lower side which is an axial direction of the piston from the piston crown surface toward the back surface of the crown portion, and each of the groove portions being positioned on an outer side in a radial direction of the piston as the each of the groove portions is positioned on the piston axially lower side, an entire of the each of the groove portions being inclined with respect to a center axis of the piston.

A piston for an internal combustion engine includes: a pair of groove portions which are positioned on the back surface side of the crown portion, and which extend along outer wall surfaces of the apron portions, each of the skirt portions having a width in the circumferential direction of the piston, the width being gradually decreased toward a piston axially lower side which is an axial direction of the piston from the piston crown surface toward the back surface of the crown portion, and each of the groove portions being positioned on an outer side in a radial direction of the piston as the each of the groove portions is positioned on the piston axially lower side, an entire of the each of the groove portions being inclined with respect to a center axis of the piston.

The invention relates to a piston for an internal combustion engine having two skirt wall (10), which are connected by connecting walls (14), which bear piston-pin bosses, wherein at least one skirt wall (10) has a greater wall thickness in a region (12) that is central along the piston periphery and in the lateral regions than between the central region (12) and each lateral region and is continuously curved on the inside of the piston in a section perpendicular to the piston axis, and wherein the wall thickness distribution is substantially constant in the direction of the piston axis.

The invention relates to a piston for an internal combustion engine having two skirt wall (10), which are connected by connecting walls (14), which bear piston-pin bosses, wherein at least one skirt wall (10) has a greater wall thickness in a region (12) that is central along the piston periphery and in the lateral regions than between the central region (12) and each lateral region and is continuously curved on the inside of the piston in a section perpendicular to the piston axis, and wherein the wall thickness distribution is substantially constant in the direction of the piston axis.