Provided is a high-pressure fuel pump which can fix a cylinder to a pump body using a simple structure, and can reduce a displacement amount inward in a radial direction of the cylinder. A high-pressure fuel pump includes a pump body which is formed with a pressing chamber and a cylinder which is inserted in a hole formed in the pump body. The cylinder is swaged to the hole by pressing a convex portion on an outside in a radial direction to fit into the hole on an opposite side to the pressing chamber, by screwing a formed screw thread into the hole, or by being swaged with the opposite side to the pressing chamber. The cylinder is formed with a clearance in the radial direction with respect to the hole of the pump body all over a region from a bonding portion to an upper end.

The present invention addresses the problem of providing a cylinder liner for insert casting, with which the bonding strength between a cylinder liner and a cylinder block can be improved by reducing voids generated on the cylinder block. The problem is solved by a cylinder liner for insert casting which includes plural projections on its outer peripheral surface and satisfies the following (i) and (ii): (i) the number of the projections is 5 to 50 per 1 cm.sup.2 on the outer peripheral surface, and (ii) when two 15.2 mm0.03 mm lines are set in parallel with a gap of 3.8 mm therebetween at an arbitrary position on the outer peripheral surface of the cylinder liner, the total number of projections that are in contact with the two lines is 8 or less.

To provide a cast iron cylindrical member capable of improving the bonding strength when metal on the outer peripheral side and the cast iron cylindrical member are integrated. For this objective, in a cast iron cylindrical member including a plurality of projections including constricted projections on the outer peripheral surface, the anchor portion index (I) represented by {(A.sub.av.sup.2B.sub.av.sup.2)/4PnPr/100}0.35H/2 is set in a specific range.

To provide a cast iron cylindrical member capable of improving the bonding strength when metal on the outer peripheral side and the cast iron cylindrical member are integrated. For this objective, in a cast iron cylindrical member including a plurality of projections including constricted projections on the outer peripheral surface, the anchor portion index (I) represented by {(A.sub.av.sup.2B.sub.av.sup.2)/4PnPr/100}0.35H/2 is set in a specific range.

A piston for a cylinder, and a method of fabrication thereof, the piston rod comprising a substrate and a coating, the substrate having a surface roughness profile comprising peaks and valleys with a peak-to-valley height in a range between 0.5 and 2 m, and the coating having a hardness in a range between 1000 and 4000 HV and a coefficient of friction in a range between 0.1 and 0.05.

The present invention relates to a piston cylinder system for a working device, wherein the piston cylinder system comprises at least one tubular element and at least one piston which is guided in the at least one tubular element. The piston cylinder system is characterized in that at least one tubular element consists of high-manganese-steel and the inner side of the at least one tubular element is machined.

The present invention relates to a piston cylinder system for a working device, wherein the piston cylinder system comprises at least one tubular element and at least one piston which is guided in the at least one tubular element. The piston cylinder system is characterized in that at least one tubular element consists of high-manganese-steel and the inner side of the at least one tubular element is machined.

A piston and cylinder assembly of an axial piston machine is disclosed which includes a cylinder having a uniform internal diameter, a cylindrical bushing press-fit against the inner surface of the cylinder and extending at least partially therein, the bushing comprising at least one circumferential groove formed on an outer surface of the bushing against the inner surface of the cylinder, a piston reciprocably disposed within the cylindrical bushing, generating a piston-bushing-interface, the piston and the bushing defining a diametrical clearance therebetween, the diametrical clearance defining a lubrication gap and a fluid-dynamic seal between the piston and the cylindrical bushing.

In a sliding structure for an internal combustion, a cylinder has recesses in a stroke center region. Piston rings have inclined surfaces on an outer circumferential surface, and a lubricating oil flows between the inner wall surface and the outer circumferential surface that relatively move via the inclined surfaces. At any RPM equal to or greater than at idle, a center friction coefficient at the stroke center region through which the piston rings pass at the highest speed is less than a center friction coefficient when no recesses are formed in the stroke center region. Contrarily, at the RPM, an outside friction coefficient when the piston rings pass through a region outside the stroke center region is less than an outside friction coefficient when the recesses are formed in the outside region. As a result, further improved low fuel efficiency is achieved for the dimple liner technique.

A sliding contact assembly includes a first surface and a second surface. The second surface of the sliding contact assembly is configured to slide over the first surface, and at least a portion of the second surface contacts the first surface to form at an interface between the first surface and the second surface. The sliding contact assembly also includes a plurality of textures on the portion of the second surface that contacts the first surface. A density of the plurality of textures is not uniform over the portion of the second surface that contacts the first surface. The sliding contact assembly can include apex seal to housing interfaces in rotary engines, roller to roller interfaces, roller to housing interfaces, bearing to surface interfaces, etc.