A method is provided for forming wear-resistant layer on the surface of cylinder bores a cylinder drum of a hydrostatic axial piston machine within which a respective piston is moved in a manner subject to intensive wear. The cylinder bores are gas nitrocarburized in two stages to minimize the wear and include a thin uniform connecting layer that has a thickness of 4 to 16 μm and a comparatively thick underlying diffusion layer.

A seal assembly includes a housing at least partially defining a seal opening and at least partially surrounding a rotatable shaft. A carbon seal is located at least partially in the seal opening and includes a sealing surface. The rotatable shaft includes a radially facing surface that has a carbide based coating and a diamond-like carbon coating in engagement with the sealing surface on the carbon seal.

A seal assembly includes a housing at least partially defining a seal opening and at least partially surrounding a rotatable shaft. A carbon seal is located at least partially in the seal opening and includes a sealing surface. The rotatable shaft includes a radially facing surface that has a carbide based coating and a diamond-like carbon coating in engagement with the sealing surface on the carbon seal.

In one aspect, fluid ends are described herein having structure and design addressing degradation mechanisms in pumping operations employing fluids comprising abrasive particles. Briefly, a fluid end for a reciprocating pump comprises a body portion comprising a bore having an inner diameter surface, and a reciprocating plunger at least partially disposed in the bore. A sleeve is positioned within the bore between the inner diameter surface and plunger, the sleeve engaging the inner diameter surface via an interference fit.

A lubricating layer having wear resistance and reliability on the wear resistance, and a compressor including a lubricating layer are provided. The compressor may include a lubricating layer coated on a frictional portion between a rotational shaft and a bearing. The lubricating layer may include at least one metal phase selected from a group consisting of Titanium (Ti); and Copper (Cu), Cobalt (Co), Nickel (Ni), and Zirconium (Zr), and may be a composite structure of amorphous and nanocrystalline materials.

A pumping mechanism is disclosed. The pumping mechanism may include a barrel formed of a barrel substrate and including a first end surface, a second end surface opposite the first end surface, and a bore between the first and second end surfaces. Each of the first and second end surfaces and the bore is coated with a metal plating. The pumping mechanism may further include a plunger formed of a plunger substrate and configured to be slidably disposed in the bore in barrel, the plunger substrate having a tribological coating.

A method is provided for forming wear-resistant layer on the surface of cylinder bores a cylinder drum of a hydrostatic axial piston machine within which a respective piston is moved in a manner subject to intensive wear. The cylinder bores are gas nitrocarburized in two stages to minimize the wear and include a thin uniform connecting layer that has a thickness of 4 to 16 m and a comparatively thick underlying diffusion layer.

A piston that moves reciprocally in the cylinder of an internal combustion engine and has a piston skirt that makes sliding contact with the inner wall of the cylinder. Solid lubrication parts are provided on the sliding-contact surface of the piston skirt. The solid lubrication parts include at least one type of silver, silver alloy, copper, or copper alloy, and at least one type of carbon material or carbide ceramics.

A pump is disclosed. The pump may include at least one pumping mechanism. The at least one pumping mechanism may include a barrel formed of a substrate having a bore and a plunger formed of a substrate and slidably disposed within the bore in the barrel. The pump may further include a coating disposed on the plunger. The coating may include a main layer containing a tribological material and a sacrificial break-in layer disposed on the main layer, the break-in layer containing a tribological material.

A pumping mechanism is disclosed. The pumping mechanism may include a barrel formed of a barrel substrate and including a first end surface, a second end surface opposite the first end surface, and a bore between the first and second end surfaces. Each of the first and second end surfaces and the bore is coated with a metal plating. The pumping mechanism may further include a plunger formed of a plunger substrate and configured to be slidably disposed in the bore in barrel, the plunger substrate having a tribological coating.