A plunger pump includes a cylinder having a cylinder chamber, and a first through hole and a second through hole that open from an inner circumferential surface toward an outer circumferential surface of the cylinder chamber, and a plunger inserted in the cylinder chamber and configured to make a reciprocating motion with respect to the cylinder chamber. An inner circumferential portion of the cylinder has an inner circumferential surface, and a helical first groove portion on the inner circumferential surface, the helical first groove portion being configured to communicate with at least one of the first through hole and the second through hole.

An insert for a cylinder liner which is capable of trapping heat in the combustion chamber is provided. The insert extends circumferentially around a center axis and longitudinally from an upper end to a lower end. The insert includes an inner portion presenting an inner surface facing the center axis and an outer portion presenting an outer surface facing away from the center axis. The inner portion is formed of an iron-based material, such as steel, and the outer portion is formed of a material having a thermal conductivity of not greater than 3.5 W/mK, for example ceria stabilized zirconia. The inner and outer portions each present a thickness, and the thickness can form a gradient between the upper end and the lower end of the insert. For example, the thickness of the outer portion can be greater at the upper end than at the lower end of the insert.

A fluid gear pump gear arranged to rotate about a first axis includes a concentrically disposed first hub portion and a plurality of first teeth radially projecting and circumferentially spaced about the first hub portion, the first hub portion and the first teeth being formed of a ceramic material. The gear also includes a first shaft on which the first hub portion is carried.

An insert for a cylinder liner which is capable of trapping heat in the combustion chamber is provided. The insert extends circumferentially around a center axis and longitudinally from an upper end to a lower end. The insert includes an inner portion presenting an inner surface facing the center axis and an outer portion presenting an outer surface facing away from the center axis. The inner portion is formed of an iron-based material, such as steel, and the outer portion is formed of a material having a thermal conductivity of not greater than 3.5 W/mK, for example ceria stabilized zirconia. The inner and outer portions each present a thickness, and the thickness can form a gradient between the upper end and the lower end of the insert. For example, the thickness of the outer portion can be greater at the upper end than at the lower end of the insert.

A plunger pump includes a cylinder having a cylinder chamber, and a first through hole and a second through hole that open from an inner circumferential surface toward an outer circumferential surface of the cylinder chamber, and a plunger inserted in the cylinder chamber and configured to make a reciprocating motion with respect to the cylinder chamber. An inner circumferential portion of the cylinder has an inner circumferential surface, and a helical first groove portion on the inner circumferential surface, the helical first groove portion being configured to communicate with at least one of the first through hole and the second through hole.

The present inventive subject matter is directed to repair compositions for thermal barrier coatings and methods of use thereof. The repair compositions include a ceramic composition, a colloidal solution, an aqueous binder, an aqueous dispersant, and an aqueous ammonia solution. The ceramic composition includes a first population of yttria-stabilized zirconia particles having a mean diameter from about 250 nm to about 1000 nm, a second population of yttria-stabilized zirconia particles having a mean diameter from about 2 m to about 10 m, and a third population of yttria-stabilized zirconia particles having a mean diameter from about 20 m to about 250 m. One method includes depositing the repair layer onto the damaged region, the repair layer including the repair composition, and heat treating the repair layer.

The present invention is directed to repair compositions for thermal barrier coatings and methods of use thereof. The repair compositions include a ceramic composition, a colloidal solution, an aqueous binder, an aqueous dispersant, and an aqueous ammonia solution. The ceramic composition includes a first population of yttria-stabilized zirconia particles having a mean diameter from about 250 nm to about 1000 nm, a second population of yttria-stabilized zirconia particles having a mean diameter from about 2 m to about 10 m, and a third population of yttria-stabilized zirconia particles having a mean diameter from about 20 m to about 250 m. One method includes depositing the repair layer onto the damaged region, the repair layer including the repair composition, and heat treating the repair layer.

A rotor-stator assembly for a gas turbine engine, the assembly including a rotor having a layer of ceramic material forming an abrasive coating deposited on its tip, the layer being constituted mainly by zirconia and possessing a void ratio less than or equal to 15%, and a stator arranged around the rotor and provided facing the tip of the rotor with a layer of ceramic material forming an abradable coating, the layer being constituted mainly by zirconia possessing a void ratio lying in the range 20% to 50% with pores having size less than or equal to 50 m.

A fluid gear pump gear arranged to rotate about a first axis includes a concentrically disposed first hub portion and a plurality of first teeth radially projecting and circumferentially spaced about the first hub portion, the first hub portion and the first teeth being formed of a ceramic material. The gear also includes a first shaft on which the first hub portion is carried.

An internal combustion engine includes a combustion chamber, a fuel injector injecting fuel into the combustion chamber, a cylinder, a piston having a crown and reciprocating in the cylinder, the crown being exposed to the combustion chamber, and an ignition delay enhancer prolonging an ignition delay of a fuel-air mixture in the combustion chamber. A ceramic member is disposed on at least a fuel injection port, to which fuel is injected from the fuel injector, of the crown of the piston.