In order to effect a seal a porous material which comprises one side of two opposing surfaces is used to restrict and evenly distribute externally pressurized gas, liquid, steam, etc. between the two surfaces, exerting a force which is opposite the forces from pressure differences or springs trying to close the two faces together and so may create a non-contact seal that is more stable and reliable than hydrodynamic seals currently in use. A non-contact bearing is also disclosed having opposing surfaces with relative motion and one surface issuing higher than ambient pressure through a porous restriction, wherein the porous restriction is part of a monolithic porous body, or a porous layer, attached to lands containing a labyrinth, the porous restriction and lands configured to not distort more than 10% of a gap created from differential pressure between each side of the porous restriction.

A solid lubricant 11 is formed by molding and firing powder that includes amorphous and self-sintering carbon material powder 12, graphite powder 13, and a binder 14. The solid lubricant has high material strength and hardness, and also excellent impact resistance and wear resistance.

A sliding member includes a carbon transfer layer and can superiorly effectively decrease friction and reduce wear. A method produces the sliding member. The sliding member includes a substrate and a carbon transfer layer. The carbon transfer layer is disposed on the surface of the substrate and includes both sp.sup.2 bonded carbon and sp.sup.3 bonded carbon. The carbon transfer layer preferably has a ratio sp.sup.3/(sp.sup.2+sp.sup.3) of the sp.sup.3 bonded carbon to the totality of the sp.sup.2 bonded carbon and the sp.sup.3 bonded carbon of 0.1 or more.

In order to effect a seal a porous material which comprises one side of two opposing surfaces is used to restrict and evenly distribute externally pressurized gas, liquid, steam, etc. between the two surfaces, exerting a force which is opposite the forces from pressure differences or springs trying to close the two faces together and so may create a non-contact seal that is more stable and reliable than hydrodynamic seals currently in use. A non-contact bearing is also disclosed having opposing surfaces with relative motion and one surface issuing higher than ambient pressure through a porous restriction, wherein the porous restriction is part of a monolithic porous body, or a porous layer, attached to lands containing a labyrinth, the porous restriction and lands configured to not distort more than 10% of a gap created from differential pressure between each side of the porous restriction.

A rolling element bearing includes inner and outer rings having raceways and rolling elements between the raceways. The raceways of the inner and outer rings are coated with a first coating, such as a phosphate coating, and the rolling elements are coated with a second, different, coating such as a black oxide coating.

A rotor shaft for a vertical take-off and landing (VTOL) aircraft having a rotor system includes a body having a first end connectable to the rotor system, a second end, and an intermediate portion defining an outer surface and an inner surface extending between the first end and the second end. The body is formed from a first material. A stiffness enhancing layer is applied to one of the outer surface and the inner surface. The stiffness enhancing layer includes a second material other than the first material. The second material has a modulus of elasticity that is about 16E6 psi (116 GPa) or greater.

A method including substituting an atmosphere in a space, in which a sliding surface formed of a metal or a ceramic material, and a slid surface are disposed, with a gas atmosphere containing a hydroxyl group-containing compound and at least one of hydrogen and nitrogen, and relatively sliding the sliding surface against the slid surface by a Hertzian contact stress of 1.0 GPa or more in the space under the gas atmosphere containing the hydroxyl group-containing compound at least one of hydrogen and nitrogen. As a result, it is possible to form, on the sliding surface, a low-friction coating that stably exhibits a significantly low friction coefficient, for example, of 10.sup.4 order (less than 0.001).

A structure including a sliding layer that is formed on a roughened surface of a substrate and that has an excellent slidability, and a method for producing the structure. The sliding layer is formed of a powder of a carbon-composition-containing resin composition filled in at least concavities of roughness on the roughened surface.

A low-friction coating includes: an aliphatic hydrocarbon group showing a peak in a region of 2,900 cm.sup.1 to 3000 cm.sup.1 in an infrared absorption spectrum; a carbonyl group showing a peak in a region of 1,650 cm.sup.1 to 1,800 cm.sup.1 in an infrared absorption spectrum; an aromatic component (C.sub.7H.sub.7.sup.+) showing a peak at mass 91.1 in a positive ion spectrum obtained by TOF-SIMS; and a condensed ring based component (C.sub.9H.sub.7.sup.+) showing a peak at mass 115.2 in the positive ion spectrum obtained by TOF-SIMS.

A rolling element bearing includes inner and outer rings having raceways and rolling elements between the raceways. The raceways of the inner and outer rings are coated with a first coating, such as a phosphate coating, and the rolling elements are coated with a second, different, coating such as a black oxide coating.