A composite ring includes a first region including a first polymeric material; a second region including a second polymeric material; and an interfacial region defining a compositional gradient between the first region and the second region; wherein a wear resistance of the first region is different from a wear resistance of the second region. A composite bearing includes a first layer including a first polymeric material and a first filler; a second layer disposed on the first layer, the second layer including a second polymeric material and a second filler; and an interfacial region defining a compositional gradient between the first layer and the second layer, wherein a wear resistance of the first layer is greater than a wear resistance of the second layer, and wherein a mechanical strength of the second layer is greater than a mechanical strength of the first layer.

A gas turbine engine with a rotor having a shaft mounted to the engine with a plurality of electrically insulating bearings is provided. The electrically insulating bearings are coupled to the shaft to support the rotor in the engine. There is at least one electrically conductive bearing coupled to the shaft and that further support the rotor in the engine. An electrically conductive path is defined between the rotor and an electrical ground of the engine. The electrically conductive path is defined through the electrically conductive bearing to reach the electrical ground of the engine. A method for electrostatically discharging a rotor supported in the gas turbine engine is also provided.

The present invention provides an all-ceramic joint bearing used in a high-temperature, corrosion and oxidation-prone environment, which mainly includes an inner ring and an outer ring which are made of zirconia, alumina or silicon carbide ceramic materials. The all-ceramic joint bearing is assembled into a whole through corresponding assembly technologies. An inner side of the outer ring is an inner arc surface, and the inner ring is an outer arc surface. A width of the inner ring is 3-5 mm greater than that of the outer ring, and a movable swing angle of the inner ring is 0-21. The joint bearing made of the ceramic materials has an optimized structure by utilizing the ceramic material characteristics of high temperature resistance, corrosion resistance, high hardness, non-magnetic permeability, wear resistance and self-lubrication.

A bearing liner includes a binder with a resin material, a pre-preg, a structural yarn and a lubricating yarn, and particles of aluminum oxide (Al.sub.2O.sub.3). The particles of aluminum oxide may be embedded within the binder or within the lubricating yarn, or may be embedded within both the binder and the lubricating yarn. A plain bearing includes an inner ring, an outer ring and such a liner interposed or disposed between the rings.

A rolling-element bearing includes a first ring element, a second ring element, a plurality of rolling elements rotatably disposed between the first ring element and the second ring element, and an electrically insulating layer on a surface of the first ring element. The electrically insulating layer is a ceramic layer containing a mixture of aluminum oxide (Al.sub.2O.sub.3) and titanium oxide, and the insulating layer includes titanium compounds that contain reduced titanium oxide (TiO.sub.x) and/or metallic titanium (Ti), and the insulating layer further includes a cured synthetic resin sealer.

A non-conventional, low temperature, process for applying a thin electrically insulating coating arrangement with high density, high purity, minimal porosity, and improved adhesion strength to a steel bearing component is provided. The bearing component is formed from steel and machined or otherwise formed to a near net shape. A high purity aluminum is electro-chemically deposited on the steel bearing component using a non-aqueous electrolyte in an inert environment to form a high purity aluminum coating at least over a portion of the steel bearing component. A surface of the high purity aluminum coating is then converted by an acid-bath into aluminum oxide to form an insulating layer. A bearing component and a bearing having such components is also provided.

A gas turbine engine with a rotor having a shaft mounted to the engine with a plurality of electrically insulating bearings is provided. The electrically insulating bearings are coupled to the shaft to support the rotor in the engine. There is at least one electrically conductive bearing coupled to the shaft and that further support the rotor in the engine. An electrically conductive path is defined between the rotor and an electrical ground of the engine. The electrically conductive path is defined through the electrically conductive bearing to reach the electrical ground of the engine. A method for electrostatically discharging a rotor supported in the gas turbine engine is also provided.

A method for coating a turbomachine part with a self-lubricating includes: providing a rotor or thrust disc of the turbomachine; applying, by a thermal spraying process, a self-lubricating coating having of a mixture of 50 to 90 wt % of alumina (Al.sub.2O.sub.3) with titanium oxide (TiO.sub.2) to a surface of the rotor and/or a surface; and finishing the coated surface of the rotor and/or thrust disc.

A method of providing electrical discharge machining protection for a bearing is provided. The method includes (a) providing a bearing ring, (b) ionizing pure aluminum and depositing a pure aluminum layer on at least a portion of the bearing ring, (c) immersing the bearing ring in acid to convert the pure aluminum layer to an aluminum oxide layer, and (d) immersing the bearing ring in deionized water to seal the aluminum oxide layer.

The invention relates to a sliding element having a coating, which comprises at least one functional layer, said functional layer having a mixed oxide-matrix and in the mixed-oxide matrix and solid lubricant particles and/or hard particles are embedded in the mixed oxide-matrix.