Abstract: A turbine blade includes a base and an airfoil. The airfoil includes a skin extending from the base and defining a leading edge and a trailing edge opposite the leading edge. The trailing edge includes an inner edge disposed proximate to the base, an outer edge disposed distal the inner edge, and a tuning region edge disposed between the inner edge and the outer edge. The tuning region edge includes an upper transition edge, a middle transition edge, a lower transition edge, an upper tuning edge, and a middle tuning edge. The upper transition edge extends from the outer edge towards the inner edge. The middle transition edge is disposed between the upper transition edge and the inner edge. The lower transition edge is disposed between the middle transition edge and the inner edge. The upper tuning edge is disposed between the upper transition edge and the middle transition edge, being at least partially closer to the leading edge than the middle transition edge.

Abstract: A turbine blade includes a base and an airfoil. The airfoil includes a skin extending from the base and defining a leading edge and a trailing edge opposite the leading edge. The trailing edge includes an inner edge disposed proximate to the base, an outer edge disposed distal the inner edge, and a tuning region edge disposed between the inner edge and the outer edge. The tuning region edge includes an upper transition edge, a middle transition edge, a lower transition edge, an upper tuning edge, and a middle tuning edge. The upper transition edge extends from the outer edge towards the inner edge. The middle transition edge is disposed between the upper transition edge and the inner edge. The lower transition edge is disposed between the middle transition edge and the inner edge. The upper tuning edge is disposed between the upper transition edge and the middle transition edge, being at least partially closer to the leading edge than the middle transition edge.

Abstract: A method of analyzing graphene includes providing a first graphene structure including graphene having grains and grain boundaries, and a support portion for supporting the graphene, generating a second graphene structure by oxidizing the first graphene structure, and detecting a shape of the graphene.

Abstract: A method of analyzing graphene includes providing a first graphene structure including graphene having grains and grain boundaries, and a support portion for supporting the graphene, generating a second graphene structure by oxidizing the first graphene structure, and detecting a shape of the graphene.

Abstract: Tapered roller bearings and gas turbine engine systems involving such bearings are provided. In this regard, a representative bearing cage for a gas turbine engine includes: an outer cage rim and an inner cage rim; the outer cage rim having a rounded edge at a location of contact between the outer cage rim and a roller.

Abstract: Tapered roller bearings and gas turbine engine systems involving such bearings are provided. In this regard, a representative bearing cage for a gas turbine engine includes: an outer cage rim and an inner cage rim; the outer cage rim having a rounded edge at a location of contact between the outer cage rim and a roller.

Abstract: Tapered roller bearings and gas turbine engine systems involving such bearings are provided. In this regard, a representative bearing cage for a gas turbine engine includes: an outer cage rim and an inner cage rim; the outer cage rim having a rounded edge at a location of contact between the outer cage rim and a roller.

Abstract: A method of constructing an integral coupling system containing a sun gear is disclosed. An integral sun gear is provided that has a sun gear component and a connection shaft. A first straight flat inner edge is machined on a first diaphragm to use as a datum point, and then the straight flat edge is fixtured. A tapered outer edge is machined on the first diaphragm, and the first diaphragm is welded to the integral sun gear. The flat inner edge is generally perpendicular to a central axis of the connection shaft.

Abstract: A coupling system for connecting a sun gear to a shaft within a planetary gear train, includes a sun gear coupling connecting the sun gear to the shaft. The sun gear coupling has at least one undulant flexible section joined to an inflexible spindle for accommodating misalignment between the sun gear and the shaft. The flexible section comprises a cylindrical ring having a diameter greater than the diameter of the spindle, and joined to the spindle by two longitudinally spaced apart diaphragms. The juncture between the diaphragms, the ring, and the spindle is curved in cross section on an outer side to improve flexibility and minimize stress concentrations, and the inner sides of the diaphragms are straight edges which result in a non-symmetric contour of the diaphragm walls.

Abstract: A coupling system for connecting a sun gear to a shaft within a planetary gear train, includes a sun gear coupling connecting the sun gear to the shaft. The sun gear coupling has at least one undulant flexible section joined to an inflexible spindle for accommodating misalignment between the sun gear and the shaft. The flexible section comprises a cylindrical ring having a diameter greater than the diameter of the spindle, and joined to the spindle by two longitudinally spaced apart diaphragms. The juncture between the diaphragms, the ring, and the spindle is curved in cross section on an outer side to improve flexibility and minimize stress concentrations, and the inner sides of the diaphragms are straight edges which result in a non-symmetric contour of the diaphragm walls.

Abstract: A method of constructing an integral coupling system containing a sun gear is disclosed. An integral sun gear is provided that has a sun gear component and a connection shaft. A first straight flat inner edge is machined on a first diaphragm to use as a datum point, and then the straight flat edge is fixtured. A tapered outer edge is machined on the first diaphragm, and the first diaphragm is welded to the integral sun gear. The flat inner edge is generally perpendicular to a central axis of the connection shaft.

Abstract: A coupling system for connecting a sun gear to a shaft within a planetary gear train, includes a sun gear coupling connecting the sun gear to the shaft. The sun gear coupling has at least one undulant flexible section joined to an inflexible spindle for accommodating misalignment between the sun gear and the shaft. The flexible section comprises a cylindrical ring having a diameter greater than the diameter of the spindle, and joined to the spindle by two longitudinally spaced apart diaphragms. The juncture between the diaphragms, the ring, and the spindle is curved in cross section on an outer side to improve flexibility and minimize stress concentrations, and the inner sides of the diaphragms are straight edges which result in a non-symmetric contour of the diaphragm walls.

Abstract: Tapered roller bearings and gas turbine engine systems involving such bearings are provided. In this regard, a representative bearing cage for a gas turbine engine includes: an outer cage rim and an inner cage rim; the outer cage rim having a rounded edge at a location of contact between the outer cage rim and a roller.

Abstract: An airfoil for a gas turbine engine component such as a turbine blade is tuned to move its natural frequency outside of a frequency which will be excited during expected speed range of an associated gas turbine engine. The airfoil is tuned about locations of the anti-nodes in an original airfoil design. The tuning affects only the interfered frequency.

Abstract: A coupling system for connecting a sun gear to a shaft within a planetary gear train, includes a sun gear coupling connecting the sun gear to the shaft. The sun gear coupling has at least one undulant flexible section joined to an inflexible spindle for accommodating misalignment between the sun gear and the shaft. The flexible section comprises a cylindrical ring having a diameter greater than the diameter of the spindle, and joined to the spindle by two longitudinally spaced apart diaphragms. The juncture between the diaphragms, the ring, and the spindle is curved in cross section on an outer side to improve flexibility and minimize stress concentrations, and the inner sides of the diaphragms are straight edges which result in a non-symmetric contour of the diaphragm walls.

Abstract: A planetary carrier includes a journal bearing for supporting a planetary gear. The journal bearing receives lubricant to produce a lubricant film to support gear loads. A torque frame is attached to the carrier housing to transmit torque and to prevent twisting of the carrier housing. The torque frame includes several lubricant communication passages to provide lubricant to each of the separate journal bearings. Each of the lubricant communication passages includes an accumulator for storing lubricant during normal operation. The accumulator stores a desired amount of lubricant to provide lubricant to the adjacent journal bearing for the interim period between primary system stoppage and reestablishment of lubricant flow by a secondary system.

Abstract: A journal bearing system includes a bushing and a journal pin within the bushing. At least one of the bushing and journal pin has an engagement surface with an engagement length comprising a substrate material and a solid lubricant. A concentration of the solid lubricant varies along the engagement length.