Abstract: A turbine apparatus comprises a rotor with a hub section defined about a rotational axis and a plurality of blades attached to the hub section. The plurality of blades comprises a first group having a first angular spacing in a first circumferential sector of the rotor, and a second group having a second angular spacing in a second circumferential sector of the rotor. The first angular spacing is different from the second angular spacing, and the rotor blades are asymmetric about the rotational axis.

Abstract: An example method of designing blade lobes of a turbomachine blade and corresponding disk lobes includes determining contact areas between the blade lobes on a blade model and the disk loads on a disk model when the turbomachine blade is in a loaded position. The method adjusts the blade lobes, the disk lobes, or both, so that gaps are established between the blade lobes and the disk lobes at the contact areas when the turbomachine blade is in an unloaded position. The size of the gaps varies.

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 radial-flow turbine wheel for a gas turbine engine includes a Scallop Radius defined between an axis of rotation and the backface between each of the plurality of turbine blades, a Tip Radius defined between the axis of rotation and a tip of each of the plurality of turbine blades such that a Scallop Radius/Tip Radius defines a ratio less than 0.6. This enables a lower temperature scallop region which drives lower transient stresses and increases the Low Cycle Fatigue life of the turbine wheel.

Abstract: A method of compensating for load-induced twisting of a gear assembly under load that includes a gear on a gear shaft, bearings on each side of the gear that support the gear shaft and a carrier fastened to a stationary support surface that mounts a proximal one of the bearings near the stationary support surface and mounts a distal one of the bearings away from the stationary support surface. The method includes the steps of determining the twisting deflection of a distal bearing axis of rotation for the distal bearing relative to a proximal bearing axis of rotation for the proximal bearing and offsetting the position of the distal bearing axis of rotation relative to the proximal bearing axis of rotation in the carrier opposite the determined deflection under no gear loading.

Abstract: An impeller shroud is configured to receive an impeller. The impeller shroud establishes a plurality of air-bleed holes configured to communicate air with an impeller. The air-bleed holes are circumferentially distributed about the impeller shroud. The circumferential spacing between some adjacent air-bleed holes within the plurality of air-bleed holes is different than the circumferential spacing between other adjacent air-bleed holes within the plurality of air-bleed holes. A diffuser vane is configured to direct pressurized air to the combustor, the diffuser vanes are circumferentially distributed about the blade exducer. The circumferential spacing between some adjacent diffuser vanes within the plurality of diffuser vanes is different than the circumferential spacing between other adjacent diffuser vanes within the plurality of diffuser vanes.

Abstract: A variable vane system includes a plurality of vanes each being pivotal about an axis. A mechanical linkage drives the plurality of vanes to rotate about the axis. The mechanical linkage includes a ring gear to rotate, and in turn drive the plurality of vanes. There is at least one rod to drive the ring gear to rotate. The rod is driven by a hydraulic servo motor. A spring bias force is provided in the mechanical linkage to resist either translational or rotational oscillation.

Abstract: A rotor bearing system for a rotating machine includes a housing having a bore that provides an inner surface. A bearing assembly is disposed within the bore and includes an outer surface. An annular cavity is provided radially between the outer surface and the inner surface. At least one protrusion extends radially outwardly from at least one of the inner and outer surfaces to an apex and into the annular cavity. A radial gap is arranged between the apex and the opposite surface from which the protrusion extends. In the disclosed example, the annular cavity is filled with an oil to provide a squeeze film damper between the housing and the bearing assembly. The protrusions exert a hydrodynamic preload on the bearing assembly, which reduces vibration during operation of the rotating machine.

Abstract: A gas turbine engine (10) provides a differential gear system (58) coupling the turbine (20) to the bypass fan (14) and the compressor (16). In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear (74), which drives a planet carrier (78) and a ring gear (80) in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

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.