A machine has: an outer member; an inner member mounted for rotation about an axis relative to the outer member; and a seal system. The seal system has: a seal housing mounted to the outer member; one or more seal rings held by the seal housing and having an inner diameter surface; and a seal runner mounted to the inner member and having a first outer diameter surface portion contacting or facing the inner diameter surface of the one or more seal rings. The seal runner has a circumferential array of mounting features. One or more weights are mounted to one or more of the mounting features.

A method of operating a gas turbine engine of a multi-engine aircraft is disclosed, where the gas turbine engine has an engine shaft mounted for rotation in a bearing of a bearing assembly. The method comprises limiting motive power supplied to the aircraft by the gas turbine engine by operating the gas turbine engine in a standby mode; and when the gas turbine engine is operating in the standby mode, using an oil piston integrated in the bearing supporting the engine shaft of the gas turbine engine to generate an axial preload force on the bearing.

A gas turbine engine including a torque frame is provided. The torque frame includes an inner shroud defined circumferentially around the axial centerline, an outer shroud surrounding the inner shroud and defined circumferentially around the axial centerline, and a structural member extended along the radial direction and coupled to the inner shroud and the outer shroud. The torque frame is configured to rotate around the axial centerline.

The blades for a rotor of a gas turbine engine are all manufactured to the same design. However, manufacturing tolerances mean that in practice each individual blade is different to the others. It is proposed to arrange the blades around the circumference of the rotor in a manner that limits excessive stress being induced in the blades due to differences in the vibration response between a given blade and its two neighbouring blades.

A balance system for an assembled engine includes a rotor mounted on a shaft for rotation within an engine casing having an inner case and an outer case; and a weight system mounted on the shaft of the rotor and having at least one weight positionable relative to the rotor around a circumference of the shaft; wherein the inner case has an inner access port, the outer case has an outer access port, and the inner access port, the outer access port and the weight system are positioned on the same radial plane of the rotor, whereby the weight system can be accessed through the outer port and the inner port to adjust circumferential position of the at least one weight relative to the rotor.

A gas turbine engine includes a first spool including a first compressor coupled to a first turbine through a first shaft, a second spool including a second compressor coupled to a second turbine through a second shaft. A first tower shaft is coupled to the first shaft through a first gear assembly and a second tower shaft is coupled to the second shaft through a second gear assembly. A first load generating device is driven by the first tower shaft and a second load generating device is driven by the second tower shaft. A controller controls each of the first load generating device and the second load generating device to vary a proportion of the total load applied to each of the first spool and the second spool to bias a direction of an axial load on each of the first spool and the second spool.

A balancing weight is disclosed. The balancing weight is engageable in a hole defined in a rotor, the hole having a predetermined cross-sectional dimension. The balancing weight comprises: a head having a predetermined weight, and a shank extending axially from the head. The shank includes at least two portions expandable in a direction transverse to a hole engagement direction between a first position in which a cross-sectional dimension of the shank is less than the predetermined cross-sectional dimension of the hole and a second position in which the cross-sectional dimension of the shank is greater than the predetermined cross-sectional dimension of the hole in the rotor. A method for installing a balancing weight to an engine rotor is also disclosed.

According to an embodiment, a turbine comprises: a casing; a rotor shaft; turbine stages; a thrust bearing which receives thrust load in the axial direction generated by a flow of a working fluid supplied to the turbine stages; a balance piston which is formed on the rotor shaft along a circumferential direction and projects in a radial direction from the rotor shaft, for adjusting a thrust contact pressure; and a thrust load adjusting mechanism which applies pressures of a pressure-increasing side and a pressure-decreasing side to at least one of a balance piston inner-side chamber and a balance piston outer-side chamber which sandwich the balance piston in the axial direction.

A system includes a gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool. The system further includes a controller configured to cause fuel flow. The controller is operable to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.

A turbine engine having a drive shaft rotatable about an axis, a multi-stage compressor, a turbine section, a thrust bearing, and a balance cavity. The thrust bearing being provided between the drive shaft and at least a portion of the multi-stage compressor section and rotationally supporting the drive shaft. During operation of the turbine engine, a first axial force is applied to the thrust bearing by the drive shaft and a second axial force is applied to the thrust bearing in an opposite direction of the first axial force by the balance cavity.