An abnormality treatment apparatus includes: a sensor which outputs a signal upon detecting an event caused by contact of a rotor of a rotating machine during rotation of the rotor; and a control unit which executes at least one of rotation number control of reducing the number of rotations of the rotor step by step, liquid injection control of injecting liquid into a housing chamber of the rotor step by step, and pressure control of lowering a discharge pressure of the rotating machine step by step based on reception of the signal output from the sensor.

Centralizer apparatuses attached around a unison ring include rub buttons at inner ends of stud attached to and spaced apart from the unison ring and include rolling bearings. Each rolling bearing rotatably trapped within bearing chamber in bearing receptacle at inner end of stud. Tip cap includes bearing aperture trapping rolling bearing within bearing chamber. Rolling bearing extends partially through bearing aperture. Rolling bearing may be spring loaded within chamber by spring between the bearing receptacle and the rolling bearing. Stud may extend through and may be threaded into mounting aperture in unison ring and nut may be threaded onto outer end of stud. Variable stator vanes rotatably mounted to a casing and connected to vane crank arms connected to the unison ring mounted exterior to casing.

Centralizer apparatuses attached around a unison ring include rub buttons at inner ends of stud attached to and spaced apart from the unison ring and include rolling bearings. Each rolling bearing rotatably trapped within bearing chamber in bearing receptacle at inner end of stud. Tip cap includes bearing aperture trapping rolling bearing within bearing chamber. Rolling bearing extends partially through bearing aperture. Rolling bearing may be spring loaded within chamber by spring between the bearing receptacle and the rolling bearing. Stud may extend through and may be threaded into mounting aperture in unison ring and nut may be threaded onto outer end of stud. Variable stator vanes rotatably mounted to a casing and connected to vane crank arms connected to the unison ring mounted exterior to casing.

A system and method for rotor bow mitigation for a gas turbine engine are provided. An elapsed time since a shutdown of the engine and an idle operation time of the engine prior to the shutdown are determined. A rotor bow mitigation period is determined based on the elapsed time and the idle operation time and, prior to initiating a start sequence of the engine, the engine is motored for a duration of the rotor bow mitigation period.

A system and method for rotor bow mitigation for a gas turbine engine are provided. An elapsed time since a shutdown of the engine and an idle operation time of the engine prior to the shutdown are determined. A rotor bow mitigation period is determined based on the elapsed time and the idle operation time and, prior to initiating a start sequence of the engine, the engine is motored for a duration of the rotor bow mitigation period.

A method is provided of controlling a gas turbine having a shaft connecting a compressor to a turbine, as well as having a reheat system, and a gas turbine. The method includes the steps of: operating the engine using the reheat system to provide a mass flow rate of reheat fuel into a gas flow of the gas turbine engine downstream of an exit of the turbine; detecting a shaft break event in the shaft; and in response to this detection, maintaining the mass flow rate of the reheat fuel being provided into the gas flow downstream of the turbine exit, whereby the maintained mass flow rate of reheat fuel raises a back pressure downstream of the turbine and thereby reduces a rotational speed of the turbine.

An assembly for a turbomachine includes a fan rotor drive shaft, a rolling element and a support of an exterior rolling-element bearing ring including an exterior annular element as well as an interior annular element coupled through a decoupling interface in the shape of a truncated sphere and configured to be retained by friction under normal operating conditions of the turbomachine, and to move with respect to one another in the event of a fan blade loss. The rolling-element bearing is designed so that each rolling element has four points of contact with the rings, and so that the interface between the ring and the support has a hollowed space for deformation routed around a central portion of the exterior ring.

An assembly for a turbomachine includes a fan rotor drive shaft, a rolling element and a support of an exterior rolling-element bearing ring including an exterior annular element as well as an interior annular element coupled through a decoupling interface in the shape of a truncated sphere and configured to be retained by friction under normal operating conditions of the turbomachine, and to move with respect to one another in the event of a fan blade loss. The rolling-element bearing is designed so that each rolling element has four points of contact with the rings, and so that the interface between the ring and the support has a hollowed space for deformation routed around a central portion of the exterior ring.

A fan is mounted on a fan shaft which constitutes part of a mainline shaft assembly centered for rotation on an engine axis X-X of a gas turbine engine. When in operation, the fan rotates about the engine axis X-X. A stub-shaft is arranged radially outwardly and concentrically with the fan shaft and adjoins an upstream facing face of a bearing sleeve. A fan catcher arm extends from the stub-shaft through the bearing sleeve and joins a fan catcher ring arranged downstream of the bearing sleeve and having an upstream facing face arranged to abut against a downstream facing face of the bearing sleeve in the event of a fan blade-off. Immediately downstream of the fan catcher ring is formed a shaft end which is configured to couple with an axially adjacent end of a low pressure compressor shaft. Immediately downstream of the bearing sleeve is a shaft end configured to connect with a turbine shaft.

A fan is mounted on a fan shaft which constitutes part of a mainline shaft assembly centered for rotation on an engine axis X-X of a gas turbine engine. When in operation, the fan rotates about the engine axis X-X. A stub-shaft is arranged radially outwardly and concentrically with the fan shaft and adjoins an upstream facing face of a bearing sleeve. A fan catcher arm extends from the stub-shaft through the bearing sleeve and joins a fan catcher ring arranged downstream of the bearing sleeve and having an upstream facing face arranged to abut against a downstream facing face of the bearing sleeve in the event of a fan blade-off. Immediately downstream of the fan catcher ring is formed a shaft end which is configured to couple with an axially adjacent end of a low pressure compressor shaft. Immediately downstream of the bearing sleeve is a shaft end configured to connect with a turbine shaft.