Curved beams stacked structures-compliant shrouds for gas turbine engines are disclosed. An example shroud assembly comprising a plurality of concave curved beams, a plurality of convex curved beams, and a plurality of bumpers, wherein a first concave curved beam of the plurality of concave curved beams is inversely coupled to a first convex curved beam of the plurality of convex curved beams, a second concave curved beam of the plurality of concave curved beams, inversely coupled to a second convex curved beam of the plurality of convex curved beams, the first and second concave curved beams configured to stack on top of the first and second convex curved beams, a first bumper of the plurality of bumpers coupled to the first and second concave curved beams, and a second bumper of the plurality of bumpers coupled to the first and second convex curved beams.

Curved beams stacked structures-compliant shrouds for gas turbine engines are disclosed. An example shroud assembly comprising a plurality of concave curved beams, a plurality of convex curved beams, and a plurality of bumpers, wherein a first concave curved beam of the plurality of concave curved beams is inversely coupled to a first convex curved beam of the plurality of convex curved beams, a second concave curved beam of the plurality of concave curved beams, inversely coupled to a second convex curved beam of the plurality of convex curved beams, the first and second concave curved beams configured to stack on top of the first and second convex curved beams, a first bumper of the plurality of bumpers coupled to the first and second concave curved beams, and a second bumper of the plurality of bumpers coupled to the first and second convex curved beams.

A power transmission system includes a shaft, a stator disposed within the shaft and substantially concentric with the shaft; and at least one supporting element positioned between the stator and the shaft and configured to support the shaft on the stator to reduce a vibration of the shaft and allow the shaft to rotate relative to the stator. A gas turbine engine including the power transmission system is also described.

A power transmission system includes a shaft, a stator disposed within the shaft and substantially concentric with the shaft; and at least one supporting element positioned between the stator and the shaft and configured to support the shaft on the stator to reduce a vibration of the shaft and allow the shaft to rotate relative to the stator. A gas turbine engine including the power transmission system is also described.

A gear reduction reduces a speed of a fan rotor relative to a speed of a fan drive turbine. A fan case surrounds the fan rotor. A core engine has a compressor section and includes a low pressure compressor. The fan rotor delivers air into a bypass duct defined between the fan case and the core engine. A rigid connection between the fan case and the core engine includes a plurality of aft connecting members rigidly connected to the fan case, and to the core engine. A plurality of fan exit guide vanes are rigidly connected to the fan case, with the fan exit guide vanes including structural fan exit guide vanes which are rigidly connected to the core engine, and non-structural fan exit guide vanes, and the non-structural fan exit guide vanes being provided with an acoustic feature to reduce noise.

The invention relates to a method and a set of balance weights for balancing a rotor particularly of a turbomachine, on which a plurality of balance weights, which are distributed over the periphery, can be arranged for balancing an imbalance. A set of balance weights, in particular plate-shaped weights, with a predetermined number of groups of balance weights, is used for balancing the rotor. Each of the balance weights of every group of balance weights has an identical weight that is assigned to this group and a shape assigned to this group, which differs in basic shape and/or thickness of the balance weights from the balance weights of the other groups.

A system (1) for vibration management comprises a stator (24, 45); a rotor (26) being mounted rotatably with respect to the stator (24, 45) about a rotational axis (9); one or more active devices (41A-41C) adapted to apply forces and/or moments on the rotor (26) and/or on the stator (24, 45); at least two sensors (42) for measuring vibrational parameter values with respect to two or more different positions, particularly along the rotational axis (9); and a controller (44) adapted to provide control signals to the one or more active devices (41A-41C) based on the vibrational parameter values of the at least two sensors (42) and on the respective position.

Embodiments of the invention are shown in the figures, where a system for vibration detection is shown, the system comprising: one or more drivelines including a rotatable component rotatable about a rotational axis relative to another component; an electrical machine having a rotor and a stator rotatable with respect to one another, the rotor being arranged to at least one of drive and be driven by a part of the driveline, the electrical machine being adapted to provide signals indicative for at least one of a motion and a force between the rotor and the stator and a torque applied on the rotor; and an analysis unit adapted to receive the signals and to detect a vibration signature of the rotatable component with respect to the other component based on the signals.

A turbomachine airfoil element includes an airfoil that has pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 3.46-3.76 inch (87.8-95.5 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 1.98-2.28 inch (50.2-57.8 mm). The airfoil element includes at least one of a first mode with a frequency of 1056 ± 10% Hz and a second mode with a frequency of 1582 ± 10% Hz.

A turbomachine airfoil element includes an airfoil that has pressure and suction sides spaced apart from one another in a thickness direction and joined to one another at leading and trailing edges. The airfoil extends in a radial direction a span that is in a range of 3.46-3.76 inch (87.8-95.5 mm). A chord length extends in a chordwise direction from the leading edge to the trailing edge at 50% span and is in a range of 1.98-2.28 inch (50.2-57.8 mm). The airfoil element includes at least one of a first mode with a frequency of 1056 ± 10% Hz and a second mode with a frequency of 1582 ± 10% Hz.