Abstract: A bearing arrangement (30) comprises an inner support annulus (33), an outer support annulus (31), and a plurality of rollers (34) therebetween. At least one of the inner and the outer support annulus (33, 31) comprises one or more radially extending rigid supports (37) and one or more damping sectors (38a, 38b, 38c). The one or more rigid supports (37) are circumferentially interposed between one or more damping sectors (38a, 38b, 38c). Each damping sector (38a, 38b, 38c) comprises at least one damping member (39) comprising an elongate flexible member held rigidly at one or both ends thereof, such that vibrational movement of the inner or outer support annulus (33, 31) causes bending of the elongate flexible members (39).

Abstract: A bearing arrangement (30) comprises an inner support annulus (33), an outer support annulus (31), and a plurality of rollers (34) therebetween. At least one of the inner and the outer support annulus (33, 31) comprises one or more radially extending rigid supports (37) and one or more damping sectors (38a, 38b, 38c). The one or more rigid supports (37) are circumferentially interposed between one or more damping sectors (38a, 38b, 38c). Each damping sector (38a, 38b, 38c) comprises at least one damping member (39) comprising an elongate flexible member held rigidly at one or both ends thereof, such that vibrational movement of the inner or outer support annulus (33, 31) causes bending of the elongate flexible members (39).

Abstract: A method of determining the torque induced in a rotating shaft (51), the shaft (51) having a torsional oscillation frequency that is dependent on the stiffness of the shaft (51), where the torsional oscillation frequency and the stiffness are dependent upon the operating conditions of the shaft (51), the method comprising: measuring (35) the torsional oscillation frequency of the rotating shaft; measuring (39) the twist induced in the rotating shaft (51) by the torque; and using (41) the measured value of the torsional oscillation frequency and the measured value of the induced twist to determine the torque induced in the shaft (51).

Abstract: A method of measuring temperature of a component capable of emitting thermal radiation and reflecting background radiation having the steps of: providing a pyrometer for measuring the radiation from the component, characterised by coating a part of the component with a first emissivity coating and a part of the component with a different and second emissivity coating, each with known emissivities EH and EL respectively, recording a first radiation measurement from the first emissivity coating RH and a second radiation measurement from the second emissivity coating RL, then calculating the true radiation RBlade from the component from the equation R Blade = ( R H E H - R L E H ? ( 1 - E H 1 - E L ) ) ( 1 - E L E H ? ( 1 - E H 1 - E L ) ) and relate the RBlade value to the true component temperature by calibration of the pyrometer.

Abstract: A method of measuring temperature of a component capable of emitting thermal radiation and reflecting background radiation comprising the steps of: providing a pyrometer for measuring the radiation from the component, characterised by coating a part of the component with a first emissivity coating and a part of the component with a different and second emissivity coating, each with known emissivities EH and EL respectively, recording a first radiation measurement from the first emissivity coating RH and a second radiation measurement from the second emissivity coating RL, then calculating the true radiation RBlade from the component from the equation 1 R Blade = ( R H E H - R L E H ⁢ ( 1 - E H 1 - E L ) ) ( 1 - E L E H ⁢ ( 1 - E H 1 - E L ) )

Abstract: A method of characterizing the vibration of a plurality of rotating blades (12), such as turbine blades in a gas turbine engine, includes the steps of providing a single strain gauge (16A) on a single one (12A) of the blades and providing either one or two tip timing probes (22A, 22B) on a casing surrounding the blades. The data from the strain gauge (16A) allows the vibration of the single blade (12A) to be fully characterized while the data from the tip timing probes (22A, 22B) allows the amplitudes or velocities of vibration of all the blades to be determined. The relationship between the data from the tip timing probes for the single blade (12A) and the stress data from the strain gauge may be established. This relationship may then be assumed to apply to all the blades, thus allowing the stresses induced in all the blades by the vibrations to be determined.

Abstract: A method of characterizing the vibration of a plurality of rotating blades (12), such as turbine blades in a gas turbine engine, includes the steps of providing a single strain gauge (16A) on a single one (12A) of the blades and providing either one or two tip timing probes (22A, 22B) on a casing surrounding the blades. The data from the strain gauge (16A) allows the vibration of the single blade (12A) to be fully characterized while the data from the tip timing probes (22A, 22B) allows the amplitudes or velocities of vibration of all the blades to be determined. The relationship between the data from the tip timing probes for the single blade (12A) and the stress data from the strain gauge may be established. This relationship may then be assumed to apply to all the blades, thus allowing the stresses induced in all the blades by the vibrations to be determined.