Abstract: The proposed vibrational energy harvester comprises a frame (118), a mass (114) coupled to first and second primary flexures (110, 112) which are configured to flex and allow the mass to move in a first direction (130), a plurality of secondary flexures (120, 122) which are configured to flex and allow the mass to move in a different second direction (132), and a transduction assembly configured to convert movement of the mass and flexures into electrical energy, preferably of electrodynamic or piezoelectric type. Each of the primary flexures is coupled to a secondary flexure at a position spaced from the mass. The resonant frequency of torsional vibration modes can thereby be raised to a frequency higher than the frequency band of ambient vibrations, which effectively prevents the energy harvester from vibrating in undesirable torsional modes that would result in wear between components.

Abstract: A shaft assembly comprises a first shaft portion, connected to a second shaft portion by a flexible coupling. The first shaft portion is further connected to the second shaft portion by a frangible coupling with the frangible coupling being configured to fail if a torsional load through the frangible coupling exceeds a predetermined maximum torsional load. The flexible coupling allows an angular misalignment between the first and second shaft portions not exceeding a maximum angular misalignment.

Abstract: A method of reducing dynamic imbalance in a bladed rotor assembly by axially adjusting one or more of the blades so as to redistribute mass along the geometric axis of the assembly. The blades may be axially adjusted to form a counterbalancing couple. Additional correction masses may be added for supplemental correction of couple imbalance or residual static imbalance in the bladed rotor assembly. The invention offers a reduction in the weight penalty associated with conventional balancing corrections carried out on the bladed rotor assembly.

Abstract: A shaft assembly comprises a first shaft portion, connected to a second shaft portion by a flexible coupling. The first shaft portion is further connected to the second shaft portion by a frangible coupling with the frangible coupling being configured to fail if a torsional load through the frangible coupling exceeds a predetermined maximum torsional load. The flexible coupling allows an angular misalignment between the first and second shaft portions not exceeding a maximum angular misalignment.

Abstract: A method of reducing dynamic imbalance in a bladed rotor assembly by axially adjusting one or more of the blades so as to redistribute mass along the geometric axis of the assembly. The blades may be axially adjusted to form a counterbalancing couple. Additional correction masses may be added for supplemental correction of couple imbalance or residual static imbalance in the bladed rotor assembly. The invention offers a reduction in the weight penalty associated with conventional balancing corrections carried out on the bladed rotor assembly.

Abstract: In a device for measuring the complete polarization state of light over a spectral bandwidth, an optical input signal (41) with wavelengths of light within a spectral band is incident on two or more diffraction gratings (42, 44, 46, 48), or incident from at least two directions on one or more diffraction gratings (72, 74), and the intensity is measured as a function of wavelength for at least four of the diffraction spectra produced by the grating(s). The polarization state of light is then calculated as a function of wavelength over the spectral bandwidth from the intensity measurements.

Abstract: In a device for measuring the complete polarization state of light over a spectral bandwidth, an optical input signal (41) with wavelengths of light within a spectral band is incident on two or more diffraction gratings (42, 44, 46, 48), or incident from at least two directions on one or more diffraction gratings (72, 74), and the intensity is measured as a function of wavelength for at least four of the diffraction spectra produced by the grating(s). The polarization state of light is then calculated as a function of wavelength over the spectral bandwidth from the intensity measurements.