Abstract: A method and apparatus for measuring the vibration of rotating blades, such as turbines, compressors, fans, or pumps, including sensing the return signal from projected energy and/or field changes from a plurality of sensors mounted on the machine housing. One or more of the sensors has a narrow field of measurement and the data is processed to provide the referenced time of arrival of each blade, and therefore the blade tip deflection due to vibration. One or more of the sensors has a wide field of measurement, providing a time history of the approaching and receding blades, and the data is processed to provide frequency content and relative magnitudes of the active mode(s) of blade vibration. By combining the overall tip deflection magnitude with the relative magnitudes of the active modes, the total vibratory stress state of the blade can be determined.

Abstract: A method and apparatus for measuring the vibration of rotating blades, such as turbines, compressors, fans, or pumps, including sensing the return signal from projected energy and/or field changes from a plurality of sensors mounted on the machine housing. One or more of the sensors has a narrow field of measurement and the data is processed to provide the referenced time of arrival of each blade, and therefore the blade tip deflection due to vibration. One or more of the sensors has a wide field of measurement, providing a time history of the approaching and receding blades, and the data is processed to provide frequency content and relative magnitudes of the active mode(s) of blade vibration. By combining the overall tip deflection magnitude with the relative magnitudes of the active modes, the total vibratory stress state of the blade can be determined.

Abstract: The invention relates to a device for extracting energy from waves and having a pump arranged to be operated by relative motion between members of the device in response to waves. The pump according to the invention has a pump body with a flexible portion extending between the members so as to define a pump chamber having a volume which varies as a result of the aforesaid relative motion. In one form of the invention the pump body is provided by a tubular bellows comprising elastomeric material. A plurality of such pumps may be disposed between the members, each pump being activated by said relative motion.

Abstract: The invention relates to a device for extracting energy from waves, the device having a pump or a number of pumps arranged to be operated by relative motion between hingedly connected members of the device in response to waves so as to displace a fluid. The device according to the invention is provided with a vane pump having a pump chamber defined by one of the members and a vane extending from an adjacent member so as to be displaced in the pump chamber by the relative motion of the members to displace the fluid. The members may be hingedly connected together at a number of locations at which a respective bearing is supported by a resiliently flexible mounting.