Rolls-royce Corporation

Ralph W Hill

Jonathan E Holt

Roger Alexander Sutherland

Christopher D Jack

Colin Richard Barnfather

A monitoring system for monitoring one or more properties associated with a rotating shaft is provided. The system includes a first phonic wheel which is mounted coaxially to the shaft for rotation therewith, the first phonic wheel comprising a circumferential row of teeth. The system further includes a first sensor configured to detect the passage of the row of teeth of the first phonic wheel by generating a first alternating measurement signal. The system further includes a processor unit configured to determine the durations of successive first speed samples. Each first speed sample is a block of n successive cycles of the first alternating measurement signal, where n is an integer, and in which the beginning of each cycle is a zero-crossing point from the previous cycle and the end of each cycle is the corresponding zero-crossing point to the next cycle. At least one axial location of the first phonic wheel every mtooth of the row of teeth of the first phonic wheel has a circumferential thickness which is different from that of the other teeth of the first phonic wheel, where m is an integer, m&#x2260;n, and m is neither a factor nor a multiple of n. When the first sensor is positioned at said axial location of the first phonic wheel and at any given rotational speed of the first phonic wheel, the durations of the successive first speed samples display a characteristic repeating pattern of longer and shorter sample durations relative to the average duration of the successive first speed samples. The amount by which the longer and shorter sample durations differ from the average duration is in proportion to the amount by which the circumferential thickness of the mteeth differs from that of the other teeth at said axial location of the first phonic wheel. The processor unit monitors the properties associated with the rotating shaft from the characteristic repeating pattern.

Shaft monitoring system

A fault-accommodating flow scheduling valve has a first inlet, outlet, and orifice therebetween. The valve has a shuttle valve member on the orifice inlet side, a primary valve member on the orifice outlet side, a compression-loaded primary spring, and first and second compression-loaded balance springs. Below a threshold differential pressure, the primary valve member engages with the outlet-side sealing face to close the valve while the shuttle valve member is spaced from the inlet-side sealing face, and on failure of the primary spring, the primary valve member moves from the outlet-side sealing face but the shuttle valve member closes the valve. Above the threshold differential pressure, the primary valve member opens the valve while the shuttle valve member remains spaced, and on failure of the primary spring, the primary valve member moves further from the outlet-side sealing face but the shuttle valve member closes the valve.

Fault-accommodating flow scheduling valve

A combustion staging system for fuel burners of a multi-stage combustor of a gas turbine engine is provided. The system has pilot and mains fuel manifolds respectively distributing fuel to pilot and mains stages of the burners. The system further has a plurality of check valves through which the mains manifold feeds fuel to the respective burners. The check valves are arranged to open when the fuel pressure within the mains manifold exceeds a predetermined fuel pressure relative to gas pressure in the combustor. The system further has a splitting unit which receives a metered fuel flow and controllably splits the received fuel flow into pilot and mains flows which are sent respectively to the pilot and mains fuel manifolds to perform staging control of the combustor. The splitting unit is operable to select the pilot manifold and to deselect the mains manifold for pilot-only operation in which there is a pilot supply to the combustor but no mains supply to the combustor from the burners. It is also operable to select both the pilot and mains manifolds for pilot and mains operation in which there are pilot and mains supplies to the combustor from the burners. The system further has a cooling flow recirculation line having a delivery section arranged to provide a cooling flow of fuel to the mains manifold when that manifold is deselected so that the deselected mains manifold remains primed with relatively cool fuel, and a return section arranged to collect the cooling flow from the mains manifold. The system further has a gas pressure sensor configured to measure gas pressure in the combustor, a speed sensor which measures a rotation speed of a rotor of the engine, and a control unit which, when the mains manifold is deselected for pilot-only operation, (i) compares the measured rotation speed with a predicted rotation speed for the metered fuel flow, and compares the measured gas pressure with a predicted gas pressure for the metered fuel flow, and (ii) is adapted to close off the recirculation line when the results of these comparisons are indicative of leakage of fuel from the cooling fuel flow into the combustor through one or more of the check valves.

Combustion staging system

A combustion staging system for fuel injectors of a multi-stage combustor of a gas turbine engine has pilot and mains fuel manifolds distributing fuel to the injectors. A splitting unit splits a fuel flow and sends portions of the flow to pilot and mains fuel manifolds to perform staging control of the combustor. The splitting unit can deselect the mains manifold so that there is no flow into the combustor from the mains manifold. A cooling flow recirculation line provides a cooling flow of fuel to the mains manifold when that manifold is deselected so that the mains manifold remains primed with relatively cool fuel. A return section collects the cooling flow from the mains manifold. One or more fuel pressure sensors detect pressure of the cooling flow on the recirculation line. A control arrangement closes off the recirculation line when the pressure sensor(s) indicates failure of the cooling flow.

A clearance control apparatus for controlling the clearance between a rotary assembly () and a casing () surrounding the rotary assembly () is disclosed. The clearance control apparatus comprises a temperature measuring device () to measure the temperature of a radially outer portion of the rotary assembly and a cooling arrangement () to cool the casing (). A control system () is associated with the temperature measuring device () and the cooling arrangement () to control the extent of cooling of the casing (). The extent of cooling is dependent upon the temperature of the aforesaid portion.

Growing community of inventors

Matlock, United Kingdom

Ralph W Hill