Tip clearance control device

摘要

A tip clearance control device adapted to control the clearance of a rotating aerofoil structure with a surrounding casing portion, and a method of controlling the tip clearance of a rotating aerofoil structure with a surrounding casing portion. The device includes a member operatively connected to the casing portion; the member having at least a first configuration in which the casing portion is at a first radial position and a second configuration in which the casing portion is at a second radial position, wherein the configuration of the member is controlled by magnetic flux in a magnetic circuit which includes at least one ferromagnetic element including ferromagnetic material, where the configuration of the member is responsive to the temperature of the ferromagnetic element.

主权项

1. A pressure activated tip clearance control device adapted to control the clearance of a rotating aerofoil structure with a surrounding casing portion, the device comprising:
a member operatively connected to the casing portion and responsive to pressurized fluid for moving the casing portion, the member having at least a first configuration in which the casing portion is at a first radial position and a second configuration in which the casing portion is at a second radial position; an aerofoil structure tip clearance control system adapted to control a radial position of the casing portion by moving the casing portion from the first radial position to the second radial position upon expansion of an expandable chamber; a conduit coupled to a fluid supply for pressurized fluid, the conduit being arranged to selectively provide pressurized fluid to the aerofoil structure tip clearance control system to move the casing portion between the first and second radial positions by selectively providing pressurized fluid from the fluid supply to expand the expandable chamber; and a sensor passage in communication with the expandable chamber, the sensor passage arranged to sense radial growth of the rotating aerofoil structure and to relieve pressure in the expandable chamber to move the casing portion from the second radial position to the first radial position, wherein configuration of the member is controlled by magnetic flux in a magnetic circuit which includes at least one ferromagnetic element comprising ferromagnetic material, whereby the configuration of the member is responsive to the temperature of the ferromagnetic element, and the magnetic circuit is disposed to restrict flow through the conduit in the first configuration and permit flow through the conduit in the second configuration.