General Electric Company

David L Joyce

John Stephen Mears

Petr Hora

Edwin K Miller

Thomas G Wakeman

Roger C Walker

David Edward Bulman

David Allen Kastrup

Kevin H Kast

Thomas C Hermans

Robert L Roberts

Scott P Reese

Ronald A Bulow

A system is provided for reducing ice mass on an aircraft engine. A compressor inlet temperature and pressure sensor measures total temperature and total pressure at the inlet to the engine compressor. An ice shield is provided, wherein a plurality of wedge portions has multiple protrusions for promoting ice formation in multiple locations. The ice shield is separable from the sensor with which it interfaces. The ice shield comprises straight angle wedge shapes and curved surfaces to separate and minimize ice accretion in desired locations. The mass of each resultant ice formation is reduced to a size that the compressor inlet blades can withstand without deformation.

Sensor ice shield

A system for changing pitch in aircraft propfans is disclosed, in which a motor, located at a stationary position, changes pitch of the blades by of a gear train. Three features of the system are that a feather brake can override the motor and drive the blades toward feather; a unison brake can prevent pitch from undergoing excursions toward fine pitch when propeller speed exceeds a limit; and the motor is non-rotating in the absence of pitch change. A pair of such systems can be used in a counterrotating propfan system, in order to independently change pitch of the propfans.

Aircraft pitch change mechanism

The invention concerns a system for controlling an aircraft propeller. A hydraulic motor controls pitch of the propeller blades. The propeller blades are characterized by the absence of feather-inducing counterweights. An overspeed governor senses when propeller speed exceeds a limit, and, in response, assumes control of the hydraulic motor and drives the blades toward a coarsened pitch position, which reduces the propeller speed. In another form of the invention, a mechanical brake can override the hydraulic motor and mechanically retard a rotating gear, which causes the propeller blades to move toward a coarsened pitch.

Propeller pitch control

The invention concerns an active clearance control for controlling clearance between a turbine and a casing in a gas turbine aircraft engine. The invention calculates the instantaneous clearance between a turbine casing and a turbine rotor, based on temperature. Two temperatures are involved. First, a steady state temperature (SSTemp) is computed for the rotor and the casing. SSTemp is a predicted, future temperature, which will be attained when the engine reaches steady state operation. Each SSTemp is computed based on presently occurring engine operating conditions, such as selected temperatures, pressures, and rotational speeds. Changes which occur in the SSTemp's indicate the second temperatures, which are the instantaneous temperatures of the casing and rotor. These changes in SSTemp are caused by changes in the present operating conditions, which occur during engine acceleration and deceleration. The instantaneous temperatures indicate the diameters of the casing and the rotor, and thus the instantaneous clearance between them. In another form of the invention, the computed instantaneous clearance is used to control air which is bled from the fan and ducted onto the casing, in order to attain a desired clearance.

Active clearance control for gas turbine engine

Growing community of inventors

West Chester, OH, United States of America

David L Joyce