Abstract: A bleed valve for use in a gas turbine engine is provided; the bleed valve may be used to relieve air pressure from a compressor stage of the engine. At normal pressure and when the engine is off, the bleed valve is in the open position. However once the engine starts, air pressure provided by the compressor closes the bleed valve. During engine operation, the bleed valve is opened to relieve air pressure by providing pressurized fluid, such as compressor air, to a valve chamber. The bleed valve is designed so that moveable parts of the valve, including contact seals and a sliding shaft, are protected by the valve structure from debris and contaminants carried in the engine's air stream.

Abstract: A bleed valve for use in a gas turbine engine is provided; the bleed valve may be used to relieve air pressure from a compressor stage of the engine. At normal pressure and when the engine is off, the bleed valve is in the open position. However once the engine starts, air pressure provided by the compressor closes the bleed valve. During engine operation, the bleed valve is opened to relieve air pressure by providing pressurized fluid, such as compressor air, to a valve chamber. The bleed valve is designed so that moveable parts of the valve, including contact seals and a sliding shaft, are protected by the valve structure from debris and contaminants carried in the engine's air stream.

Abstract: A novel digital servo valve system for use in displacing an actuator is capable of operating either in closed or open loop mode. The system includes a controller that compares computed values of actuator parameters with preselected parameter values and iteratively determines therefrom command signals for the servo valve. The servo valve is characterized by a ball screw mechanism that eliminates mechanical backlash and a torsion bar which increases radial and angular compliance. A servo valve provided according to the present invention also displays reduced flow forces using a simple, inexpensive valve body in combination with a uniquely configured displaceable spool.

Abstract: A novel digital servo valve system for use in displacing an actuator is capable of operating either in closed or open loop mode. The system includes a controller that compares computed values of actuator parameters with preselected parameter values and iteratively determines therefrom command signals for the servo valve. The servo valve is characterized by a ball screw mechanism that eliminates mechanical backlash and a torsion bar which increases radial and angular compliance. A servo valve provided according to the present invention also displays reduced flow forces using a simple, inexpensive valve body in combination with a uniquely configured displaceable spool.