The function of the core inlet guide vane (CIGV) actuator is to mechanically position the inlet guide vanes when commanded by the full authority digital engine control (FADEC). During normal operation, the actuators are modulated according to the FADEC based upon feedback from the master’s linear variable differential transformer (LVDT) signal. Typically, there are two types of CIGV actuators, master and slave.  The master is the only one that contains an electro hydraulic servo valve (EHSV) and a LVDT position sensor provides electrical feedback to the FADEC.

Generally, core inlet guide vane (CIGV) actuators are fuel or oil operated. Fuel enters the EHSV cavity of the spool/sleeve area through the “P” inlet port. Electrical signals sent to the dual-coil servo from the full authority digital engine control (FADEC) cause the servo to modulate pressures Control 1 (C1) and Control 2 (C2). C1 and C2 are connected to the two chambers of the actuator piston.

A pressure force difference between C1 and C2 causes the pistons to move (in the direction of higher to lower pressure force) and the actuators to travel to the indicated position. When C1 pressure force equals C2 pressure force, the pistons remain in place due to a force balance and the actuator positions are held constant.

APPLICATIONS: Commercial aircraft engines

FEATURES AND ATTRIBUTES:
Features of the core inlet guide vane (CIGV) actuator include:
• Use of light weight, high strength 2618-T61 aluminum alloy bar for the piston cylinder/housing; proven to be light weight and high strength in numerous engine actuator applications
• Piston made from high purity 15-5 PH grade stainless steel with tungsten carbide plated (no chrome) shaft seal surfaces to enhance reliability and service life
• Sizing and geometry of internal fluid flow passages have been optimized to minimize pressure losses, improving efficiency
• High-reliability, high-performance Parker Jet-Pipe® EHSV, capable of superior low-temperature performance and chip shear force to ensure valve operation under all conditions
• Sealing system proven to have low-external leakage, minimal friction, and reduced contamination  
• LVDT adjustment feature which guarantees actuator-LVDT assembly and interface accuracy
• Internally-routed LVDT wiring prevents EMI and RFI related issues; provides superior wire management for vibration resistance and prevents damage during handling and installation
• Dual connectors, dual LVDT dual-servo coils