This disclosure relates to a variable vane actuation system for a gas turbine engine.
A gas turbine engine typically includes a fan section, a compressor section, a combustor section, and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-speed exhaust gas flow. The high-speed exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different and typically slower than the turbine section so as to provide a reduced part count approach for increasing the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a reduced speed such that both the turbine section and the fan section can rotate at closer to optimal speeds.
Some areas of the engine may include variable vanes. The compressor, for example, may include one or more stages of variable vanes. Within each stage, vane arms connect each of the variable vanes to an actuation or synchronization ring. The actuation ring rotates about a central axis of the engine to pivot the vane arms, which then pivot the variable vanes to a vane angle that optimizes engine operability.