DOC AIRBUS | AMM A320FVARIABLE STATOR VANE (VSV) SYSTEM - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
1. General
The Variable Stator Vane (VSV) actuation system consists of two VSV hydraulic actuators with dual independent Linear Variable Differential Transducers (LVDT) for position feedback and two actuation mechanisms and linkages. Fuel pressure from the Hydro-Mechanical Unit (HMU) is the hydraulic medium used to operate the VSV actuators.
** ON A/C NOT FOR ALL The Variable Stator Vane (VSV) actuation system consists of two VSV hydraulic actuators with dual independent Linear Variable Differential Transducers (LVDT) for position feedback and two actuation mechanisms and linkages. Fuel pressure from the Hydro-Mechanical Unit (HMU) is the hydraulic medium used to operate the VSV actuators.
Compressor Control - VSV System - General2. System Description
The VSV system surrounds the High Pressure Compressor (HPC) from the Inlet Guide Vanes (IGV) through stage 4. The purpose of the VSV system is to control the amount of airflow through the HPC to give optimum compressor performance at steady conditions and to prevent compressor stall during engine acceleration and deceleration including engine start and engine shutdown. The VSV actuation system varies the angle of the first 5 stages of HPC stator vanes (IGVs and HPC stages 1 to 4) to maintain a smooth airflow through the compressor at all engine operating speeds, temperatures and altitudes.
The VSV mechanical system translates the linear motion of the VSV actuator rod into a rotating motion to set the proper angle of each IGV and VSV stage.
The two VSV actuators are located on the front HPC case at the 3 o'clock and 9 o'clock positions. The outer trunnion of each IGV and VSV (MSI 72-30-00) is connected to an individual lever arm. Each lever arm pin is connected to the appropriate actuation-ring half. There are two actuation ring halves for each stage. The two actuation-ring halves of each stage are connected with two bridge connectors at 3 o'clock and 9 o'clock to form a 360 degree ring.
** ON A/C NOT FOR ALL The VSV system surrounds the High Pressure Compressor (HPC) from the Inlet Guide Vanes (IGV) through stage 4. The purpose of the VSV system is to control the amount of airflow through the HPC to give optimum compressor performance at steady conditions and to prevent compressor stall during engine acceleration and deceleration including engine start and engine shutdown. The VSV actuation system varies the angle of the first 5 stages of HPC stator vanes (IGVs and HPC stages 1 to 4) to maintain a smooth airflow through the compressor at all engine operating speeds, temperatures and altitudes.
The VSV mechanical system translates the linear motion of the VSV actuator rod into a rotating motion to set the proper angle of each IGV and VSV stage.
The two VSV actuators are located on the front HPC case at the 3 o'clock and 9 o'clock positions. The outer trunnion of each IGV and VSV (MSI 72-30-00) is connected to an individual lever arm. Each lever arm pin is connected to the appropriate actuation-ring half. There are two actuation ring halves for each stage. The two actuation-ring halves of each stage are connected with two bridge connectors at 3 o'clock and 9 o'clock to form a 360 degree ring.
3. Component Description
A. VSV Actuators
The two VSV actuator/bell crank assemblies are located on the front HPC case at the 3 o'clock and 9 o'clock positions.
The two VSV actuator/bell crank assemblies are located on the front HPC case at the 3 o'clock and 9 o'clock positions.
B. IGV and VSV Vanes
The outer trunnion of each IGV and VSV is connected to an individual lever arm. Each lever arm pin is connected to the appropriate actuation-ring half. There are two actuation ring halves for each stage.
The outer trunnion of each IGV and VSV is connected to an individual lever arm. Each lever arm pin is connected to the appropriate actuation-ring half. There are two actuation ring halves for each stage.
C. Actuating Rings and Bridge Connectors
The two actuation-ring halves of each stage are connected with two bridge connectors at 3 o'clock and 9 o'clock to form a 360 degree ring.
The two actuation-ring halves of each stage are connected with two bridge connectors at 3 o'clock and 9 o'clock to form a 360 degree ring.