TAIL ROTOR DRIVE SYSTEM – MAIN COMPONENTS
TAIL ROTOR DRIVE SHAFTS
The tail rotor drive shafts make the connection and transmit the torque
between the gearboxes. Two different length shafts connect the Main Gear
Box (MGB) to the IGB. The drive shaft no. 1 starts at the forward end of the
drive-train and connects the MGB tail flange coupling to a support bearing
assembly. The same support assembly makes a connection to the forward
end of shaft no. 2. The rear end of this no.2 shaft connects to the IGB input
drive pinion.
One slanted shaft connects the IGB to the TGB.
Shafts no.1 and no.2 have damper-assemblies used to dampen the shaft
flexing movements that can happen at critical rotational speeds.
The drive shaft no.2 is a critical component because of a resonance can
occur. For this reason an anti-flail assembly is installed in case of failure or
disconnection of shaft no. 2.
The damper no.1 is installed on the drive shaft no.1 and decreases the
vibrations transmitted to the airframe.
INTERMEDIATE GEAR BOX (IGB)
The Intermediate Gear Box (IGB) is installed on the lower tail-fin structure
and changes the direction of the drive by 49°. The IGB reduces the rotational
speed from the input speed of 4532 rpm to the output speed of 3458 rpm.
The IGB is splash lubricated and includes one oil low level sensor, one oil
temperature sensor and one chip detector.
A visual oil level indicator allows to monitor the oil level for maintenance
purposes.