What is the purpose of the elastomeric bearing located within each main rotor spindle assembly?

What is the purpose of the elastomeric bearing located within each main rotor spindle assembly?

• A. Permits each blade to flap, lead, and lag
• B. Provides electrical insulation
• C. Reduces blade vibration
• D. Increases blade stiffness

Answer: (A)

The elastomeric bearing is a flexible interface between the blade root and the rotor spindle that allows the blade to move in three directions: flap, lead, and lag. This motion is essential for the blade to respond to aerodynamic loads and gusts without binding, while the elastomer damps some of the vibration transmitted into the hub. So its primary role is to permit those motions; it also helps reduce vibration as a beneficial side effect. Electrical insulation or increasing blade stiffness isn’t the function of this bearing.

The elastomeric bearing is a flexible interface between the blade root and the rotor spindle that allows the blade to move in three directions: flap, lead, and lag. This motion is essential for the blade to respond to aerodynamic loads and gusts without binding, while the elastomer damps some of the vibration transmitted into the hub. So its primary role is to permit those motions; it also helps reduce vibration as a beneficial side effect. Electrical insulation or increasing blade stiffness isn’t the function of this bearing.