US Patent 7775770 Pitch bearing containment seal

A flexible, resilient seal protects a bearing in a pitch joint of a helicopter blade assembly from contaminants. The seal includes a flexible, resilient body having a first end bonded to a stationary portion of the joint, and a second end biased into sealing engagement with a displaceable portion of the joint. The body includes an intermediate bellows section surrounding the bearing that expands and contracts to accommodate displacement between the stationary and movable portions of the joint. The second end of the seal includes a lip that rubs on a sacrificial wear layer formed on the second portion of the joint.