Abstract: According to one embodiment, a helicopter rotor system has a bearing disposed between the drive train and the rotor blade. The bearing comprises an elastomeric material, a housing member coupled to the elastomeric material, and an anti-rotation member coupled to the housing member opposite the elastomeric material. A bearing mount is coupled to the grip and comprises a first opening configured to receive the anti-rotation member of the bearing. The first opening is defined at least in part by a first surface that receives the anti-rotation member and prevents the anti-rotation member from completing a rotation within the first opening.

Abstract: A damper has a piston having an axis, an outer surface, and opposing ends. Elastomeric seals are in sealing contact with the outer surface of the piston, the seals being coaxial with the piston and limiting movement of the piston to a path along the axis of the piston. The seals also define fluid chambers adjacent the ends of the piston. A primary passage communicates the fluid chambers, and a selectively switchable valve for controls a flow of fluid from one of the chambers to another of the chambers through the primary passage. When the flow of fluid through the primary passage is permitted, movement of the piston is resisted by a first spring rate due to a shear force required to cause shear deflection of the seals. When the flow of fluid through the primary passage is restricted, movement of the piston is resisted by a second spring rate due to a fluid force required to cause bulging deflection of the seals.