Aircraft landing gear is designed to support the load of the aircraft when the aircraft is on the ground. The landing gear is attached to structural members of the aircraft. However, the landing gear is retracted into the aircraft during flight, for example by pivoting the landing gear into the aircraft via an actuation assembly. Typical actuation assemblies include multiple linkages pivotally connected to one another, the structural members of the aircraft and one or more actuators, by one or more bearings. The linkages include a pintle pivot joint which includes a pintle pin mounted via bearings on the pintle pivot joint. The landing gear rotates about and is supported by the pintle pin when the landing gear is extended and retracted relative to the aircraft. The pintle pin, pintle pivot joint and the bearings therein are highly stressed during landing maneuvers. The bearings typically include an inner ring mounted in an outer ring each of which have spherical bearing surfaces that slidingly engage one another. The inner ring of such bearings may be rotatingly mounted to a shaft in the actuation assembly or extending from the aircraft structure. However, such bearings are known to wear and require periodic maintenance for proper low torque operation.
The prior art bearings typically include corrosion resistant (CRES) stainless steel outer rings with copper alloy inner rings. However, such prior art bearings are heavy and tend to wear rapidly due to high friction experienced during misalignment of the inner ring relative to the outer ring.
Thus, there is a need for an improved bearing for aircraft landing gear that is light weight, has optimum tribology properties and operates at low torques.