Life Improvement of Plain Airframe Bearings by Preventing Contamination

Safe, Inc. proposes a physical shield to protect spherical bearings from the abrasive particulate. Since many rotorcraft rod-ends are installed in exposed locations, sand and dirt cause damage to the spherical bearings and their liners. By preventing these particulate from contacting the spherical ball, the shield will prevent much of the contamination damage that shortens bearing life on rotorcraft. By allowing inspection without removal or with partial removal, the shield will further reduce maintenance requirements. Incorporation of the shield concept into future bearing production can lead to increased shield life and further reduce costs. Safe"s strategy is to select a shield material that will minimize heat build-up due to hysteresis and also enable heat dissipation for whatever heat is developed due to flexure. The shield material will be selected for inherent temperature resistance and in particular, a material that is chemically stable will be chosen. In order to minimize the weight and volume of the bearing shield, Safe has created a concept which remains close to those bearing surfaces which require protection. This design strategy will minimize the impact of the shield on the assembly weight, on the flexural resistance, and on the overall bulk of the assembly.