Life Improvement of Plain Airframe Bearings by Preventing Contamination
Navy SBIR FY2013.1

Sol No.: Navy SBIR FY2013.1
Topic No.: N131-016
Topic Title: Life Improvement of Plain Airframe Bearings by Preventing Contamination
Proposal No.: N131-016-0366
Firm: SAFE, Inc.
5032 S. Ash Avenue, Ste. 101
Tempe, Arizona 85282-6842
Contact: Lance Labun
Phone: (480) 820-2032
Web Site:
Abstract: 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.
Benefits: The benefits anticipated through wide-spread adoption of the proposed product will be longer spherical bearing life, reduced maintenance costs in both labor time and materiel, and greater dependability for critical aircraft systems. More importantly, the down-time for critical helicopter assets will be reduced as the bearing replacement cycle is extended to its normal and predictable period. Commercial aircraft use the same or similar rod-ends and spherical bearings as military aircraft. Commercial aircraft operators will benefit through lower maintenance overhead costs, better reliability, and reduced aircraft downtime, thereby reducing overall operating costs while allowing better operational safety.