Edited by Amy Higgins & Sherri Koucky
The self-lubricating bearing is fitted to a primary load-carrying rod-link fitting, each of which is stabilized by three struts. |
Prelubricated bearings normally used in landing gear helped designers from the Airborne Systems Div. of Aero Union Corp., Chico, Calif., mount huge tanks of fire-retardant material to the side of twin-engine turbo props.
The tanks do not mount rigidly to the fire-fighting planes. Connecting struts vertically translate the loadcarrying tank-to-aircraft struts due to deflections from changing retardant and aircraft loads. DU Series bearings from Glacier Garlock Bearings, Thorofare, N.J., helped the translation.
The steel-backed, self-lubricating bearings handle rotation, oscillation, and sliding with little lubrication and control vibration. For short-term operations, the bearings are rated to 100,000 psi/fpm with a compressive strength of 44,000 psi and a static-load capacity of 20,000 psi.
The bearings' inner structure of porous bronze creates a continuously restored, low-friction surface. A layer of powdered bronze is sintered onto the steel backing and impregnated with a homogeneous mixture of PTFE (polytetrafluoroethylene) and lead. Relative motion of the mating parts draws material from the porous bronze inner structure, increasing lubricant in severe conditions.
In addition to handling vertical-load translation, the DU Series bearings have the compressive strength to react to combined fore, aft, and lateral loads, adds designer Fritz Watson, Aero Union.