Bearing Improvement Program for Large Rolling Element Bearings

Numerous premature failures of large azimuth bearings (up to 13-1/2 feet in diameter) in the AN/FPS-24 and AN/FPS-35 radars were a major cause of concern to the Air Force because of reduced availability of the radars and the high cost of bearing replacements. An intensive program was undertaken to increase bearing life and to reduce the impact of bearing failures on system operation and maintenance. Much of the information developed by this program is applicable not only to the specific problem covered here, but to any large bearing application. The program consisted of three phases: (1) An immediate effort to determine possible means of increasing the life expectancy of four point contact balls and crossed roller bearings then in use and to improve the means of detecting failures and replacing bearings; (2) Design and fabrication of a different type (2 row ball-roller) bearing for the AN/FPS-35 radar, and accelerated life testing for rapid evaluation of its capabilities; (3) The development of a hydrostatic bearing for the AN/FPS-24 radar and the design of a similar bearing for the AN/FPS-35.